Sikaoa. et ee a ~~ ren , : ‘ . eee _~“T) ve STA ae beet aay eae ier Vouayeee yeast bat GA ais wis Sam we nahacdiase ; . ~T ~ SI er rateetatcannes Wee sere oF : SES = ee wh . . ~ = aw noma sts ———_ avtemteat amid: Neen NANPA OW LAAD B/Aeran there ones eee OS, era ea eRAey yj Fenian nat'@ aah ee te, - — AER Bem On Se tee ge ot oe Seen Son Pan rethainrnnn ewe 0 pete he ee ~ fm mente “ TE DO SOA ee De © md gel natn’ vend neal enti Pde Mie nad ee ee ee ee Hee ie Wott WM mn nee eee, Nn A He eer intitle ee iota co — ~~ ee ee - n os ete ee aa FE ee, Pe ~e<- - : ene oat oe oti P - Ue hy Ont tele OH awe I a ot Ne Amgen EA el) Seemann ; ee LAI ae LIBRARY OF THE UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN NOTICE: According to Sec. 19 (a) of the University Statutes, all books and other library materials acquired in any man- ner by the University belong to the University Library. When this item is no longer needed by the department, it should be returned to the Acquisition Department, University Library. ILLINOIS NATURAL HISTORY SURVEY 5 - : , TANF (a . -_ 7 , v4 -, ns ’ =p ae eae wy | toes BS Lesage we aw i ae Digitized by the Internet Archive in 2010 with funding from University of Illinois Urbana-Champaign htto://www.archive.org/details/illinoisnaturalh123252197 The Illinozs NATURAL HISTORY Hot Angling Spot — Ridge Lake This summer, under a system of feeding and with fall drawdowns every third year, aquatic biologists George W. Bennett and H. Wickliffe Adkins obtained the largest fish yield ever recorded from Ridge Lake in Fox Ridge State Park near Charleston. The lake contains large- mouth bass, bluegills, warmouths, channel catfish, and lake chubsuckers. A summer feeding program consists of spreading pre- pared fish pellets (32 percent protein) in the shallows around the edges of the lake at the rate of two pounds per acre per day (thirty-two pounds per day at a cost of about ten cents per pound). This fall after summer fishing was over the lake level was (sixteen acres) lowered nine feet (maximum depth twenty- five feet at the outlet) to pull the water from the beds of aquatic vegetation and cause a reduction in the number of small bluegills. The catch of fish from controlled public g, which began in early June and ended the last of August, totaled 139.6 pounds per acre with 338 man-hours of fishing, fishing per acre. Nearly half of the catch was composed of channel catfish which averaged two and a half pounds each. These catfish represented 442 of 691 re- turned to the lake in 1970 after the spring draining and fish census. They originated from catfish farming stocks obtained from Arkansas and propagated at our Sam A. Parr Cooperative Fisheries Research Center at Marion County. Channel catfish do not reproduce successfully at Ridge Lake, and replacement stock must be added as these fish are taken. Catfish grow very rapidly in this lake A Sift + under the supplemental feeding program. The largest fish taken in 1972 weighed a few ounces over ten pounds. We plan to stock about 1,000 to 2,000 catfish per year to maintain the high level of catch return. With a 14-inch minimum limit, the small catfish have a chance to reach useful sizes before being taken by fishermen. Bluegills were next in importance in the 1972 catch, and 5,745 fishes weighing 914 pounds were taken. This catch amounted to 359, weighing 57 pounds per acre. Be- cause the catch of bluegills of less than six inches total length exceeded those of more (3-100; to: 2:600)), it than six inches was Channel catfish caught in Ridge Lake. (Photograph by George W. Bennett) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey decided that it was time to make a fall drawdown. This was done beginning August 29, when in a period of seventy- two hours the lake was gradually lowered nine and a half feet. The drawdown re- duced the surface area to 69 percent of the full lake and the total volume of water more than 50 percent. Small fishes were forced out of aquatic vegetation and shore- line debris into open water where the larger fishes could prey upon them. During late May and early June an unusual source of food became available to the fishes of Ridge Lake. A heavy emer- gence of 1972, Brood XIX, 13-year cicadas occurred in Fox Ridge State Park and_ around the lake. Cicadas falling into the water were immediately eaten by fishes. Counts of these downed insects in measured strips of lake shallows gave basic figures for an estimate of the total number falling into the lake per day, and the cicadas were abundant over a 21-day period. As the average weight of these insects was approx- imately 0.6 gram, the weight of insects falling into the lake was estimated to be 363 pounds per day or 3.8 tons for the 21- day period. This food source probably added materially to the fish production of the lake. Wood Ducks — Tagged and Bagged Wood duck ducklings were marked with metal tags attached to their toes during the nesting season in 1971 and again in 1972. Most of the ducklings were marked when less than twenty-four hours old while they were still in nest houses. However, in 1971 about 60 marked ducklings were from broods deserted by their mothers in Havana. These ducklings were tagged and released in Quiver Creek. In 1971 a total of 613 wood duck ducklings were marked, about half of which were males. This tag- ging program was carried out by wildlife biologist Robert Crompton. Out of about 300 female ducklings tag- ged in 1971, 38 were captured in 1972. Of these, 35 were found nesting in wood duck houses and 3 others were captured in band- ing traps after the nesting season. Biologist Frank C. Bellrose feels that the 3 ducks found in banding traps had nested in natural cavities rather than the nesting houses provided for wood ducks in the area. No web-tagged males were captured, but one male banded while flightless in 1971 was recaptured in 1972. From these and other data, Bellrose concludes that yearling females home to their natal area to a much greater extent than do male wood ducks. Surprisingly, five of the returning birds were from the sixty orphaned ducklings picked up in Havana and released in Quiver Creek. Their survival rate was com- parable to that of ducklings with mothers. Ejther the orphaned ducklings had unusual ability to survive without parental brooding and guidance, or more probably, they were readily adopted by hens with broods. Yearly differences in the rate of homing by wood ducks will provide information on differences in their survival resulting from changing habitat conditions. For example. during the summer of 1971, brood habitat was poor for wood ducks due to unusually low water levels. In 1972, however, brood habitat was excellent because of high water levels. Robert Crompton web-tagged 969 ducklings during the 1972 nesting season in order to compare differences in the survival of wood duck ducklings with changing habitat conditions. Nowhere in the country have as many ducklings been marked as on our Quiver Creek study area during the past two years. Environmental Research Facility Completed After months of frustrating delays, the new Natural Resource Studies Annex, located at the intersection of Griffith and Hazelwood drives on the Urbana-Cham- paign campus of the University of Illinois, was declared “essentially completed” on December 8, 1972. Designed specifically for greatly accelerated research on problems of environmental quality, the Natural History Survey portion of the new building includes several dozen laboratories and offices plus a greenhouse containing some sixteen cubi- cles which can be individually programmed for specific light and temperature regimes. The State Geological Survey occupies lesser Natural Resource Studies Annex. (Photograph by Survey photographer Wilmer Zehr) laboratory and office space plus a large storage area for its library of drill cores. About half of the new laboratory and office equipment required for the structure is now installed and operative. It is hoped the remainder can be obtained this year. A portion of the Survey’s existing staff has moved to the new laboratories. Additional talents not represented in depth among the present staff are expected to be em- ployed within the next six months. When fully equipped and staffed, the Natural Resource Studies Annex, augmented by the existing facilities and staffs of the Natural History Survey and the Geological Survey and our nearby Aquatic Research Field Facility, will constitute one of the finest analytical research activities in the nation. The Natural History Survey has long been engaged in studies of environmental quality — particularly those which involve pesticides and heavy metals. The capabil- ities afforded by the new facility will permit the Survey to place increased emphasis on investigations designed to produce a more penetrating understanding of environmental contamination. These areas of study will include: the behavior and fate of pesticides in the soil and water environments and the degradation mechanisms involved; ‘the spe- cific primary and_ secondary effects of various levels of soil and water- borne pesticide residues in animals and plants; the biological response of animals and plants to atmospheric pollutants; and biological the impact of contaminants on plant and animal community structure. Thus, we hope to find more meaningful and precise answers to a variety of questions related to the kinds and amounts of environmental contamination man and his animal and plant colleagues can or will tolerate in the tradeoffs for the sustained production of products and services that contribute to the standard of living which we strive to maintain. Crop Pests of 1972 The twenty-fifth annual Custom Spray Operators Training School will be held January 23-25, 1973, in Urbana. During this session a report will be presented deal- ing with insect pests and their control in Illinois during the previous year. This report, prepared by Survey entomologists Roscoe Randall and Donald E. Kuhlman, is a summary of data received from county extension advisers in agriculture and in- cludes comments on major problems of the past year and an outlook for the coming season. Each year is different in terms of insect activity. Insect problems, although varied, did not present any major incidents in 1972. Black alfalfa weevils were the most troublesome cutworms, armyworms, and agricultural pests, especially in the southern half of the state. The major nonagricul- tural insect problems in Illinois involved mosquitoes, periodical cicadas, and sod The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 webworms. For several years Illinois has not had any catastrophic outbreak of pests as occurred years ago before the advent of modern insecticides. Western corn rootworm beetles were found for the first time in Douglas, Greene, Macoupin, Montgomery, Moultrie, Piatt, Schuyler, Scott, and Vermilion counties in 1972. This pest has now been found in sixty-three counties in Illinois since first discovered in the state in 1964. The areas with the greatest potential for corn root- worm damage in 1973 will be in western, northwestern, and central sections of IIli- nois. In general, fields in continuous corn production for three years or more in the area north of a line from Pittsfield to Springfield and Joliet may incur moderate to severe damage by corn rootworms. This area may also expect damage to second- year corn by the western corn rootworm. A wet, cool spring favored armyworm populations this spring, and the south- western and southeastern areas of Illinois were plagued by large numbers of army- worms. This insect is a southern migrant into Illinois and presents problems in some areas every year. The moths generally select thick, dense stands of grass in which to de- posit their eggs, and it is impossible to accurately predict infestations more than a few weeks in advance. Many fields of corn in the southern half of Illinois were damaged by black cut- worms during the past year. Damage in northern Illinois was less widespread. Ex- cellent control of this insect was obtained by most farmers by using carbary] (Sevin) - apple pomace bait, carbaryl-molasses, or carbaryl-Tractum spray. The few instances of poor control were due to extremely wet or extremely dry weather. In the first in- stance the bait was broken down rapidly and rendered ineffective by heavy rain. In the second case the cutworms fed below the soil surface to avoid heat and were. not attracted to the bait on the surface. An estimated 6,769,000 acres of Illinois field crops were treated with insecticides in 1972, resulting in a savings from crop losses (above treatment costs) to farmers of about $23,800,000. The control of soil insects in corn accounted for 90 percent of these savings. It is clear that insecticides are necessary for the profitable production of certain field crops in Illinois. January 1973. No. 123, Published every month by the Illinois Natural History Survey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinows NATURAL Quail Abundance Not Reduced by Hunting The bobwhite quail is a very popular up- land game bird in southern Illinois. On the southern part of the state where quail are abundant, bobwhites provide the bulk of state-owned conservation areas in game bird hunting. Since two of these areas are managed and hunting is regulated by the Illinois Department of Conservation in cooperation with the Illinois Natural His- tory Survey, it has been possible for Survey scientists to study the effect of hunting pressure on quail populations. The study areas are Stephen A. Forbes State Park (2,300 acres) in Marion County and Sam Dale Lake Conservation area (1,300 acres) in Wayne County. Hunting regulations on the areas are identical with state regulations except for hunting hours HISTORY REPORTS and a compulsory game checking proce- dure. During the period of the study re- ported here, hunting hours were from 8:00 a.m. to 4:00 p.m. daily from mid-November to December 31, with a daily limit of eight birds. Hunters are required to check in at the ranger station before and after hunting and declare all game taken. Quail censuses are conducted three times each year: a postharvest census in late January, a prebreeding census in March, and a prehunt census in November. Results 1964-70 were recently summarized by Survey wild- life specialists D. R. Vance and J. A. Ellis with the following conclusions: of census and harvest data for Bobwhite populations on the Forbes and Dale areas have been intensively utilized by hunters since 1964, with an average of 60- 70 percent, and as high as 81 percent, of Young bobwhite quail. (Photo by Survey photog- rapher Wilmer Zehr.) Material in this publication may be reprinted if credit is given to the I|linois Natural History Survey. fall quail populations being harvested with no apparent detrimental effects on sub- sequent population levels. Although other workers have suggested a safe harvest limit of 45 to 50 percent of prehunt quail popula- tions, Vance and Ellis feel that, under ex- isting environmental conditions and hunt- ing regulations in Illinois, the annual harvest of bobwhites on managed public hunting areas in Illinois may safely remove 70 percent of the quail population. They also concluded from these data that hunt- ing interest is directly related to quail abundance; therefore, this high level of harvest will not occur in years of low quail abundance due to a lack of hunter interest. ~ Merely providing the land and opening the season does not provide hunting opportu- nity. Hunting opportunity can be increased on existing public hunting areas by pro- viding more game through effective habitat management. Several facts disclosed by this study should be of interest to quail hunters and those contemplating taking up the sport. The “average” hunter on both the Dale and Forbes areas flushed about one covey per trip and killed one bird out of the covey. Hunting time required averaged about three hours per bird. The most suc- cessful hunters were residents of the six- county regions surrounding the areas, with hunters from the St. Louis and Chicago metropolitan areas only about half as suc- cessful. The highest hunting success oc- curred on weekdays during the first week of the season. With these facts in mind, it looks like quail hunting is here to stay in Illinois but fellows, you’ve got to get out and work for “em! Good luck, quail hunters! Biochemical Markers in Corn Earworms The corn earworm is one of the most destructive pests of American agriculture. Many millions of dollars in damage are caused by this pest each year and millions of pounds of pesticides are applied annu- ally for its control. Although corn and cot- ton are the insect’s preferred host plants, the earworm also attacks several other cul- tivated plant species. Because of its great economic importance, the earworm is a prime target for an insect management program. Before an effective program can be insti- tuted, a thorough knowledge of the in- sect’s life history and habits must be at hand. One habit of the earworm that has been a great mystery to entomologists for many years is it migratory ability. The ma- jor portion of the earworm population probably cannot overwinter successfully in northern Illinois. Yet, once every two or three years during late August to early Sep- tember, northern Illinois is invaded by very large numbers of earworm moths. It is strongly suspected that these moths have come to this area from somewhere outside of the state. Although the earworm is considered to be one species of insect, many strains or perhaps subspecies exist in nature. These cannot be separated on the basis of visual characters. In recent years, increased emphasis is being placed on the use of bio- chemical techniques to separate or char- acterize insect populations. Survey entomol- ogist D. K. Sell has recently developed a biochemical test which may prove highly useful in working with the earworm. Insects, like all other organisms, differ genetically and Survey scientists have been searching for genetic markers of a bio- chemical nature in corn earworm larvae that can be easily monitored in populations of this insect. One such marker has now been found in the form of a genetic locus which controls the synthesis of an esterase present in the blood or hemolymph of corn earworm larvae. This locus was chosen as a model system and will be subject to further genetic and ecological analysis. Since three pairs of genes are present at the locus, six different phenotypes of the insect are possible in any population. Once these types can be identified biochemically and separated, it should be possible to study certain key population parameters, includ- ing migratory ability, for each type. In this manner the source of the earworm infesta- tion might be traced and certain key facts associated with this type would be known that would aid in selecting an effective pest management system. Hybrid Vigor in Bass Although people have realized for a long time that certain hybrids, the mule for ex- ample, grow to a larger size, are stronger, and are more resistant to diseases than their parent species, it has only been in recent years that some of the genetic causes of this phenomenon have been clarified. New bi- ological techniques have recently been per- fected which permit the genotypes of indi- viduals to be determined. One such technique is electrophoresis. Each species has characteristic proteins, and by electrophoretic methods, it is pos- sible to identify the proteins of each species. Consequently, in a hybrid, proteins from both parental species can be identified. If a first generation hybrid (F,) is backcrossed to one of its parents, the offspring will ex- hibit many different characteristics ranging from those of the parental species to those of the F, hybrid. However for a specific single genetic trait, half of the backcrossed individuals should be like the F, hybrid parent and the other half like the parent species that was used. Survey aquatic biologists W. F. Childers and J. A. Tranquilli hybridized largemouth bass with smallmouth bass. They then back- crossed a male F, hybrid with a female largemouth bass. The reciprocal cross (fe- male F, hybrid x male largemouth bass) was also made. The backcrossed hybrids were produced in separate ponds. Collec- tions of approximately two hundred back- crossed hybrids were made from each pond when the young fish were about two months old. Each backcrossed hybrid was weighed, measured, and analyzed by electrophoresis. The electrophoretic analyses were con- ducted by Dr. Gregory Whitt and Mr. Thomas Wheat of the University of Tlinois. Each individual was identified as being like the largemouth bass parents or the F, hy- brid parent for three different proteins. Backcrossed hybrids from the male F, x female largemouth bass showed great dif- ferences in rates of growth. Electrophoresis revealed that individuals which were ge- netically like the F, hybrid grew approxi- mately twice as fast as those which were genetically like the largemouth bass parent. Hybrid bass. Cross between male smallmouth and female largemouth. (Photo by Dr. G. W. Bennett.) Offspring from the reciprocal cross (female F, hybrid x male largemouth bass) showed no appreciable differences in rates of erowth. Sperm contains almost nothing other than genetic material, and eggs contain ge- netic material and egg cytoplasm. The egg cytoplasm is utilized as food by the develop- ing embryo. Consequently, the results of this experiment indicate that in these spe- cies hybrid vigor results when mixed genetic material from two species interacts with pure species egg cytoplasm but not when mixed genetic interacts with mixed egg cytoplasm. material Environmental Inpact Info Sought The Cooperative Wildlife Laboratory of Southern Illinois University at Carbondale, Illinois, is researching an Environmental Inpact Statement for the U.S. Army Corps of Engineers, concerning the effects of a Mississippi River channel- Research The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 ization project. ‘They are specifically inter- ested in the area between the bluffs on each side of the river from St. Louis to Cairo, Illinois. ‘The study encompasses a survey of the plants, mammals, amphibians, reptiles, birds, and nonaquatic invertebrates. Re- search will be completed by May 1, 1973. One aspect of the project is to discuss with biologists and other biologically oriented citizens their observations of the flora and fauna, both unusual and com- mon, in the floodplain. Since channeliza- tion of a waterway can drastically alter the ecosystems in the floodplain as well as in the river itself, it is essential to obtain as much information as possible on the plants and animals in the affected area before the project is approved. After channelization is approved and funded, it is too late to pre- vent undesirable environmental effects. If any readers feel they could contribute some information about the plants or ani- mals in the study area, please contact: Mrs. Virginia A. Terpening Assistant Investigator, River Project Cooperative Wildlife Research Laboratory Southern Illinois University 80642 South Marion Carbondale, Illinois 62901 Time is running short. Your cooperation would be appreciated. February 1973. No. 124. Published every month by the Illinois Natural History Survey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by D. F. Schoeneweiss, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Ilkinozs NATURAL The Shrike and Its Prey So often in biological studies, what we perceive as the truth is strongly biased by the technique of observation we employ. Recently, in the course of summarizing the Illinois data on birds of the family Laniidae (shrikes), Richard and Jean Graber were impressed, both from the literature and their own field notes, by the importance of vertebrates in the diet of the loggerhead shrike (Lanius ludovicianus). Shrikes are prone to establish food caches, pinning dead prey on the thorns of various trees or on the barbs of Examination of such caches has been a major source of information on the food of shrikes even though the function of the caches has never been fully understood. Food caches fences. HISTORY REPORTS may vary in content from one item to dozens of items. One typical cache in cen- tral [llinois contained twenty-four mice, six snakes, a frog, and a grasshopper. The caches usually contain mice, most fre- quently voles (Microtus) and deer mice (Peromyscus), but also house mice (Mu musculus). They also often contain birds, house sparrows (Passer domesticus) being most frequent, but also such native species as juncos (Junco hyemalis), vesper spar- rows (Pooecetes gramineus) , field sparrows (Spizella pusilla), and bluebirds stalis). The shrike food Sialia snakes most often found in caches are garter snakes (Thamnophis), and the frogs are probably mainly Hylids, especially Acris, though very few have actually been identified. The in- Loggerhead shrike at nest (on left) and cache of shrike consisting of a house mouse on a locust thorn. (Photos by Richard Graber) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey vertebrates that most often appear in the food caches are short-horned grasshoppers (Acrididae) and beetles, especially Scara- beidae. Prey size in the caches is relatively large and seems to correlate well with the most commonly witnessed method of hunting by shrikes. Hawklike, the shrike looks for prey from an elevated perch or from the air, hovering, then shoots downward to capture prey on or near the ground. Shrikes also chase other birds relentlessly, but just how most of the birds are captured is unknown. This is the way the shrike’s food habits look from studies of food caches. Recently the opportunity presented itself to examine the stomachs of a number of shrikes col-— lected for pesticide studies by William L. Anderson and James W. Seets. The stom- ach contents of the shrikes formed a pic- ture of the food and foraging habits of Illinois shrikes notably different from that indicated by the food caches. The principal prey item in the stomachs, at least in terms of frequency of occurrence, was not mice, birds, or snakes, but small ground beetles (Carabidae) which occurred in from 40 to 80 percent (depending upon the season) of the seventy-one stomachs examined. Also prominent were caterpillars, which ento- mologist George Godfrey determined to be European corn borers (Ostrinia nubilalis) . The prey items in the stomach that most closely paralleled the food cache data were the short-horned grasshoppers and scarab beetles. Vertebrates were much less fre- quent in the stomachs, varying from 0 to about 20 percent frequency, depending upon the season. Not only was the food in the stomachs different from that in the caches, it implies a different method of foraging. Just how the shrikes get the corn borers is not clear, but the large number of small ground beetles in the stomachs seems to indicate that shrikes forage much of the time on the ground. Such foraging behavior would likely be much less visible than the hawk- like techniques used to catch vertebrate prey and large invertebrates such as grass- hoppers. The case is of special interest as an example of why it is so difficult to learn the truth about natural phenomena. An observer is led to one conclusion by observ- ing the food caches and to quite a different conclusion from the examination of stom- achs. Both sets of data undoubtedly repre- sent some truth, but they leave us with unanswered questions about the shrike and its influence on other populations. The bio- logical literature is replete with contradic- tions and paradoxes warning the scientist that every problem needs the careful appli- cation of all possible means of study. Fishes, Keys, and Names The arousal of public interest in the quality of the environment has precipitated several intensive pollution studies in Illinois and elsewhere by scientists in many agen- cies and universities. Before the scientist can develop a research program, he or she must know the names of the plants and animals in the study area. In studies of water pollution, the scientist will encounter fishes, and accurate species identification is, of course, imperative. To enable the pollution worker to iden- tify Illinois fishes, the Division of Fisheries of the Illinois Department of Conservation has just published a booklet entitled “A Key to the Fishes of Illinois with a Dis- tributional Checklist.” This publication, written over a period of several years by Survey ichthyologist P. W. Smith, should fill the need for an identification aid by professional biologists, students at both the high school and university levels, and inter- ested amateur biologists. A key is a document consisting of num- bered couplets composed of contrasting statements. Its user selects the series of statements that best describes the specimen before him and then proceeds to the couplet number indicated in the right-hand margin until eventually he arrives at the name of the species. Many illustrations of structures or pattern-features of specimens in this key allow the user to recognize readily these items in the specimen he is attempting to identify. The pollution worker and student can thus identify the 185 species of fishes that presently occur in Illinois waters. An ap- pended distributional checklist gives the scientific and common names of each species and indicates where each is found in the state. The checklist also lists eight species that formerly occurred in certain parts of Illinois but have now been extir- pated. The distributional data are the results of a ten-year cooperative study on Illinois fish populations by the Illinois Natural History Survey and Division of Fisheries. Copies of this publication are available free of charge from the Division of Fish- eries, Illinois Department of Conservation, State Office Building, Springfield, Illinois 62706. They may be requested by the title of the booklet or as Fishery Bulletin No. 6. Corn Rootworm Disease Two of the most important insect pests of corn are the northern and western corn rootworm. Adults of the corn rootworms are small beetles which in central Illinois begin to appear about July 1 and lay their eggs in the soil around corn plants from July 15 through September. These eggs diapause and remain in the soil in this dor- mant condition until the following spring. The eggs hatch about the time the corn seed begins to germinate. The corn root- worm larvae which hatch from these eggs feed on corn roots and, when numerous, can seriously damage the corn plant. The actual number of corn rootworm Western corn rootworm adults. The difference in color between the sexes is highly variable, and the sexes are separated by the difference in antennae, rather than color. (Photo by Survey photographer Wilmer Zehr) eggs present in a heavily infested cornfield is astounding. Survey entomologists have calculated that such a cornfield may con- tain over 16 million corn rootworm eggs per acre. These eggs are no larger than the period at the end of this sentence, and yet if placed end to end, this number of eggs would span six and a half miles and collec- tively weigh over three and a half pounds. As is the case with most insect populations, natural mortality factors destroy most of the eggs or larvae of the corn rootworm be- fore they develop into adults. As a part of the corn rootworm pest management pro- gram, Survey entomologists John Shaw, J. V. Maddox, and W. H. Luckmann are attempting to evaluate the mortality factors. These entomologists recently found a dis- ease caused by a tiny Protozoan called a microsporidan in both northern and west- ern corn rootworm adults. This is the first record of a microsporidan infection in the corn rootworm. The disease is transmitted transovarially, or through the egg from an infected female adult to her progeny. The microsporidan is also transmitted from one adult to another by small resistant forms called spores. The fecal material of an in- fected adult contains large numbers of these spores, and when ingested by another corn rootworm adult, the spores germinate and produce an infection. The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 Although both species appear to be equally susceptible to the disease in the laboratory, the incidence of infection in field-collected adults is always higher in the northern than in the western corn root- worm. This is probably the result of con- gregating feeding behavior of the northern adults on corn silk, whereas the western adults are less selective in their feeding sites and often feed individually. The congre- gating feeding behavior of the northern corn rootworm adults increases the possi- bility of a healthy corn rootworm adult feeding on material contaminated by fecal material of an infected adult. The disease occurs throughout the state, but the rate of infection varies greatly in adults collected from different cornfields. Over 90 percent of the northern corn root- worm adults from some fields was infected, while the disease was completely absent in adults collected from other fields. Field populations of northern corn rootworms with a high infection rate will contain nu- merous small adults, most of which are in- fected with the microsporidan. Several fields which had a high percent- age of diseased adults in 1972 are being monitored intensively through the winter, spring, and early summer to evaluate the effect of the disease on eggs, larvae, pupae, and emerging adults. It is possible that this disease is an important natural control factor of the corn rootworm in Illinois. March 1973. No. 125. Published every month by the Illinois Natural History Survey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinors NATURAL SURVEY Getting Together on Pest Management On May 1, 1972, the National Science Foundation authorized the University of California’s International Center for Bio- logical Control to set up a large-scale pest management study as part of the U.S. In- ternational Biological Program. This major study will involve eighteen other univer- sities, including the University of Illinois and Illinois Natural History Survey, and segments of the U.S. Department of Agri- culture. The principal objective of this study is to develop programs for integrated pest control that will utilize the most effective combinations of cultural practices, breed- ing for pest resistance, chemical control, and insect predators and parasites to opti- mize the cost/benefit ratio of control on a long-term basis. Such programs will benefit the farmer directly and will benefit society in general in various less direct but highly important ways. Crops included in this study are cotton, alfalfa, and stone and pome fruits. Illinois scien- citrus, coniferous trees, soybeans, tists are cooperating in studies on alfalfa and soybeans, with Survey entomologist Ed Armbrust serving as leader of the alfalfa subproject and Survey entomologists W. G. Ruesink and Marcos Kogan cooperating on certain phases of the studies. The alfalfa ecosystem is unique among field-crop systems in that it represents a relatively long lasting, well-established pe- rennial system that exists nationally over a variety of climatic, geographic, and edaphic conditions. Because of these many sub- systems, the interactions with other agro- nomic or natural ecosystems are equally as HISTORY APRIL 1973, NO. 12é varied. Alfalfa supports a wide variety of insects, including destructive insects, polli- nating insects, species that inhabit the fields because of the lush habit but have little effect on the crop, and many associated predators and parasites. Because of the pe- rennial growth habit of alfalfa, many pests and beneficial insect species of other crops overwinter or build up in alfalfa fields be- fore migrating to neighboring crops. Since many potentially injurious insects that inhabit alfalfa fields are restricted by naturally occurring biological control, and many pollinating species are normally pres- ent, insecticides must be used with great care. The impact of pesticides on wildlife and the possibility of unacceptable pesti- cide residues in meat and dairy products must also be taken into account when ap- plications of pesticides are included in a pest Management system. According to Dr. Armbrust, we cannot presently expect to control alfalfa pests with a single-factor approach. Predators and parasites alone will not control such economic pests as the alfalfa weevil, nor will the use of tolerant or resistant varieties. It will not be one factor, but an integration of many cultural, chemical, and biological factors, that will be important in the man- agement of alfalfa pests. Although the formal project on alfalfa pests has been initiated only recently, much information is already available and is be- ing incorporated in integrated pest control programs. As more information is obtained by Illinois scientists and those in other co- operating states, control programs will be constantly modified to make the best use of the current knowledge on pest control. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. All available tools, including computer models, improved sampling techniques, and breeding programs are being utilized to develop the most effective pest manage- ment systems. This relatively new, large- scale cooperative approach to pest control should result in the development of more effective pest management with less chance of adverse environmental effects than man has ever been able to achieve in the past. Female Quail Accumulate Dieldrin In recent years, many of the pesticides commonly used in crop protection have come under close scrutiny because of their adverse effects on wildlife. In particular,_ the use of chlorinated hydrocarbons such as aldrin, dieldrin, and heptachlor has be- come suspect since these materials leave persistent residues that are concentrated in the food chain in the ecosystem. Although the use of aldrin is declining in Illinois, some 2 million acres are still being treated annually for control of soil insects. In the course of studies on the effects of pesticides on wildlife, Survey wildlife spe- cialist W. R. Edwards recently analyzed tissues of bobwhite quail that had been ex- posed for fourteen days to soil treated with 2 pounds per acre of aldrin, the rate com- monly used for control of soil insects in corn. Six mating pairs of birds were placed in open-bottomed pens on treated soil and a similar number on untreated soil. The pens were moved daily so that no bird was ex- posed more than twenty-four hours on the same spot. Egg laying and nest initiation were recorded during the fourteen-day pe- riod. At the end of the two week exposure, all test birds were sacrificed and the tissues analyzed for chlorinated hydrocarbon con- tent. Since aldrin converts to dieldrin in soil, and dieldrin accumulates in animal tissues, dieldrin content is used as a mea- sure of the effect of aldrin treatments. Results of the tissue analyses indicated that dieldrin accumulates in the female quail, particularly in the ovaries. No dif- ferences were detected in egg laying or nest initiation as a result of dieldrin ac- cumulation, and no significant differences were found in dieldrin content in males from treated and untreated soil. This pilot study indicates that female bobwhites acquire low but significant levels of dieldrin as a result of exposure to soil treated with normal rates of aldrin. Al- though no effects on reproduction were detected, this was a limited experiment of short duration. The accumulation of diel- drin in the ovary tissues of quail should be viewed with concern, and the possibility of adverse effects merits further investigation. How Verticillium Gets into Trees A soil-inhabiting fungus known as Ver- ticillium albo-atrum invades the sapwood and causes wilting in many species of trees and other woody plants. Due to the wide host range and distribution of the fungus throughout the United States, Verticillium wilt is one of the most common and de- structive diseases of trees and shrubs. Like Dutch elm disease and oak wilt, Verticil- lium wilt is an internal or vascular disease. The disease is conspicuous because the leaves on affected plants wilt or turn yel- low in early summer and die as the fungus, which usually invades the plant through the root system, spreads up the trunk and into the branches. Many trees and shrubs show wilt symptoms after they have been transplanted from nursery fields to land- scape plantings. Although Verticillium wilt is a common problem on woody plants, certain aspects of the disease cycle are not clearly under- stood. For example, does the fungus need a wound to penetrate the roots, or can it grow directly into the root? To understand how plants become infected, Survey plant pathologist G. L. Born conducted a series of tests using redbud and sugar maple seedlings, both of which are susceptible to Verticillium wilt. Results of these tests showed that the fungus gains entrance into the vascular sys- tem through root wounds while bypassing the periderm layer of cells. Any injury serves as an infection court, but a wound deep into the vascular cylinder, which places the fungus in direct contact with the vessels, is more conducive to penetration by hag oe Por % ~ SUGAR Verticillium wilt symptoms on seedling sugar maple. Roots of the plant on the : right were inoculated with CHECK | MAPLE INOCULATED Be sees secniey ae the fungus. No infection occurred on un- wounded roots. The older the wound, the less chance for infection by the fungus. This may be cor- related with growth responses by the plant at the wound site. Following wounding, a layer of dried cells forms on the surface of the wound. These cells died as a result of injury by the knife. Adjacent to the dead cells is a zone which becomes infiltrated with wound substances. This growth re- sponse results in a barrier that prevents the fungus from invading the functional vessel members. The sequence of wound healing may take place much faster on younger root tissue. Vigor of the host plant will affect the time in which root wounds heal over. Research studies such as these provide information which can be used to improve control recommendations for plant diseases. For Verticillium wilt, good cultural prac- tices should be followed when planting sus- ceptible hosts in soil that may be infested with the disease fungus. When digging plant material, care should be taken to keep wounds to a minimum, and root pruning should be avoided. After planting, fertilizer and water should be applied to decrease transplanting shock and increase vigor of the plant. If the vigor of the plant can be increased, then the root wounds will heal more quickly, decreasing the chances of infection. New Aquatic Study on Pesticides Recent figures show that pesticides are being applied in increasing quantities on agricultural lands in Illinois. For example, the percentage of total crop acreage treated with herbicides and insecticides in the state increased steadily from 66 percent in 1969 to 74 percent in 1971. Several million pounds of pesticides were applied to 15 million acres of crops in Illinois in 1971. Additional quantities of these chemicals are used by local government units each year for abatement of pests such as mosquitoes and to control the elm bark beetles which transmit Dutch elm disease. Through improper applications, spills, and erosion, significant quantities of pesti- cides find their way into streams, lakes, and ponds annually. Since these chemicals are present in the state’s waters, Survey scien- tists have placed a high priority on deter- mining what their effects might be on aquatic life. Although some general studies have been conducted in the past, a new approach to the problem of pesticide effects on aquatic systems is being taken by a Survey team composed of entomologists Keturah Rein- bold and R. L. Metcalf and aquatic biolo- The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 gist W. F. Childers. Studies on the toxicities of selected insecticides and a herbicide used extensively in Illinois agriculture to a na- tive fish species, the green sunfish, are being carried out in aluminum pools. ‘These pools contain 264 gallons of water each and are models of natural ponds. They are placed outdoors where they are exposed to normal light and weather conditions and to the entry of aquatic plants and insects. During the winter months, the pools are moved into a plastic greenhouse which is heated enough to prevent freezing of the water but maintained at low winter temperatures. The combination of outdoor and green- house facilities allows studies to be made under year-round variations in light and temperature. The information that may be gained under the special conditions of this re- search project should aid in making future recommendations for pesticide usage which are consistent with healthy aquatic environ- ments. This project is of particular concern to fishermen and sportsmen interested in aquatic wildlife, to farmers who wish to maintain farm pond fishing, and to Illinois residents who use the state’s waterways for recreational purposes. April 1973. No. 126. Published every month by the Illinois Natural History Survey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by D. F. Schoeneweiss, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinozs NATURAL HISTORY REPORTS Return of the Cicada In 1956, Brood XIII of the 17-year peri- odic cicada emerged primarily in northern Illinois, eastern Iowa, and southern Wis- Scientists elsewhere enormous numbers. Illinois, and came to our state to observe and study them. Hikers, school children, and mush- room hunters had to shout to make them- selves heard over the din of the cicada’s consin in from Michigan, oO song. Some gardeners and _ horticulturists complained of the “flagging” of the trees where the twigs died after being nearly girdled by the egg-laying of the cicadas. From middle May through June the ci- Adult twig. (Photo by Survey photographer Wilmer Zehr) 17-year cicada and cast skin of nymph on cadas held sway and then no more until this year. The broods, mostly composed of two species of return of one of Illinois’ largest cicadas, one smaller and one larger in size 1973. seen in the forest floor in early May. Many will occur in 3urrow holes will be of these holes will be covered with turrets. By the middle of May if the weather is favorable, the nymphs (which have spent the last 17 on roots) years underground feeding will crawl out of the burrows onto weed stalks or tree trunks, shed their skins, and emerge as adults. As many as 1,500,000 per acre might emerge from low- land woods whereas far fewer (130,000 or so) per acre may emerge from upland woods. By the end of May the male cicadas will be singing in unison, the wild birds will be engorging themselves on this abun- dant supply of insects, and then the female cicadas will mate and lay their eggs in slits sawn out by their ovipositor in the terminal twigs of trees and bushes. Finally the eggs will hatch and the young nymphs will drop to the ground, not to be heard from again until 1990. Survey entomologists will be monitoring this brood once again to determine the de- crease expected due to the cutting of forests and the recent urban sprawl over forme cicada grounds, as well as to further test the hypothesis now being formulated that each brood of cicada occupies its own woods. The data gathered will be shared with other entomologists in other states to improve our knowledge of the entire popu- lations of these species and to give those 1990 base who make the observations in data for future comparison. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey Trace Elements and Pheasants The possibility that a deficiency or excess of some chemical element might be pre- venting pheasants from extending their range southward in Illinois continues to be an intriguing research problem. In 1966 and 1967, with funds provided by the Illinois Department of Conservation, Sur- vey Wildlife Biologists William L. Ander- son and University of Tennessee ‘Trace Element Analyst Peggy L. Stewart studied 24 elements in soil, grit, corn, and pheas- ants from good (Sibley), fair, and poor (Neoga) pheasant range. For that study, pooled samples of as many different en- vironmental materials and as many differ- ent pheasant tissues as possible were analyzed. The findings, which were pub- lished in 1969 in the Journal of Wildlife Management, indicated that the inorganic chemistry of the physical environment and of pheasants differed appreciably in good, fair, and poor range in Illinois. In more recent research, also funded by the Illinois Department of Conservation, Anderson and Stewart (now with Stewart Laboratories, Inc., Knoxville, Tennessee ) attempted to progress from where their published work had left off, and most of their analytical work was conducted on individual samples. In 1968, they analyzed samples of unsorted grit and blood and livers from February-collected juvenile hens from Sibley and Neoga for 62 chemi- cal elements. They found 28 of these ele- ments in either the grit or the pheasant tissues. Continuing their research in 1969, they analyzed calcitic grit and blood and livers from August-collected adult hens from the same two areas for the 28 ele- ments detected during the 1968 work. The findings for unsorted grit, calcitic grit, and indicated that, of the elements studied, a deficiency of sodium was most apt to be limiting the abundance of pheas- ants in poor range. livers In an attempt to confirm the findings of the previous two years, Anderson and Stewart collected juvenile hens at Sibley and Neoga during February 1970, and analyzed livers, sternal muscles, and femur bones from these birds for sodium and four other major elements. However, con- firmation did not occur. In 1971, still suspecting sodium, they analyzed femurs from the juvenile hens collected in 1968 and the adult hens collected in 1969 for sodium and the other four major elements. This work also failed to confirm that so- dium was deficient for pheasants in poor range. Second on Anderson’s and Stewart’s list of elements likely to be limiting pheasant numbers in poor range was barium. This trace element was six times more abundant in unsorted grit and 17 times more abun- dant in livers from February-collected juve- nile hens, Neoga compared with Sibley. In early 1972, they analyzed for barium femurs from all of the hens collected during the more recent research and found that Neoga pheasants were carrying relatively high levels of this element. This was true for the juvenile hens collected during Feb- ruary 1968, the juvenile hens collected during February 1970, and the adult hens collected during August 1969. Thus, for the first time, these workers had uncovered a clear-cut difference between Neoga birds and Sibley birds for all three groups of pheasants studied. Because of these find- ings, Anderson and Stewart decided to analyze the femurs for the other 22 trace elements to determine whether any of these elements were also relatively high in the birds from Neoga. None was, which height- ened suspicion that barium is limiting the distribution and abundance of pheasants in Illinois. Anderson and Stewart believe that if an excess of barium is adversely affecting pheasants in poor range, the problem is complicated by low levels of environmental calcium. Such a relationship between bar- ium and calcium would explain why pheas- ants occur primarily — but not exclusively —on recently glaciated (calcitum-rich) soils. Water Quality in Shelbyville The Kaskaskia River and its two main- stream impoundments, Carlyle Lake and Lake Shelbyville, represent a major water resource in I]linois. Minor sources of pollu- tion exist in the watershed, but most of these pollutes are quickly assimilated, and the river and its reservoirs are still rela- tively unpolluted. In late April 1970, scientists at the Sur- vey’s Sullivan Laboratory on Lake Shelby- ville began a water quality monitoring program, funded by the U.S. Army Corps of Engineers, to define preimpoundment conditions in the basin (closure of Shelby- ville Dam was in August 1970), to investi- gate the effects of impoundment upon water quality, and to provide warning of degradation of water quality which should be controlled or might require restriction of water-use in the reservoir. Since its in- ception, this program has expanded to in- clude a network of ten monitoring stations visited on a regular basis in the Lake Shelbyville basin. Nearly 15,000 separate analyses were performed during 1972! Re- cently the Survey established a similar ten- station network in the Carlyle Lake basin downstream from Lake Shelbyville. Results to date have been compared to the State of Illinois Environmental Pro- tection Agency’s Water Pollution Regula- tions of Illinois by Survey Aquatic Biologist Allison R. Brigham in collaboration with R. Weldon Larimore. These general stan- dards are intended to protect Illinois waters for aquatic life, agricultural use, primary and secondary contact use, most industrial uses, and also to guarantee the esthetic quality of the aquatic environment. In general, Lake Shelbyville water qual- ity measurements have been within the acceptable ranges of the established stan- dards. With the exception of a minor spill Survey biologists Ed Doyle and Jack Wurm- nest taking bottom samples from Lake Shelbyville. (Photo by R. W. Larimore) of anhydrous ammonia in a_ tributary stream and a build-up of hydrogen sulfide in the deep water of the lake during the summer of 1971, the lake has been free of toxic substances. Since we have become more aware of the role of nutrients, especially nitrogen and phosphorus, in contributing to nui- sance algal blooms and, in general, the problem of rapid eutrophication, concen- trations of these substances are important. Levels of nitrates in the lake are well below established limits. While total phosphorus exceeds the new, stricter standards, soluble orthophosphate, the form most readily available to the phytoplankton, is well be- low established limits in Lake Shelbyville. Dissolved oxygen may be limiting to fish and other aquatic life in the deeper por- tions of the lake during summer. In fact, the benthic community which develops in Lake Shelbyville and other such lakes is composed chiefly of organisms able to withstand low concentrations of dissolved oxygen, such as midges and sludge worms, and organisms able to migrate to oxygen- ated water, such as the phantom midge. Corn Pest Management Integrated pest management has been practiced in Illinois to some extent for the past century. Forbes in his work on a chinch bug disease caused by a fungus pioneered some of this. LeBaron studied the wasp parasites of the oyster shell scale 15 years earlier than that. Since those studies of a century ago, Survey entomol- ogists have studied insects, their life his- tories, and recommended methods of The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 control. Methods of control involved ad- justment of planting dates, tillage varia- tions, harvesting techniques, and use of insecticides, along with imported parasites of foreign pests. Because of their economy, use of insecticides increased tremendously after World War II with the synthesis of many organic chemicals having insecticidal properties. Knowledge about economic thresholds of insect populations on most crops was indefinite for most insect species, and ap- plications of insecticides to avoid possible future damage became common practice as the public demanded more and better food uncontaminated by insect feeding. No longer could farmers gamble on yield losses of 10 to 25 percent. With this greatly expanded use came the question: By de- tailed insect population counts, can farm- ers have greater precision in insecticide application? Cotton insect scouting is well established and growers actually hire young people to make these counts for them. Then the farmer himself, the county extension ad- viser, or some other agricultural authority interprets these counts as they relate to need for insecticide application. In 1972 Survey and University of Illi- nois Extension entomologists, H. B. Petty and D. E, Kuhlman, began a corn insect scouting program in Boone County, Illi- nois, and John Zotz of Rockford visited 115 cornfields once each week to deter- mine insect pest populations. This year, the Illinois Cooperative Ex- tension Service has enlarged this program with USDA Cooperative Extension Service grants. Mr. John Walt has been employed to supervise this program in the field. War- ren, Hancock, and Shelby counties have been added to this study. All insect pests will be studied, but special account will be taken of wireworms, cutworms, corn root- worms, corn leaf aphids, corn borers, and grasshoppers. Nebraska, Iowa, Missouri, Ohio, and Indiana are developing similar programs for 1973. Eventually, it may be possible to accurately advise farmers whether or not these insects will be prob- lems before the damage is done and with- out automatically applying a soil insecti- cide just in case. May 1973. No. 127. Published every month by the Illinois Natural History Survey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation Prepared by Dr. W. E. LaBerge, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 6180] The Illinovs NATURAL HISTORY REPORTS Squash Vine Borer Control by Breeding squash types for further selection during ad : ; : the 1973 growing season. [he squash vine borer is a persistent and aa , 5 Since these crosses show resistance to the destructive pest of nearly all squash and pe i . ; ae. ; . squash vine borer and in some cases to pumpkin varieties throughout much _ of arch "s uh, t, x ; Pas 2 , other insect species such as cucumber North America. Production of suitable crops ; [ ‘bl ag 1 beetles and squash bugs, they may be of susceptible varieties has nearly always . - fi au ate s : - 3 , o Sie y entered into gene pools for the breeding of require sriodic applications of insecti- ans : : An oa - ; pas - “ : varieties resistant to insect attack. Selection ides to contro POEL. ecent researcn ze pens : : a * ‘ is one A oS as : ‘bl for fruit quality and type among the resis- las shown, however, that 1t May be possible : ic 27. . . i {EIA NOUS, I tant crosses will hopefully provide lines to breed natural borer resistance that occurs suitable for food production without the in wild cucurbits into cultivated varieties hazards of squash vine borer damage on and provide adequate insect control with- applications of insecticides for borer control. out the use of pesticides. The breeding of vegetable crosses re- sistant to insect attack has lagged far be- hind that of field crops. One of the most lucrative sources of insect resistance in many crop plants has been that found in cross compatible wild ancestors. Dr. A. M. Rhodes of the University of Illinois De- partment of Horticulture has crossed the Hubbard squash types with wild strains of cucurbits for many years using backcross and direct cross techniques. Although he was not searching for insect resistance when he made these crosses, the progeny were available for such studies. During the course of investigations on genetic resistance to economic insects, Sur- vey entomologist W. L. Howe recently tested many of Dr. Rhodes’ crosses and found sources of resistance to the squash vine borer in successful crosses between susceptible squash varieties and a species of wild gourds. The fact that F- backcrosses and Fs crosses were practically immune to squash vine borer damage indicates the dominance of this characteristic. Back- crosses have been made onto cultivated Squash vine borer larva in the stem of a Hubbard squash. (Photo by Survey Photographer Wilmer Zehr) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. Calcium Barometers in Pheasants The pheasant has established thriving populations on areas covered by the geo- logically young Wisconsin glacial drift in the Midwest but does not seem to do well on older drift. The first major hypothesis to explain this enigma was set forth by Aldo Leopold some forty years ago. He believed that a lack of calcium in the soils or plants on the older drifts was the limiting factor in preventing the establishment of pheasants in these areas. Yet today, after four decades of research, the precise role of calcium in delineating the range of the pheasant is still not clearly understood. This volume of research has shown, how- ever, that calcium is perhaps the most multifaceted element in the vertibrate body and as such can, in excess or defi- ciency, directly or indirectly affect the physiological balance of an animal. Thus an imbalance of calcium may be of critical importance to the well-being of the pheas- ant, but is the problem one of too much or too little calctum? The parathyroids are endocrine glands that function importantly as regulators of calcium. High levels of circulating calcium act on the glands to inhibit the secretion of the parathyroid hormone; conversely, low levels of calcium stimulate this secretion. Because the circulating level of calctum is ultimately dependent on the dietary intake of the mineral, the size of a pheasant’s parathyroid glands should reflect the amount of available calcium in the bird’s environment. To investigate this relation- ship, Survey wildlife specialists R. F. Lab- isky and W. L. Anderson, who were already studying the organic and inorganic nutri- tion of the pheasant, carefully examined the relationship between the dietary intake of calcium and parathyroid size among penned, juvenile hen pheasants in the fall of the year. They found that, after an eight-week feeding trial, the parathyroid glands of hens fed exclusive diets containing 14,000 parts per million of calcium were less than half the size of those fed diets (corn, for example) containing 40 ppm of calcium. Furthermore, in spring, the glands of wild adult hens from thriving populations were smaller than those of penned adult hens that had been fed diets containing low levels of calcium during winter. Hypertrophication of the parathyroids in the pheasant, therefore, offers strong clin- ical evidence of a negative calcium balance. Thus, among pheasants, parathyroid glands can act as indicators of the levels of en- vironmental calcium. Hill Prairies a Thing of the Past? On the sunny, windswept upper slopes of some bluffs along major streams are grassy openings clothed with prairie plants. These grasslands, when they occur on pronounced slopes, are defined as hill or bluff prairies. In Illinois, such prairies occur on the brow slopes of the bluffs of the Mississippi, Illi- nois, Rock, Sangamon, Fox, and Cache rivers as well as those of smaller streams. Between October 1948 and February 1952, Survey plant taxonomist R. A. Evers visited sixty-one of the many hill prairies — in Illinois, observing, making plot studies. and collecting plants. (The results of these studies were published in the Jilinois Nat- ural History Survey Bulletin, Volume 46, Number 5, 1955.) During the course of those field studies, he visited many of the sites only once or twice. To obtain a better knowledge of these prairies, he revisited some of them again in 1968 and 1969 and was impressed by the altered aspect in many cases. In April 1970, he began sys- tematic visits to each prairie in the months of the growing season when visits were not made during his earlier studies. On the first visits in 1970, seven of the sixty hill prairies were eliminated from further observations because they were no longer prairie. They had become dense thickets or woods, overgrazed pastureland, homesites, or were otherwise altered by man’s activities. The original number was thus reduced to fifty-four for more detailed study. Dr. Evers found that no prairie remained as it was twenty years earlier. The sites showed degrees of change from prairies to thicket or forest. Some exhibited little change with only a few forest species in- vading them. Others were strongly invaded Prairie openings on a bluff southeast of Chalfin Bridge, Monroe County, Illinois, in February 1952. (Photo by former Survey Photographer W. E. Clark) The same bluff in February 1972. (Photo by R. A. Evers) and were mere remnants of once larger prairies. Red cedar is a strong invader in this kind of prairie. It thrives on these dry, cal- careous, sun-baked slopes. On some prairies it grew and spread tremendously during the past two decades. Prairie species could not tolerate its shade. Black locust, because it can root sprout, is also a very strong invader. Although an introduced plant in central Ilhnois, it has spread out from plantings, invaded openings, and has mate- rially reduced the size of some _ bluff prairies. T'wo other common invaders were rough-leaved dogwood and smooth sumac. Some eighty-five other woody plants, trees The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 or shrubs, invaded Illinois hill prairies in various locations. Some plants of foreign origin were also invaders of hill prairies. White and yellow sweet clover were common in those which served as pastureland and some of the seed was, without doubt, planted. Multiflora rose grew in six of the prairies studied and Kudzu vine, which was possibly planted for erosion control, had smothered more than one-third of a hill prairie at Edgemont near East Saint Louis. Man’s activities, other than agricultural pursuits, are responsible for the loss of many bluff prairie stands. Removal of sand from a bluff north of Quincy destroyed most of the prairie plants. At two other sites the windblown glacial soil called loess, which had capped the bluff and supported prairie plants, was removed and used as fill for highway construction. In March 1972, three of the stands had been burned, whether purposely or acci- dentally is not known. The fire had little effect upon the herbaceous plants of the prairie but destroyed the seedlings of trees and shrubs. However, the larger woody plants suffered little or no damage. They either sprouted from the base or produced leaves in a normal manner on the existing branches. In March 1973, two bluff prai- ries, one in Adams County and the other in Monroe, were found burned for the second time in two years. These stands will be closely observed to record the effects of two-year burning. Apparently present climatic conditions favor forest rather than prairie and the area of hill or bluff prairie has been re- duced in the past twenty years. NOTICE: The July and August issues of the Illinois Natural History Survey Reports will not be published this year. June 1973. No. 128. Published every month by the Illinois Natural History Survey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by D. F. Schoeneweiss, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinozs YATURAL Adult Eastern Gray Squirrel. (Photo by W. E. Clark) Gray Squirrel History in Illinois Gray squirrels were abundant in the forests of Illinois at the time of settlement. In primitive times, gray squirrel popula- tions apparently attained much _ higher densities than today, according to Survey wildlife biologists Robert E. Greenberg and Charles M. Nixon. The historian of White County presented an account of a great “Squirrel Raid” which took place in 1834: “In the fall of 1834 there was a great immigration of squirrels from Kentucky, which crossed the Ohio River by swim- ming, and made their way through Gallatin White overrunning the country and doing im- northward and counties, mense damage to the corn crop. They were killed in immense numbers by the citizens, especially as_ they rivers and were exhausted by crossed the the labor of swimming. They were then taken and slain by a club. “In the neighborhood where Phillips- easily over- HISTORY SEPTEMBER 1973, NO. 129 town is now situated, a number of citizens banded they could kill in one day. ...The men divided together to see how many into two parties, of ten on a side, for the sake of competition. They were to scalp the squirrels, and meet at a certain place the next day (probably Sept. 10), and count the scalps. The result was 4,000 or 5,000 on each side. The defeated party, that is, the party surpassed in number of scalps collected, paid for the whisky used on the occasion, according to a previous understanding. They had a merry time; but they scon afterward went far beyond these numbers. They made up two parties again, and divided their Crooked Creek. They made their raid on the poor but mischievous squirrels, and territory by the day before Christmas they met and counted scalps, which numbered about 30,000 on a side! “The squirrels were numerous for some years after this, but they gradually dimin- ished, without renewal by general immi- erations, until they reached their present (1883) scarcity. They seemed to have emi- erated westward.” Kennicott, ported an also. re- 1857, “almost incredible abundance” writing in of gray squirrels in pioneer times. He also noted that “this species appeared to in- crease in numbers, in certain districts, for a time after their settlement.’ But as large areas of prime hardwood timber were cleared for agriculture, the abundance and distribution of the gray squirrel declined, while that of the fox squirrel increased. An examination of the distribution of forest land in 1820 provides insight into Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. the probable distribution of both gray and fox squirrels during the early nineteenth century. About 60 percent of presettlement Illinois was prairie, with forests found mostly along streams and in the ungla- ciated southern and northwestern areas. Within the prairie, forests extending along rivers provided some habitat for gray squirrels, but most of these woodlands were occupied by fox squirrels. Gray squirrels were rarely found in east-central Illinois in what is now Ford, Iroquois, Livingston, Grundy, La Salle, and Mc- Lean counties. It seems likely that fox squirrels were plentiful in areas where forest and prairie coexisted but were rare or absent in the heavily forested southern counties. Isolated (relict) populations of gray squirrels in towns and parks today may be the remnants of former wild popula- tions. This assumption is open to challenge in that there are known cases of success- ful urban introductions of gray squirrels by man. However, where isolated areas of forest (in 1820) coincide with present distribution of pockets of gray squirrels (such as the “Big Woods” in the center of Champaign County), it seems reason- able to accept these as remnants of for- merly abundant wild populations of gray squirrels. Continuous grazing and burning of many woodlots rendered them less suitable for gray squirrels and the gray squirrel was becoming relatively scarce in the 1880s and 1890s. Today gray squirrels are com- mon only in the southern third of Illinois, and in some of the heavily timbered river bottoms remaining in the central and northern parts of the state. Catfish and Bass Ponds In southern states intensive channel cat- fish culture has been wedded to intensive sport fishing by catchout ponds or fee fish- ing areas. Information on management and angler success, however, has remained scarce in the literature. During 1970 aqua- tic biologists D. H. Buck, Richard Bauer and Russell Rose began researching the management of a channel catfish catchout pond to see if certain techniques could be amplemented to benefit both the angler and the pond owner. During the first two summers when only channel catfish were stocked, it was found that the larger fish in the popula- tion were caught more readily than the smaller fish and that fish reared in wire cages in the same pond were more easily caught after release than fish originally stocked free in the pond. Although the re- lease of cage-reared fish improved the anglers’ catch rate, there were still un- avoidable slumps in angler success occur- ring at about the same time each year. _In 1972 largemouth bass trained to ac- cept pelleted feed were stocked along with the channel catfish. In sixty-five fishing days anglers harvested 90 percent of the catfish and 83 percent of the bass stocked in the pond as compared to 42 percent in 1970 and 73 percent in 1971. It was felt that the unusually large angler harvest in 1972 was due primarily to competition be- tween the two species. The same slumps in catfish angling occurred in 1972, but when the catfish refused to bite, the bass did bite, and vice versa. In this manner the bass maintained angler interest during the periods when catfish refused to bite. Another advantage of this bass-catfish combination was that both species were maintained on a pellet diet throughout the fishing season. In addition to main- taining growth, the feeding program was used to manipulate the angler catch by feeding less when the catch rate declined and feeding more when the catch rate rose unusually high. After viewing the success of adding a second species, and consequently more total pounds to the catchout pond, it is interesting to speculate on how far one might go with this type of management. If good fishing, and not necessarily good growth is desired, and if all species utilized can be maintained on artificial pellets, dense populations of diverse species may provide an answer to the growing demand for high yield, put-and-take fishing. The James P. Nielson Insect Collection Contributions to the Science of Ento- mology have often been made by ama- Survey entomologists accepting collection from Mr. James P. Nielson. From left to right L. J. Stannard, D. W. Webb, J. P. Nielson, W. E. LaBerge. teurs: doctors, lawyers, teachers, and schoolboys. The first collection given to the Illinois Natural History Survey was made by Cyrus Thomas (Carbondale schoolteacher) and Benjamin Walsh (emi- grant English farmer of Rock Island). Among these amateur entomologists were the second Chancellor of the University of Illinois, Selim H. Peabody, who gave the Survey a substantial collection of beetles; Decatur’s physician, Dr. Joseph P. Barnes, who donated a large number of moths and butterflies; and Carlinville’s physician, Dr. Charles Robertson, who contributed his famed collection of bees. These local collections of insects made by learned and thoughtful people, in their spare time and as an intriguing hobby, are more than just additions to the Survey’s reference cabinets. The specimens repre- sent a thorough picture of the fauna of that region, painstakingly searched for over many years and many seasons. As such they represent a good basic indicator of the fauna for future studies of change due to pollution or human activities on the natural conditions. They also are highly useful for studies on ancient insect dispersal back into glaciated areas, on regional evolution or on clinal adjustments to microhabitats, and on survival. On the these amateur collections, Sur- vey scientists have been able to monitor basis of changes in the state every thirty or so years, one of the unique contributions to the natural sciences for which the Survey is noted. The latest donated Museum has just come from Attorney James P. Nielson, Quincy, Illinois. Mostly and microlepidoptera (tiny moths), the collection of 10,000 specimens represents Attorney Niel- collection to our hard-to-find rare nearly son’s intensive activity over twenty years (1935-55) within a fifty-mile radius of Quincy in Adams County. Many of the species are new to our main collection, and all help round out the total data on The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 the fauna of the state, especially in the western region. Entomologists from the state, nation, and other museums of the world will be invited to study this collection to further our knowledge of the role of insects in the environment. These moths, despite their diminutive size, are not the least of the organisms that affect plants, animals and man in Illinois. Our appreciation and thanks are extended to Mr. James P. Nielson for giving the public his valuable collection of exquisitely prepared and carefully labeled moths and other insects so that science may profit from his labors. Butterfly Directory Butterflies are one of the natural won- ders which come to the attention of nearly every person at sometime in his or her life. It may surprise the reader to learn that within the state of Illinois 146 species of butterflies have been recorded. A few of these records are of rare species, some of which may have accidentally strayed into this area or have been carried here by winds, animals, or man, and are not permanent inhabitants of Illinois. Roderick R. Irwin, research affiliate of the Survey, and John C. Downey, Univer- sity of Northern Iowa, have recently pub- lished an annotated checklist to the Illinois butterflies (Illinois Natural History Sur- vey Biological Notes, No. 81, May 1973). | In this checklist all Illinois butterflies are listed together with important locality rec- ords, distribution maps for most species, and other scientific notes. Three halftone plates of butterflies are an aid to the identification of some species. Irwin and Downey point out that at least three species of butterflies have been extirpated from the Illinois fauna. Other butterflies which seemingly were not pres- ent in the state during early years of collecting have made their appearance in our fauna and a few have even become abundant. With the increasing alteration of the environment by man, it becomes ever more important to record conditions as they now exist and to document the records with specimens collected and de- posited in recognized institutions for per- manent care in order to be available for scientific use. Copies of the butterfly checklist (Biolog- ical Notes, No. 81) are available upon request. September 1973. No. 129. Published monthly except the months of July and August by the Natural History Survey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL SURVEY New Insect Laboratory Construction of an insect laboratory by the University of Illinois at Urbana-Cham- paign Department of Forestry was com- pleted in July 1972 at the Dixon Springs Agricultural Illinois. The laboratory is designed for basic studies Center in southern on the biologies of insects attacking forests and ornamental trees in southern Illinois. E. Appleby and entomologist R. G. Survey entomologist J. University forest Rennels are cooperating on these studies. This laboratory will complement similar Champaign-Urbana and in the northern part of the state at the facilities located at Morton Arboretum at Lisle. Climatic factors greatly alter insect ac- tivity. Because of the drastic variations in such factors between northern and southern Illinois, especially during the spring months, the life cycles of insects vary considerably between the different regions of the state. Regional information is needed as to the span of adult emergence, period of egg deposition, host plants, type of damage, duration of immature stages, number of generations per year, parasites, and pred- Such before control programs can be initiated. ators. basic information is essential A small nursery planting of ornamental trees and shrubs will be established adja- cent to the laboratory. The plants will be infested with insects so that close observa- tions can be made on insect behavior. The infested plants will later be used in control studies. A permanent collection of lepidopterous insects injurious to ornamental trees will be Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. HISTORY OCTOBER 1973, NO. 13 made. Such a collection is valuable in com- parative studies of species variation. It will be useful also as a reference collection fo1 students, control personnel, and collectors. Results of studies in progress and con- templated, at this laboratory and at the insect laboratories in central and northern [linois, will be useful to nurserymen, home- owners, and forest land owners in insect recognition and control programs. a ca ad uel 3? “aa se SL ? SS Feat an. % 4 fom mat { yk rover ra ig : — 7. ~ . ~ ms Wd mote ae Par ee wm —— mn fi |___Fan : Jae a A a /* a Lae le ® 02004 aD fees ti va oe PP ne ee } y. — Bs ——— —— poe _fown y * — ae + Seok J y rm ca <2 Location of insect laboratories in northern, central and southern Illinois. Trunk Treatment for Pin Oak Chlorosis Yellowing of pin oak leaves, usually re- ferred to as lime-induced chlorosis, is a major problem in alkaline soils in Illinois. Pin oaks are unable to obtain an adequate supply of iron from alkaline soils, and iron compounds must be applied to chlorotic trees to restore them to a healthy condition. Many methods of application have been used, including foliar sprays, soil treat- ments, and stem or trunk injections. Since iron is not transferred from old to new leaves, foliar sprays give only very tempo- rary results. Soil treatments have been effective but results vary with soil type, moisture, and other conditions. Trunk in- jections have shown promise but the tech- niques developed were often too complex or involved special equipment which made the methods impractical for common usage. Recently, Survey plant pathologist Dan Neely conducted a series of tests on chlo- rotic pin oaks in nursery and landscape plantings to evaluate a method of trunk treatment which involves implanting gela- tin capsules containing iron salts into holes bored in the trunks of affected trees. Of the compounds tested, the two found to be most effective with the least amount of injury were salts of ferric citrate and ferric ammonium citrate. Chlorotic leaves of affected trees regained a normal green color within two to four weeks following treatment. Results thus far indicate that trunk implantations of iron citrate salts should correct lime-induced chlorosis for approximately three years, although rapidly growing trees may exhaust the implanted iron supply earlier. Since trunk implanta- tion gives only temporary results, affected trees will probably have to be treated peri- odically for correction of iron chlorosis. For best results, Dr. Neely suggests that chlorotic trees be treated in April, May, or June and that implantation be done using plastic cartridges available on the market for this purpose or that holes be sealed with doweling, cork, or asphalt after treat- ment. ‘This is to prevent leakage and to protect tree wounds from invasion by i1n- sects and disease organisms. Treated trees should be watered immediately after treat- ~ment and during dry periods. For trees one to four inches in diameter at breast height, gelatin capsules containing .4 grams of iron citrate salts should be placed in holes two inches apart and at different heights on the trunk. For trees four to twelve inches in diameter, capsules containing 1.4 grams should be placed three inches apart and for larger trees they should con- tain 2.8 grams and be placed four inches apart. Implantations should be made in the trunk below the lowest branches for max- imum distribution of iron in the tree. Mineral Patterns in Goose Feathers Most wild geese grow their flight feathers while in the vicinity of their breeding grounds. As these feathers grow, minerals ingested with the food and water become incorporated in the keratin of the feathers. The quantities of minerals ingested by geese reflect the mineralogy of the local ecosystem and the origin of the birds can be determined on the basis of mineral patterns of the main flight feathers or primaries. This correlation was pointed out in Survey Notes No. 115 in May 1972 by Survey wild- life specialist H. C. Hanson and Robert L. Jones of the Unwversity of Illinois at Urbana- Champaign Department of Agronomy. Using the mineral pattern technique, the origins of as high as 85 percent of blue and snow geese were accurately determined. With races of Canada geese, which nest in regions with highly diversified geology, the feather mineral technique is even more accurate in determining not only origins but races or subspecies as well. In a recent computer analysis of feather mineral patterns from 388 individual geese comprising seventeen races, 92 percent were correctly identified on this basis. Few taxonomists using common morphological characteristics could score as well. Feather mineral patterns have also pro- vided some unique and valuable insights into basic aspects of mineral metabolism. A study of twelve minerals in feathers of geese from breeding grounds spread over three-quarters of the North American con- tinent revealed that levels of the bulk minerals calcium, sodium, potassium, and ELEMENT CALCIUM MEAN S.D. RANGE POTASSIUM PHOSPHORUS IRON BORON SILICON ALUMINUM \4 12 HUNDREDS wai SQ34ONNH » 5 ol % of wv Ke w (7) z o wi ra € a) / ° aN ji i 1B Diagrammatic representation of mineral levels found in primary feathers of a snow goose. Geese from the same origin show similar patterns. phosphorus appeared to be under meta- bolic control, although the levels also re- flected environmental concentrations. The trace minerals, iron, manganese, and cop- per, and the inert minerals boron, silicon, and aluminum were apparently freely ab- sorbed and more directly reflect environ- mental levels. Magnesium, a bulk mineral in the body which plays an important role (like the trace minerals) in enzyme activa- tion, appears to be freely absorbed. Levels of zinc, a trace element, were under rigid metabolic control. The question naturally arises as to whether rates of absorption or excretion are more important in regulating mineral levels. From these studies, excretion was judged the more important mechanism for all minerals except potassium. The bulk minerals which are required in large quantities must be present in ade- quate amounts in the ecosystem or the birds would not be there in the first place, and metabolic systems have evolved to control the levels of these minerals. The trace elements, on the other hand, are generally in short supply and are absorbed freely, along with silicon and aluminum, since there was no need to evolve mecha- nisms for regulating their absorption. Levels of these minerals, therefore, reflect levels present in the ecosystem and are useful in determining the origins of geese. In brief, feather mineral patterns have proven to be a valid reflection of mineral levels in the nutrient chain of the environ- ment and provide valuable insights into mineral metabolism. Predisposing Factors in Plant Diseases When symptoms of injury or decline appear on trees and shrubs, the disturbed owner nearly always asks “What disease is affecting my plants and what should I spray with to cure them?” In most cases he is disappointed with the answer he receives from plant scientists since the majority of injuries are not due to disease organisms and only a few diseases of woody plants can be controlled satisfactorily with pesticide chemicals. More often the damage is caused by physical or climatic injury, toxic chem- icals, insects, or in some instances by disease organisms that attack stressed or weakened The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 plants but not vigorous ones. Such diseases can be very damaging to woody plants but surprisingly little is known about. stress factors that influence disease susceptibility and how they can be reduced to keep plants free of disease. Some of the reasons for this lack of knowledge are obvious. Plants growing under field conditions are subjected to many stresses during the year which may effect their susceptibility to attack by dis- ease organisms. Usually these — stresses (drought, freezing, and defoliation for ex- ample) are unpredictable and difficult to duplicate under controlled conditions so that their influence can be studied scien- tifically. To better understand which stresses in- fluence disease susceptibility in woody plants, Survey plant pathologist D. F. Schoeneweiss has developed methods for creating several plant stresses under labo- ratory conditions. Special chambers have been constructed in which field conditions associated with drought and _ freezing stresses can be simulated. In this manner the level and duration of these stresses re- quired to alter disease susceptibility can be determined. Results of this research indicate that stresses such as drought, freezing, defolia- tion, stem girdling, and transplanting shock can cause plants to become susceptible to certain diseases, even though the same plants are highly disease resistant when in a vigorous condition. In most cases, the level of stress required to affect a change in disease susceptibility is considerably less than that which results in injury in the absence of disease organisms. Thus stems inoculated with canker fungi and exposed to given levels of drought or freezing may form cankers, whereas these same plants usually recover from the stresses without ill effects if no disease organisms are present. These findings correlate well with field ob- servations on the occurrence of diseases that appear to be related to environmental stresses. Information obtained from research on stress factors that predispose plants to dis- eases should lead to improved methods of handling and maintaining ornamental plant material to reduce losses caused by disease organisms. October 1973. No. 130. Published monthly except the months of July and August by the Natural History Sur- vey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by D, F. Schoeneweiss, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 The Illinovs NATURAL Lead in Aquatic Ecosystems As part of an interdisciplinary study of environmental pollution by lead, a group of Survey aquatic biologists headed by R. Welden Larimore, John McNurney, and Tom E. Hill are studying lead distribution in the Saline Ditch drainage above May- view, Illinois. This study is being carried on in cooperation with the University of Ilh- nois. The Survey team is determining the distribution of lead in the fish, the aquatic plants, and the invertebrates in the study area, and measuring the movement of lead and characterizing the exchanges of lead between trophic levels in the system. The lead distribution has been derived by measuring the size of the major plant and animal populations and their lead con- tents. Of the organisms of interest, only the drifting constitute a measurable transport of lead through the study area and the amount of drift has invertebrates HISTORY REPORTS been measured. Arriving at exchange rates between trophic levels is the most difficult assignment. Lead levels of individual orga- nisms, experimental investigations of lead uptake and loss, and reviews of the biology of certain species have been employed to indicate the dynamics of individual accu- mulation mechanisms. The use of lead in automotive fuels sig- nificantly influences the distribution of lead in aquatic ecosystems. The runoff charac- teristics and concentrated traffic volumes of an urban area cause high lead levels in primary drainage channels. The lead lev- els in aquatic organisms are substantially higher in urban drainage areas than in rural areas. The concentrations of lead in organisms in any area of a stream are variable. There are fairly rapid changes in lead accumula- tion in organisms over short time periods. These fluctuations can be detected in areas The saline ditch in an urban environment (Ur- bana). (Photo by John McNurney.) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. where the tissue levels of lead are higher than 20ppm. Where large individuals are involved (more than 2.0 grams of wet weight) extreme, nonnormal distributions of individual lead levels can be discerned. There are wide variations in lead concen- trations in different organisms from one area. The lead levels are apparently lowest in organisms which are high in the food web and not associated with the stream sediments and highest in organisms that are detritus feeders and closely associated with the bottom. The dynamics of lead in aquatic en- vironments can be further defined by in- vestigating some of the aforementioned observations. A multiple correlation anal- ysis of time-variable lead levels of orga- nisms and measurements of environmental parameters is needed. A large population of some species of fish of sufficient size for individual analysis will be examined for lead content, size, condition, and age in an effort to understand the variation in lead levels. Some lab experiments and field investigations have been designed to examine the variation that exists between different organisms from the same area. The distribution of lead in the aquatic organisms in an area can be adequately predicted. The dynamics of accumulation in particular organisms from one area and at certain times in one species are yet to be determined. Rare and Endangered Fish “Every living thing on earth is unique. Once gone, it can never be replaced. It is part of .. . ‘the genetic pool’ — the great reservoir of life on earth... .As passengers on this spaceship Earth, we'd be foolish to wipe out any of our shipmates.” This quote from “A Law for Wildlife,” pub- lished by the Conservation Department of Winchester-Western Division Olin in developing model legislation for state non- game wildlife conservation programs pref- aces a brochure recently issued by the Department of Conservation’s Division of Fisheries. The fifty-three-page publication is en- titled “Rare and Endangered Fish of Illi- nois.” Its authors are A. C. Lopinot of the Division of Fisheries and P. W. Smith of the Survey. The objectives of the report are to identify the species of fishes in Illinois that are rare and/or endangered and to summarize the pertinent information neces- sary to preserve them. For each of the twenty-five species discussed, a line drawing of the fish with diagnostic characters indi- cated by arrows and a map showing both former and present distribution of the species are presented. A small inset map shows the distribution of the fish in the United States. The text includes informa- tion on characteristics, present and former distribution, range in Illinois, fecundity, reasons for decline, protective measures already taken, protective measures pro- posed, and management recommendations. The new publication will alert fishery biologists, conservation organizations, and governmental agencies as to which native Illinois fishes are in greatest danger of ex- tirpation and which streams, lakes, and swamps should be protected from dredging, channeling, damming, excessive polluting, and other modification by man that will hasten the disappearance of these fishes. It also outlines our present knowledge of the life histories of these species and points out aspects that need more intensive study. A limited number of copies of this publi- cation are available from the Division of Fisheries, Department of Conservation, Springfield, Illinois 62706. The Pheasant: He Adds Green to the Economy The pheasant is, without question, one of the most exciting and popular game birds in North America. Each autumn, hunters stream to the field to hunt this unpredict- able long-tailed bird from the Orient. And, each autumn, these same hunters dispense a considerable amount of money in the pursuit of their favorite sporting adversary. Just what does it cost for a hunter to bag a pheasant? Survey wildlife specialist Ronald F. Labisky and his Department of Conservation colleague William L. Preno decided to provide an answer to that ques- tion. They devised a questionnaire to solicit information on pheasant hunting costs from Illinois hunters, and encouraged their col- Economic factors in pheasant hunting. (Photo by former Survey Photographer W. E. Clark.) leagues in other midwestern states to use the same questionnaire for sampling their pheasant hunters. The results! Illmois resident hunters averaged an expenditure of $16.50 to bag a pheasant in 1971. With an annual harvest of 957,000 pheasants, hunters contributed $15,790,000 to the Illinois economy in 1971. How did they spend it? The two big expenditures were for travel and dogs, accounting for 26 and 23 cents, respectively, of every dollar spent. Guns took 18 cents more of the dollar, whereas ammunition, food, and clothes absorbed 9 cents each; miscellaneous costs totaled 7 cents. License fees were not included in these cost analyses. The cost per pheasant bagged by resident hunters in 1971 averaged $29.73 in Mis- souri, $17.42 in North Dakota, and $12.95 in Nebraska. In Iowa, resident hunters spent $15.11 to bag a pheasant, and non- resident hunters, $22.61. The final step is to look at pheasant reve- nues in the United States. Labisky and Preno estimated that the 1971 harvest of pheasants in the U.S., which totaled 12 million birds, contributed about $225,000,- 000 to the nation’s economy. The pheasant is big business! Almond Moth in Stored Soybeans Millions of tons of soybeans are stored every year from harvest to the time they are moved for export or processing. While many stored grains such as wheat, oats, barley, and corn have very serious insect problems that require constant surveillance and special protection, stored soybeans in the United States, in general, do not. How- ever, in other parts of the world such as Thailand and India the almond moth causes considerable damage. The almond moth does occur in the United States and has already been reported attacking soy- beans that were punctured by stink bugs. The almond moth is being studied under the direction of Survey entomologist Marcos Kogan. Mr. Sathorn Sirisingh, a graduate student from Thailand, is analyz- ing the conditions under which the almond moth is able to grow and reproduce on soybeans. The moth is pale gray in color, one- fourth to one-half inch long. The head and tail are slightly raised and the wings are held in a rooflike position when the insect is resting. The larva damages grain. The caterpillars when fully grown are about three-fifths inch long, tinged with brown The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 and faintly striped with darker dots. The young caterpillar spins a silken web formed into a little tube in which it lives and feeds. It is this web-spinning that causes the greatest amount of damage by the insect. The moth lays its eggs on soybean pods in the field before harvesting. Mr. Sirisingh studied the development of the larvae in the green seed and found that larvae developed normally when the moisture content was between 50 and 60 percent. When the moisture content was only 25 percent, development dropped very sharply. The moth cannot develop on beans that have a complete seed coat and a low moisture content. But if the seed coat is cracked the moth will develop even though the rate of development is slow at low moisture. Development of the moth im- proves when the soybean is boiled and dried. This is probably due to softening and cracking of the seed coat and to the in- activation of growth inhibiting enzymes in the seed. Developmental rates are near normal on soybeans put through a blender. This is of particular interest because new uses of soybeans for human consumption may require the storage of flaked or cracked soybeans. Partially processed beans are particularly susceptible to attacks. Besides soybeans, this insect is known to be a pest of stored rice, peanuts, wheat, sorghum, maize, linseed, and sesame. November 1973. No. 131. Published monthly except the months of July and August by the Natural History Sur- vey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by W. E. LaBerge, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL SURVEY Herons Reflect Environmental Quality The use of birds as environmental sensors dates back more than a century, when coal miners used canaries to detect toxic gases 1n mine shafts. The birds fell victim to the gases much more quickly than humans did and, in this way, served as a special warn- ing system. In somewhat the same way, but on a much broader scale, bird and other wild animal populations are probably reliable sensors of environmental quality on a worldwide basis. If we are to use wild pop- indicators of environmental need population data than we now have. For the ulations as change, however, we much_ better vast majority of free-living populations, we lack even crude measurements for a single locality in a single year. With no better in- formation than this, we can scarcely know that a given population has changed, let alone understand the causes of change. Certain species of birds, the herons for example, seem particularly well suited as sensors. Herons represent the ends of sev- eral food chains, all associated with aquatic habitats that are also heavily used and often polluted by man. Most herons are also colonial nesters that return year after year to a traditional nesting place, which helps facilitate censusing once the colonies Illinois, the are located. In locations of some heron colonies have been known for years but the statewide population has never been determined. In the spring and summer of 1973, Sur- vey wildlife specialists Richard R. Graber and Jean W. Graber initiated a search to locate all the major nesting colonies of HISTORY DECEMBER 1973, NO, 132 herons in the State of Illinois. Using: air- craft and boats and by walking, they cov- ered perhaps a third of the best habitat for herons in Illinois. Once the heronries were located, they were censused from the air, from the ground, or both. Counts of oc- cupied nests and of young per nest pro- vided data on productivity of the colony. oth population level and productivity of a colony are believed to be reflective of en- vironmental quality. In addition, informa- tion on food habits of herons was acquired at some colonies. Because nesting herons have a habit of reourgitating recently in- gested food when the colony is disturbed, A great egret (one of several heron species) at a nesting colony near Plainfield, Ill. (Photo by Dr. J. W. Graber.) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. samples of food could be collected from - under the nests. These samples are being saved and can be analyzed later for the presence of toxic substances. The heron survey in Illinois will be con- tinued again next spring when the birds return. When all of the colonies have been located, their population levels, productiv- ity, and food relationships will be moni- tored annually. These data are of value in relation both to the conservation of species and to the matter of environmental quality. Treatment for Salt-Injured Trees In the interest of safety, it is considered imperative that highways be maintained free of ice and snow. Therefore highway maintenance organizations have found it necessary to use large quantities of deicing compounds such as sodium chloride and calcium chloride. The rapidly increasing use of these deicing salts in recent years has had some detrimental effects on the environment, particularly on _ roadside vegetation. Numerous reports indicate that trees along treated highways are less vigorous than those near highways where salts have not been applied, and in some cases are seriously injured or killed. These injurious effects are attributed to salt deposits from spray drift and to saltwater runoff onto the roadside soil. Responses of plants to salt stress are manifest in numerous ways and are often difficult to assess visually. On deciduous plants, excess salts on the soil cause stunted growth, killing of terminal buds, twig die- back, leaf scorch, and, in severe cases, death of plants. Symptoms on evergreens may in- clude needle burn and death of terminal buds and twigs. Since most of our highways are already landscaped, the only ways to reduce salt damage are to reduce highway salting or go to the great expense of replacing pres- ent plantings with more - salt-tolerant species. Whether trees injured by salt can be restored to a vigorous condition has re- ceived little attention in the past. To determine if declining trees along heavily salted highways could be success- fully treated to restore vigor, in 1972 Sur- vey plant pathologist E. B. Himelick initi- ated a research project using combined mulching and fertilizing on hawthorn and green ash trees growing along the Edens expressway in Chicago. Four inches of wood chip mulch was placed around sev- eral declining trees of each species and the mulched trees were fertilized with am- monium nitrate in the springs of 1972 and USS: When the growth rate of treated trees was compared to that of adjacent untreated trees of the same species, a pronounced stimulation in growth was observed. Growth of treated hawthorns increased 39 percent i 1972 and 49 percent in 1973, while green ash increased 26 percent in 1972 and 22 percent in 1973. Visually, the treated trees appear in better vigor with decreased dieback of twigs when compared to trees receiving no fertilizer or mulch. When available soil moisture is reduced, such as during a drought, soluble salt con- - centrations increase and can cause exten- sive injury. Since abnormal amounts of heavy rainfall occurred in both 1972 and 1973, the full effectiveness of the combined fertilizer and mulch treatments may not be determined until a normal season or drought season occurs. This study will con- tinue at least one more year before the pro- cedure is offered to the Illinois State High- way Department as a means of preventing or reducing further tree losses. Fate of Diquat Herbicide in Lakes Many diverse compounds such as the chlorinated organic insecticides, polychloro biphenyls, and various metals including mercury have been introduced into the environment by man. Although some of these compounds may be metabolized in the ecosystem, such as the conversion of DDT to DDE or inorganic mercury to methylmercury, all of these compounds accumulate in the environment. In light of the serious consequences that have re- sulted from these introductions, the federal Environmental Protection Agency has un- dertaken a review of many of the chemical compounds used as pest control agents, in- cluding those used as aquatic herbicides. One of the most effective herbicides for control of aquatic vegetation is diquat. Working with this compound in the past, Survey biochemist R. C. Hiltibran found that diquat provides control of some of the common aquatic plants. More impor- tant, however, it is effective against diffi- cult-to-control species such as American elodea, southern naiad, and waterstar grass. To find out more about this herbicide and to determine how and where it accumu- lates, Dr. Hiltibran recently conducted an investigation of the interaction between diquat and the aquatic environment. ‘This work was supported in part by a grant from the Water Resources Center of the Univer- sity of Illinois. Laboratory experiments, conducted in cooperation with research assistant Denny Underwood, revealed that diquat was not degraded extensively in water and could be detected in water for long periods of time. However, if diquat was introduced into a natural pond free of aquatic vegeta- tion, it was rapidly removed and could not be detected after 72 hours. It appeared that the diquat was being adsorbed on the hydro- soil in the pond. In cooperation with research assistant James Fickle, the adsorption of diquat by the hydrosoil from six natural bodies of water was investigated. These particular bodies of water were selected because they were of different ages and they represented aquatic systems influenced by gravel or coal stripping operations or damming of an existing water way. The binding of diquat by hydrosoils in the various waters was related to the cation exchange capacity of the hydrosoil and to a lesser extent the clay and silt content, but was not correlated with the organic content of the hydrosoils. The diquat adsorption on the hydrosoils in the different bodies of water are shown in the accompanying diagram. These studies also revealed that diquat could be readily desorbed or released from the hydrosoil from Miller Pond, which had a low cation exchange capacity, but not from hydrosoil from Allerton Lake, which had a_ high cation exchange capacity. Research information of this type is needed in order to make intelligent recom- 900 4-11 ALLERTON LAKE BIG ty 800 POND o © 500 BLUEBIRD n < DUCK 300 MILLER © HEDGE —_ oO > 100 250 500 UG/G AVAILABLE 1000 Adsorption of diquat by hydrosoils from six different ponds or lakes. mendations for the use of pesticide chemi- cals in the environment. Rootworm Management in Canning Corn Three species of corn rootworms, the northern, southern, and western corn root- worms, attack sweet corn in Illinois. Only two of these, the northern and western species, cause significant damage in the northern half of the state where sweet corn is grown for the canning industry. The northern corn rootworm is well distributed in the state and has been around for some time, whereas the western species invaded the northwest corner of Illinois in 1964 and has spread rapidly throughout much of the northern half of the state since then. These insect pests can cause severe dam- age by larval feeding on corn roots and, in some cases, by adult feeding on corn silk. In the past, rootworm control has been accomplished by the annual applica- tion of soil insecticides. Recently, however, Survey entomologist W. H. Luckmann, with the aid of research assistants J. T. Shaw and A. H. Redborg, has developed a pest management program for controlling rootworms in sweet corn grown for the Illinois canning industry. Insect pest man- agement programs attempt to utilize as many biotic and cultural factors for con- trol as possible, with a judicious use of insecticides. In this program, the key to rootworm control is to plant sweet corn each year in the same ground and to design the The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 planting schedule to coincide with the harvesting schedule of the previous season. The program is divided into four cate- gories, depending upon the date of harvest the previous year, the planting date for the current crop, and the number and timing of sprays applied the previous year for corn borer and corn earworm control. Since insecticides used for borers and ear- worms are toxic to rootworm adults, appli- cations of these insecticides can serve a dual purpose in corn insect control when integrated into this program. : Details of this program will be presented to growers and canners before planting time this coming spring. In this manner, the growers will be able to design their own corn insect control programs, based on sound scientific knowledge, which will fit into their individual planting schedules. Thus canning sweet corn can be grown profitably with a minimum use of soil insecticides. carefully designed December 1973. No. 132. Published monthly except the months of July and August by the Natural History Sur- vey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by D. F. Schoeneweiss, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinozs NATURAL SURVEY Waterfowl Migration and Weather With up to 2,000,000 ducks and 400,000 geese arriving in Illinois during the fall from northern breeding grounds, this state is one of the most important for migratory waterfowl in the nation. Most of the ducks pass through Illinois to winter in more southern areas, but most of the geese re- main through the winter in southern TIIli- nois. The opening and closing of hunting seasons on waterfowl are established by the [llinois Department of Conservation within WES: Bureau of Sport Fisheries and Wildlife. Therefore, it is important to determine the broad limits promulgated by the chronology of migration by various species of waterfowl to assist the Department of Conservation in setting the season at the most judicious time. This poses a real prob- a state 29o0¢ lem in 382 miles long, north to south. HISTORY JANUARY 1974, NO. 133 Data obtained from aerial censuses of waterfowl in the Illinois and Mississippi river valleys, 1946-72, made by Survey biologist Frank C. Bellrose and his field assistant, Robert Crompton, reveal the chronology of passage for each important species each fall. The extremes in time of 1946-72 mallard, 20 days; pintail, 21 days; wigeon, arrival between the years are: 22 days; green-winged teal, 20 days; lesser scaup, 18 days; canvasback, 30 days; and ring-necked duck, 20 days. Departure dates for these species varied by a similar numbe1 of days among years. If reasons can be found for the yearly variation in waterfowl passage through Illinois, the open season can be set more advantageously. The first step in seeking these reasons was an analysis of the in- weather conditions. that weather items were responsible for only fluence of short-term This analysis indicated short-term Canada goose migratory flight formation near Havana, Illinois. (Photo by former Survey Photog- rapher C. L. Scott.) Material in this publication may be reprinted if credit is given to the Illinois Natural History Su rvey. 4 to 47 percent of the arrival flights of the different species. These weather conditions influenced the late migrating mallards and canvasbacks most, the lesser scaups and ring-necked ducks least. To supplement this analysis of weather and waterfowl migration, weather maps were studied in relation to dates that water- fowl were observed arriving or departing the Illinois and Mississippi river valleys. The relationship of duck departures from Fargo, North Dakota (equated to arrivals in Illinois) and from Peoria, Illinois with several types of weather fronts was studied. Slightly over half of the arrivals and depar- tures occurred when fronts were not in juxtaposition to the departure area, and the frequency of departures appeared un- related to the existing type of weather fronts. Thus far, the evidence indicates that the yearly variation in the chronology of waterfowl migration is poorly correlated with short-term weather conditions. Addi- tional study is needed to discover natural factors that will explain the variation in timing between years. Mission: Information Since communication through the spoken word is, by its nature not enduring, it is imperative that research scientists inform others of their findings in writing. Biologists at the Illinois Natural History Survey have been doing this for over a hundred years. In Illinois in the mid-nineteenth century, formalized research recorded in print was just getting under way. As phrased by James Ayars, former technical editor at the Sur- vey, “It was a time of rapidly expanding agriculture, hordes of hungry insects, and distressed and vocal farmers.” Because re- search in applied science came along in answer to the needs of the time, most of it was biological. Illinois was one of the leaders in making known the results of scientific research. Organization of the State Agricultural Society in 1853 and the Horticultural Society in 1856 opened important publica- tion outlets to biologists. Reports of that era included such subjects as the origin and ~character of prairie soils, birds of the state, strawberry and tree culture, and the educa- tion of farmers’ daughters. Today the specific subjects number in the hundreds among five major areas of research at the Natural History Survey: economic entomology, aquatic biology, wild- "fe research, faunistic surveys and insect identification, and botany and plant pathol- ogy. And the “reach” of this information goes far beyond the borders of the state. The Survey’s widely known library ex- changes publications with about 700 li- braries and other institutions all over the world. In the days when appropriations were meager for the dissemination of research results, State Entomologist Stephen A. Forbes emphasized the folly of conducting investigations and neglecting the means to publish them properly. In 1886 he withheld his biennial report because funds were lack- ing to publish the paper and include perti- nent illustrations. At its next session the Illinois General Assembly provided $300 for publication of State Laboratory of Natural History bulletins and $500 for illustrating the biennial report. Special problems in handling biological information arise from its diversity of sub- ject matter and approaches toward phe- nomena of the living world. Thousands of technical and scientific periodicals are de- voted to biology alone, more than in any other field of science. Since biologists deal with some of the world’s vital concerns, including the effects of man’s activities on the environment, failure to communicate their research findings can have serious consequences. The users of this information are many, including the scientists and scholars, the “practitioners,” the policymakers or ad- ministrators, and individual citizens who need help with their everyday problems. The Illinois Natural History Survey issues publications in three major categories — scientific bulletins, technical reports, and popular circulars—and maintains an “Office of Publications and Public Rela- tions,’ currently headed by O. F. Glissen- dorf. Their primary task is to aid the biol- ogists in their preparation of about a dozen Strip-mine ponds in Kickapoo State Park. (Photo by former Survey Editor James Ayars.) Survey publications and some 80 to 100 articles for scientific journals each year. Crawling Water Beetles As man’s awareness of environmental problems increases, the need for detailed physical, chemical, and biological environ- mental studies has become apparent. Such studies provide our only means of assessing existing environmental conditions and the ecological impact of resource development programs. Because the species, composition, diversity, and abundance of the biological community in an area provides a sensitive means of monitoring ecological changes, the ability to identify organisms accurately has become critical to the ecologist. The large number of investigations presently underway, however, precludes the partici- pation of specialists in every project. In the resulting division of labor, a principal role for the taxonomist is one of providing identification aids to plants and animals for use by the nonspecialist. To this end Survey Biologists Warren U. Brigham and Milton W. Sanderson have undertaken a taxonomic and _ ecological study of the water beetles of Illinois and adjacent areas. Presently their study has concentrated upon the crawling water beetles of the family Haliplidae. These beetles are generally less than one-quarter of an inch long and usually are yellow with black spots. Twenty-two species are known to occur in Illinois. Of these, two were un- known to science before the present study. An interesting assemblage of haliplid species was discovered in the stripmine ponds of Kickapoo State Park, Vermilion County, Illinois (see photo). To date, fif- teen species have been taken in the park, twelve from a single pond. This is nearly twice the number of species previously re- ported from a single locality in any part of the world. Stripmine operations in the Kickapoo area began approximately 100 years ago, shortly after prairie-marsh drain- age became widespread. Apparently these stripmine ponds provided a refuge to the haliplids and other aquatic insects whose natural habitats were being destroyed. Ref- ugia such as this one provide valuable in- formation to the scientist regarding the once widespread prairie fauna of Illinois. Pests of 1973 and Outlook The twenty-sixth annual Custom Spray Operators Training School will be held January 9-10, 1974, in Urbana. During this The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 meeting a report will be presented dealing with insect pests and their control in Illi- nois during the past year. This report, prepared by Survey Entomologists Roscoe Randell, Donald Kuhlman, and T. A. Cooley, is a summary of data received from county extension advisers in agriculture and includes comments on problems of the past year and an outlook for the coming season. There is no normal year when consider- ing insect problems; each season has its special troubles. Green cloverworms, corn rootworms, fall armyworms, and _ alfalfa weevils were the most troublesome agricul- tural pests in 1973. The major nonagri- cultural pests in Illinois during the past year were bagworms, roaches, spiders, and white grubs. For several years Illinois has had no catastrophic outbreak of pests as occurred before the advent of modern insecticides. The green cloverworms were awarded the “insect-of-the-year” title for 1973. About 735,900 acres of soybeans were treated for this insect. Populations were ex- tremely high in many fields in the northern two-thirds of the state during late July and early August. Fortunately, overall damage to soybeans was light, due primarily to a fungus disease and a parasitic fly which together decimated the cloverworm popu- lations during early to mid-August. The green cloverworm overwinters in the pupal and adult stages. Two to four generations occur per year and a gradual buildup in populations occurs under good weather conditions. Heavy infestations of fall armyworms were present in many fields of late-planted corn over the entire state in 1973. Late- planted fields of corn are preferred by the moths while egg-laying and are most sub- ject to damage. The dark-brown to dull- green, smooth-skinned worms feed in the whorl, giving the corn plants a ragged ap- pearance as the leaves emerge. Ordinarily, only one worm will be found deep in the whorl since the worms are cannibalistic. Several instances of damage from com- mon stalk borers occurred in no-till corn in 1973. Ordinarily, damage by this insect is confined to the border rows of conven- tionally tilled cornfields. In no-till corn, the infestations often covered the entire field or large portions of the field. An estimated 7,194,618 acres of field crops were treated with insecticides in 1973, with a savings from crop losses to farmers of $24,018,473 above treatment costs. The control of soil insects in corn accounted for 80 percent of the estimated profits from using insecticides. Regardless of statements to the contrary, insecticides are Clearly necessary for the profitable pro- duction of field crops in Illinois. January 1974. No. 133. Published monthly except the months of July and August by the Natural History Sur- vey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by W. E. LaBerge, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL HISTORY REPORTS New Lab Supports Water Quality Work The impact of man’s activities on en- vironmental quality is a subject that has much attention Nearly everyone who reads the newspapers or watches TV is now aware of the deteri- received in recent years. oration of the environment. Increasing de- mands for more energy and greater food production mean that more and more waste products, chemicals, and other types of pollutants are being released into our air, soil, and water. How much can the en- vironment absorb? It is obvious from the ereat controversies raging among environ- mentalists, governments, and industry that, although many people claim to have the answers, much factual information is still lacking. Scientists at the [linois Natural History Survey have been studying the natural re- sources of Illinois for many years and are in a position to obtain much of the infor- mation needed to evaluate the conse- quences of environmental pollution in our state. One of the areas in which changes in environmental quality can have pronounced effects involves aquatic sys- tems. The close interrelationships between aquatic organisms and the quality of their environment have made these systems sub- jects for intensive study by the Survey staff. With the opening of the Survey's new research annex at Urbana in December of 1972, an analytical chemistry laboratory was established, under the supervision of aquatic biologist Allison Brigham, to pro- vide water quality data for the many re- search projects on aquatic systems at the Survey. The staff of this laboratory, in ad- dition to their own research projects, coor- the Survey and presently perform approxi- dinate surveillance work for entire mately 6,000 water analyses per month in cooperation with ongoing research projects. These include: (1) the aquatic studies por- tion of the Oakley-Sangamon Environ- mental Research Project; (2) water quality monitoring in the Lake Shelbyville Basin; (3) the continuous monitoring of water An automated analyzer which is capable of making multiple water analyses without operator attention. (Photo by former Survey photographer Wilmer Zehr.) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. quality in the series of experimental ponds - established in connection with the new facility at Urbana; (4) the aquatic portion of an interdisciplinary study of environ- mental pollution by lead and other metals; (5) the aquatic portion of a study on nitro- gen as an environmental quality factor: (6) the relationship between algae and eutrophication; and (7) the chemical fac- tors affecting fish growth. To maximize the efficiency of the labora- tory staff while maintaining a high level of precision and accuracy, laboratory instru- mentation is automated wherever possible so that a large volume of water-quality data is obtained. For example, the large autoanalyzer pictured in the accompanying photo is capable of performing six different analyses simultaneously on each of 100 samples without the attention of an opera- tor. A computerized output is presently being incorporated into this system to pro- vide rapid calculation and tabulation of data. With the exception of heavy metal and pesticide determinations, which are per- formed in other Survey laboratories, staff members are able to analyze for most cri- teria of water quality. Other specialized capabilities include organic nitrogen de- terminations, total carbon analyses, and oxidation of radioactive samples for liquid scintillation counting. ‘These combined capabilities make this laboratory versatile in its ability to perform a wide variety of analyses. Additional computer analysis is applied to data generated by the larger projects of the laboratory. As a result, these tech- niques make it possible to quickly scan enormous amounts of water-quality data. This ability is important in detecting changes or trends in water quality. For example, the staff can be alerted to changes due to water impoundment or the degrada- tion of water quality by pollution. The Survey staff have recently expanded their research efforts to include a study to determine the effects of thermal discharges from a coal-fired generating plant on a 2,100-acre lake in central Illinois. ‘They hope to characterize the effect of this addi- tional heat on the annual cycles of nearly fifty physical-chemical properties of the water to see whether or not this waste heat exerts any adverse effect on the normal an- nual cycles observed in lakes. In addition, they are especially interested in determin- ing if the unusual plankton community of the lake is a natural phenomenon or a com- munity which developed in response to the use of lake water for condenser cooling. Over 50,000 individual measurements and observations will be made during the first year alone. Survey scientists feel confident that, with such data available, they will be able to make reliable recommendations re- lating to the effects of thermal discharges on the ecology of Illinois lakes. Now that the energy crisis is here, with the probable relaxation of some environ- mental quality standards, our environment may be expected to absorb even greater quantities of pollutants. This means that the data on water quality being gathered at the Survey will be of increasing impor- - tance in the years ahead. Toxicity of the Illinois River In the period 1954-56, the fingernail clams died out in the middle section of the Illinois River. As recently as the spring of 1973, the clams had failed to recolonize areas where masses of dead shells indicated they formerly had been abundant. The tiny, thin-shelled clams are an important food for diving ducks and fish, and Survey waterfowl biologist Frank Bellrose found that diving ducks, which once migrated up the Illinois Valley, shifted their route to the Mississippi Valley, where the clams are still abundant. The species composition and the general condition of the fish in the Ih- nois River also indicate that serious pollu- tion problems exist. There are many factors that could affect the organisms in the river; silt, toxic chem- icals, and low dissolved-oxygen levels, for example. The resources available to com- bat problems, including pollution, are usu- ally limited, and the highest return per dollar, or effort expended to solve a prob- lem, will be obtained if the most damaging components of the problem are identified and controlled first. In order to clean up a river, it is essential to know which factors do the most damage, then to control these factors at the source, whether industry, municipality, or farm. R. E. Sparks, Survey aquatic biologist, and K. S. Lubinski, a research assistant from Western Illinois University, are using chemical data generated by the State En- vironmental Protection Agency and_ the State Water Survey to develop a toxicity index for the Illinois River that may aid in identifying some of the pollutants that are damaging aquatic life in the river. The index may also be used to estimate the joint toxicity of several pollutants, an im- portant consideration where organisms are exposed to many adverse factors acting in combination. The research is supported by the Water Resources Center of the Univer- sity of Illinois at Urbana-Champaign. The toxicity of chemicals known to occur in the river to a reference organism, the bluegill, is determined from bioassays re- ported in scientific literature or performed at the Survey laboratory on the Illinois River at Havana. Toxicity is measured in common units so that the concentration of a particular chemical at a given sampling location can be evaluated and the units can also be added to provide an estimate of the total toxicity at that location. Based on chemical data obtained for a sixteen-month period in 1972 and early 1973, the toxicity index indicated that the upstream portion of the river is generally more toxic than the downstream portion, primarily due to higher levels of ammonia. Cyanide, copper, zinc, and lead occasionally contribute significantly to the total toxicity of the river. Total toxicity is within the range that could be expected to have long- range effects on fish. The predictive capability of the toxicity index will be tested under field conditions this coming summer and may be modified on the basis of these results. It is possible that unknown pollutants, not presently measured, may be contributing to the toxicity. In addition, the relative impor- tance of low dissolved-oxygen levels and silt will have to be assessed. Whatever the result, it is likely that additional bioassays and chemical measurements can reveal the relative importance of these factors. Typical bark swellings on the trunk of a ‘Redmond linden tree. (Photo by Dr. D. F. Schoeneweiss.) The ultimate goal of this project is to establish conditions in the river that are not merely sublethal for fish and other or- ganisms, but that are conducive to main- tenance of healthy, flourishing populations. Linden Swelling Many problems of trees and shrubs come to the attention of Survey plant patholo- gists each year. Most of these are readily recognized and diagnosed. A few, however, defy diagnosis even after intensive field and laboratory examinations. When affected plants show symptoms that indicate a pos- sible disease condition, further studies may be initiated to find the cause and to deter- mine whether control measures are war- ranted. In this manner, the pathologists are able to keep abreast of as many new prob- lems as possible. In late summer of 1971, a very unusual tree problem appeared in a northern Illi- nois commercial nursery in a field planting of ‘Redmond’ linden trees. The symptoms were large, corky swellings of the bark on 25 trees in one corner of a 534-tree nursery block. The swellings occurred in rows 6 inches to +42 feet in length up and down the trunks, with the rows located below the lowest branches. Only an occasional small swelling was detected above any branch. The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 An inquiry from the concerned nursery- man brought this problem to the attention of Survey pathologist Walter Hartstirn. Since no problem of this type had been pre- viously reported on linden, Dr. Hartstirn made extensive examinations of affected trees in the field and in the laboratory. No known disease organisms were found and the symptoms suggested that the problem may be due to a virus or mycoplasma, or possibly to some type of chemical injury. If the problem is caused by a virus or myco- plasma, the disease might spread to healthy trees. Therefore the cooperation of the nurseryman was obtained so that the trees would not be removed, and an experiment was set up to try to determine the cause of the swellings. Ten unaffected trees were budded with fifteen buds each from affected trees. Al- though the budding was successful, no swellings occurred and no evidence of transfer of a virus or mycoplasma was noted after one year. Since some viruses are known to move slowly in tree hosts, ob- servations of the budded trees will continue for at least another year. In addition to this experiment, the entire block of lindens was kept under close ob- servation. Another affected tree was found in 1972 and three more in 1973. All of these were adjacent to the trees previously affected. Since no evidence of a disease organism has yet been found, the possibility that some chemical is involved is also being in- vestigated. Only one chemical was used in the block in its seven-year history but one other chemical could have leached from an adjacent farm field. Both of these chemicals will be applied to healthy trees during the coming year to see if they cause the swellings. Keeping abreast of problems like this will not only add to our knowledge but may help avoid the spread of new diseases. February 1974. No. 134. Published monthly except the months of July and August by the Natural History Sur- vey, a Division cf the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by D. F. Schoeneweiss, with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 6180) The Illinovs NATURAL SURVEY Lice, Youth, and Schools During the past several months, Survey entomologists have been receiving nu- merous inquiries about head lice and pubic lice. at least six schools in [Jlinois have reported widespread infesta- This winter tions of head lice among young children and schoolteachers. Many older youths and college students have been plagued with pubic lice. Louse cases were generally very low in Illinois until the 1970s; now lice are becoming commonplace. Human beings can be infested by three kinds of lice: the body louse (Pediculus humanus humanus), the head louse (Pe- diculus humanus capitis), and the pubic <¢ 4 ) wy” Adult head louse, Pediculus humanus capitis. (Photo by Survey Photographer Larry Farlow.) ~ f ¢ ( U \ HISTORY MARCH 1974, NO louse (Pthirus pubis). Some great apes and monkeys have closely related lice, but these are not found on man in this country. Body lice are not much of a problem here, prob- ably because clothing (where the eggs are laid) are regularly cleaned and ironed by most families. Head lice, however, lay their eggs directly on the hair, and washing with mere soap and lukewarm water is not effec- tive in destroying the lice or their eggs. Once an infection is present, especially in schools, the spread of head lice from child to child can be rapid as children often come into close physical contact in their play. sy contrast, pubic lice never occur on the head but are centered in the pubic region, although they may range onto the hairs of the arms, legs, chest, and even beards. They do not occur on children. These lice are also spread by bodily con- tact, and infrequently from clothing freshly exchanged from infected persons. Ordinarily lice cause mild itching and discomfort, referred to as pediculosis. Years ago, in the eighteenth and nineteenth cen- turies and even after World Wars I and II, relapsing fever was associated with human lice. So far, our current crop of lice has not introduced any fevers or diseases in [llinois. In response to the many requests for control of lice, the University of Illinois Extension Service, in cooperation with the Survey, has prepared a fact sheet (NHS- 105 describing these lice and the best methods to use to control them. These sheets may be obtained free by writing to the Survey. Survey Entomologist Steve Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey Moore III, head of the entomology exten- sion service, recommends the use of 1 per- cent malathion or 5 percent carbaryl (sevin) as a safe control for lice on the head or in the pubic region. ‘The treatment should be repeated in about ten days to destroy newly hatched lice. Insecticides in Lake Michigan Mud Organochlorine insecticides have been found to accumulate in tissues of fish in Lake Michigan to levels greater than the maximum recommended by the Food and Drug Administration in fish shipped in interstate commerce. The presence of these toxic, relatively stable products of our technological society threaten the very existence of the Lake Michigan commercial fishery. Although a substantial number of data are available on organochlorine insecticides and their degradation products (principally dieldrin, DDT, DDD, and DDE) in fish from Lake Michigan, few published data exist on concentrations of these chemicals in the lake sediments. Survey Entomologist Willis N. Bruce, in cooperation with Harry V. Leland of the Department of Civil Engineering (University of [Illinois at Urbana-Champaign) and Neil F. Shimp of the Illinois State Geological Survey, has recently published the results of a study of the distribution and concentrations of organochlorine chemicals in the sediments from the southern part of Lake Michigan (Environmental Science, Vol. 7). The organochlorine chemicals are pres- ent in extremely low quantities in the water itself, but accumulate in the bottom sedi- ments where they are bound chiefly to finely divided particles (clays) which are transported naturally into the deeper parts of the lake. The organic chemicals are stable in such situations, but they are picked up and concentrated in the fatty tissues of the organisms that live and feed in the sediment. ‘These organisms in turn form a food source for larger predators (fish). Thus, the chemicals are moved up the food chain and are repeatedly con- centrated until they appear in the tissues of larger fish in concentrations above five ppm (parts per million). In the present ~ study, concentrations of all organochlorine chemicals together in the sediments ranged from a trace to over 36 ppb (parts per billion) . Data on the distribution of insecticide residues in sediments of Lake Michigan will have a direct bearing on methods de- vised for solving or mitigating the problem of residues in the future. This study will also facilitate additional studies of these chemicals and predictions as to their move- ments in biological organisms. Green Sunfish Diet Among the most popular sport fishes in Illinois are members of the sunfish family including small mouth bass, bluegill, redear sunfish, crappies, and green sunfish. Man- agement techniques have been improved by many studies which have given us in- formation on life histories of these fishes. Our ability to increase production of sport fish depends on the formulation of pelleted - diets based upon the nutritional require- ments of each fish. This has been done with great success for the channel catfish and the rainbow trout. One of the most important nutritional needs of fish are proteins which consist of basic amino acids. Survey Aquatic Biologist George Lewis has been studying the amino acid requirements of the green sunfish to determine which of these are essential. An essential amino acid is one which the fish cannot synthesize but which must be in- corporated in its diet. A purified amino acid test diet used by previous researchers in trout and channel catfish studies was modified and used for this work. This test diet consisted of eighteen individual amino acids serving as the sole protein source. The remainder of the diet included white dextrin as a carbo- hydrate source, cellulose flour as a source of fiber, corn oil as a fat source, vitamins and minerals, and carboxymethyl-cellulose as a binder. The qualitative amino acid requirements were determined by omitting a specific amino acid from the diet and comparing the average daily gains of fish to the aver- age daily gains of those receiving the test diet containing all eighteen amino acids. The green cyanellus. Childers.) sunfish, Lepomis (Photo by W. F. Fish receiving diets lacking an essential amino acid did not grow and had average daily gains of zero or less. It was deter- mined that the essential amino acids for the green sunfish are arginine, histidine, isoleucene, leucene, lysine, metheonine, phenylalanine, threonine, tryptophan and valine. It is interesting that these are the same ten amino acids required for growth in most juvenile domestic animals. The adult human and some adult domestic animals lose the requirement for histidine and arginine, but fish do not. This differ- ence may occur because fish have indeter- minate growth and mammals and _ birds do not. With the development of this experi- mental diet, further studies can be under- taken to learn more about the nutritional requirements of the sunfish family. By de- leting individual amino acids and adding them back to the diet in graded levels, quantitative requirements for optimal growth can be determined. Using the same methods, vitamin, mineral, fat, and energy requirements can also be studied. Weather, Agriculture, and Rabbits The feasibility of cloud seeding to in- crease rainfall in Illinois is being studied by the Illinois State Water Survey. For the ecological aspect of the study, Survey Wild- life Biologist Stephen P. Havera examined the relationship of weather and agriculture to the leading small game species in IIli- nois, the eastern cottontail. According to information compiled by Preno and Labisky (1971), the Illinois cottontail harvest has been declining severely. The figures show a decrease of approximately 68 percent from 1956 to 1970. Wildlife biologists would like to know the reason for such a drastic decline. In most regions of Illinois, a July-August cloud seeding program would benefit pro- duction of corn and soybeans. Biologists would like to determine the effects of both an approximate 25 percent increase in July and August total precipitation and the relationship of acreages of corn and soy- beans to populations of cottontails and other wildlife species. To get an overall picture of weather- cottontail relationships, a total of nine monthly parameters for rainfall, tempera- ture, snowfall, and sunshine were compared to the cottontail harvest from 1956 through 1970. A contiguous sixty-eight—county block of central Illinois that contains most of the state with the highest cottontail harvest and also most of the state’s corn and soy- bean range was analyzed. Results showed that weather factors in general were not highly correlated with cottontail data. The only weather param- eter that appeared to correspond to the success of the cottontail rabbit harvest was total snowfall for December through March preceding the hunting season. The three years with the highest snowfall from December through March in the area studied (1959-60, 1963-64, and 1964-65) showed a corresponding noticeable de- crease, and the years with lowest snowfall (1957-58 and 1965-66) showed a general increase in the rabbit harvest the following fall. Heavy snowfall can be expected to de- crease the survival of breeding females, The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 reduce the physical condition of females sufficiently to impair their reproductive capabilities, and reduce the amount of juvenile breeding, either by decreasing the survival of early season litters born in March or by delaying the initiation of the breeding season in February. It is doubtful that increased precipitation through cloud seeding in July and August not exceeding normal limits would have a direct effect on the cottontail harvest. It was found that the principal reason for the drastic decline in cottontail popula- tions in Illinois was habitat deterioration. Cottontails, like other wildlife species, re- quire a suitable habitat to maintain their populations at desirable levels. No matter how favorable weather conditions are, rabbit populations will fail to maintain themselves without adequate food, water, and cover. In Illinois, there was a decline of almost 5 million acres of favorable hab- itat from 1956 through 1970 that paral- leled the 68 percent decrease in the cotton- tail harvest during this period. Cottontail harvest had significant negative correla- tions with corn and soybean acreages, which increased by 3.5 million acres from 1956 through 1970. Increasing acreages of corn and soybeans along with modern farming techniques and urban expansion are the principal reasons for our decreasing wildlife habitat. Pre- cipitation enhancement along with the recent high prices offered for cash-grain crops may influence farmers to increase corn and soybean acreages which could further reduce wildlife habitats. March 1974, No. 135, Published monthly except the months of July and August by the Natural History Sur- vey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by W. E, LaBerge, with the collaboration of the Survey staff, Second-class postage paid at Urbana, Illinois. Office of Publication 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 6180) The Illinors NATURAL White Amur Controls Aquatic Weeds The white amur, also known as the grass carp, is a member of the minnow family and is native to certain large rivers in Siberia and China. It spawns only in rela- tively fast-flowing streams and thrives on a variety of common aquatic weeds. The white amur is cultured throughout Asia and in parts of eastern Europe as a food fish and for its value in the control of noxious weeds. The culture of such exotic fishes is restricted in the United States be- cause of the potential danger to native species, and the white amur cannot be le- gally introduced into Illinois. Two adults have been recovered from the Mississippi River, but there is no evidence of natural reproduction although the potential exists. Survey biologist Homer Buck and his associates at the Sam A. Parr Fisheries Re- search Center began experiments in May Pa7s to’ (1) influence the white amur might have on associated fishes measure the through its recycling of energies accumu- lated in the tissues of aquatic plants, and (2) to compare the biological control of plants by the white amur with control by a chemical means. The experiments were conducted in twenty plastic pools, each ten HISTORY REPORTS feet in diameter. Five of our commonest species of pondweeds were established in twelve pools, and a filamentous alga was established in eight pools. All pools were stocked with fingerling bluegills and golden shiners. Of the eight pools stocked with algae, four received white amurs, and four were left as controls. Of the twelve pools stocked with pondweeds, four were left as stocked amurs, and four were treated with Kar- controls, four were with white mex, a herbicide which kills many kinds of algae and higher aquatic plants. By July 23 the effects on the pondweeds of both the chemical and the white amurs were obvious. The volumes of plant mate- rial in treated pools decreased rapidly, but plant densities in uncontrolled pools in- creased throughout the summer. By August 8 the white amurs had removed as much as 99 percent of the algae, and the growth of white amurs slowed thereafter, whereas growth by the associated fishes was ac- celerated., In late September the weights of fishes, algae, and higher plants were inventoried. The total reduction of pondweeds by Kar- mex was 92 percent and by white amurs was 79 percent. Bluegill production was The white amur or grass carp. (Photo by Wilmer Zehr.) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. improved by either biological or chemical ~ weed control. The greatest production of shiners occurred in the chemically treated pools, but the final average standing crop of white amurs was equivalent to 426 pounds per acre in pools stocked with waterweeds, and 371 pounds per acre in those containing filamentous algae. Walnut Anthracnose Study The eastern black walnut is one of our most valuable hardwood trees. The wood is widely used in furniture, gunstocks, and cabinetmaking, and buyers tour the coun- tryside to bargain for individual trees. The distinctively flavored nuts provide food for man and wildlife. The black walnut grows throughout the eastern half of the United States, generally as scattered trees in fields, along fence rows, or in hardwood stands. In recent years, however, intensive man- agement of high-value hardwoods has be- come an accepted forestry practice. Many extensive plantations of black walnuts have been established in the north-central and Appalachian regions. Growing a single tree species in large plantations favors the rapid buildup of disease-causing organisms that would spread slowly in forests. Walnut anthracnose, or leaf blotch, is a fungus-caused disease that is particularly destructive to the eastern black walnut. The disease may quickly become epidemic during wet weather in the growing season and cause many walnut trees to lose most of their leaves by late July or early August. This premature defoliation slows tree growth, weakens trees, and sometimes kills them. Consequently, Survey Plant Pathologist Dan Neely has initiated a research pro- gram on walnut anthracnose. Dr. Neely has successfully conducted research on anthrac- nose of the sycamore and oak caused by fungi related to that causing walnut an- thracnose. He and the plant pathologist working with him will conduct laboratory, greenhouse, and growth-chamber experi- ments at the Natural History Survey head- quarters in Urbana. Field studies will be carried out in the Survey arboretum and on walnut plantations managed by U.S. Forest Service personnel stationed at Car- bondale. Other study areas may also be used in the course of the study. The Survey researchers will try to deter- mine how light, temperature, moisture, pH, nutrient source, and substrate affect fungus growth, spore formation, and germination. Such knowledge may help in understand- ing the disease cycle and in selecting effec- tive control practices. They will isolate the causal fungus from diseased trees and use the isolate in attempts to infect other trees of the same and related species, thus estab- lishing the virulence of various fungus isolates and the susceptibility of various walnut species or hybrids. The Survey plant pathologists and the U.S. Forest Service plant physiologists and geneticists will also attempt to discover the precise effects of the disease on tree growth and nut production. They will try to learn how and where the fungus overwinters, what conditions affect or regulate renewed growth or spore production, how spores are discharged and disseminated, what climatic factors affect foliage infection, how the fungus penetrates the leaf tissue, and what climatic factors affect the establishment of the fungus within the leaves. The researchers will also test the effec- tiveness of fungicides, both as foliar sprays and as systemic fungicides that are injected into the tree or into the ground around the tree. When these studies are completed in about three years, we will have much more knowledge than we now have about walnut anthracnose and the economically feasible methods of controlling it. Calling Bobwhite Wildlife managers and researchers have for years attempted to estimate numbers of bobwhite quail. Two methods that have been used to estimate prehunt bobwhite populations are (1) censusing an area with bird dogs to locate coveys of quail and (2) adding the number of birds killed by hunters to the census figures obtained after the hunting season. The latter method was considered more reliable during periods of high quail population densities. However, both methods provide minimum estimates of the population. Counts of whistling bobwhites also have long been used to indicate the relative summer abundance of these birds, but such counts were not satisfactory in pre- dicting autumn quail populations. Now, however, Survey Wildlife Specialist Jack El- lis, former Survey wildlifer Keith Thomas, and Paul Moore of the Department of Conservation have found an apparently reliable predictor of the fall bobwhite population. Working on Stephen A. Forbes State Park in Marion County and on Sam Dale Lake State Park in Wayne County between 1964 and 1971, these researchers considered not only the number of bob- whites calling, but, more important, the number of bobwhite calls heard in a set time period. Call counts were made at about weekly intervals along an established route in each park from mid-May to mid-July. Counts of two minutes’ duration were made at each stop. The number of bobwhite calls and as many of the individual whistling cocks as could be distinguished were recorded. In their analysis Ellis, Thomas, and Moore evaluated the number of bobwhite calls per listening stop, the prebreeding census data gathered in the field with bird dogs, and the number of whistling cocks as bases for predicting fall bobwhite popula- tions. Census data were evaluated by using multiple correlation analysis performed by computer facilities of the University of Illinois, Urbana. Estimates for the pre- breeding census, average numbers of bob- Bobwhite quail, Colinus virginianus. (Photo by Wilmer Zehr.) white calls, and average numbers of whis- tling males were treated as independent variables, and the prehunt population esti- mates were used as the dependent variables. Although data for only eight years were available, it was obvious that bobwhite call counts were closely correlated with prehunt bobwhite density, particularly on Dale Park. About 94 percent of the annual fluctuation in the prehunt population esti- mates for quail in Dale Park and 71 per- cent for Forbes Park were associated with changes in the prebreeding census and with the call counts. Data for several more years and infor- mation from other areas are needed before final decisions can be made about predict- ing prehunt quail density from call counts. However, for now, these wildlifers conclude that on public hunting areas in southern Illinois carefully standardized call counts will provide reliable indications of the autumn abundance of bobwhites in the area censused. Captan Tested in Model Ecosystem As a part of a continuing program in- vestigating the environmental fates of pesti- cides widely used in Illinois, the fungicide Captan has been examined by Economic Entomologist James Sanborn in the ter- restrial-aquatic model ecosystem developed by Professor Robert L. Metcalf of the University of Illinois. Captan is used ex- The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 tensively as a seed treatment for corn and soybeans and as a dressing on seeds planted by the home gardener. The model ecosystem can be thought of as an Illinois farm pond surrounded by a watershed which is planted in corn. The laboratory ecosystem, which is housed in an aquarium, models this farm pond-water- shed situation, as there are water and terrestrial segments. The water contains the organisms of a typical pond, including a fish, snails, mosquito larvae, algae, and Daphnia (tiny freshwater crustaceans). On the sand, sorghum is grown for the applica- tion of the pesticide being tested. Because Captan is used as a seed treatment, ento- mologist Sanborn mixed Captan in beneath the surface of the sand in which the sorghum was grown. After thirty-three days the animals and plants of the ecosystem were examined for Captan residues. The data indicated that no residues of Captan were in the water, fish, snails, mosquitoes, algae, or Daphnia. This experiment with Captan in the model ecosystem corroborates the field data for this fungicide, as no adverse food-chain accumulation has been demonstrated after more than twenty years of the extensive use of Captan. Again, the use of this ter- restrial-aquatic model ecosystem is vali- dated as a useful method for determining the persistence and food-chain accumula- tion of pesticides. April 1974. No. 136, Published monthly except the months of July and August by the Natural History Sur- vey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 | | | The Illinots NATURAL SURVEY Some Illinois Aquatic Crustacea Among the important organisms con- sidered in assessing aquatic ecosystem con- ditions and in preparing environmental im- pact Malacostraca (higher Crustacea). To facilitate develop- ment of statements for Illinois, Dr. L. M. Page has compiled a list of species of statements are the aquatic Malacostraca recorded for Illinois, citing references to their occurrence in the state and describing the habitats occupied and the distributions of the species within Illinois. ‘The type-locality and a synonymy (alternative names used in the literature for the Illinois fauna) are also given for each species. The list will soon be published by the Illinois State Academy of Science and made available for distribution. A total of 53 species of aquatic Mala- costraca has been recorded for Illinois, four of them erroneously. Of the remaining 49 species, 13 are isopods (sowbugs), 18 are amphipods (scuds), and 18 are decapods (crayfish). Most species occur in restricted areas of the state, and only six of the 49 species are known to be statewide in distribution. Thirteen species of aquatic Malacostraca were originally described from specimens collected in Illinois. Two isopods (Asellus brevicauda and Asellus intermedius) and a crayfish (Orconectes illinoiensis) were de- scribed from Union County, two amphi- pods (Gammarus acherondytes and Gam- marus troglophilus) and an isopod (Asellus packardi) from Monroe County, an amphi- pod (Bactrurus mucronatus) and a cray- fish (Procambarus gracilis) from McLean County, a blind isopod (Asellus kendeighi HISTORY MAY 1974, NO. 137 from Champaign County, an isopod (Asel- lus spatulata) from St. Clair County, an amphipod (A pocrangonyx lucifugus) from Knox County, an amphipod (A pocran- gonyx subtilis) from Jackson County, and a crayfish (Orconectes Marshall County. Preparation of the list of Illinois Mala- costraca immunis from revealed the fauna to be very Orconectes illinoiensis, a species of crayfish originally described from specimens collected in Union County, Illinois. (Photo by Survey photographer Larry Farlow) Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey. poorly known. Long periods of time and much research need to be devoted to clar- ify the identification and relationships and to discover the ecological requirements of the Illinois species. Accordingly, a study of the present distribution, systematics, and ecology of the aquatic Malacostraca of Illinois has been started. Initially the in- vestigators will be concerned primarily with reidentifying and curating the speci- mens presently housed in the Survey col- lection. As time permits, field observations on natural populations are being made. Dur- ing the past year, field collections added over 6,000 specimens to the Survey collec- tion, including two species of crayfishes (Cambarellus puer and Procambarus viae- viridis) previously unrecorded for Illinois. Their occurrence in the state, along with new crayfish records for Kentucky, Indi- ana, and Missouri, were recorded by tax- onomists L. M. Page and B. M. Burr in a 1973 issue of the “Transactions of the Ken- tucky Academy of Science.” Controlling Flies on Pastured Cattle Face flies, horn flies, stable flies, and horse flies comprise the main fly complex attacking pastured cattle in Illinois, ac- cording to extension entomologist Steve Moore III. Populations of these flies were above normal in 1973. An 18 percent reduction is a conserva- tive estimate of the production loss (in weight gain or milk flow) caused by flies on pastured cattle during the summer of 1973 (Table 1). The stable fly, the least often recognized, caused the greatest loss. Eye problems were common in most herds when face flies were not controlled. The costs of eye treatments of permanent eye damage are not included in these loss estimates. Increasingly, farmers are using insecti- cide dust bags for fly control. Farmers like the convenience (animals treat themselves ) and relatively low cost. Tests were conducted during the past three years with several insecticide dust bag formulations. Under ideal conditions for ~ obtaining the best possible results, forced treatments with insecticide dust bags effec- tively controlled horn flies but failed to provide satisfactory control of face flies and stable flies. Many insecticides applied as oil or water base sprays have been tested. The insecti- cide crotoxyphos is the most effective, as shown in tests in 1963. For best results, apply a 2 percent crotoxyphos spray at a rate of one to two ounces per animal two to four times per week, beginning about June 1 and continuing through early Sep- tember. Treatments should be applied even when fly numbers are low, since crotoxy- phos does not give quick results. Studies in 1973 with 1 percent crotoxyphos plus 0.25 percent dichlorvos spray applied at one to two ounces per animal daily gave satisfac- tory control of face flies and horn flies but did not effectively control stable flies. Most farmers with beef or nonlactating _ dairy cattle on pasture are reluctant to adopt a spray program which requires fre- quently gathering, penning, and spraying the animals. This past summer a herd of approxi- mately 125 cows and 85 calves was treated every three days with a 1.25 percent di- chlorvos water base spray applied from a tractor-mounted, mist-blower unit. The effective length of the swath was about sixty feet in still air. Nozzles were used to provide a coarse, wet mist. Approximately 3 ounces of spray were applied per animal per treatment. About 1 ounce or less of the spray actually reached each animal. About eight minutes were required to treat the herd. ‘Total time for mixing and applying the insecticide and cleaning the sprayer was approximately thirty minutes. The treat- ments were applied in the pasture. Except for the first two times the animals were treated, they stood quietly during treat- ment. The results showed the method to be highly effective in controlling the fly com- plex. Most farmers check their herds of pastured cattle every few days, and a fly control treatment could be applied easily at this same time. Damage to pine shoots caused by the Nantucket pine tip moth. (Photo by former Survey photographer W. E. Clark) Table 1. Potential Production Loss from Flies Attacking Pastured Cattle in Illinois in 1973 Production Number of flies Production loss per fly per animal, loss per Fly species per day, percent June-August animal, percent IF AEE TIN 0 cut) 3 SHON ORC CHER ERCECROR AD RnE CnC enone Oslds 42.6 6.4 MCRAE VM oP oer opis cio colo. 6 ae sess 's,Sei.01:8)5,,0481 8 6 0.02* SES 0.8 Beira ea tl meters ciara Gia adv elets dene wae wpeveie Ore 14.0 9.8 LELIOIS@ IKY 019 eed eto AROS eRe ena Renee ZA0s 0.7 1.4 SIN chtcll Mes ces oss| Established loss (Bruce and Decker 1958. J. Econ. Entomol. 51(3) :270-4). Nantucket Pine Tip Moth eggs hatch in seven to ten days, and the larvae burrow into the bases of needles and later into the shoots. Larval feeding even- tually results in the death of the bud or shoot. Several generations of this insect occur during the spring and summer months in southern Illinois. Control studies were initiated at the Dixon Springs Agricultural Center to find insecticides that would control this moth. Field plantings of loblolly and_ shortleaf pines four to six feet high, showing severe symptoms of tip moth attack, were selected for the experiment. Foliar sprays of the The insect overwinters as a pupa inside _jnsecticides dimethoate (Cygon), acephate a damaged branch. The adult moth (Orthene), oxydemetonmethyl (Meta-Sys- emerges during warm days in early spring tox-R), and Supracide were applied on and lays eggs on the needles or twigs. The May 3, 1973, when the larvae were very Nurserymen and forest managers in southern Illinois are concerned with the destruction of spring shoots of the loblolly, shortleaf, and Scotch pines. Damage is particularly severe to the terminal growth of young trees. Repeated injury of this kind causes stunting and crooked growth. The insect causing this damage is the Nan- tucket pine tip moth, Rhyacionia frustrana (Comst.). Although this insect occurs throughout the state, severe damage caused by it is limited to southern Illinois. The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 tiny and were feeding at the bases of the new shoots or just under the bark tissues. On June 11 the new shoots were examined for damage. All treatments resulted in ex- cellent control with no injury to the foliage. Acephate and oxydemetonmethyl are pres- ently registered for use on pines to control other insects but are not specifically registered for control of the Nantucket pine tip moth; however, dimethoate is registered for use on pines to control this pest. Supra- cide is not registered for use on pines. Fu- ture studies are planned throughout the summer to see if these insecticides will be as effective during other stages of the moth’s development. May 1974. No. 137. Published monthly except the months of July and August by the Natural History Sur- vey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois, Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL Grub Control in Turf Grass Annual white grubs, probably the most common grubs found in sod, damaged many home lawns and other turf areas dur- ing the fall of 1973, according to Survey entomologist Roscoe Randell. Lawn dam- age was most apparent in September. This insect has a one-year life cycle, the eggs hatching in June and grubs feeding on grass roots until cold soil temperatures cause the grubs to go below the frost line to overwinter. White grub damage was present in the fall of 1973 where chlordane had been ap- plied in 1972. Instances occurred of poor control or no control from chlordane ap- plications made in 1973 to moderately or severely damaged lawns. However, diazi- non as a soil drench had been tried on grub-damaged lawns in 1972 with good SUCCESS. During September 1973, eighteen differ- ent lawn areas were treated for moderate to severe grub infestations. Chlordane, di- azinon, Dursban, trichlorfon (Dylox), and Primicid were applied to one or more of these infested areas. Spray formulations of all five insecticides were used as well as granular applications of diazinon and Dursban. All treated areas were irrigated to soak the insecticides into the soil. Chlordane at the application rate of five pounds of active ingredient per acre gave poor control of severe grub infestations. Primicid also did not control grubs. Durs- ban at four pounds of active ingredient pel acre gave some control of grubs but not enough for recovery of the infested turf. Trichlorfon Dylox) at four pounds per HISTORY REPORTS acre gave satisfactory control. Diazinon as a spray or in granular form provided satis- factory control of grubs, and recovery from damage had begun a week after treatment. Diazinon was applied at the rate of five pounds of active ingredient per acre. Similar results were obtained when Sur- vey entomologists Ralph Sechriest and Dan Sherrod tested six insecticides in the labo- ratory for control of annual white grubs. Grubs were placed in the bottoms of one-gallon ice cream cartons. One thou- sand grams of insecticide-treated soil were poured over the grubs, and a layer of sod was placed on top of the soil. Insecticides used and parts per million (ppm) incor- porated with the soil were: chlordane, 2.5 ppm; diazinon, 2.5 ppm; Dursban, 2 ppm: trichlorfon (Dylox), 4 ppm; Aspon, 2 ppm; and Imidan, 2 ppm. were replicated five times. Live and dead ‘Treatments grubs were counted every forty-eight hours, and live grubs were returned to the bot- toms of the cartons. Diazinon gave excel- lent control of grubs in these small soil- One of the white grubs found in lawns. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey sample tests, and trichlorfon (Dylox) gave acceptable control. Diazinon and Dursban are labeled for control of grubs. Elm Diseases A twenty-nine-year study of the loss of elms in Champaign-Urbana to phloem ne- crosis and Dutch elm disease has been completed by Survey plant pathologist J. C. Carter and Mrs. Carter. The results of this study are being published as I1linois Natural History Survey Bulletin, volume 31, article 4. In this study, data were re- corded on the spread of and losses caused by elm phloem necrosis and Dutch elm disease in a municipal area which had ne community-wide control program for either disease. Phloem necrosis appeared in the Cham- paign-Urbana area in 1944, when two trees were affected. Dutch elm disease did not appear until 1951, when one tree was af- fected. The initial spread of phloem ne- crosis was not influenced by Dutch elm disease, since Dutch elm disease was not present in 1944. The early spread of Dutch elm disease was influenced by phloem necrosis because the elms killed by phloem necrosis were heavily colonized by the smaller European elm bark beetle, carrier of the Dutch elm disease fungus. Also, phloem necrosis—af- fected elms can harbor the Dutch elm dis- ease fungus, and many of the phloem necrosis—affected elms were not removed before the bark beetles emerged. The greatest number of elms affected by phloem necrosis in one year was 555 trees in 1952, eight years after the disease was discovered in Champaign-Urbana. The greatest number of elms affected by Dutch elm disease in one year was 2,116 trees in 1957, six years after the disease was dis- covered there. Of the original population of 14,103 elms, 2,994, or 21.23 percent, were killed by phloem necrosis in twenty- nine years, while Dutch elm disease killed 11,062, or 78.41 percent, in twenty-two years. Both diseases killed 14,048, or 99.70 percent, of the elms. Current recommendations for the con- trol of Dutch elm disease include the de- struction of elm wood suitable as sites for insect infestation, application of an insec- ticide to protect healthy elms, and chemi- cal destruction of roots to inhibit root-graft transmission of the causal fungus. Follow- ing the DDT controversy, widespread foliar applications of insecticides have become increasingly unpopular in urban areas, and new, environmentally acceptable control measures are being sought. Research evalu- ating the efficacy of the systemic fungicide benomyl (DuPont's Benlate) is being con- ducted at the Survey. Benomy] has been registered by the En- vironmental Protection Agency (EPA) for use under defined, limited conditions. It has shown effectiveness in laboratory and greenhouse trials and now is being tested in the field. Foliar sprays were applied by plant pathologist Dan Neely to large nur- sery elms in the Survey arboretum in 1971, 1972, and 1973. Curative treatments have been more effective than protective treat- ments, but neither possesses an efficacy that warrants a recommendation for use. In only one test has the reduction in tree mor- tality been as high as 30 percent. Preven- tive insecticide sprays may reduce tree mortality by 75 to 100 percent. Applica- tion of benomyl suspensions into the soil throughout the root zones of large nursery elms has greatly reduced or prevented elm mortality in trees inoculated with the Dutch elm disease fungus. High rates of application are required, and this method of treatment is not registered by the EPA. Treatments made in 1971 remained fully effective against fungus inoculations in 1973, as did treatments made in 1972 and 1973. The ecological impact of benomy] in soil on elm roots, mycorrhizae, and earth- worms is being studied. Copper or Lead Shot As our waterfowl resource continues to decline because of losses in habitat, increas- ing demands are placed on the remaining waterfowl resource. Lead shot causes sub- stantial mortality of wild waterfowl each year, as Survey wildlife specialist Frank C. Bellrose reported in 1959. Lead pellets are picked up by ducks and geese and remain in their gizzards. There the lead shot dis- integrates, and toxic lead enters the system iS & oF <4 7 fk as Survey wildlife specialist Frank Bellrose with ducks killed by lead poisoning at Rice Lake near Banner, Illinois. (Photo by George Arthur, Illinois Department of Conservation) of the waterfowl. Therefore, in recent years there has been interest in finding a substi- tute for lead shot for use in waterfowl hunting. Copper is ballistically a suitable substi- tute for lead in shot. However, before man- ufacturers proceed with expensive develop- ment costs, the effect of ingested copper pellets on waterfowl should be investigated. Survey wildlife biologists Glen Sanderson and Ken Walker and University of Illinois veterinarian Paul Beamer, with coopera- tion from the Winchester-Western Division, Olin, conducted a preliminary study of the effects of ingested copper shot on wild- trapped male mallards. Eighty male mallards were placed in experimental groups of ten each, and each duck was given either No. 4 lead shot or No. 4 copper shot in doses of one, two, four, eight, sixteen, or thirty-two. The lead shot in the gizzard eroded much faster than did the copper shot. The rate of erosion of the copper shot remained constant up to 160 days, the length of the experiment. Ingested copper may have caused the deaths of some mallards although the data are not conclusive. In surviving ducks, cop- per shot were retained in the gizzards longer than was lead shot, and the ducks were, therefore, subjected to a longer ex- posure to copper than to lead. Both mor- tality and weight losses of control ducks and ducks fed shot indicated that corn is an inadequate diet for wild mallards in captivity for a period as long as 100 days. Because of this dietary deficiency, the study did not demonstrate a conclusive effect of ingested copper shot on body weights of ducks, and this point needs further study. Numerous cellular changes indicated that ingested copper was toxic to wild mallards on a corn diet in captivity. The most pronounced effects seemed to be on the liver and possibly on spermatogenesis. Although the results of this study are not conclusive because of the adverse effects of the corn diet, the study does suggest that copper shot is not a satisfactory substitute for lead in hunting waterfowl. Additional studies are needed before copper receives further consideration. Aquatic Plant Control With the construction of multipurpose ponds and lakes for uses such as flood con- The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 trol, soil conservation, watershed manage- ment, and water supply, coupled with the increase in leisure time, more and more people are using these resources. To their dismay, reports Survey biochemist Robert C. Hiltibran, they often find that the water becomes inhabited by a variety of aquatic plants, ranging from small nonvascular plants, known as algae, to vascular plants capable of occupying the water space to depths of twelve to fifteen feet. It appears that many bodies of water are weed in- fested throughout the summer, and once infested, remain weed choked. Drastic changes have been found to occur in the aquatic plant communities within a body of water in one year, and the aquatic plant communities may vary from year to year. Such changes in aquatic plant communities require corresponding changes in plant control methods. In con- trast, in some bodies of water relatively little change in the aquatic plant commu- nities has been observed and efforts to alter the aquatic plant communities have not been successful. For example, attempts to eliminate curlyleaf pondweed from Mansion Pond at Allerton Park have not been completely successful. From 1960 through 1962 two stands of curlyleaf pondweed were elimi-. nated each year. However, since 1962 curlyleaf pondweed, while present in Man- sion Pond each year, has not been a serious problem. These results, plus data obtained in many other bodies of water, indicate that the control of many aquatic plants is now possible. Although the initial cost of aquatic herbicides may be relatively high during the first few years, this cost coupled with that of the subsequent maintenance over the next several years, indicates that the overall cost of aquatic herbicides may not be great. The effort to control aquatic plants must be continuous so that plant infestations and the required amounts of aquatic herbicides will be small, reducing their impact on the aquatic environment. Thus, fishing and other water recreation, such as swimming and boating, become possible in one body of water. June 1974. No, 138. Published monthly except the months of July and August by the Natural History Sur- vey, a Division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois Office of Publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL IR CHIEF, ILLINOIS NATURAL HISTORY SURVEY. URBANA, ILLINOIS 61801 | The Illinovs NATURAL SURVEY Modeling and Alfalfa Weevils The alfalfa weevil, a native of Europe and North Africa, first appeared in Illinois ten years ago and rapidly spread through- out the state. Today it is our most serious insect pest of alfalfa. Although chemical control is essential for producing maxi- mum yields, there are two other methods of reducing alfalfa weevil populations. One is to manipulate the timing of the first harvest in the spring. After considera- tion of many factors such as population size, plant growth, prevailing weather con- ditions, and so on, the cutting date can be timed so that the grower can achieve the same effect as applying an insecticide. The other method involves biological control agents, such as parasites and _ predators. One of the biocontrol agents in Illinois is a small parasitic wasp, Bathyplectes curculionis, which lays its eggs inside young weevil larvae. Parasite most successful larvae develop within their hosts, and when their developmental requirements have been satisfied, they kill their hosts. The principal reason that we have a research program on alfalfa weevil control is that these three control methods are mutually interdependent. Insecticides kill parasites and predators as well as alfalfa weevils. Furthermore, the economics of considering three control methods simul- taneously is complex. Slight changes in cutting dates may slightly reduce yield, but if the change benefits the biological control agents and reduces the weevil pop- ulation, it may be financially advanta- geous. Illinois is one of eight states cooperating HISTORY SEPTEMBER 1974. NO. 139 in a nationwide project to develop and use mathematical models to help resolve the problems posed above and Survey ento- mologists E. J. Armbrust, W. G. Ruesink, and D. P. Bartell are involved in this proj- ect. In the process of developing the mod- els, three kinds of biological research are required to support the modeling effort. One kind of research involves periodic sampling of the alfalfa weevil population to provide a data base against which to validate the models being developed. For the past year samples have been taken, sometimes as frequently as twice a week, from six fields in Washington County. Only one area of the state is being studied, in contrast to earlier projects, with the ob- jective of reducing travel time and costs. The samples have been processed in our laboratory in Urbana, and the resulting data entered into files in the University of Ilinois’ IBM 360 computer. Another kind or study of the population dynamics and the behavior of B. curculionis. It was discov- research involves a ered that nearly all past work lacked suffi- cient quantitative aspects. Consequently, we are looking at such things as survival rates of cocoons of the parasite (overwin- tering stage), longevity of adult parasites, and their reproductive potential. The third kind of research involves de- veloping new and improved techniques for measuring population densities of the alfalfa technique of sweep net catches of adult weevil and of B. curculionis. A weevils is being studied in order to fore- cast the best combination of control meth- ods for the field in question. Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey. During the coming year, we expect to complete the validation of our preliminary models and use these models to manage alfalfa production in our study fields. If successful, the program will be expanded to fields in other parts of the state and finally made available to all growers in the state via the extension service. Power, Heat and Lakes A cooperative research effort was funded by Commonwealth Edison Company in September 1973 to investigate the effects of their 1100 megawatt Kincaid Power Plant on the local environment and _ to gather data which could be used to pre- dict environmental effects of cooling lakes at power plants that may be built in the future. Aquatic biologist Weldon Larimore is the director of this interdisciplinary study, conducted by the Illinois Natural History Survey, which includes basic re- search, applied research, and monitoring services. Lake Sangchris, located in central Illi- nois, is a 2,/00-acre impoundment that is used for cooling purposes by the coal-fired Kincaid Power Plant. Power plants alter the thermal characteristics of the lakes which they rely upon for cooling purposes. These increased water temperatures some- times referred to as “thermal pollution” can be deleterious to aquatic environ- ments. In addition, coal-fired power plants have the potential for emitting mercury and other trace metals into the environ- ment when large quantities of fuel are burned. This study will help determine if thermal effluents are, indeed, deleterious to aquatic systems and whether trace met- als and other by-products of the combus- tion process are serious environmental contaminants around power plants. Morphologically, Lake Sangchris con- sists of three long narrow arms which con- verge near the dam. The thermal effluent of the power plant is circulated through two of these arms creating a temperature gradient. The third arm is relatively unaf- fected by the thermal effluent and serves as a control area for the investigations. This rather unique morphology makes Lake Sangchris ideal for studying the ef- ~fects of increased water upon aquatic organisms. Aquatic biologists Allison Brigham and Bob Moran are investigating the zooplank- ton and phytoplankton communities as well as monitoring thirty-five water qual- ity parameters. Supplementary studies in- clude phytopigment analyses, primary production measurements, and bacterial counts. The spatial distribution of benthic or- ganisms in relation to the thermal effluent is being studied by entomologist Don Webb. Artificial substrate samplers are being employed to help determine why so few benthic organisms are present. Aquatic biologists John Tranquilli, Rich Kocher, and John McNurney are studying the abundance, distribution, and behavior of fishes in various parts of the cooling loop. Growth rates, food habits, reproduc- tive condition, and the incidence of para- sitism are being investigated. In addition, © radio-telemetry techniques and fish tags are being used to study the movements and behavior of largemouth bass. A complete ecological study of mercury and other trace metals in the vicinity of Lake Sangchris is being conducted by wildlife specialists Bill Anderson and Ken Smith. This study involves collection and analyses of airborne dust, soil, lake sedi- ments, aquatic macrophytes, fish, and wa- terfowl. Coal samples and samples of slag and fly ash are also being analyzed. Lake sediments are being analyzed for pesticide residues which might be adversely affect- ing benthic organisms. The studies are being coordinated through the Lake Sangchris Laboratory, a new INHS field station located in Kin- caid, Illinois consisting of an office and a laboratory for two resident biologists, space for storage of scientific equipment, and overnight accommodations for biologists. temperatures Life History of the Spottail Darter Among the native fishes of Illinois are two species of fantail darters restricted to rocky streams in the Shawnee Hills of southern Illinois. One of these, the spottail darter (Etheostoma squamiceps), was the subject of a life history study recently pub- lished by Survey ichthyologist L. M. Page as Illinois Natural History Survey Biologi- cal Notes No. 89. Copies of this publica- tion may be obtained free by writing to the Chief, Illinois Natural History Survey. Three years of field and laboratory ob- servations on a population of the spottail darter in Big Creek in Hardin County, Illinois, revealed that the spottail darter primarily inhabits slabrock riffles and pools, reaches sexual maturity at one year of age, feeds primarily on aquatic insect larvae and crustaceans, and lives to a maximum age of slightly over three years. Males attain a larger size than females and during the spring spawning season be- come much more boldly patterned than females. Most females spawn at one year of age but most males, although sexually mature at one year, apparently do not successfully spawn until a minimum of two years of age. Spawning occurs from late March to late May or early June. As the spawning season approaches, the male spottail darter selects a cavity beneath a large stone as a future nesting site and vigorously defends it against intruders. When ready to spawn, a female joins the male beneath his nest- stone. After nosing about the stone for a time, the female rolls to one side and si- multaneously rises to press her venter against the underside of the nest-stone. Usually almost immediately after the fe- male inverts, the male rolls to one side and Spottail darters spawn- ing in an aquarium. A nest of eggs is on the underside of the stone above the pair of dart- ers. (Photo by L. M. Page) positions himself alongside and _ slightly overlapping the female, in an inverted head-to-head position. Pressed against the stone, the female begins quivering slightly, barely moving forward as she does so, and lays a series of two to five eggs on the stone. As she lays the eggs, the male trem- bles and releases sperm. Then both fish immediately return to a right-side-up posi- tion beneath the stone for a short time before courting by the male begins the sequence again. From 30 to 360 eggs are laid by each female, the larger females laying more eggs than smaller females. Several females may spawn with a single male, and nests having up to 1,500 eggs were found in Big Creek. After spawning the female leaves and the male remains to guard the eggs until they hatch. The eggs hatch in five to eleven days and the young darters leave the nest. Conditions and Stresses in Pheasants The actions of toxins in birds appear to be strongly influenced by the physiological status of the specimens being studied. Thus, knowing whether test specimens are in positive or negative energy balance is minimal background information for any study of interrelationships between toxic substances and birds. In pheasants, it is well known that body weight and weights of muscular tissues and fat deposits un- dergo important changes as the birds pro- The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 gress through the annual cycle. But how do these condition parameters respond to seasonal stresses the birds must endure to survive and reproduce? Survey wildlife biologist William L. Anderson attempts to answer this question in his recent Survey bulletin Dynamics of Condition Parame- ters and Organ Measurements in Pheas- ants by analyzing data for wild pheasants actively engaged in laying, incubating, or molting activities with statistical correla- tions. Copies of this bulletin (vol. 30, art. 8) can be obtained by writing to the Chief, Illinois Natural History Survey. Anderson designated body weight and weights of muscular tissues and fat depos- its as the dependent variables, and the number of eggs laid, days of incubating, or number of primaries molted as the in- dependent variable. The dates that pheas- ants were collected were also included in the correlations and were considered to be the second independent variable. Hence, the statistical tests evolved into multiple correlations. With few exceptions, significant corre- lations existed between the condition pa- rameters and the independent variables. Additional statistical tests were conducted to determine whether the first indepen- dent variable, or the second, or both, contributed significantly to the multiple correlations. Surprisingly, these tests indi- cated that the second independent vari- able, collection date, contributed as much or more to the correlations as the first in- dependent variable. In general, the condi- tion parameters for breeding and for incu- bating pheasants decreased in value, and those for molting pheasants increased in value, as the date advanced. The reason that date collected would emerge as a dominant variable in dictating the changes in condition parameters of laying, incubating, and molting pheasants is difficult to pinpoint. Date alone is rather meaningless. However, many factors (e.g., photoperiod, temperature, precipitation, humidity, plant phenology, behavior and physiology of birds) can be associated with date, as well as with each other. In any event, the entire body, muscular tissues, and fat deposits of pheasants decrease in weight during the laying and incubating periods, and increase in weight during the molting period, as date progresses. September 1974. No. 139. Published monthly except the months of July and August by the Natural History Survey, a Division of the State Department of Registration and Natural Resources and Conservation. Education, operating under the Board of Prepared by Dr. W. E. LaBarge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of Publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 6180) er ee The Illinots ATURAL SURVEY Illinois Still a Pheasant Power Keeping track of a state’s pheasant pop- ulation takes a staff of hundreds to do the job right. And that is exactly what Illinois has. Every five years, in April, about 800 postmasters and 1,200 rural letter carriers voluntarily assist Survey wildlife specialist Ronald F. Labisky in a census of Illinois pheasants. The postmasters distribute the census materials to the letter carriers, and the carriers count all the pheasants that they observe along their routes during a five-day period. In the last pheasant cen- sus, in April 1973, participating rural letter carriers drove 351,150 miles and observed E7354 northernmost seventy-four Illinois; found in pheasants in the counties of wild pheasants are not southern Illinois. The that the abundance of pheasants in the seventy- census revealed relative four northern counties had decreased from 5.5 to +.9 birds per 100 miles of driving, or eleven percent, between April 1968 and April 1973. Comparatively, the 1958 and 1963 censuses yielded 7.6 and 9.9 pheas- ants per 100 miles. The 1963 population represents the all-time high in pheasant Thus, during the abundance for Illinois. pheasant populations in Illinois past fifteen years have exhibited a marked in- crease (32 percent) in abundance between 1958 and 1963 and a substantial decline 1963 1973. Pheasant abundance, as recorded by these 50 percent) between and censuses, was 36 percent less in 1973 than it was in 1958. [llinois’s best pheasant range is still in the east-central The sector of the state. HISTORY OCTOBER 1974. N¢ ten counties in which pheasants were rela- tively most abundant in April 1973, were rank Ford, Livingston, Logan, Iroquois, Moultrie, De Witt, Cham- paign, McLean, Macon, and Piatt. How- ever, the abundance of pheasants increased in only four— Ford, De Witt, Iroquois, and Macon 1968 and 1973. Although pheasant abundance in_ the in order of between northwestern part of the state is still only fifth of that excellent gains were made in Jo Daviess, Carroll, Stephenson, Winnebago, White- side, Ogle, and Lee counties between 1968 about a in our best range. and 1973. Other counties that posted some encouraging gains in pheasant numbers in- cluded Mason, Christian, and Shelby. The discouraging news comes from-the once- major pheasant counties of De Kalb, Put- Marshall, Woodford, pheasants were less than half as abundant nam, and where in 1973 as they were in 1968. Although about 11 percent more range was occupied by about 50 percent fewer pheasants in 1973 than in 1963, the ef- fective change in pheasant abundance throughout much of Illinois’s range was not as drastic as it appeared at first glance. To illustrate, Labisky points out that in 1.612 ships contained more than fifty pheasants 1963, sixty-one of Illinois’s town- per 100 miles of driving; these sixty-one townships accounted for 53 percent of all 1963 However, in 1973 only one Illinois town- fifty it contained | percent ol pheasants observed in_ the census. ship had more than birds per 100 miles of driving: the pheasants observed in the 1973 census. In the final analysis, excluding the “hot- 15:02 spot” townships, pheasants were Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey Sin! 74 ay CREAM 5 ah x SS came another step the commercial grower / ha or home gardener could use to avoid this ea s . ~ - disease. ae White break symptoms show as white streaks and : : k splotches on the normally dark red King David is carried over from one year to the next. gladiolus. (Photo by J. L. Forsberg) Questions arose about how much disease Material in this publication may be reprinted if credit is given to the Illinois Natural History . Survey This step is the removal and destruction of ~ all infected plants as soon as they are noticed. This action prevents aphids from feeding on diseased plants and carrying the disease to healthy plants. The scientists then asked whether the cormels (bulblets) from an infected plant carries the disease. Research indicated that most, but not all, of the cormels produce infected plants if the parent plant had white break. Cormels from infected plants, therefore, should be destroyed. Other research was designed to deter- mine if white break could be transmitted by the pollen carried by bees. It was found that not only is there no transmission by this method, but not even the seeds formed on diseased plants carry the disease. ‘This fact was considered important for those who hybridize gladioli to develop new varieties and use white or yellow varieties. White and yellow varieties sometimes are infected with white break but show no symptoms. Many other facts about the disease, such as its symptom variations and _ its relationships with other diseases, were learned along the way. These should prove of value to future research that may be necessary on gladioli or other plants. Squirrel Hunting in Illinois Game populations should be managed with seasons and bag limits that protect the game resource, but most of our hunt- ing regulations are based on tradition, not biology. However, Survey wildlife biolo- gists Charles M. Nixon and Stephen P. Havera find no evidence that Illinois squir- rels are being overharvested under the present squirrel season and bag limit. Hunters like to hunt squirrels during the seed-maturing stage of oaks and hickories in late summer when squirrels often are still breeding, pregnant, or nursing young. However, the loss of nestling or fetal young, when breeding females are shot, is not a serious problem in Illinois. Such losses of nestlings represent less than 10 percent of the fall squirrel population. Many biologists believe that squirrel popu- lations are underharvested, at least in exten- sive forestland, and could support addi- tional hunting pressure. Thus, conservation agencies try to choose opening dates for squirrel hunting that are neither so early as to waste large numbers of young in the nest, nor so late as to jeopardize hunt- ing success. The obvious solution is to delay opening the squirrel season until the young are weaned, usually in late September or early October. But such a delay would eliminate hunting recreation during the summer and early fall when sportsmen have nothing else to hunt. A responsibility of wildlife managers is not only to provide seasons and bag limits that protect the game resource, but also to provide sportsmen with the maximum opportunity to pursue their sport. The present season framework is a suit- able compromise. Hunter interest is highest from mid-August until mid-October. The- present seasons give the southern Illinois hunter 8 to 9 weeks and the northern hunter 6 weeks of prime hunting time. The small, scattered tracts of forest in northern Illinois are potentially vulnerable to overshooting. The opening on August 1 in the south zone places the most sustained hunting pressure in the more extensive forests of southern Illinois, where squirrel populations are least likely to be overshot. Hunters are generally satisfied with the present opening dates in both zones. They are not so certain about an extension of the season past November 15. Nixon and Havera recommend that the squirrel season end no later than November 15. It makes little sense to extend the season into a time span that most hunters will not use and when a majority of hunters oppose an ex- tension. In addition, squirrel breeding be- gins in the south zone before December 15, and a season extending into the breeding season would be unwise. Hunters are generally satisfied with the present bag limit although a few prefer a reduction to a limit of four. Nearly all hunters oppose an increase to six squirrels. Nixon and Havera believe that far better estimates of how many squirrels are shot each year in Illinois are needed. They do not believe that Illinois squirrel hunters annually bag nearly one squirrel per 1.5 acres of forest; no other state approaches such a squirrel harvest. Thus, if we are to manage the squirrel crop more effectively, we must improve the estimates of the annual squirrel harvest. In summary, the Survey biologists make these recommendations on the squirrel season and limit: south zone — August 1- November 15; north zone — September 1-November 15; bag limit — five squirrels. Model-Ecosystem Pesticide Tests Modern agricultural practices involving superior plant varieties, improved cropping methods, heavy applications of fertilizers, and strong reliance on agricultural chem- icals have been largely responsible for the tremendous agricultural productivity of Illinois. Such innovations have resulted in increases in the average corn yield in Illinois from 30 bushels per acre in 1920 to 105 bushels per acre in 1973. The use of pesticides has increased phenomenally over the years, and in Illi- nois more total acreage is treated with pesticides (more than 14 million acres) than is treated in any other state. Such Survey wildlife biologists have found no evidence that Illinois squirrel populations are being’ overharvested under the present season and bag limit. (Photo by George W. Bennett) heavy use of pesticides and the rapid in- troduction of new pesticides require care- ful, continuing surveillance of the effects of these chemicals in the environment. A year ago the Illinois Natural History Survey Reports told about economic ento- mologist James Sanborn’s test of the fungi- cide Captan in the terrestrial-aquatic model ecosystem developed by University of IIli- nois Professor Robert L. Metcalf. This laboratory ecosystem, housed in a 20-gallon aquarium, is a small-scale model of an Illinois farm pond surrounded by a water- shed planted in corn. The model had both water and terrestrial portions. In the water portion are such typical pond organisms as a fish, snails, mosquito larvae, algae, and Daphnia (tiny freshwater crustaceans). On the sand portion, sorghum is grown and each pesticide tested in this model eco- system is applied to the plants. After a specified number of days, the animals, plants, and water of the ecosystem are ex- amined for pesticide residues to determine whether the pesticide is ingested and broken down or accumulated by the various links in the food chain and whether it persists in the environment. Recently Sanborn has published a re- port on 17 organic pesticides and five industrial chemicals that he tested in the The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 terrestrial-aquatic model ecosystem. Sev- eral types of pesticides were represented in the tests, since one or more insecticides, herbicides, miticides, and plasticizers, and other pesticides were tested. These model ecosystem tests generate data which can be compared with data from the field to pro- vide the background information needed to assess the potential environmental impact of new pesticides before they are recom- mended or rejected for general use. In general, Sanborn found that most of the chemicals tested, with the exception of the persistent soil insecticide dieldrin, April 1975. No. 146. Published monthly except the months of July and August by underwent extensive degradation. Dieldrin was exceptional in that more than 96 per- cent of the radioactive materials isolated from the organisms of the model ecosystem was unchanged dieldrin, clearly showing the extreme inability of this chlorinated hydrocarbon to undergo biological and chemical modification. Sanborn’s new publication, The Fate of Select Pesticides in the Aquatic Environ- ment, was published by the U.S. Environ- mental Protection Agency and is available from the Superintendent of Documents, U.S. Government Printing Office, Wash- ington, D.C. 20402. the Natural History Survey, a division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 The Illinors NATURAL SURVEY | Spring Goose Migration Aldo Leopold once wrote, “What a dull world if we knew all about geese!” The mystery surrounding the beautiful V’s of Canada geese against the sky as they mi- grate south in the fall or north in the spring is encapsulated in Leopold’s words. The Mississippi Valley goose popula- tion winters in southern Illinois and ad- joining states and nests in northern Ontario. This population has grown from a_ post- hunting season level of 22,000 in 1945, to about 300,000 today. The fall migration of these geese to their wintering areas is well known and studied, but the spring migra- tion has received less public attention. Sur- HISTORY MAY 1975, NO. 147 Hanson together with Richard A. Hunt, research biologist with the Wisconsin Department of Natural Resources, has recently pub- lished an article in Wisconsin Conservation vey wildlife specialist Harold C. Bulletin describing the feeding behavior of Canada geese in Wisconsin during their spring migration northwards. About three-fourths of the spring migra- tion of geese (amounting to nearly 400,000 geese) passes through Wisconsin on the way to their northern breeding grounds. This migration, though lacking the hunt- ing pressure of the fall migration, is not the leisurely, carefree flight home it first ap- pears. Instead, it 1s a very critical time of energy storage that may affect the bird’s Canada geese in flight over winter grounds in southern Illinois. (Photo by Harold C. Hanson) Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey. reproductive success and possibly survival’ of weaker immature geese. It 1s now ap- parent that Wisconsin’s role as a primary host is more significant during the spring migration than its role in the fall when so much management has been directed toward affording food and a sanctuary area. In the spring the Canada geese stop in fields in Wisconsin to feed on waste corn in the thousands of acres of cornland in the dairy areas of the southeast portion of the state. The geese also feed on highly nutritious green shoots of grasses and other plants in these fields. However, careful observation revealed that the geese receive surprisingly large quantities of nutrition from manure which is spread over the fields from dairy barns. The cattle, having fed on ensilage containing whole grains of corn, pass much corn undigested. The geese glean this corn from the manure spread over the land and also may obtain significant amounts of vitamin By,» pro- duced by the microflora in the cow's gut and also present in the manure. From a management standpoint, the welfare of the geese in spring is almost cost free, thanks to the farmers on whose land the birds feed. While some crop dam- age does occur each year, Wisconsin has a law which pays farmers for such_ losses. Unlike the shrinking wetland habitat for migrating ducks, the wealth of food avail- able to migrant geese in the southeastern quadrant of Wisconsin in spring seems secure unless the dairy economy declines precipitously. Corn Rootworms and Sweet Corn Three species of rootworms — the north- ern, southern, and western corn rootworm — attack sweet corn in Illinois. The south- ern corn rootworm, though present through- out the state, rarely is a serious problem in central and northern Illinois. The northern corn rootworm (Diabrotica longicornis) and the western corn rootworm (Diabrotica virgifera) are both serious pests of sweet corn in the northern two-thirds of the state. The northern corn rootworm and _ the western corn rootworm are small beetles in the adult stage which can be found feeding on the pollen, silks, and leaves of corn from mid-July until the first frosts in the fall. The females lay eggs in the soil chiefly from August until mid-September. The eggs remain in the soil over winter, affecting corn planted in the following year. The larvae feed on the roots of the corn, weak- ening the roots enough to cause lodging on windy days and decreasing the yield of affected plants. Survey entomologists W. H. Luckmann, J. T. Shaw, D. E. Kuhlman, R. Randell, .and C. D. LeSar have recently published Survey Circular 54 entitled, “Corn Root- worm Pest Management in Canning Sweet Corn.” In this circular several factors affecting the abundance of corn rootworms in sweet corn fields are described and a management program is outlined for sweet corn in fields that were planted to sweet corn the previous year. This program is not intended for fields of sweet corn planted where field corn was grown the previous year, as some of the factors affecting root- worm oviposition and consequent popula- tions are quite different. Some of the factors affecting corn root- worm populations in a field of sweet corn are as follows: Fields harvested before August 8 will attract few egg-laying root- worm adults, since the fields are harvested before intensive oviposition begins, and little or no damage need be expected the next year. Fields of sweet corn are not attractive to egg-laying adults after they have been mechanically harvested (no standing stalks in the field following har- vest). Aerial or ground sprays of carbaryl insecticides applied for control of the European corn borer and the corn ear- worm are very toxic to adult rootworms, and egg-laying adults are eliminated from sprayed fields once the spray program is begun. A copy of Circular 54 can be obtained by anyone interested in the full details of this management system by request from the Chief, Illinois Natural History Survey, Urbana. Illinois’ Periodical Cicadas Over the past ten years, Survey entomol- ogist Lewis J. Stannard, with the help of the staff of the Illinois Natural History Survey, Farm Advisers, and many private citizens, has investigated the ranges and occurrences of the broods of periodical cicadas in Illinois. From the resulting data forecasts of the emergence of these insects can be made with good accuracy for the benefit of orchardists, nurserymen and any- one concerned with protecting choice trees from damage to twigs. Periodical cicadas are among the world’s longest lived insects, some living 13 years and some 17 years, with most of this time spent underground as nymphs feeding on tree roots. The adults emerge in late May and early June at the end of their 13 or 17 year development period. During the short time of their life above ground, periodical cicadas congregate in the hundreds of thousands, sing in deafening choruses and mate. The females slit twigs and lay then eggs in these slits, an action which often causes girdling and destruction of the twigs. When hatched, the young nymphal cicadas drop to the ground and dig in to feed on Seventeen-year cicadas on tree trunk. (Photo by former Survey Photographer Wilmer Zehr) tree roots to begin a new generation of 13 or 17 years duration. Ordinarily those with 13-year life cycles are southern broods and those 17-year cycles are northern broods, the dividing line being roughly from north of Quincy to north of Danville. Only five separate broods of periodical with cicadas are found in Illinois, three with a 17-year life cycle and two with a 13-yean life cycle. Each brood is generally separated from other broods with few woods having more than one of the five broods. None occur in sandy soils, although some fairly small cicadas, not periodical species, do occur in some sandy areas. Dog-day cicadas are present every year and appear begin- ning early July. The next appearance above ground of a brood in our state will be in 1976 in two disjunct areas (several counties several this and River southwest Wabash brood has a 13-year life cycle. in the extreme counties alone the Biochemistry and Pollution One definition of a pollutant is a chem- ical agent which severely alters the bio- chemistry or physiology of an organism for such periods of time that the organism dies. The Illinots NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 The mechanisms of toxic action of many possible pollutants to aquatic organisms are not known; however, many hypotheses for their action have been suggested. For example rotenone, used for many years as a fish toxicant and as a tool in fishery man- agement, was thought to cause suffocation of fishes by blocking the blood circulation in gills and destroying the gill tissue. Pre- viously, it had been shown that rotenone reduced oxygen uptake by fishes and in- sects. European workers indicated that in severe rotenone poisoning the circulation in the gill tissue was normal, and the de- struction in gill tissue was due to secondary changes. These workers found that rote- none inhibited the uptake of oxygen in the presence of pyruvate and glutamate, but not in the presence of succinate. Japanese workers also have made similar observa- tions. It was further reported that rotenone inhibited the flow of electrons between sub- strate and oxygen. This has been the only biochemical action shown for rotenone. Survey aquatic biologist, Robert C. Hilti- bran, has been investigating the effects of possible pollutants on the oxygen and phosphate metabolism of bluegill liver mitochondria. Together with Mike John- son, Hiltibran estimated the effects of rote- none on oxygen uptake by bluegill liver mitochondria and found that rotenone completely inhibited oxygen uptake at a level of less than a hundred thousandths of a gram of rotenone per milliliter of re- action medium, whereas at less than a millionth of a gram per milliliter oxygen uptake was not altered. Hiltibran and his associates have investi- gated the effects of several herbicides, metals, and insecticides on the oxygen and phosphate metabolism of bluegill liver mitochondria. They have found that some herbicides, metals, and insecticides severely alter oxygen uptake in the presence of succinate as substrate, but did not alter the oxygen uptake in the presence of alpha- ketoglutarate as substrate. Further, some of the chemical agents did not alter oxygen uptake but altered phosphate uptake. To date, the effects of approximately 125 pos- sible pollutants have been estimated. The data suggest that there must be some corre- lation between the observed biochemical effects and the toxicity of pollutants to bluegill. May 1975. No. 147. Published monthly except the months of July and August by the Natural History Survey, a division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation Prepared by Dr. W. E, LaBerge with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61 The Illinors NATURAL HISTORY REPORTS Control of the Fall Cankerworm The fall cankerworm, Alsophila pome- taria, feeds on many species of deciduous trees. The larvae emerge about the time spring foliage appears and may be so numerous that trees are nearly defoliated. When mature, the larvae drop from the trees on silken threads and pupate in the soil and in soil debris. Because of the eco- logical hazards associated with some of the chemicals formerly used to control the fall cankerworm, Survey entomologist J. E. Appleby with P. Bristol and W. E. Eick- horst of Morton Arboretum, Lisle, Illinois, initiated experiments to find less hazardous substances. On May 15, 1973, seven lower branches were selected on each of three American linden trees that were heavily infested with fall cankerworm larvae in the next-to-last development stage. On each tree about six feet of the distal portion of each of the selected covered with a branches were nylon mesh bag. Just prior to treatment each bag was removed, sprays were ap- plied, and the bag was replaced. Acephate, Bacillus thuringiensis (Dipel), Sevimol, Gardona, and malathion were sprayed on the selected branches. Each treatment was applied to three of the covered branches on each tree. On May 18, 1973, the bags were untied and opened, and the live and dead cankerworm larvae were counted on the branches, on foliage, and in each bag. In bags where the larval mortality was less (Left) Fall cankerworm larva on an American elm leaf. (Photo by W. D. Zehr) (Right) Horse chestnut tree almost completely defoliated by the fall cankerworm. (Photo by J. E. Appleby) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. than 90 percent, the bags were replaced, ~ and counts were taken again on May 25. The second experiment was initiated on May 22, 1974, on the trees used in the first experiment except that six branches on each tree were selected. The larvae were mature and feeding on the foliage. Prior to treatment, the live larvae were counted on each of the selected branches. The same insecticides, with the exception of Gardona, were applied in the same manner, except that bags were not used. On May 23, 1974, the live larvae were counted on the selected branches. Counts were repeated on June | on branches con- taining any live larvae. : In the first experiment three days after application, acephate, Sevimol, Gardona, and malathion gave excellent control, but no mortality was observed as a result of the B. thuringiensis; however, seven days later the B. thuringiensis treatments resulted in complete control of cankerworm larvae. The fact that no mortality resulted three days after the B. thuringiensis treatments is not surprising, as sufficient time is required for the bacteria of this insecticide to invade the body cavity. Larvae stop feeding soon after ingestion of a lethal dose of B. thurin- giensis although the larvae may remain alive. Unfortunately, in some cities having municipal insect-control programs, the public is not informed about the expected results of this treatment, quickly conclude that the treatment is ineffective, and de- mand that another insecticide be used. All insecticide treatments in the second experiment gave complete control one day after application, except B. thuringiensis; however, ten days after application no live larvae could be found on the branches in this treatment. No tree poisoning resulted from any of the treatments in_ either experiment. In areas that have a history of canker- worm outbreaks, tree branches should be examined carefully for fall cankerworm eggs in late winter. If large numbers of eggs are found, branches containing eggs should be pruned and held at room tem- perature for about ten days to ascertain the viability of the eggs. If many eggs hatch, control preparations should be started. Unfortunately, in most municipal areas public complaints are voiced when the larvae are mature and damage has occurred. Fungi in Freshwater Habitats The role of the substrate, that is, the material that a fungus lives on, in deter- mining fungal populations in fresh water is extremely important. Certain fungus species are encountered only on submerged woody substrates, while entirely different populations are found on submerged de- _caying leaves, or as parasites or sapro- phytes of algae and microscopic animals. Recent studies indicate that fungi play a unique role in preparing substrates for use as food by other microscopic animals and plants in freshwater systems. Lee Crane, Survey mycologist, has there- fore undertaken a study of three types of freshwater habitats in I]linois to determine which fungi are present and their distribu- tion in fresh water. The habitats investi- gated were three artificial ponds, a mid- western river, and four freshwater swamps in southern Illinois. Blocks of balsa wood were submerged for one month in each of these habitats and were then collected along with natural substrates, such as sub- merged decaying leaves and wood. The balsa wood and natural substrates were in- cubated for one year in moist petri dishes. The incubated substrates were examined monthly to determine the kinds, relative abundance, and distribution of the fungi present. This study indicates that there is a large, previously unknown population of fungi that colonize submerged wood and leaves in freshwater environments. Many of these fungi have unusual adaptations to the aquatic habitat in the form of four- armed or S-shaped spore forms which ap- pear to aid in their dispersal in water. Preliminary studies also indicate that the relative abundance and the kinds of fungi observed on the incubated substrates vary according to the type of substrate and the season. Certain species, such as Neta patuxentica and Stachybotrys atra, are en- Spores of Flagellospora penicillioides (left) and Triscelophorus monosporus (right). These fungi are typical of those that colonize wood and leaves submerged in fresh waters. The S shape of F. penicillioides and the four arms of T. monosporus appear to aid in their dispersal in water. (Photos by J. L. Crane) countered in all seasons, while Gonytri- chum macrocladium predominates during the summer months and Conioscypha varia is a cold-weather species. Consider- ably more study will be necessary before it will be possible to classify all of the fungi that Crane has found and understand how they interact with their substrates and with other organisms. Additional Experiments with the White Amur The white amur, or grass carp, is ex- tremely controversial because of its po- tential threat to some of our native fishes and to aquatic ecosystems should it estab- lish breeding populations. The extent of such damage is unpredictable, but it could be great and almost irreversible. For this reason the Illinois Department of Conser- vation has banned the importation of the white amur into Illinois, except by written permit to qualified research agencies, and this action is fully endorsed by the Illinois Natural History Survey. On the other hand, the fish has rather remarkable capabilities of such great po- tential value that further study is definitely warranted. The white amur consumes large quantities of potentially noxious aquatic plants and recycles the released nutrients to the benefit of associated fish species, and it can grow rapidly and pro- duce highly desirable food on a diet of coarse vegetable matter. Aquatic biologist Homer Buck believes that there could be great value in exploiting these capabilities under properly controlled conditions. In 1973 Buck and his associates con- ducted experiments in ten-foot diameter plastic pools to (1) measure the influence that the white amur might have on asso- ciated fishes through its continuous recy- cling of the nutrients stored in the tissues of aquatic plants, and (2) compare the biological control of plants by the white amur with control by chemical means (di- uron). They found that the use of the white amur permitted a “bonus” production of fish (the weight of the white amur was al- most double that of the companion fishes) without loss in production of the associated bluegills and shiners. At the same time a desirable level of control of both water- weeds and filamentous algae was achieved with less effort and expense than would be required with a herbicide and without the possible side effects of a chemical. In 1974 they extended the study to eight l-acre ponds, four of which contained largemouth bass (LMB) and bluegills, and the other four, smallmouth bass (SMB) and bluegills. Each of four ponds (two having LMB, two having SMB) was stocked in mid-April with 18 white amurs weighing approximately one pound each. All of these ponds have a history of rather heavy growths of weeds (mostly Potamoge- ton and Najas) or of filamentous algae. The Illinois " NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 These are the first year’s observations: 1. The survival of white amurs through the growing season was 100 percent, and their growth was equally impressive, some individuals attaining weights of eight pounds (as much as seven pounds of gain in five and a half months), with an aver- age weight of 5.74 pounds. 2. The removal of vegetation was com- plete, suggesting that satisfactory control could have been achieved with less than 18 one-pound fish per acre. 3. The removal of vegetation in the large- mouth ponds increased the vulnerability of small fish to predation. This fact caused a desirable reduction in numbers of small bluegills and faster growth by surviving bass and bluegills, but it also caused such severe decimation of young-of-the-year largemouth bass that the survival of the bass population was endangered. 4. The effect was similar but less pro- nounced in the smallmouth ponds, reflect- ing the less predacious nature of the smallmouth bass. Bluegill populations were less effectively reduced in the weedless June 1975. No 148 Survey, a Published State and Conservation. monthly division of the Department of Natural Resources Prepared by Robert M Second-class Office of publication Zewadski with the collaboration postage paid at Urbana, Illinois 75 Natural Resources Building except the Registration and Education ponds which contained white amurs, and the survival of young smallmouth bass was substantial and not significantly different than it was in the weedy ponds containing no white amurs. A final word of caution. Results to date are only tentative and it is now unknown whether potential benefits will outweigh the potentially harmful effects of the white amur. This report should by no means be considered a recommendation for the use of this highly controversial species. Cicadas Publication Available All Survey publications are available to interested persons who request them as well as to libraries and research organiza- tions. A booklet on periodical cicadas, re- ported on in the May issue of INHS Sur- vey Reports, has recently been published. If you want more information on this sub- ject, write to Dr. George Sprugel, Jr., Chief, Illinois Natural History Survey, Natural Resources Building, Urbana, Illi- nois 61801, and ask for Biological Notes No. 91, The Distribution of Periodical Cicadas in Iilinois. months of July and August by the Natural History operating under the Board of of the Survey staff Urbana, Illinots Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY Sl RVEY, URBANA Lif The Illinots NATURAL Freezing Stresses and Plant Disease Most disease organisms that cause stem cankers and diebacks of trees and shrubs only attack plants that are low in vigor or are suffering from some type of stress. The appearance of stem diseases is often associated with unfavorable environmental conditions, such as drought, flooding, or rapid and extensive drops in temperature that occur when cold fronts move through in the fall or spring. Such diseases are also common on plants weakened by trans- planting or defoliation. Although this association between dis- ease and plant stresses is common knowIl- edge among plant pathologists, little is known about how stresses affect disease susceptibility or what mechanisms in the host plant prevent disease organisms from attacking the tissues. The main barrier to gaining such knowledge has been the lack of workable techniques to control environ- mental stresses for plant disease research. In recent years, Survey plant pathologist D. F. Schoeneweiss has succeeded in de- veloping model systems for exposing plants to controlled drought, freezing, and de- foliation stresses. One of these systems in- volves the differential freezing of tissues on intact, container-grown trees and shrubs. stem Portions of the test stems are wrapped with pipe insulation and heating cables, whereas other portions are left exposed. The plants are then placed in a large walk-in freezing cabinet and the air tem- perature is lowered at a controlled rate to well below the freezing point. Some of the plants are removed at each of several HISTORY REPORTS predetermined freezing levels. When in- sulated (unfrozen) and frozen stem por- tions are inoculated with canker disease fungi, changes in disease susceptibility as- sociated with freezing stress can be de- tected. Results indicate that disease resistance in dormant woody stems breaks thus far down following exposure to levels of freez- ing temperature that are not low enough seedlings Tree cabinet. lated to prevent freezing. (Photo by D. F. Schoene- weiss) placed in a programmed freezing Roots and portions of the stems are insu- Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. to cause direct freezing injury or dieback- Thus, damage commonly attributed to a sudden disease outbreak may actually be a secondary effect of a stress that occurred some time earlier, predisposing the plant to disease. Another advantage to the differential freezing method is that stem tissues resis- tant and susceptible to disease are present on the same intact stem, which makes an ideal system for studying the mechanisms responsible for disease resistance. Deter- mining what mechanisms are responsible for disease resistance in woody stems and how these mechanisms are affected by environmental stresses are objectives _of continuing research at the Survey. The knowledge gained should find application in developing recommendations for pre- venting damage by disease organisms that attack plants under stress. Land-Use Trends Disastrous to Prairie Chickens, Quail, and Rabbits Assessing losses of habitat and declines in wildlife populations on private land is often difficult because of the absence of records. Fortunately, such records exist for 1939 for a 2,760-acre area near Hunt in Jasper County thanks to the efforts of the late Survey wildlife biologist, Dr. Ralph E. Yeatter, and Charles S. Spooner, Jr. Yeatter conducted counts of booming prairie chickens on the area each spring, 1936-1963, and he censused quail and rab- bits in October, using bird dogs. Spooner mapped the game cover of the area in detail in 1939. Survey wildlife biologist D. Russel Vance duplicated the censuses and cover-mapped the area again in 1974. Vance found that the rapid intensifica- tion of cash-grain farming during the past 35 years has dramatically altered the land- scape of the Hunt area and has decimated the prairie chicken, quail, and rabbit pop- ulations. In 1939 grassy cover (including pastures and redtop and timothy harvested for seed or hay) constituted 47.1 percent of the area. In 1974 only 1.0 percent of the area remained in grass, and this remnant was primarily overgrazed pasture. Soy- beans, then used mainly for hay, covered only 9.4 percent of the area in 1939. In 1974 soybeans were planted on 68.8 per- cent of the land. As cash-grain farming expanded, average field size more than doubled (from 10 acres to 23 acres) at the expense of fencerows. In 1939 the 2,760-acre Hunt area contained about 43 linear miles of woody fencerow in the medium and dense categories. Now the area contains less than 6 miles of good fencerow cover. The extensive loss of habitat in the past 35 years has resulted in equally dramatic losses in prairie chicken, quail, and rabbit _ populations. Yeatter found at least 131 prairie chickens booming on the Hunt area in the spring of 1939; none have been seen there since 1968. Yeatter flushed 226 quail on two sections of the area in 1939, a den- sity of 15.3 quail per 100 acres. Vance found only three coveys totaling 49 birds on these two sections in 1974, a density of only 3.3 quail per 100 acres. Yeatter also flushed 57 rabbits on the area in 1939, a ratio of 2.07 rabbits flushed per 100 acres. During the 1974 census, two rabbits were flushed, a ratio of only 0.07 rabbit flushed per 100 acres. As the trend toward clean farming in- tensifies in southeastern Illinois, only those sites left by accidents of topography or by the decisions of individual farmers will contain the brushy, grassy cover essential for the existence of many species of wild- life. The current world food crisis makes it very unlikely that the game cover we once had will soon be reestablished on Illinois’s highly productive soils. Ladybug, Ladybug, Fly Away (to Your New) Home As we all know, ladybugs, also called ladybird beetles, are abundant in Illinois, and most species feed on other insects or their eggs. Thus, they help to control in- sects that damage agricultural crops and ornamental plants. In their quest for addition to chemical, means of controlling harmful insects, Survey en- tomologists have recently introduced a new species of ladybug into Illinois in the hope that it will be even more effective than natural, in native species. The new ladybug is about twice the size of the native ladybug, and it feeds voraciously on aphids. The story goes back to November 1974, when Dr. William Luckmann, head of the Survey's Section of Economic Entomology, visited with Dr. Richard Dysart, formerly with the Survey and now with the USDA Beneficial Insects Research Laboratory in Newark, Delaware. Dr. Dysart mentioned that a colony of ladybugs of the spe- cies Coccinella septempunctata, commonly found in Europe, had become established at Lyndhurst, New Jersey. Survey entomologists Luckmann and Clarence White asked the USDA to send them some of the beetles for further study. Accordingly, in March 1975 they received 100 ladybugs from Dysart, and the insects were placed in special cages in Survey laboratories and greenhouses. The beetles thrived on an aphid diet and produced a new generation. When the ladybugs became abundant in New Jersey this summer, the Survey re- searchers were informed that August 1 would be about the right time to collect Survey entomologist Clar- ence White preparing to release ladybugs in a cornfield. (Photo by Larry Farlow) large numbers of the beetles. White made the trip to Lyndhurst, and on August 1 and 2 (with the help of two members of his family, who traveled at their own ex- pense) collected more than 4,500 ladybird beetles. After White’s return with his collection, he and Luckmann released the ladybugs on August and alfalfa on the Illinois Agricultural [Experiment Station farms, Urbana. Dur- 5 in fields of corn, sorghum, ing August the beetles were observed feed- ing on corn leaf aphids colonizing on corn and sorghum. The beetles will be carefully late fall, winter, and spring to determine their dis- watched during the summer, persal and whether they successfully estab- lish permanent residence here. Herbicides and Bluegills For many years derivatives of the herbi- cide 2.4-D have been used in efforts to rid farm ponds, lakes, and other waters of excessive growths of aquatic plants. In a previous report Survey biochemist Rob- ert Hiltibran stated that the 2.4-D deriva- tives had been found to be about equally The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 effective against such aquatic plants~ as northern water milfoil and coontail. How- ever, the different derivatives of this herbi- cide had been found to have different levels of toxicity to bluegills. As a part of his investigation of herbi- cides in the aquatic environment and their effects on fish, Hiltibran and his associates decided to attempt to determine why vari- ous 2,4-D derivatives affected bluegills in different ways. Thus began a study of the effects of the 2,4-D derivatives on the oxygen and phosphate uptake of bluegill liver mitochondria (minute, granular, rod- like or threadlike lipoprotein complexes in the cytoplasm of most cells). The 2,4-D derivatives, or esters, could be placed into two general groups. ‘The first group includes the larger and heavier esters, which, because of their greater molecular weights, are commonly called high-molecular-weight derivatives. ‘These include the propylene glycol butyl ether (PGBE), or isooctyl, esters. The second group contains the smaller and _ lighter 2,4-D esters, such as isopropyl and butyl] esters, which contain three and four car- bon atoms, respectively, and are commonly referred to as low-molecular-weight esters. Hiltibran found that the isopropyl and butyl esters of 2,4-D decreased oxygen and phosphate uptake of bluegill liver mito- chondria more than did the isooctyl ester. However, other high-molecular-weight es- ters (PGBE) of 2,4-D decreased oxygen and phosphate uptake more than did low- molecular-weight esters, such as the ethyl ester of 2,4-D. These observations indicated that a sim- ple relationship between molecular weight and biological effects did not exist. Fur- ther, those 2,4-D derivatives which were more toxic to bluegills altered oxygen and phosphate uptake more than did the 2,4-D derivatives which were less toxic to blue- gills. These results suggest a correlation between the biochemical effects on oxygen and phosphate uptake and the toxicity of these 2,4-D derivatives to bluegills. The data indicate a specific interaction between each 2,4-D derivative and each enzyme complex which could not be predicted on the basis of molecular weight. September 1975. No. 149. Published monthly except the months of July and August by the Natural History Survey, a division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinors NATURAL HISTORY REPORTS Ground-Nesting Bee Andrena erigeniae is a solitary bee about half the size of a honey bee. Solitary means that each female bee builds her own nest, and provisions each cell with pollen and nectar by herself, and lays an egg on the pollen ball. In the case of Andrena en- geniae, which can be called the spring- beauty bee, the nests are short burrows in the ground with cells excavated in the eround near the bottom of each burrow. The nest biology of the spring-beauty bee is described and illustrated in the Survey’s Biological Notes No. 95 (June 1975) by Lloyd R. Davis (now located at the Uni- versity of Florida) and Survey entomologist Wallace E. LaBerge. This biological note can be obtained from the Chief of the Sur- vey upon request. The spring-beauty bee is so named be- cause the females depend entirely upon pollen and nectar from spring beauties Claytonia virginica), a beautiful spring flower which carpets the forest floor of many Illinois’ woodlands before the leaves of the trees have emerged. The bees nest in the forest soil in well-drained areas. The burrow excavated by the female is short, being only 6.5 to 15 cm below the surface, and from 3 to 14 horizontal cells are at- tached to the bottom of each burrow. Fe- cundity of the female seems low, but reproductive success must be very high, as these bees are usually abundant in woods where spring beauties abound. Nesting begins about the first of April and is fin- ished by mid-May in the latitude of Central Illinois. hatches from its egg, The bee larva devours its bee-bread (a spherical ball of pollen and nectar) and pupates in the cell by late July. The adult emerges from the pupa in September and remains in the cell until the sun warms the soil in early spring. Davis and LaBerge describe a fly which acts as a kleptoparasite (stealing the bee larva’s bread). The fly locates a bee’s bur- row by following the bee. The fly enters the burrow after the bee has left and de- posits one or more eggs in the burrow. The fly larvae locates the cells and eats the bee larva’s provisions causing the death of the bee larva. The spring-beauty bee is the most im- portant pollinator of spring beauties. With- out this bee these plants would produce Andrena erigeniae collecting nectar from a flower of Claytonia virginica. (Photo by Lloyd Davis) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. fewer seeds, at least be scarce, and would not grace our early spring woodlots as it now does. Thrips and Soybeans An outbreak of soybean thrips, Serico- thrips variabilis, occurred early in the season in the southern half of Illinois. Par- ticularly heavy infestations were noted on soybeans at Effingham, Dale, Harrisburg, and Dixon Springs. Survey entomologist L. J. Stannard in cooperation with the Survey’s economic entomologists has main- tained surveillance of soybean thrips and mites throughout the past summer. Unifoliate and trifoliate soybean leaves, if not completely destroyed, turned yellow as the result of thrips feeding on them. In one instance, over 800 thrips were found on a sample of 20 leaflets in the Harrisburg area. Such great numbers so early in the season is believed to have been due to the mildness of last winter. An outbreak had been anticipated, in fact, because winter monitoring had revealed active thrips on clover on warm days in January and Feb- ruary as far north as Monroe County. Although the soybean thrips had not previously appeared in epidemic numbers, Stannard was fortunately well prepared to meet the unexpected situation. One of his students, T. C. Vance, in 1974 had pub- lished in the Survey’s Bulletin series a life- history study of this species and had dis- covered that a predacious anthocorid bug, Orius insidiosus, could provide excellent biological control. Concerned farmers in southern Illinois were asked by Extension entomologists via radio and letters to county farm advisers not to spray for thrips control until Survey entomologists could assess the magnitude of the outbreak. Intensive monitoring of the areas revealed that, as expected, within three weeks large populations of Orzus had developed and decreased the number of thrips to below economic levels. ‘The resul- tant high numbers of the predators also aided in control of species of Lepidoptera that invariably deposit eggs on soybean leaves later in the summer. ‘Thus, while some damage was done to the crops early in the season, the appearance of large num- bers of Orius insured less damage by other pest species for the remainder of the grow- ing season. The censusing data on thrips and Orius are presently being analyzed. When harvest data become available this fall, a publication will be prepared describ- ing this near classic case of sound biological control and practical application of basic research data. The presence at the Survey of a thrips specialist, who had just com- pleted a study of the genus Sericothrips, spared soybean farmers in southern Illinois substantial amounts of money that they . might have spent unnecessarily on chemical sprays. Pheasant Population Increases Former Survey wildlife biologist G. Blair Joselyn estimated that in 1974 the late summer pheasant population on the Sibley Study Area and Ford County Management Unit had declined 40 to 50 percent from 1973. In the following fall and winter, poor hunting success and mild weather resulted in relaxed survival pressures for the pheas- ant populations. In 1975 wildlife biologist Richard E. Warner concluded from roadside census data collected in April and May that the breeding population was 50 to 60 percent lower than in 1974. Roadsides, small grains, hay, pasture, and nonagricultural cover on the Ford County Management Unit study area yielded an estimated 510 successful nests in 1973, 297 in 1974, but only 165 in IEE In contrast to the decline of successful nests in cover types, early morning brood counts during August of 1975 revealed a substantial increase in pheasant broods over 1974. In the Ford County study area this increase was from 17.1 broods per 100 miles in 1974 to 54 broods per 100 miles in 1975. The incongruity between early season nesting studies and the later brood census is clarified by two considerations. First, the weather conditions at the time brood counts were made may have contributed as much as 50 percent of the difference. In 1974 at the time of the brood census there was little Pheasants along a roadside in Illinois as seen by the census-taker. (Photo by former Survey photographer W. E. Clark) or no dew in the mornings, whereas in 1975 heavy dew was present. From other studies, it is known that such a difference in dew is a significant factor causing variation in brood counts. Second, weather conditions in 1975 permitted early planting of row crops such as corn and soybeans and early cultivation of these crops, in contrast with 1974 when wet weather delayed planting. This permitted successful nesting in the soybean and corn fields, not counted in the nesting surveys early in 1975. The outlook for the 1975 pheasant hunt- ing season in Illinois is encouraging. A conservative estimate, in view of the 1975 August brood census, is that there are two to three times as many pheasants this year as compared with 1974. Furthermore, crops ought to be harvested earlier in 1975 than in 1974 and pheasants ought thus to be concentrated in the remaining cover areas. New Golf Course Grubs A new pest of annual bluegrass and bent grasses in golf courses has been dis- covered damaging greens in St. Clair and Madison counties in Illinois. This pest is the grub of a small beetle, Ataenius spret- ulus Harold, which has not been given a common name as yet. Survey entomologist Roscoe Randall has been following the damage reports from Illinois and devising recommendations for control of the grubs. The beetles are about a quarter of an inch in length, appear as adults in August, and overwinter as adults in decaying vege- tation such as grass clippings or in cow- dung or fungus. In May or June they lay eggs in the turf. The larvae feed by clipping the roots of the grass at or near the surface. As a result, the grass wilts, turns brown and the sod can easily be lifted from the soil in patches. The larvae are full-grown by mid- July and pupate in the soil. This insect was first reported in Illinois by Stephen A. Forbes in 1905 who sug- gested that it might become a pest in this state. It was first reported as a pest of turf grasses in golf courses in Minnesota in 1934 and then in New York in 1969. In 1974 it was reported to be destroying turf grasses in Cincinnati, Ohio, and in golf courses in St. Clair Co., Illinois. In 1975 reports indicated that the grubs are affect- ing turf grasses in golf courses in several eastern states. The grubs were found to attain popula- tions as high as 240 per square feet in bent grass and annual bluegrass greens in IIlinois in 1975. The peak of damage occurs be- tween July 4th and 25th in northern IIlinois and control measures need to be applied early during an infestation. Organic phos- phate soil insecticides such as _ Dylox, Proxol, Dasanit, and Diazinon have been used to control the grubs. Roscoe Randall reports that Proxol was applied to an in- The Illinois f = NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 festation in northern Illinois with geod of the adults and the amount of egg laying results. in the spring. The insect may be a minor The damage caused by this grub in 1976 pest to turf grasses, but could increase in will depend on the success of overwintering importance, at least locally. October 1975. No. 150. Published monthly except the months. of July and August by the Natural History Survey, a division. of. the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinors NATURAL SURVEY Control Mosquitoes with Minnows St. Louis encephalitis in epidemic pro- precipitated throughout most of Illinois in the late summer and fall of 1975. Since adult mos- quitoes transmit the disease, Survey sci- portions serious concern entists received numerous inquiries from agencies and individuals about the control of mosquito larvae (wrigglers) in proposed and existing ponds, borrow pits, and back- yard goldfish pools. Survey ichthyologist P. W. Smith recommends a trio of small fishes for introduction such ponds, but he acknowledges that many native into HISTORY NOVEMBER 1975, NO. 15] other native species might be extremely useful if detailed studies of their food habits could be funded. The three species presently recom- mended are the blackstripe topminnow, the golden shiner, and the fathead min- now. All are common and widely distrib- uted native minnows. The topminnow has its mouth on the top of its head; the other two fishes have sharply upturned mouths. All three feed at the surface and in mid- water and presumably prey on mosquito wrigglers, although to what extent is un- fortunately not known at present. Tolerant "SA dal SRR bi Three native Illinois fishes recommended for mosquito control in ponds. Top: blackstripe topminnow male (I) and female (r). Bottom: golden shiner (lI) and fathead minnow (r). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. of water with no flow over a substrate of silt or clay, they can stand a certain degree of pollution and high water temperatures and are thus admirably suited for intro- duction into small artificial ponds. In the past the gambusia, or mosquito- fish, has been widely used to control larval mosquitoes, but it is native only to extreme southern Illinois. The modern, enlightened view is that animals and plants should never be introduced outside their natural ranges because of the risk that exotic spe- cies may upset the ecosystem. Fortunately, the blackstripe topminnow and_ golden shiner exist virtually statewide in Illinois, . and the fathead minnow occurs in all parts of the state except in the Wabash and Ohio drainages. If it is desirable to stock other species to provide fishing for children, Smith rec- ommends the yellow bullhead and black bullhead. Sunfishes and basses, which have more appeal to adult anglers, would prey on the small fish. However, bullheads are bottom feeders and scavengers and much less predatory. Goldfish have similar habits and are ornamental, but they are neither sport fish nor native to Illinois. The three recommended fishes are easily recognized. Regional fishery biologists of the Department of Conservation may be contacted for local sources of these min- nows. If other questions should arise, write to the Chief, Illinois Natural History Sur- vey, Urbana 61801. Tree and Shrub Problems Diagnosed Each year the Survey’s Section of Bot- any and Plant Pathology receives many tree and shrub samples for disease diag- nosis. Most of the samples are received from May through September. Between January 1 and September 30, 1975, plant pathologist Gene Himelick and his asso- ciates received 1,712 samples. Included were 722 elm samples to be cultured for the Dutch elm disease fungus, 85 samples of trees and shrubs to be cultured for wilt diseases, and 905 tree and shrub samples, most of which were examined microscopi- cally to diagnose the specific disease. A total of 190 plant samples were brought directly to Himelick’s office for disease diagnosis. He received approxi- mately 550 phone calls requesting mea- sures for disease control. The persons who seek these services are homeowners, farm advisers, nurserymen, arboriculturists, and others. The most prevalent problems encoun- tered this year have been chemical injuries resulting from the use of weed killers, wilt and canker diseases, needle diseases of pines, and a condition called spring leaf tatter, which occurs on many tree species but appears to be most common on maples. Chemical injury to trees and shrubs re- sulting from the use of herbicides in lawns was a serious problem throughout most of Illinois this year. In many cases unusual climatic conditions in late spring appeared to be related to the increasing amount of plant injury and number of deaths. Most tree and shrub species are highly sensitive to 2,4-D and 2,4,5-T, and Himelick rec- ommended that their use be avoided as much as possible in residential areas. Other chemical injuries appeared to result from spray drift, which often occurs when chem- icals are carelessly applied on a windy day. Some of the other chemicals involved are those applied for mosquito abatement in residential areas and for weed control along roadways and on corn and soybean crops. Oak trees are declining in many areas of northeastern Illinois. Much of the death and decline is due to the excessive rains that occurred in the springs of the past two or three years. Other oak decline prob- lems appear to have resulted from past heavy defoliation by insects, such as the spring canker worm, and from construc- tion injury. New homeowners have con- tinued to write or call concerning the losses of large numbers of oaks around their homes in recently developed sub- divisions. Since oak species are quite sus- ceptible to site disturbances and oaks are the predominant species, the tree loss in most subdivisions has been very high in all of Illinois in the past few years. Many samples of maples and oaks which appeared to be suffering from spring leaf aa Tulip tree leaves (I) and maple leaves (r) that are cupped, distorted, and yellowed as the result of chemical injury. The herbicide 2,4-D was used on the lawns around these trees. tatter were received. This condition causes the tissue between the leaf veins to turn brown, and a large percentage of the total foliage area is killed. The cause is believed to be a physiological problem related to specific climatic conditions. It is most se- vere when the leaves are very succulent after abundant spring rains and cool nights, followed by drying winds. Some of the other tree and shrub prob- lems encountered were Verticillium wilt; oak wilt; anthracnose of sycamore, ash, and maple; pin oak chlorosis, which causes the leaves to turn yellow from lack of iron; drowning of roots from excessive rains, which cause root suffocation; deaths from transplanting shock; several leaf spot dis- eases; winter injury; mechanical injuries caused by lawnmowers and construction machinery; and other problems caused by such animals as insects, squirrels, birds, and dogs. Mercury Studies at Lake Sangchris The investigation of the physical and biological dynamics of mercury at the Kin- caid Power Plant—Lake Sangchris complex in central Illinois has been completed by chemist Dr. Kenneth E. Smith and wild- life biologist William L. Anderson. The study included the collection and analysis of samples of coal, slag, fly ash, airborne particulate matter, soil, lake sediment, fish, plants, and ducks. These materials were analyzed by cold-vapor atomic absorption spectrophotometry, a technique that is capable of detecting less than 0.001 part per million (ppm) of mercury. The Kincaid Power Plant consumed 2.7 million metric tons of coal during the year the study was conducted. From the mean concentrations of mercury found in the coal, slag, and fly ash (0.20, 0.039, and 0.037 ppm, respectively), it can be esti- mated that 530 ke of mercury, or 97 per- cent of the mercury contained in the coal, was volatilized and emitted into the atmo- sphere through the smokestacks. Analyses of the soils surrounding the plant show that the highest mercury con- centrations (0.022 ppm) are to the north- east of the plant and the lowest (0.015 ppm) are to the southwest. This distribu- tion was expected, as the locally prevailing winds are from the southwest. Estimates of the amounts of mercury in the soil above the natural background values ac- count for up to 68 percent of the total mercury emitted from the power plant. Mean concentrations of mercury in the lake’s sediment were higher (0.049 ppm) in deposits occurring after the power plant began operating in 1967 than in deposits made earlier (0.037 ppm). The total amount of mercury in the sediment esti- mated from these values accounts for only 1 percent of the power plant’s probable emissions of mercury. The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 It seems, however, that these mercury emissions are not accumulating in the fish that inhabit Lake Sangchris. All of the 120 fish analyzed, representing seven species, contained surprisingly low amounts of mer- cury in their lateral muscle tissues, the edible portion of the fish. For example, total mercury averaged only 0.07 ppm in the filets of largemouth bass, only 10 to 50 percent as great as concentrations in largemouth bass from three other lakes in central Illinois. It appears that some un- identified factor in the environment at Lake Sangchris has suppressed mercury ac- cumulations in the fish. November 1975. No. 151. Published monthly except in July and August by the Natural History Survey, a division of the State Department of Registration and Education, operating under the Board of Natural Re- sources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL HISTORY REPORTS Some Rare Fishes Saved In 1970 the U.S. Department of Agri- culture Forest Service reclassified some of its swamp holdings in the Shawnee National Forest of Union County from the Pine Hills Scenic Area to the LaRue-Pine Hills Ecological Area. The new and un- precedented classification was designed to give protection to some of the unusual plants and animals and to their habitats in this unique spring-fed swamp. The Forest Service contracted with the [llinois Natural History Survey to do a year-long study of some of the threatened and unique fishes in the swamp. The species selected for intensive study were the banded pygmy sunfish, spotted sunfish, bantam sunfish, starhead topminnow, and spring cavefish. Survey ichthyologists con- ducting the study were J. M. Boyd, B. M. gurr, L. M. Page, and P. W. Smith. The results of the investigation have just been released by the Forest Service in a booklet entitled ‘““Those on the brink of doom: A study of rare fishes in the Shawnee Na- tional Forest.” Survey ichthyologists visited the swamp once each month throughout the year to collect physical and chemical data and to make quantitative samples (number of fish per square meter) of fishes at eight pre- selected stations. On each visit additional sites were examined to see if the rare species occurred elsewhere in the Shawnee National Forest. The Survey team found that populations of the banded pygmy sun- fish, starhead topminnow, and spring cave- fish were higher in the swamp than had been anticipated, and that all five species studied Shawnee National Forest. As a result, the that the Forest it chooses, remove the also occurred elsewhere in the scientists recommended Service could, if banded pygmy sunfish and starhead top- minnow from the list of species that may not be collected even by permit. They also recommended that the spotted sunfish be added to the list of protected species. Other View of swamp habitat (photo by P. W. Smith). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. specific recommendations to manage and protect all of the fish species and their habitats were included. Thanks to the foresight of authorities in the Forest Service, the status of each of the unique species is now known, and the future of several seems secure within the Ecological Area, where every effort is made to protect them. The Forest Service is also to be commended for seeking expertise from Survey ichthyologists already familiar with the swamp and for establishing guide- lines for the management of the Ecological Area based on Survey recommendations. Pesticides and Environment Modern agricultural practices, such as use of superior plant varieties, improved cropping methods, high-nitrogen fertilizers, insecticides, and herbicides, have been re- sponsible for immense increases in the productivity of Illinois croplands. These practices are responsible for Illinois corn yields increasing from 30 bushels per acre in 1920 to 105 bushels per acre in 1973. The use of pesticides has been described as being as “‘significant as the plow.” Pesticide use has increased phenomenally and many of the chemicals used are dispersed throughout the environment, entering air, water, and food through volatilization and air currents, runoff and leaching, and up- take and concentration in food chains. Rapidly changing agricultural technol- ogy and rapid introduction of new chem- icals present a continuing demand _ for evaluation and surveillance of the effects of pesticides on environmental quality. New pesticides are being introduced at a much faster rate than is our scientific ap- preciation of their side effects. During the 30 years since World War II, the number of different chemicals used on farms has risen from less than 100 to over 900. Dur- ing 1974 alone 10 new pesticides were introduced into Ilinois under experimental permits. The use of pesticides in large quantities and their rapid introduction have prompted a real need for a screening method which could serve as a simple early-warning system against potentially undesirable or hazardous effects of new chemicals or combinations of chemicals. The wait-and- see system operating in the past, requiring a generation or more to recognize side effects which are harmful or even disastrous to the environment, simply is not tenable for the future. The development of the model-ecosys- tem technology by Survey entomolgist Rob- ert L. Metcalf has provided a quick and sensitive laboratory tool for providing an- swers to questions about environmental pollution by pesticides. Basically this sys- tem uses radiolabeled pesticides to follow the movement and degradation of the ‘chemicals from a terrestrial (farm) to an aquatic (lake) environment and to demon- strate passage of the compounds or their derivatives through aquatic food webs. This is accomplished in the laboratory in an aquarium containing both terrestrial and aquatic organisms. Survey entomologists Robert L. Metcalf- and James R. Sanborn report on the re- sults of testing 48 pesticides using the model-ecosystem technology in a published report entitled “Pesticides and environ- mental quality in Illinois” (Jllinots Natural History Survey Bulletin, volume 31, article 9, August 1975). This technical report can be obtained upon request from the chief of the Survey. Pollutants and Bluegill “Out of sight, out of mind” is a cliché which frequently seems to apply- to the disposal of wastes and may have contrib- uted to the use of water for the disposal of wastes. Water is a very convenient disposal medium and appeared to work satisfac- torily when the waste products from the primary life support systems were of bio- logical origin, human populations were rel- atively low, and the quantity of wastes entering the water did not exceed the ca- pacity of the biological life in the water to degrade the materials. The development of the chemical industry, in part a response to the need for additional food and fiber for a greater number of people, placed greater stress on the aquatic system. Wastes are now being placed in lakes, streams, and SORGHUM ESTIGMENE GAMBUSIA OEDOGONIUM Drawing of a model-ecosystem. The aquatic environment is represented on the left with fish, snails, and aquatic plants, the terrestrial environment on the right with sorghum seedlings and a caterpillar. rivers that aquatic biological systems can- not utilize or decompose. Although man is not directly affected by the systems of dis- posal, the aquatic fauna are affected, since they are immersed in the disposal medium. However, man has been found to be in- directly affected by these same pollutants. Robert C. Hiltibran, Survey biochemist, and his associates have been investigating the biochemical effects of possible pollu- tants on one member of the aquatic system, the bluegill. One aspect of this investiga- tion is the bluegill’s uptake of chemical agents directly from water and their dis- tribution in the various tissues of the blue- gill. Much has been written about the ac- cumulation in fishes of chemical agents that have found their way into the aquatic environment. The food web is one of the routes by which fishes accumulate chemical agents within the aquatic environment, as has been shown by the results obtained using the model-ecosystem. However, Hilti- bran and his associates have found that bluegill removed 98 percent of the C**- labeled DDT directly from water during a 48-hour period of exposure, and most of the DDT was removed during the first 24 hours of exposure. The fish were not fed during the exposure periods. In contrast, Hiltibran and associates found during the same exposure period that the bluegill re- moved from 1 to 3 percent of the C**- labeled 2.4-D or 2,4,5-T directly from water. Thus the body burdens of these chemical agents would be considerably different. The bluegill rapidly removed methoxy- chlor from water during the first 24 hours of exposure, but during the second 24-hour period of exposure C-labeled products were excreted into the water by the blue- eill. Since it is known the methoxychlor is metabolized by fishes, these products were assumed to be methoxychlor or the meta- bolic products of methoxychlor. Further, bluegill 8 hours of exposure the chemical concentration in tissues is less after than after 24 hours of exposure. Similar patterns have been observed for several other agents investigated. The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 Many of the pollutants to which the aquatic fauna are exposed are toxic to bluegill. How the toxicity is mediated is not known. In order for the toxic effect to be observed, either the biochemistry or physiology of the fishes is altered to such an extent or for such periods of time that the bluegill cannot survive. Hiltibran and his associates have also been investigating the biochemical effects of many of the above pollutants, but additional data are needed before the mode of toxic action of pollutants can be fully explained. December 1975. No. 152. Published monthly except in July and August by the Natural History Survey, @ division of the State Department of Registration and Education, operating under the Board of Natural Re- sources and Conservation. Prepared by Dr, W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinors NATURAL HISTORY REPORTS “Washing Machine” Extracts Corn About 10 years ago researchers at the > / ta) Rootworm Eggs from Soil University of Missouri developed a ma- The northern and western corn root- Chine for separating rootworm eggs from worms are well-established insect pests in Sl. A sample of soil containing sis Ge Illinois cornfields. They deposit their eggs saturated with sodium hypochlorite and in the soil in August and September. The W@%€T; and the sample ves agitated lor eges develop slightly, go into a resting 15-20 minutes on a ball mill. The sample stage during the winter, and hatch in the Was then passed in small amounts through following spring. The potential for dam- a slowly revolving screen cylinder and age by the larvae of these insects in the Washed with sprays of water. The eggs next erowing season can be determined WE collected in a fine-mesh screen trap by counting the number of eggs per unit °F final processing. of soil. However, it is physically impossible Using the basic design of the Missouri to count these eggs without some means _ separator, John Shaw of the Section of of extracting them from the soil, since Economic Entomology and Robert Ellis rootworm eggs are about the size of the of the Section of Administrative Services period at the end of this sentence. refined that design and engineered and It by 4 } ne i _ ' + Fal ‘at ¥ “Washing machine’ and doors are in place, and in the right picture they have been removed. A soil sample is placed in the sieve located inside the funnel at the top and is washed with water from the shower head (controlled by a foot pedal). The water, carrying soil particles and eggs, runs down into the revolving, inclined screen cylinder and finally into a collecting trap. Soil and waste water are collected in the garbage can be- neath the machine. When in operation, the electric motor is protected by a steel mesh shield. which extracts corn rootworm eggs from samples of soil. In the left picture all covers Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. constructed a larger, enclosed machine that extracts rootworm eggs from a pint of soil in only 3-4 minutes. The final stages of separating eggs from debris require another 5 minutes after which the eggs can be counted under a microscope. The Illinois Natural History Survey ma- chine and the final separation of eggs, using magnesium sulphate, are highly effi- cient, and the entomologists have repeat- edly recovered 97 percent of rootworm eggs manually placed in samples of soil. Scientists working in the weed pest-man- agement program of the Department of Agronomy, University of Illinois, also have used the machine to extract weed seeds from soil samples. The Natural History Survey will soon publish an illustrated leaflet describing the machine and giving its dimensions and information about its operation and con- struction. When more such “washing machines” have been constructed, they should greatly help farmers, county agri- cultural advisers, agricultural researchers, and others who wish to predict the num- bers and damage potential of corn root- worms in the next growing season. Largemouth and Smallmouth Bass Diets As part of their continuing study of the largemouth and smallmouth bass life his- tories, aquatic biologists Homer Buck and Richard Baur monitored the food habits of adult bass in separate, 1-acre, bass-blue- gill ponds. Adult bass were procured bi- weekly by angling, and their stomachs were pumped to obtain samples of their food. A total of 284 largemouth bass were sampled from late May to early September 1974. They had an average length of 11 inches and an average weight of 0.63 pound. A total of 278 smallmouth bass were sampled during the same _ period. These bass averaged 9.5 inches and 0.39 pound. Empty stomachs totaled 14 (4.9 per- cent) for the largemouth bass and 15 (5.4 percent) for the smallmouth bass. Some stomachs contained only a slight trace of well-digested food; these totaled 31 for the largemouth and 33 for the smallmouth. Unidentifiable animal parts were the most frequently found food item in both bass. The most frequently found, recog- nizable food items in largemouth bass stomachs were dragonfly larvae, bluegill, mayfly larvae, assorted plant matter, and crayfish. In smallmouth bass stomachs the most frequently found, recognizable food items were crayfish, dragonfly larvae, may- fly larvae, assorted plant matter, and blue- ell. Items making up the greatest volume _ of food in largemouth bass stomachs were bluegill, dragonfly larvae, assorted animal parts, largemouth bass, and mayfly larvae. In smallmouth bass stomachs the items of greatest volume were crayfish, dragonfly larvae, bluegill, assorted animal parts, and mayfly larvae. Although food preferences of both spe- cies appeared quite similar, the large- mouth bass were found to be much more likely to feed on fishes than were the smallmouth. Fish remains of some kind were found in 51.1 percent of the large- mouth bass stomachs which contained food, whereas only 28.1 percent of the smallmouth bass stomachs contained fish. In 39.5 percent of the largemouth bass stomachs fish made up the greatest bulk of the food eaten, while the percentage was only 17.3 for the smallmouth. Large- mouth bass were also more cannibalistic than the smallmouth. Largemouth bass were positively identified in 12.2 percent of the largemouth bass stomachs contain- ing food items. Smallmouth bass remains were found in only 1.1 percent of the smallmouth bass stomachs. This information, along with similar data collected during 1975, will be cor- related with total fish production in the ponds to assess the relative efficiencies of these bass species living in identical but separate ponds. Discovery in Plant-Leaf Chemistry The outermost layer of plant leaves is composed largely of cutin embedded in wax. The cutin is the backbone and con- Left, electron micrograph of a tobacco leaf surface. On the right side is the normal leaf surface, and on the left side part of the wax has been removed. Right, electron micrograph of a diterpene aggregate center. sists of cross-esterified polymerized hydroxy fatty acids. The wax is mainly a mixture of hydrocarbons, alcohols, and esters of a number of compounds. In studies of the deposition and penetration of chemical agents, such as herbicides, air pollutants, and insecticides, it is important to under- stand the chemistry and physical arrange- ment of the leaf cuticle. Except for certain generalizations, little is known about the cuticle of plant leaves, and even less is known about the mechanism by which chemicals penetrate the leaf surface. For many years it was believed that plant damage caused by oxidants, such as ozone, was directly correlated to the open- ing of leaf stomata (pores in the leaf sur- face for gaseous exchange) ; more recently it has been found that sto- matal openings cannot be correlated with oxidant damage in all cases. Plant physi- ologist Claus Grunwald, in cooperation with Dr. Sai Chang, a biochemist of the University of Arizona Medical Center, is investigating the differences that might exist between the cuticles of oxidant-sensi- tive and oxidant-insensitive plants. The tobacco plant, which is quite sensitive to air pollutants, was selected for this study. The surface wax layer, or cuticle, of its leaves is easily removed by washing it for a few seconds with an organic solvent, such as chloroform. Chemical analysis of the tobacco leaf however, wax revealed a _ heretofore unreported polar diterpene, and its exact chemical structure has been identified. Diterpenes can be broadly classified as lipids. This diterpene has not been found in oxidant- resistant plants. In young tobacco leaves the diterpene accounted for almost 50 percent of the total leaf wax, and the young leaves are the most ozone damage. Older leaves are less sensi- tive to oxidant damage, and the waxes of these tissues were very low in the diter- sensitive to pene concentration. Electron microscopic investigations show that the polar diter- pene is aggregated and embedded in the nonpolar wax of the leaf cuticle. Grun- wald and Chang theorize that the polar diterpene center may be responsible for the oxidant sensitivity of tobacco leaves and the leaves of other plants. However, considerably more study is required to prove this working hypothesis. New Book on Waterfowl Biology A 544-page book, The Ducks, Geese, and Swans of North America, has recently been published. The book is jointly spon- sored and published by the Illinois Natural History Survey and the Wildlife Manage- ment private foundation. The book covers the identifi- Institute, a conservation cation; population status; breeding, mi- gration, and winter distribution: migration chronology; reproductive capability; life The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 history; and food habits of more than ~50 species of waterfowl. The material was prepared by Dr. Frank C. Bellrose with the assistance of Dr. Glen Sanderson and Mrs. Helen Schultz, all of the Illinois Natural History Survey’s Wild- life Research Section. Lloyd LeMere, Sur- vey technical illustrator, supervised the preparation of the maps and charts used to illustrate the breeding, migration, and winter distribution and the chronology of fall and spring migration of most of the waterfowl species. Even though Natural History Survey personnel were deeply involved in pro- ducing this book, neither the Survey nor any of its staff members will receive royal- ties or any sort of monetary compensation from the sale of the book. Profits will be used to help finance the activities of the Wildlife Management Institute. This book has been chosen as the January selection of Outdoor Life magazine’s book club, and it will soon be available at bookstores. It can also be ordered from the printer, Stackpole Books, Harrisburg, PA. This book is expected to be the standard reference for waterfowl biology for many years. Its publication should result in im- proved efficiency in management of the waterfowl resource in II]linois and through- out North America. January 1976. No. 153. Published monthly except in July and August by the Natural History Survey, @ division of the State Department of Registration and Education, operating under the Board of Natural Re- | sources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL The Stripetail Darter The stripetail darter (Etheostoma kenni- cotti), a small Illinois fish growing only as large as 65 mm (2.5 inches) in length, was the subject of a life history study recently published by Survey ichthyologist L. M. Page. Copies of this publication, Biological Notes No. 93, may be obtained free by writing to the Chief, Illinois Natural His- tory Survey. The stripetail darter is found only in small rocky streams in the Shawnee Hills of southern Illinois, Kentucky, Tennessee, and small areas of Alabama, Georgia, and Mississippi. Three years of field and labo- ratory observations were made on a popu- lation in Big Creek in Hardin County, Illinois. The stripetail darter was found to occupy slab-rock pools, to live a maximum age of 2.5 years, to grow to a maximum size of about 65 mm, and to feed princi- pally on crustaceans and immature aquatic insects. At one year of age and a minimum size of 30 mm, the stripetail darter spawns Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey. HISTORY REPORTS in slab pools on the undersides of stones previously selected and guarded by the males as breeding territories. After an elaborate and complex courtship, up to 130 eggs are laid by each female. Several females may spawn with a single male, and nests having as many as 400 eggs were found in Big Creek. After spawning, fe- males leave the nest and the male remains alone to guard the eggs. Eggs hatch in about six days (at 20° C) and the young leave the nest. Detailed life history studies such as this provide an understanding of the ecological requirements of a species throughout its life, and provide information now much in demand by persons doing environmental studies. The study on the stripetail darter was the sixth life history study on _ Illinois darters completed at the Survey. Prelimi- nary investigations presently are under way toward the selection of additional species to be studied. The criteria for selection of Breeding male stripetail darter from Big Creek in Hardin County, Illinois (photo by Larry Farlow). a species are a demand for information on the species, the availability of one or more study areas in Illinois, and a population large enough to be sampled at least monthly without depletion. Being con- sidered as subjects are Etheostoma micro- perca in northern Illinois, and FE. proeliare and EF. chlorosomum in southern Illinois. The Heron Problem Between 1958 and 1964, in the course of his studies on waterfowl populations from aerial censuses, wildlife specialist Frank Bellrose also located and censused heron colonies on the Illinois River between La . Salle, Illinois, and Grafton, Illinois, and-on the Mississippi River between Alton and Rock Island (Mills et al. 1966). Annual variation in the counts was high, but the data suggested that heron populations might be declining. One problem in assess- ing the heron counts was the possibility that the birds were relocating their colonies —that apparent declines were merely movements to new locations. In 1973 wildlife specialists Jean and Richard Graber decided to follow up the important earlier heron counts and extend the study by locating and censusing all of the heron colonies in and adjacent to the State of Illinois. The large colonial herons, great blues and great egrets, nest primarily in bottomland forest, and Illinois, along with its adjacent river boundaries, is par- ticularly rich in this productive habitat. By 1975 much of the best bottomland habitat in this very large study area had been searched from the air or ground, or both. Though further searching will be done, the Grabers believe that they have seen and censused most of the major colonies in the study area, including all of the existing colonies of great blue herons and great egrets on the Mississippi and Illinois rivers. It is clear that the populations of the large herons are indeed in serious decline in Illinois. The lowest counts of nests pro- vided by Bellrose for the years 1958 through 1964 for the Illinois River Valley included 385 great blue and 375 great egret, whereas the Grabers located 170 great blue and 80 great egret nests for the same area in 1975. The lowest numbers of — nests reported by Bellrose for 1958-1964 were 515 great blue and 505 great egret in the Mississippi River Valley, whereas the Grabers in 1975 found only 270 great blues and 115 great egrets in this area. It is important to have factual evidence of the decline, but it is even more impor- tant to understand why. Such understand- ing depends upon historical perspective, which is not acquired in one or two years of study. The heron problem is an example of one of the most important aspects of the work of the state’s scientific Surveys, and that is to tell us where we have been, and, as Lincoln phrased it, “Whither we are tending.” Predicting Fish Populations The earliest stages in the life of a fish (called larvae) are highly vulnerable to a fluctuating environment, and their survival determines the size of future populations of these fish. Survey aquatic biologists Don Duffor and Ted Storck have been studying the ecology of larval fish in Lake Shelby- ville for the past three years. The larval fish are captured with small mesh, conical nets towed through the water from the bow of a boat. Some species are more easily captured than others and the technique is especially useful for the gizzard shad, an important forage fish. Thus far attention has been directed at determining what areas of the reservoir are important for spawning, the interval over which each species spawns, the relationship between spawning success and the future size of the population, and the role fluctuating water plays in governing spawning success. Lake Shelbyville is an 11,100-acre flood control reservoir in central Illinois and fluctuates substantially in the spring de- pending on the magnitude of rainfall. Water levels were stable but high in 1973, started low but rose to record high levels in 1974, and remained relatively low throughout the entire 1975 spawning season. The interval over which gizzard shad spawned remained relatively constant from year to year, but specific peaks in spawning in 1974 seemed to be triggered by rising water. Furthermore, a relation- ship appears to exist between spring water levels and the number of shad produced. The most shad were captured in 1974, the year of highest water, and by far the fewest were captured in 1975, the year of lowest water. Shad numbers and water level were both intermediate in 1973. In 1975 the distribution of spawning activity within the reservoir was studied. Sampling was conducted throughout the length of the reservoir and included coves, flooded portions of tributary streams, bays, and midlake stations. The results indicated that spawning activity is most intense at the shallow upper end of the reservoir near the mouth of the major tributary stream. At the lower end of the reservoir signifi- cant spawning appeared to be restricted to the inundated floodplains of tributary streams. The large number of gizzard shad pro- duced in the spring of 1974 were still present in the fall of the year. Yet the following spring this group represented only 2 percent of the total population. This suggests that, at least for shad, the impor- tance of an age group in future years may not be predictable at the larval stage col- lected by the technique utilized in this study. The correlation between water level and larval shad production suggests that water level manipulation may be a useful management technique to increase spawn- ing success, but this may have little rela- tionship to the resulting adult population. Other species have not been collected in adequate numbers to establish distribu- tion patterns or relationships between numbers produced and water level. Future efforts will be directed at establishing the location of these species and monitoring their numerical response to environmental conditions. Hopefully the information ob- tained will provide insight into the factors which govern the success of fish popula- tions, and provide clues for managing reservoirs for maximum fish production. Crop Pests in 1975 Extension entomologists of the Univer- sity of Illinois at Urbana-Champaign and the Illinois Natural History Survey held the Twenty-eighth Annual Custom Spray Operators Training School at the Univer- sity on January 6-8, 1976. Extension ento- mologist John Wedberg presented a de- tailed report at this school on the pests affecting crops and other human activities in Illinois during 1975. The information in this report was compiled from reports sub- mitted by County Extension advisers con- cerning the use and methods of application of insecticides in their counties and from information on file in the Illinois Natural History Survey. Insect pest problems during 1975 were more severe than during the past few years. Problems varied from soybean thrips and red-headed flea beetles to black cutworms. Potato leafhoppers were numerous through- out the state, and damage to alfalfa was more extensive than in previous years. Alfalfa weevil damage, although severe in some areas, was not as extensive as had been anticipated. Numbers of first-brood European corn borers were generally low, but second-brood numbers reached eco- nomic numbers in several areas. Extension entomologist Don Kuhlman discussed the corn rootworm situation in Illinois. Corn rootworm damage was more severe during 1975 than during 1974. Al- though it is believed that adverse soil and weather conditions, planting dates, insecti- cide rate, and tillage practices were major contributors to this situation, the possibility of developing insecticide resistance is being studied. In 1976 the greatest potential for eco- nomic damage in Illinois is north of a line from Pittsfield to Decatur to Danville. Fields planted to corn for two or more consecutive years in the area north of this line may experience moderate to severe damage from northern and western corn rootworms. Farmers who have experienced rootworm damage in past years, and who grow continuous corn, should use a root- worm soil insecticide at planting. Research indicates that corn growers ought to make two corn rootworm counts between August 5 and August 25 in 1976. If these show an average of one or more adult rootworms The Illinois ~ NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 per ear tip, a rootworm insecticide should be applied if the field is to be replanted to corn in the following year. The most common pests of garden, yard, and home were vegetable and ornamental insects. County Extension advisers each responded to an average of 776 contacts pertaining to insect problems. Of these, 352 were about agricultural insects and 424 were concerned with home, lawn, and garden pests. An estimated 7,268,590 acres of field crops were treated with insecticides in Illinois during 1975 with a savings from crop loss to farmers of $46,823,220 above treatment costs. Control of soil insects in corn accounts for 65 percent of the esti- mated profits from the use of insecticides. February 1976. No. 154. Published monthly except the months of July and August by the Natural History Survey, a division of the State Department of Registration and Education, operating under the Board of Natural Re- sources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL SURVEY Cottontail Population Remains Stable at Allerton Park Cottontail trapping on the 4-H Area at Allerton Park was conducted in the fall of 1975 for the 20th consecutive year. The data suggest that, except for the years 1962-1965, 1967, and 1971, the rabbit population on the study area has been relatively constant at about 250 individ- uals, or roughly two rabbits per acre. Sur- vey wildlife specialist Dr. William Edwards has no ready explanation for the low pop- ulations during the six years mentioned. Whatever the cause, the factors responsible appear to have been of relatively short duration. This tendency toward stability at Allerton Park is in direct contrast to the declining trend in estimates of abundance and population. Edwards reports that several tentative conclusions are possible. First, the data harvest for the statewide cottontail suggest that factors regulating the state- wide population are largely independent of those regulating cottontails at Allerton Park. In another series of analyses, it was observed that fluctuations in the abundance of the statewide population were closely correlated with agricultural land Taken together, these findings suggest that the statewide cottontail recent years has had a negative response to the increased intensity of Illinois agricul- ture, whereas at Allerton, which is not farmed, the rabbit population has showed relative stability. If an area is left undisturbed, plants will invade bare ground, and over a period of years the kinds of plants will gradually use. population in HISTORY MARCH 1976, NO. 155 change in a predictable sequence called succession. Because of forestry plantations, numerous heavy, dense stands of multiflora rose, and the maintenance of access trails and fire breaks, no clear picture of the successional relations of the cottontail is emerging from the study. However, it is possible that the species may be adapted to a longer time segment of a successional sere than was previously supposed. (A sere is a series of ecological communities that follow one another in the course of the biologic development of an area. ) There is no strong indication of cyclic tendencies in the data on cottontails at Allerton Park. Whether the cause of this lack of cyclic tendencies is that other factors mask cyclic tendencies or that the species is relatively acyclic at this latitude is not known. In terms of management and _ harvest, there appears to be no possibility of a significant increase in the statewide cotton- tail population under the present intensive, Common eastern cottontail rabbit photographed at Brownfield Woods near Urbana. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. row-crop dominated agriculture. In the management of public lands, it is becom- ing increasingly evident that an abundance of heavy, dense escape cover is essential to the maintenance of rabbit populations at high levels. Field Survival of Larvae of an Alfalfa Weevil Parasite The growing emphasis on biological con- trol in insect pest management demands that scientists acquire knowledge of the basic biology of parasites and predators. Factors preventing the establishment or impairing the performance of artificially introduced enemies of insect pests should be known. In many biological control pro- grams, however, scientists simply do not understand why certain natural enemies succeed or fail in controlling pest insects. In an effort to control the alfalfa weevil, in 1911 entomologists first released in Utah a small wasp from Europe. This wasp, Bathyplectes curculionis, lays its eggs in the bodies of alfalfa weevil larvae, and after the wasp larvae hatch, they feed on the alfalfa weevil larvae. However, the wasp spends about 10 or 11 months of the year as a resting-stage larva in a cocoon in the alfalfa field, where it may be vulner- able to parasites, predators, field cultiva- tion, and insecticides. As a part of their research directed at creating a pest management program for Wire cage containing field litter and B. curculionis co- coons being placed in an alfalfa field. the alfalfa weevil, Survey entomologists Edward Armbrust and Ronald Cherry con- ducted experiments between June, 1974, and June, 1975, to determine what factors caused wasp larvae deaths during this seemingly susceptible stage of their devel- opment. The entomologists also gathered data on the rate of survival of the wasp larvae. To carry out this program Armbrust and Cherry collected alfalfa weevil larvae that had been parasitized by the B. curculionis wasps. The weevils were held until the wasp larvae had emerged and had enclosed themselves in cocoons. Cocoons containing live wasp larvae were placed in small cages made of win- dow screen and left open at the top. The cages were placed in a predetermined pat- tern in alfalfa fields in southern Illinois. The fields were subject to normal cultiva- tion and spraying methods. The cages were observed regularly, and new cages con- taining wasp cocoons were placed in the fields at about 30-day intervals. At the same time cages with cocoons that had been in the field were returned to the labo- ratory for inspection. Cocoons that came back to the labora- tory intact were stored for 27 to 28 days at room temperature to determine whether they, in turn, had been attacked by para- sites. Then the cocoons were dissected to discover the percentage of larvae still living. In addition, the alfalfa fields were sampled for wasp larvae cocoons in the summer and fall of 1974 and in the spring of 1975 to measure changes in wasp larva populations under natural conditions. Armbrust and Cherry found that preda- tion by other invertebrates caused more deaths among wasp larvae than did the combined effects of other mortality factors, such as weather, parasites, and insecticide spraying. High heat in the summer may also have been a significant cause of death in the warmer areas of the wasp’s range. The overall survivorship of the wasp larva population in the cocoon stage from early summer, 1974, to the next spring was about 16 percent. These findings are the first to show that predators may substan- tially reduce parasite populations in a field crop. This point deserves careful study in attempts to use biological controls on insect pest species. The Effect of a Soil-Injected Fungicide on Earthworm Populations The valuable role played by earthworms in litter decomposition and soil aeration is well established. Any activity of man re- sulting in the depletion of the earthworm population would, therefore, be considered harmful to the soil ecology. Recent studies in Canada and Europe have indicated that many of our most commonly applied fungi- cides kill earthworms. In these studies Intact cocoons (left) of B. curculionis and cocoons mu- tilated by predators (right). earthworm mortality often approached 100 percent when fungicides were applied directly to the soil. Bill Black, a graduate student in the Survey’s Botany and Plant Pathology Sec- tion, studied the effect on earthworm populations of the fungicide benomy] when injected into the soil. Test plots were located at the Survey arboretum near Urbana. Benomyl was selected for this study because it is one of the fungicides most widely used in the United States. Benomyl has the ability to suppress a great number of our most serious plant patho- gens, and it has low mammalian toxicity. The test plots used for this investigation were those used by Dr. Dan Neely, Survey plant pathologist, for his studies on soil- injected benomy] in controlling Dutch elm disease. The plots were treated by pressure- injecting benomyl into the soil in May, 1970, 1971, 1972, 1973, or 1974. The soil of the control plots was not treated with benomyl. To estimate the earthworm pop- ulations, Neely and Black poured a solu- tion of formalin onto the soil of each plot, forcing the earthworms onto the soil sur- face. The number of earthworms to emerge within each plot in 20 minutes was re- corded. In untreated soil the earthworm popula- tion increased as the growing season pro- eressed, A reduction of the earthworm population was observed in the most recently treated plot. The average substantial The Illinois = NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 number there was 8 worms, compared with 48 in untreated soil. As the time following the benomyl treatment increased, the dif- ferences between the numbers of earth- worms in treated and untreated soils de- creased, The results obtained from this experi- ment indicate that the earthworm popula- tion is reduced following the soil injection of benomyl. However, at this site near Urbana, the earthworm population re- turned to normal within a year following the fungicide application and remained at that level thereafter. No long-term reduc- tion in the earthworm population occurred. Earthworms are only one part of the total soil ecology. The lack of a significant long-term effect on earthworm popula- tions, as shown by this experiment, is by no means proof that benomyl has no long- term effect on the soil ecology. Further studies on other components of the soil ecology will be required before the full effect of soil-injected benomyl is known. March 1976, No. 155. Published monthly except in July and August by the Natural History Survey, a division of the State Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinows NATURAL Prehistoric Squirrels Tree squirrels have been present in North America at least since the Miocene (some 29 million years Before Present). By least nine i sciurids existed, but the place of origin for the Miocene, at genera of the species found in early Pleistocene (1 million years B.p.) deposits is not known. Living species may have evolved inde- pendently in the Palearctic and Nearctic regions and migrated back and forth from one region to another. A study of pre- historic tree squirrels by wildlife biologists Charles Nixon and Stephen Havera, funded by the Illinois Department of Conserva- tion, is near completion. The remains of squirrels found with remains of prehistoric man or his encampments can tell us some- thing about the ecology of Illinois before the white man’s appearance in this area. By the time of the Wisconsinan ice ad- HISTORY REPORTS vance (25.000-15,000 B.p.), both man and squirrels were present in Illinois. The last stage of the Wisconsinan ice advance, the 11.000-5.000 forms Valders substage, occurred The land drainage patterns in Illinois date from this years B.P. present and period. The archaic people were present in southern Illinois, and squirrel remains have been identified from one site contemporary with the Valders period. Both fox and gray squirrel bones have been identified in the Modoc rock shelter site, located in western Randolph County adjacent to the Mississippi River. Midden material at this site dates from 11,000 years B.P. with occupancy by man extending for 6,000 years until about 4000 B.p. Squirrel remains were found in small numbers throughout the midden. Because squirrel bones were rarely worked into tools or ornaments, it is assumed that the animals were killed locally and not obtained by Fox squirrel (photo by former Survey photographer W. E. Clark). Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey barter or transported from more southern tribes. After the Valders substage retreated, there were several climatic changes that affected forest composition. In north-cen- tral Iowa, the sequence was cool-wet (a boreal forest of spruce-fir dated at 11,725 + 200 years B.P.), warmer-dry (transition to a deciduous forest of oak, ash, beech, maple, and birch by 8140 + 200 years B.P.) , and warm-dry (oak, hickory, and begin- ning of grass dominance by 6575 + 200 B.P.). The grasslands spread nearly to the east coast before there was a return to the cool, humid climate of today which favors _ forest advancement. Squirrels, no doubt, spread northward from their refuge in southern Illinois, Indiana, and Missouri as the forests invaded the prairie peninsula. By this time (5000 B.p.), man was using fire to maintain the boundaries of extant prairies. If we can assume that habitat require- ments of fox and gray squirrels have re- mained unchanged for the past 10,000 years, ratios of fox squirrels to gray squirrels in these prehistoric middens can tell us something about the habitat surrounding these settlements. Thus the preponderance of fox squirrels found at sites in the counties of Peoria (Kingston site, A.D. 1100-1400) and Will (Fisher site, a.p. 200-1600) would indicate that prairie probably dominated the landscape of north-central Illinois. Gray squirrels pre- dominated in the counties of Crawford (Riverton site, 1600-1169 B.c.), Lawrence (Robeson site, 1600-1169 B.c.), and Rock Island (Crawford farm site, A.p. 1790- 1810), indicative of extensive forests with little or no prairie. A mixture of gray and fox squirrels found at sites in the counties of Madison (Cahokia site, a.p. 1200-1550) , Randolph (Modoc Cave site, 11,000-5,000 B.P.), and Greene (Apple Creek site, 600 B.c.-A.D. 1200) suggest that a mosaic of prairie and forest occupied these counties. Such general descriptions of habitat for these counties usually concur with those provided by white men when settlement of Illinois began in the early nineteenth century. Pesticide Study Guide Pesticides play an important role in controlling pests. They protect humans, animals, and plants from diseases, para- sites, and predators; prevent damage to buildings; and help increase production of food and fiber. But pesticides should be used only when necessary, and they must be applied wisely, stored safely, and dis- posed of properly. Over a 13-year period (1961-1973), 35 people died in Illinois from pesticide poisoning. About 6 percent of the acci- dental ingestion of hazardous substances (about 664 cases annually) by Illinois children under 12 years of age involves pesticides. Although this is a much lower percentage than for medicine or other hazardous household substances, the im- portant point is that misuse of pesticides does result in accidents. All pesticides should be treated as potential poisons that may endanger some part of our natural environment. New federal and state laws have been enacted in recent years regulating the sale and use of pesticides and setting standards for their proper labeling, dispensing in the environment, and disposal. A commercial pesticide operator or applicator must now pass a written examination before being issued a license certifying him to purchase or use a restricted-use pesticide. Stevenson Moore, Survey extension ento- mologist, and Wayne Bever, Loren Bode, Barry J. Jacobsen, and Marshal D. Me- Glamery of the University of Illinois Col- lege of Agriculture have authored a booklet titled Illinois Pesticide Applicator Study Guide (Cooperative Extension Service, Special Publication 39). It can be obtained for the nominal sum of $1.00 by writing to the Extension Entomologist, Room 169, Natural Resources Building, University of Illinois, Urbana, Illinois 61801. This book- let will serve to help prepare a prospective pesticide applicator for certification as a Private Pesticide Operator or as a Com- mercial Pesticide Applicator or Operator. In addition to providing the basic infor- mation covering various sections of the amended Federal Insecticide, Fungicide, 2 Nett {K es Zs Map showing the distribution of Brood XXIII of the periodical cicada (prepared by L. J. Stannard and Survey artist Lloyd LeMere). and Rodenticide Act, the publication con- tains a glossary of common pesticide terms, a list of poison control centers in Illinois, and directions for obtaining certification. Other chapters deal with such subjects as: the types and toxicity of various pesticide chemicals, symptoms and treatment of pesticide poisoning, safe handling of pesti- cides, labels and labeling, application equipment and calibration, persistence in the environment, pests and their relatives, and plant diseases and weeds. Periodical Cicada Time Again Like tides, death, and taxes, the appear- ance of our periodical cicadas is certain to occur with ineluctable predictability. This year Brood XXIII, the Lower Mississippi River Valley Brood of Peri- odical Cicadas, will emerge from the soil in May and June after 13 years of feeding underground. The adults of this brood were last seen in Illinois in 1963, when they swarmed and sang in enormous num- bers, laid eggs in twigs, and then perished. Their eggs hatched, and the young fell to the ground and burrowed down to feed on tree roots for these past 13 years. According to our records, Brood XXIII will emerge in Illinois south of Interstate 70 with heavy concentrations in the follow- ing counties: Alexander, Jackson, Perry, Pulaski, and Union in the southwestern portion of our state; and Crawford, Jasper, Lawrence, and Wabash in the southeastern portion of Illinois. Because the females lay their eggs in twigs, and in so doing sometimes kill the tips of the twigs, considerable damage can be done by these insects to fruit, nursery, forest, and specimen trees. Roscoe Randell, extension entomologist, recommends that home fruit growers protect their young trees by covering them with cheesecloth. For larger trees, or where many trees are involved, he suggests that sprays of Sevin be applied when the female cicadas are laying their eggs to help reduce damage. The Survey staff will monitor this brood again to further determine its exact bound- aries. Any information, specimens, or re- ports of singing, damage, and sighting of cast-off skins will be welcomed and grate- fully accepted for our records. We have only one chance every 13 years to survey this brood. Biological Notes No. 91 on the distribu- tion of periodical cicadas in Illinois, au- thored by Survey entomologist L. J. Stan- nard, is available free of charge from the Chief, Illinois Natural History Survey, Urbana, Illinois 61801. Aquatic Life and Ammonia Ammonia is a common pollutant occur- ring in Illinois waters and usually results from the decomposition of organic waste such as sewage or waste from animal feed- lots. Ammonia-containing effluents are also produced by industrial processes and cleaning operations which use ammonia or The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 ammonia salts. Most unpolluted rivers have ammonia concentrations below 0.2 parts per million (ppm) — in contrast, the average ammonia concentrations in the upper 100 miles of the Illinois River ranged from 0.6 to 2.6 ppm during the period 1972-1974. Ammonia places aquatic organisms in double jeopardy because it has both an indirect and direct effect. The bacterial conversion of ammonia to nitrate robs oxygen from the water, thus indirectly affecting organisms which depend on oxy- gen, and one chemical form of ammonia (un-ionized ammonia) is directly toxic to aquatic organisms. Under conditions of low oxygen, un-ionized ammonia becomes more toxic. The amount of ammonia present in the toxic form is governed by factors such as the hydrogen ion concen- tration (pH), temperature, and presence of other dissolved chemicals in the water. Because of the importance of the above modifying factors and because different species of aquatic organisms are apt to have different tolerances for un-ionized ammonia, Survey aquatic biologists Rich- ard E. Sparks, Carl M. Thompson, and Jana G. Waite, in cooperation with several other investigators, are testing the effects of un-ionized ammonia on several species of "aquatic organisms common in Illinois, and are using water similar in quality to water in some Illinois streams. The information derived from these experiments is ex- tremely important because ammonia re- moval is expensive, and any level of waste treatment beyond that which is necessary to protect aquatic organisms represents a- waste of economic resources by industries and municipalities. The research involves seven investigators from five state and federal agencies, and is supported in part by the Illinois Institute for Environmental Studies and by funds provided by the U.S. Department of the Interior, Office of Water Research and Technology, administered by the Water Resources Center of the University of Illinois. Richard Sparks, Carl Thompson, and Kevin B. Anderson, graduate research assistant from Western Illinois University, are measuring the acute, lethal effects of ammonia on bluegill sunfish, fathead min- nows, and channel catfish, and ammonia effects on survival, growth, and reproduc- tion of fingernail clams. Physiologist Anthony A. Paparo of Southern Illinois University is assessing the effects of am- monia on the gills of clams, and Jana Waite is measuring the metabolism of clams in response to ammonia. April 1976. No. 156, Published monthly except the months of July and August by the Natural History Survey, a division of the State Department of Registration and Education, operating under the Board of Natural Re- sources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinors NATURAL Mimosa Webworm Control The matted foliage of honey locust and mimosa trees is a common sight from early summer until late fall in eastern and cen- tral regions of the United States. The in- sect responsible for this damage is the mimosa webworm. The webworm overwinters in the pupal stage in white cocoons on the trunk of the tree or in nearby debris. In late spring the tiny gray moths emerge, and the female moths deposit their eggs on leaves. The HISTORY S REPORTS eggs hatch, and the small gray-yellow- green larvae begin constructing the char- acteristic mats of foliage. According to the results of tests con- ducted by Survey entomologist Jim Ap- pleby, each of five insecticides applied as foliar sprays in early July gained complete control of the actively feeding larvae. The 3acillus (Or- mala- insecticides tested were diazinon, (Dipel), thene), carbaryl thuringiensis acephate (Sevimol), and thion. It is extremely important to control A mat or nest constructed in honey locust foliage by mimosa webworm larvae. A mimosa webworm larva and honey locust leaflets. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. this insect when the tiny webs are first seen on a tree, as Appleby found that larvae were not killed when insecticides were ap-_ plied after the larvae had matured and finished feeding. Appleby further notes that an Indiana researcher, D. L. Schuder, has found that certain honey locust clones are much less susceptible to mimosa webworm attack than are others. ‘The clone Moraine ap- pears considerably less susceptible to at- tack than Imperial. Unfortunately, Mo- raine is the preferred host of the honey locust mite, which is responsible for the nearly complete defoliation of that clone during the late summer and fall months. Appleby suggests that Shademaster and Skyline might be better choices of honey locust clones, because both are somewhat resistant to mites and the mimosa web- worm. The Illinois River Valley in Retrospect Wildlife specialist Frank Bellrose has spent his entire life near the Illinois River, the first 21 years at Ottawa and the next 38 at Havana. During his high school years he canoed on it. Later he covered most of its lakes, making maps of their aquatic and marsh plants. From 1938 un- til 1946 he censused waterfowl throughout the valley from the shores and by boat. For the next 25 years he used an aircraft to make observations on the abundance of waterfowl. During his almost 50 years of observing the Illinois River and its adjacent waters, Bellrose has seen many changes. When he lived at Ottawa, there was no fish life in the river, and it smelled like a sewer. The waters were black, with bubbles of fetid gas gurgling to the surface. The first big change came with the Starved Rock Dam in 1933. In that year other dams were completed at Marseilles, Dresden, and Brandon Roads. The trans- parency of the water improved, the odor lessened, and fish began to appear. How- ever, parts of the wooded bottomlands of Starved Rock and Buffalo Rock state parks were cleared of trees and inundated. In the late 1930s Bellrose saw large col- onies of nesting herons, large marshes of river bulrush and American lotus, and thousands of acres of stumps marking for- mer bottomland forests. The stumps were a reminder of the increased river level resulting from the diversion of water — through the Chicago Sanitary and Ship Canal — in the early 1900s. This higher river level greatly increased the surface areas of bottomland lakes. Upon moving to Havana in the spring of 1938, Bellrose became acquainted with levee and drainage districts. About half of the floodplain of the Illinois Valley was leveed and drained between 1900 and 1922. The levee districts removed many important fish and waterfowl habitats from the floodplain. In addition, the levees in- creased flood heights by several feet on unleveed lands. It seems logical to assume, Bellrose says, that the restriction of waters in the floodplain produced increased rates of sedimentation in the remaining natural — waters of the valley. The closing of the navigation dams at Peoria and La Grange in 1939 also had its effect on the Illinois River. The rise in low water levels of 10 feet at La Grange and 11 feet at Peoria increased the sur- face area of lakes. Moreover, a reduction in the velocity of the river resulted in ac- celerated deposition of silt on the bed of Peoria Lake. The increasingly flocculent bottom of the lake resulted in increasing turbidity of the water from wave action. As a consequence, sago pondweed, wild celery, and coontail — aquatic plants that once formed extensive beds in Peoria Lake in years of stable or semistable water levels — disappeared after 1955. Siltation appears to be increasing in the Illinois Valley. Since World War II the practices responsible for increased sheet erosion are a near doubling of the area de- voted to row crops (corn, soybeans), fall plowing of corn and soybean stubble, and a reduction in the land devoted to contour plowing, terraces, and grass waterways. Bellrose says that it is disheartening to witness the degradation of waters in the x a * i ae ~~ ~~. An aerial photograph showing part of Lake Chautauqua, a small section of the Illinois River, and a group of agricultural fields that were leveed off from the river about 1920. Some of these fields were formerly cov- ered by Thompson Lake, once a renowned fishing lake. floodplain lakes of the Illinois Valley from siltation at a time when urban and in- dustrial pollution is lessening. Since World War II a steady reduction has occurred in the pollution in the upper river from urban and industrial sources, and dissolved oxy- gen and fish life have increased. The net result of man’s activities in the Illinois Basin is that the fish and wildlife resources have declined as habitat has been destroyed or degraded. Aquatic and marsh plants have almost completely dis- appeared as a result of increased turbidity and fluctuation in water levels. The loss of plants has reduced food supplies for game fish and waterfowl. In addition, the loss of fingernail clams from many bottom- land lakes above Beardstown from a pol- lutant in 1955 reduced food supplies for diving ducks and some species of fish. During the 37 years that Bellrose has spent studying waterfowl and aquatic plants in the Illinois Valley, he has reached the conclusion that siltation is the most destructive and insidious form of pollution affecting its quality for wildlife. Only by changing farming practices can any great improvement be accomplished. Fortu- nately, there are practices that permit high crop yields and still protect the land from severe sheet erosion. The most promising practice is termed minimum tillage. Bell- rose says that we need to get farmers to change from the moldboard plow to the chisel plow and its attendant equipment. He hopes that this change will occur be- fore the damage done to the lakes of the Illinois Valley makes their restoration impossible. Aquazine — New Aquatic Herbicide Simazine, widely used in Illinois agri- culture, was recently approved by the U.S. Environmental Protection Agency (EPA) for use in the control of algae and submersed aquatic plants. It will be dis- tributed as a wettable powder under the trade name Aquazine. Previously, simazine The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 had been registered for use in ornamental ponds and in backyard swimming pools. The control of algae, primarily filamen- tous algae, frequently has been a difficult task. For many years copper sulfate was the principal chemical agent available for the control of algae. Currently, copper sul- fate is the only aquatic herbicide approved by the EPA for use in water intended for human consumption. Dr. Robert C. Hiltibran, Survey bio- chemist in the Aquatic Biology Section, and his associates have investigated the effects of simazine in I]linois farm ponds for several years. Simazine, a systemic herbicide, is particularly effective at rela- tively low rates of application against many of the filamentous algae species com- monly found in bodies of water in Illinois and has given from 6 to 8 weeks of control after application. Simazine is also effective against phytoplankton algae and against chara, a higher-branched alga. Dr. Hiltibran and his associates also found that simazine is effective as an aquatic herbicide in total pond applica- tions, eliminating the stands of some aquatic plants present at the time of ap- plication and apparently suppressing the growth of vascular aquatic plants. How-_ ever, they found that simazine is not effec- tive as a preemergence aquatic herbicide. Two important water uses are fishing and swimming. Although several effective postemergence aquatic herbicides can be used to control various aquatic plants, their use also requires a suitable delay before using the fishes for food or the water for swimming. Fish from water to which simazine has been applied can be used for food, and the water can be used for swimming immediately after the applica- tion. However, the water cannot be used for irrigation or other purposes for 1 year after application. Thus, with the availabil- ity of simazine, the pond or pool owner has an additional tool for the control of algae and aquatic plants. Information concerning the use of sima- zine can be obtained from Dr. Hiltibran at the Natural History Survey. May 1976. No. 157. Published monthly except the months of July and August by the Natural History Survey, a division of the State Department of Registration and Education,-operating under the Board of Natural Re- sources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinors NATURAL HISTORY REPORTS New Alfalfa Weevil Parasites The most serious pest threatening alfalfa in Illinois is the alfalfa weevil, Hypera postica (Gyllenhal). A native of the Old World, this weevil was first discovered in 1904 near Salt Lake City, Utah. For nearly 50 years it remained confined to 12 western states. In 1952 it was discovered in Mary- land, and from there it has spread rapidly through the East, South, and Midwest. Since its first appearance in Illinois about ten years ago, it has spread to every county of the state. In many regions of the state, alfalfa pro- duction is almost impossible without some Adult of the alfalfa weevil (photo by former Survey photographer Wilmer Zehr). type of weevil control. Although chemical control has been the most widely used method, two other methods are common. One method is to manipulate the timing of the first harvest in the spring. After con- sidering factors such as size of the pest population, plant growth, and prevailing weather conditions, the grower can time the cutting date so that he can achieve the same effect as if he had applied an insecti- cide. The other method involves biological control agents, and predators. One of the most successful bio- such as_ parasites agents in Illinois is a_ small Bathyplectes (Thomson). This wasp lays its eggs inside control parasitic wasp, curculionts young weevil larvae. ‘The wasp larvae de- velop inside the weevil larvae, and when they have satisfied their needs, they kill their hosts. Populations of B. curculionis have been monitored Illinois for the last three years, and data from these studies closely in indicate that one parasite species cannot sufficiently suppress pest populations. Con- sequently, in recent weeks and in the weeks to come, additional parasite species have been or will be released in Illinois. Hope- fully, through these releases, a better bal- ance will be achieved between pest numbers and beneficial insects. Bathyplectes anurus (Thomson) is very similar in appearance and behavior to B. curculionis. Its distribution has been lim- ited to a few eastern states but recently it has shown some success in Ohio and Ken- tucky. Research entomologist Dr. Richard Dysart of the USDA-ARS Beneficial In- sects Laboratory in Newark, Delaware pro- Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey vided 795 female and 334 male parasites for release in Illinois. The releases were made in April on the Victor Schubert farm near Coulterville. Mr. Schubert has been coop- erating with the Survey for the past three years by providing alfalfa fields for re- search with alfalfa insects. Microctonus aethiopoides (Nees) has a fairly limited distribution also and appears to be most successful in northern areas such as lower Michigan and _ northern Ohio. The female of this wasp attacks adult alfalfa weevils instead of larvae. Eggs are laid in the weevil, and parasite larvae hatch and feed internally until their devel- opment is completed. Instead of killing the host, this parasite severely damages host tissue, including the reproductive organs. Consequently, parasitized weevils (females) cannot produce viable eggs. Dr. John Neal, research entomologist, USDA- ARS Field Crops Laboratory, Beltsville, Maryland, provided 251 parasitized adult weevils for release. Release was made in April on the Henry Leithoff farm near Havana. Mr. Leithoff has also been coop- erating with the Survey for the past three years. Release sites will be monitored for the next few years and additional releases made as material becomes available. Given time, a little luck, and continued research efforts, it is the intention of the alfalfa research team to have a complex of para- sites and predators actively suppressing alfalfa weevil populations in Illinois to a point where insecticide usage can be greatly reduced in alfalfa production systems. Pheasants and Inversity In 1945 the late Paul Errington, one of North America’s premier wildlife ecolo- gists, published a classic paper on the population dynamics of gallinaceous game birds. In his paper he set forth a concept that the rate of summer gain among differ- ent gallinaceous birds, including the pheasant, tended to be inversely related to the density of adults in the preceding spring. This concept, now commonly termed the principle of “inversity,” has had wide application in wildlife ecology during the past 30 years. The principle of inversity relies on the interaction of two density-dependent population mecha- nisms: the rate of reproduction among the adults and the rate of mortality among the young. The result of the interaction is that spring-to-fall gains are greater for small spring populations of breeders due to in- creased reproductive rates and decreased juvenile mortality rates, and smaller for large spring populations due to decreased reproductive rates and increased juvenile mortality rates. Support for inversity among pheasant populations has come principally from ex- ‘tensive population statistics and often from population indices. Intensive studies of the reproductive ecology of pheasants in east- central Illinois by Survey wildlife specialist Ronald F. Labisky, however, does not sup- port the principle of inversity. This Illinois investigation, conducted during the five years 1957-61, revealed that the rate of re-_ cruitment of young into the fall population was neither directly nor inversely related to the spring density of hens, but was a static biological parameter. The spring density of hens averaged 77 per square mile; the coefficient of variation was 32 percent. The rate of recruitment of young averaged 333 percent annually; the coefficient of vari- ability of these annual rates was only 5 percent. The correlation coefficient (r) between the abundance of hens in spring and the abundance of young in fall was —0.38 (P > 0.05). Thus there was no significant inverse relationship between the spring population of hens and the fall pop- ulation of young. Intensive studies of reproductive ecology of pheasants in east-central Wisconsin, published in 1975 by J. M. Gates and J. B. Hale, support Labisky’s findings in Illinois. The correlation coefficient (7) between the spring density of hens and the fall density of young for the six years 1959-64 was —0.21 (P> 0.05); thus there was no significant indication of inversity in this east-central Wisconsin pheasant popula- tion. Interestingly, the rate of recruitment of young in the east-central Wisconsin population averaged 313 percent annually — very close to the 333 percent statistic for Illinois. These studies cast doubt that the prin- ciple of inversity is applicable to the rate of recruitment of young pheasants. The pro- duction of young pheasants does, however, appear to be under density-dependent reg- ulation. The number of young pheasants hatched per hen appears to be inversely re- lated to spring density; but the mortality of young is also inversely related to the number of young hatched per hen. Conse- quently, these two density-dependent mechanisms oppose rather than comple- ment one another. The trademark of pheasant populations is a relatively fixed rate of recruitment of young; hence, the production of young is a function of the number of hens in spring. Swine and Fishes Continuing studies at the Survey field station near Kinmundy, Illinois, represent the first known attempt to adapt certain Asian cultures and techniques to some of our own special environmental problems. The studies are being conducted by aquatic biologists Homer Buck, Dick Baur, and Russell Rose. Important preliminary infor- mation was obtained in three-meter diame- ter pools in 1974, and the work was pro- jected into earth ponds in 1975. Two ponds (11 and 12) of similar size received nearly identical stockings of fish (4 Asian, 3 native species), but differing amounts of swine manure. Pond 11 re- ceived the total wastes from 5 growing pigs (about 39 pigs/hectare of water area); pond 12 received the wastes from 8 pigs (66/ha). Two consecutive lots of pigs were fattened during the experiment. Water levels were lowered approximately 0.5 meter at mid-season to improve natural circulation, but conditions were otherwise static, with no artificial circulation or aera- tion. Over a growing period of about 170 days (May to October), the net increments in fish biomass were at the rates of 2,971 kg/ha in pond 11, and 3,834 kg/ha in pond 12. The production in pond 12 was particularly impressive because it more than doubled our best previous production, which involved channel catfish fed large quantities of an expensive, high-protein, commercial feed, and achieved with no expenditure of protein because it was beyond that contained in the hog manure. The surprisingly high rates of production were attributed to (1) the high quality of the swine rations; (2) a fortuitous choice of a fish-stocking ratio; (3) an efficient production of plankton algae; and (4) effective water-level management. It was equally impressive that levels of dissolved oxygen were continuously adequate for the survival of the relatively tolerant largemouth bass. The apparent success of the system may be attributed to the highly specialized feed- ing habits of the Asian fishes, including the filter-feeding silver carp, which feeds pri- marily upon plankton algae, the bighead carp, which filters zooplankton, the grass carp, which utilizes filamentous algae as well as most common aquatic weeds, and the omnivorous common carp, which con- sumes bottom organisms and most forms of organic detritus, including the fecal ma- terial from the associated fishes. When used in the proper numbers and ratios they collectively consume such a large percent- age of available organic matter that the water is to a large degree purified. All of these species are fast growing, have a high tolerance for low oxygen levels, and rate from good to excellent as table fare. The results suggest that the use of these remarkable fishes for the recycling of organic wastes can yield important bene- fits in such critical areas as pollution con- trol, animal waste management, the con- servation of energy, and the production of useful protein. It must be pointed out, however, that the Asian fishes are now restricted for private use in Illinois, as in most American states, and may be used only by recognized research agencies for experimental purposes. Such restrictions are justified because we do not yet know the effects that these exotic fishes might have on certain native fishes, and on cer- tain sections of our aquatic environment. pollution-in- The Illinois NATURAL HISTORY SURVEY = NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 « June 1976, No. 158. Published monthly except the months of July and August by the Natural History Survey, ; a division of the State Department of Registration and Education,-operating under the Board of Natural Re- sources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL HISTORY REPORTS Studies on Aquatic Fungi In Illinois Freshwater hyphomycetes are a_ very specialized group of fungi that produce asexual spores called conidia. These fungi usually occur on partially decayed, submerged leaves and occasionally on the wood of angiosperms (plants producing seeds enclosed in an ovary). These highly specialized fungi are encountered in most Illinois waters. However, the role they play in the aquatic environment is poorly understood. There is some indication that these predispose submerged leaves for colonization by other aquatic organisms organisms. The main body of the fungus grows all through the leaf tissue, especially in petioles and The spore-producing parts project into the water, and the conidia de- velop and are liberated under water. Ma- ture conidia can also be found in the sur- face most streams, and lakes in Illinois. The conidia of the major- ity of these fungi are either tetraradiately branched (having four divergent arms) or sigmoid (wormlike) with the curvature in more than one plane. A special feature of these conidia is that while suspended in water, even over long periods, they do not germinate. However, if they come to rest veins. foam of rivers, on a solid surface, germ tubes are produced within a few hours. Studies on spore growth in aquatic hy- phomycetes have clearly shown that the mode of conidium development differs markedly between fungi having either tetraradiate or sigmoid spores and other fungi. Most students of conidial aquatic fungi have considered these differences as fundamental and have suggested some spe- cial biological advantage for the tetra- radiate and sigmoid conidia over those of a more conventional shape in the aquatic environment. Two explanations have been postulated: first, that the branched or sig- moid conidium may settle slowly in water and hence be carried some distance in a stream before coming to rest; second, that either of these conidial types may act as a minute anchor and have a better chance of becoming caught on a substrate suitable Scanning electron micrograph of the surface of a maple leaf, illustrating the tetraradiately branched spore of Tefracladium marchalianum De Wild., an aquatic hyphomycete. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. for the growth of the fungi. Many investi- gators have observed that aquatic conidia frequently accumulate in the foam which collects behind barriers of twigs or stones below waterfalls and in areas where the water is moving rapidly. Thus, these trapped conidia may be transported great distances with the foam, suggesting that the value of the tetraradiate or sigmoid adaptation may be in dissemination. Ecological investigations of freshwater hyphomycetes have been limited to sub- strate, habitat, dispersal, and the role of the fungi in the enhancement of leaf sub- strates as food for aquatic invertebrates. The most common substrates of these or- ganisms are submerged, decayed leaves, such as those of alders, oaks, elms, maples, chestnuts, brambles, ashes, and willows. Submerged gymnosperm (plants produc- ing naked seeds) leaves are usually totally devoid of aquatic hyphomycetes. The usual habitat of these fungi is well oxygenated water, such as alpine brooks, mountain streams, and fast-flowing rivers. However, they have also been found in slow-running, often contaminated, rivers: stagnant or temporary pools; melting snow; and soil. Usually, there is an in- crease in the number of species and indi- viduals of aquatic hyphomycetes from fall until spring, with a decline between April and June. The usual sampling methods for aquatic hyphomycetes involve the collection of foam samples or partially decayed, sub- merged angiosperm leaves from most types of freshwater environments. The leaf and foam samples are transported on ice to the laboratory in sterilized bottles and kept under refrigeration until the time of exam- ination. The leaf samples are washed in distilled water. One to three leaves are placed in sterilized petri dishes 2 inch deep, containing pond, river, or lake water that has been sterilized in an autoclave, and the dishes are maintained at room tem- perature (20°-25° C). Within one to two days the main body and conidia of fresh- water hyphomycetes develop. The spore- producing parts and conidia can be ob- served with a dissecting microscope on any portion of a leaf surface, but are most fre- quently encountered on petioles and veins. Grackles Nest On Interstates While many Illinois bird populations are struggling to survive, certain hardy species are not only surviving, but seem to be benefiting from man’s labors. Such is the case of the common grackle (Quis- calus quiscula). It is ironic that while hu- man action so often destroys habitat of our most interesting and vulnerable species of birds, we are inadvertently creating habitat for the grackle, a species whose supply seems to be ample. Grackles have a high tolerance for hu- ‘mans and frequently breed in urban resi- dential habitat, often placing their nests in dense shrubbery 3 to 20 feet high. Land- scape architects generally favor mass plant- ings of shrubs for their interesting displays of flowers, fruits, and foliage, and such plantings have been made along interstate highways. Many such plantings are of. thorny species, such as hawthorn and Russian olive, which are attractive to a number of bird species. Grackles prefer spiny thickets as nesting areas and domi- nate such places along the interstates. Grackles tend to be colonial and can pack many nests into an area of such habitat. They also sometimes prey on the nests of other birds. Survey wildlife specialists Jean and Richard Graber have seen many colonies of grackles along the Illinois interstates and often wondered how well nests sur- vived in this expanding, noisy habitat. With the discovery in April 1975 of a grackle colony in the median strip of I-57 south of Effingham, the Grabers decided on a short study to learn something about the bird’s tolerance for heavy automobile and truck traffic. The 54 nests estab- lished there in a Russian olive planting were so Close to traffic (7-15 feet) that they were sometimes moved vigorously by the wind of passing vehicles. The noise and ex- haust fumes were strongly disagreeable to the human observers, who chose not to re- main in the colony more than 2 hours at a time. However, the adult female grackle, for a successful nesting, had to remain on or at her nest of eggs most of the time through the incubation period of 13-14 days, after which the nestlings were con- fined to the nest 14-16 days. Questions asked about the birds in this ~ seemingly hostile environment were: (1) would there be massive desertion of nests, or (2) for any other reason, would hatch- ing or fledgling success be poor? Also of in- terest was the possibility of lead contami- nation of the colony from auto emissions, but because the primary emphasis of the study was to be nesting success, no birds were collected. However, through arrange- ment with Drs. Arnold Hartley, Gary Rolfe, and Raymond Vogel of the Uni- versity of Illinois Environmental Research Laboratory, lead determinations were made on soil samples from the colony and on eggs that failed to hatch. For purposes of comparison, a second colony near I-57 was chosen for study. Though similar in size and habitat to the Effingham colony, the second colony, near the Ina exit, was chosen because it was farther from the traffic disturbance, about 215 feet from the edge of the pavement to the nearest nest. Lead in the soil at different locations in the Effingham colony ranged from 25 to 52 parts per million (ppm) (average 34 ppm) and in the Ina colony from 19 to 22 ppm (average 20 ppm). Lead in eggs from both colonies was below the detect- able level. At both colonies adult birds flew away from the highway to forage for themselves and their nestlings; so there was little chance of contamination through food. The nesting success at the two colonies indicates how tolerant this species is of human traffic. No unusual amount of nest desertion occurred at either colony even during heavy surges of traffic on weekends and on Memorial Day. Clutch size was similar at the two colonies, an average of 4.6 eggs per nest at Effingham and 4.5 per nest at Ina. A remarkably high percentage of nests produced young — 64 percent (45 per- cent of eggs) at Effingham and 75 percent (48 percent of eggs) at Ina. By compari- son, success (of eggs) was only 8 to 17 percent in different years at a colony studied by other researchers, and success rates for other open-cup nesters (brown thrasher and catbird) in southern Illinois ranged from 29 to 42 percent. Further study of birds nesting near inter- state highways is warranted as a measure of things to come, as unfortunately, the interstate fauna may be the predominant fauna of the future. Now, however, there are far more pressing conservation prob- lems; for example, declining bird popula- tions (herons) and declining habitats (bottomland forest, grassland, and marsh ) that deserve priority in studies. Automated Chemical Analyses To determine tolerances and environ- mental requirements of aquatic organisms, the Survey’s analytical chemistry labora- tory performs analyses to evaluate more than 50 water quality parameters. The instruments in this laboratory are capable of analyzing water samples for principal nutrients, major components of organic and inorganic pollution, and mass ion bal- Automated system for organic nitrogen analysis. The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 ance. To maximize the efficiency of the laboratory staff while maintaining a high level of precision and accuracy, laboratory instruments are automated wherever pos- sible so that large volumes of water-quality data are obtained quickly and easily. In many instances this sophisticated instru- mentation includes a computerized print- out for rapid calculation and tabulation of data. The staff members of this laboratory, in addition to working on their own research projects, are able to coordinate water- quality surveillance work for the entire Survey and perform analyses required for ongoing research projects. These research projects include: (1) water quality moni- toring in the Lake Shelbyville basin, (2) the monitoring of water quality in the Survey’s experimental ponds at Urbana, (3) determining the effects of land use upon water quality, (4) investigating the effects of thermal discharges from a coal- fired generating plant on the water quality of a 2,100-acre reservoir in central Illinois, and (5) studying watersheds to develop meaningful environmental-impact analyses. One of the areas in which changes in environmental quality can have pro- nounced effects involves aquatic ecosys- tems. The close interrelationships between aquatic organisms and the quality of their environment have made these ecosystems the subjects of intensive study by the Sur- vey staff. Recently, Survey scientists began a cooperative multidisciplinary research agreement with the U.S. Department of Agriculture, Soil Conservation Service, to study seven selected watersheds in central and southern Illinois. Water quality and — biological studies are necessary for mean- ingful environmental-impact analysis. One of the major outcomes of this multi- disciplinary cooperative research effort is to be the description of the environmental requirements of aquatic macroinverte- brates, such as midges, crayfish, caddisflies, and stoneflies. Water quality conditions vary in the watersheds under investigation from good to extremely degraded. Staff members will be able to update aquatic invertebrate distribution records within the state, and with the detailed knowledge of over 25 water-quality parameters, includ- ing, in many instances, nutrient concentra- tions, heavy metal levels, dissolved oxygen concentrations, and substrate composition, will begin to quantify the factors governing the distribution and abundance of aquatic macroinvertebrates in IIlinois. September 1976. No. 159. Published monthly except in July and August by the Natural History Survey, a division of the state Department of Registration and Education, operating under sources and Conservation. the Board of Natural Re- Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinovs NATURAL HISTORY REPORTS What’s In a Name Every Illinois resident probably has or will have a problem with insects some- time during his or her lifetime. The prob- lem may be simple curiosity about an un- usual beetle or caterpillar found in the backyard. Frequently it is related to the destruction of crops, clothing, and forestry products. Diseases, such as encephalitis, remind us that some insects are important medically. One question asked about the suspected insect in nearly all cases is, What is it?” The Illinois Natural History Survey em- ploys several persons who are trained to help answer questions of this type. They are the insect taxonomists (not taxiderm- ists) of the Section of Faunistic Surveys and Insect Identification. These specialists identify insects and work closely with the extension entomologists to help diagnose insect problems. Once the problem-causing insect is accurately identified, the need for controlling the pest and the best control be ascertained and chances of successful control are increased. There are thousands of different kinds measures may the of insects in Illinois. Each insect tax- onomist on the Survey staff, by necessity, studies the classification of and identifies only certain insect groups to insure that Illinois residents are provided accurate an- swers to their questions. One large, com- mon group, the butterflies moths, is studied by George L. Because it is the caterpillars of these in- sects that create the biggest worry to the general public, insect and Godfrey. Godfrey is continually familiarizing himself with the different kinds of caterpillars. Police officers occasionally rely on den- tal characteristics to identify deceased vic- tims of crimes and accidents. Similarly, many kinds of caterpillars are identified on the basis of certain characteristics of their mandibles. Other clues used to help iden- tify caterpillars include color patterns, type of damage caused to a plant, choice of foodplant, and occasionally even odor! Like other Survey taxonomists, Godfrey's summer laboratory includes the croplands, forested river galleries and prairie sites in Illinois. Using special collecting equipment and lights he does much of his work at night when many moths and caterpillars are most active. Information gathered from Caterpillar of Ceriera borealis (Boisduval) on wild cherry (photo by Survey photographer Larry Farlow). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. this work eventually is made available to the public in the form of service identifica- tions, published reports on the classifica- tion and life histories of moths, or talks to school groups. Not all taxonomic research is designed to support control programs directly. Knowing what an animal is not, can be as important as knowing what it is. There- fore, we must learn as much as _ possible about all insects whether or not they are pests at present. Sometimes the work useful in conserving and protecting rarer species that are unique to certain eco- logical areas. Recently Godfrey has been locating small populations of an uncom- mon and unnamed noctuid moth that feeds exclusively on horse gentian (J riosteum). Godfrey is now raising horse gentian in his own back yard with hopes of establishing a colony of the moth so that more can be learned about it. What Whiteflies See Whiteflies are small plant-sucking in- sects. They frequently build up large popu- lations on many field crops, vegetables and ornamental plants. In Illinois they may be found on tomatoes and other plants in home gardens. Whiteflies are most dam- aging to plants in greenhouses but certain species can be found on field crops such as soybeans. One of the most common species — the greenhouse whitefly, T7zaleurodes va- porariorum — was studied by Survey ento- mologists and a research assistant from India, S. M. Vaishampayan as part of his Ph.D. program at the University of Illinois. This whitefly displays strong attraction to yellow surfaces. Adult whiteflies could be trapped in large numbers on_ surfaces coated with a sticky substance if the sur- face transmitted or reflected light in the yellow-green region of the spectrum (520- 610 mm). Since the leaves of most green plants re- flect light in that same wavelength it was assumed that whiteflies used visual orienta- tion to find their host-plants. ‘This hy- pothesis was tested using leaves of different plants sandwiched between layers of trans- parent glass plates. The whiteflies could “see” the leaf and detect its color but they could not sense the odor of the leaves. Tests were conducted with leaves and bracts of poinsettia — the common Christ- mas plant. Red or white bracts of poin- settia support the growth of whiteflies just as well as the green leaves. However, when offered a choice of glass-sandwiched leaves and bracts of poinsettia the great majority of the whiteflies were trapped on the green leaves. They responded to the yellow- green light reflected by the leaves. If, a yel- low filter backed a white bract, however, the bract would be more attractive than the green leaf, because the “amount” of ‘yellow was greater in this combination of white bract and yellow filter than in the green leaf. The response of the greenhouse white- fly and many other insects to yellow light may have some practical applications. Spe- cial yellow dyes could be mixed with in- secticides to assure the contact of the in-_ sect with the toxic substance. Researchers have found that certain yellow oils in mix- ture with pyrethrum sprays almost doubled the effectiveness and persistence of the treatment. The use of yellow traps could also be considered in the detection and control of whiteflies, particularly in green- houses where they are extremely difficult to control. In this case the yellow traps would be coated with a contact insecticide or simply with a sticky substance. The de- sign and effectiveness of these yellow traps have not been investigated as yet. Genetic Engineering of Largemouth Bass Many unique thermal environments have been created by the effluents from electric power generating plants. Since these environments are of recent origin, populations of fish have not yet evolved which can efficiently utilize them. It is not realistic to expect to find natural popu- lations of fish preadapted to these recently created environments. Natural selective processes would probably require thousands of years to produce fish populations well adapted to these distinctive new environ- ments. Consequently, to permit the most efficient utilization of these new environ- ments, populations of fish need to be cre- ated through genetic engineering. William F. Childers of the Natural His- tory Survey and Gregory S. Whitt of the University of Illinois are investigating the biochemical genetics of largemouth bass, Micropterus salmoides. They are beginning a study of the degree and type of genetic biochemical variation among populations of largemouth bass currently existing in different thermal environments within the United States. New methods for deter- mining biochemical differences between bass populations are proving to be particu- larly powerful probes in this study. The separation of specific chemicals in a starch gel medium by use of strong elec- trical currents is one such method. Starch gel electrophoretic analyses of enzyme vari- ants for enzymes encoded in a total of 25 genetic loci will be used to detect allelic variants associated with specific thermal environments. The investigators will then conduct kinetic analyses of specific puri- fied allelic isozymes to determine the ex- tent that the genetic alteration of these en- zymes directly or indirectly contributes to the thermal tolerance of individual bass. Preliminary data have revealed that a striking north-south clinal distribution ex- ists for two different alleles at the B locus of malate dehydrogenase (MDH). The predominance of an enzyme phenotype in a particular thermal environment and the demonstration of its high kinetic efficiency at the corresponding temperatures would be persuasive evidence of the involvement of the enzyme phenotype in controlling the Large-mouth bass (Microp- terus salmoides) (photo by W. F. Childers). thermal fitness of bass. This thermal kinetic relationship has already been clearly dem- onstrated for other enzyme systems in other species of fishes. This concept is readily testable and applicable to popula- tions of largemouth bass in thermal lakes. Once the genetic markers associated with temperature tolerance have been identified and characterized, recommendations will be made indicating the most efficient means of producing populations of large- mouth bass which could most efficiently utilize the new thermal habitats. Waterfowl Power Line Collisions An unusual opportunity for studying collisions of waterfowl with power lines presented itself in the fall of 1973 when wildlife biologist William L. Anderson and several other Survey personnel initiated a 4-year chemical and biological investi- gation at the Lake Sangchris-Kincaid Power plant complex. A diked area, called the slag pit, located immediately northeast of the power plant, contains 32 hectares of water surface and is traversed by two high- voltage transmission lines. Large numbers of waterfowl are attracted to the slag pit each autumn and collisions with the power lines are commonplace. Dead and crippled birds are relatively easy to find because they tend to remain in the confines of the slag pit’s steep-sided dikes. A total of 453 waterfowl were found dead or crippled in the slag pit from Sep- tember to December 1973, 1974, and 1975. Autopsies of 230 of these birds indicated that 75.7 percent (343 birds) had broken wings, lacerations on the anterior of the The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 breast or head, or other injuries probably sustained by collisions with the power lines. The remaining birds had been shot, were victims of lead poisoning, or had died of or been injured by undetermined causes. The 343 waterfowl known to have col- lided with the power lines, combined with a recovery rate of 57.5 percent for mal- lards dead or with broken wings — planted in the slag pit, suggest that about 200 ducks, geese, and coots succumb to the lines at the slag pit between 1 September and 15 December each year. Anderson be- lieves that another 200 waterfowl are lost to the power lines at the three points where the lines cross Lake Sangchris. hus, mor- tality of waterfowl due to collisions with power lines at the Lake Sangchris-Kincaid Power Plant complex could total about 400 birds (0.4 percent of the number pres- ent at the peak of migration) each fall- winter period. Anderson recognized five factors that influence the frequency of waterfowl col- lisions with the power lines at the slag pit. First, the number of birds present was im- portant. A direct correlation existed be- tween the number of birds found dead or crippled and the number present. Second, observations revealed that waterfowl al- most never collide with the power lines during daylight hours. Thus, most of the birds found dead or crippled must have collided with the lines during the night time, when weather was adverse, or under other conditions of poor visibility. Third, additional observations implicate disturb- ance as a factor. Birds startled into flight or otherwise excited frequently hit the lines. Fourth, the species present and their — behavior was a factor. The numbers of casualties attributed to the power lines per 1,000 bird-days of use of the slag pit were 0.44 for blue-winged teals and 0.30 for coots, but only 0.03 for mallards and 0.16 for all other species combined. Fifth, An- derson acquired the impression that power- line casualties increased with influxes of new birds, thus, familiarity of birds with the area seems to be a factor. To minimize losses of waterfowl] via col- lisions with power lines, Anderson recom- mends that lines not be built over water unless alternate routes do not exist; lines should not cross areas where waterfowl concentrate or are likely to concentrate; visibility of lines in problem areas should be enhanced; and waterfowl should not be disturbed in the immediate vicinity of power lines. October 1976. No. 160. Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E, LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL SURVEY Hello, World! Bass Number 2 Calling Radio tracking of largemouth bass in Lake Shelbyville was initiated in July 1975 by aquatic biologists R. Weldon Larimore and Donald W. Dufford. They are study- ing the effects of fluctuating water levels on largemouth bass movements and habitat preference. Miniature radio transmitters developed by William Cochran, a Survey wildlife biologist, were surgically implanted in the body cavities of 21 largemouth bass during 1975 and 1976. All of these fish were re- leased at the point of capture following a short recovery period. Tracking from a boat equipped with a large antenna and a receiver was con- ducted by Dufford weekly on a Monday- Wednesday-Friday schedule when possible. When a fish was located, its position was determined by triangulation, and the re- searchers attempted to get as close as pos- sible to the fish to determine habitat char- acteristics. Location, time, type of habitat, transmitter frequency and pulse rate, esti- mated depth of the fish, air and water temperature, sky condition, and wind di- rection and approximate velocity were re- corded. The depth of a fish was determined by comparing the maximum distance at which each signal could be received with known signal attenuation for known depths. The daily minimum distance traveled by each fish was calculated by marking suc- cessive locations on a map and measuring the shortest possible distance via water between locations. Range was measured as the minimum distance via water between HISTORY the two extreme points. The total mini- mum distance traveled by each fish was the sum of all of the daily minimum dis- tances. Fish number 2, a 1,165-gram male, trav- eled a minimum distance of 3,135 meters in 33 minutes when released near the point of capture, or 3.6 times its total length per second for 33 minutes at a water tempera- ture of 25°C. A review of the literature suggested that largemouth bass weighing less than 200 grams should be able to maintain a speed of approximately 2.5 total lengths per second for 25 minutes at DIAC The maximum movement was made by a 1,495-gram female that moved a total (Top) Miniature radio transmitter about 55 mm long, including antenna. (Bottom) Transmitter, covered with protective material, being inserted into the body cavity of an anesthetized largemouth bass. (Photos by John Tranquilli) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. minimum distance of 30,478 meters be- tween 28 April 1976 and 21 July 1976 over - a maximum range of 16,733 meters. This is an average daily movement of 362.8 meters. The entire maximum range and 22,786 meters of the total minimum dis- tance was traveled from 25 June to 21 July 1976. The average daily movement during this 27-day period was 843.9 meters. The minimum average daily movement was made by a 1,030-gram male with an average daily movement of 15.0 meters over a 52-day period. The minimum range was covered by a 900-gram female that moved over a range of 221 meters in 31 days before being removed from the lake by a fisherman. . None of the six fish with radios im- planted in 1975 was captured by fishermen. Thirteen of the fifteen bass with radios implanted in 1976 were captured by fisher- men. Two fish were captured three times each and two fish were captured two times each, making a total of nineteen captures by fishermen. Five of the nineteen cap- tured fish were moved considerable dis- tances by the fishermen and then released. None of these fish showed any indication of homing, or returning to the point of capture. Eight of the nineteen captured fish were released in the same area where captured. Seven of these remained in the immediate area, and one moved a mini- mum distance of 3,425 meters in a max- imum of 20 hours. ‘The remaining six cap- tured fish were removed from the lake by the fishermen. Three of the thirteen re- leased bass died, probably as the result of being hooked by fishermen, 19, 20, and 21 days after being caught. Because so many of these fish have been captured and re- captured, it is clear that the radios do not prevent the fish from feeding or taking anglers’ hooks. Zine Toxicity Around Smelters Zinc toxicity is rare in nature and is limited to the vicinities of mines and smel- ters. Vegetation surveys conducted by wild- life specialist William Edwards in the vi- cinities of zinc smelters near Sandoval and Beckmeyer, Illinois, suggest that the flora there has been extensively modified directly and indirectly by zinc pollution. Much of the woody vegetation near the zinc smelters in south-central Illinois ap- pears stunted and twisted. Soils near the plants evidence severe erosion and are increasingly devoid of vegetation as the smelters are approached. Zinc is an essential constituent of sev- eral metaloenzymes and thus is essential to plant growth and metabolism. The zinc requirements of seed plants are in the gen- eral range of 0.02 to 0.20 parts per million (ppm). Other researchers have observed that plants take up zinc from the soil and that the zinc content of plants is affected by zinc levels in the soil. Others have found that zinc toxicity in plants is shown by retardation of growth, sometimes induces iron chlorosis, and affects photosynthesis but not respiration. Zinc in concentrations of 1 to 100 ppm has been found to be moderately toxic to plants. Edwards notes that it is not possible to understand the implications of zinc pollution on faunal and floral communities without some knowledge of the distribution of that element through the soil profile and, particularly, through the surface soils. Preliminary examination of data on zinc pollution of surface soils in the vicinity of a smelter near Sandoval suggests several points: Zinc tends to be concentrated in soil materials deposited along streams draining the smelter site. High levels of zinc were found in stream bed deposits as far as 3 miles from the smelter. High levels of zinc are found in surface soils near the smelter. Zinc concentrations decrease as distance from the smelter in- creases. No agricultural crops are being grown closer than 300 meters from the smelter complex. Levels of zinc are considerably lower in agricultural fields than they are in adjacent noncropped areas. This pattern is not fully explainable by the distribution of zinc from the smelter. It is possible that the lower zinc levels in cropland soils reflect the re- placement of crop-absorbed zinc by cal- Sparse, stunted vegetation near a zinc smelter in south-central Illinois. (Photo by Survey photographer Larry Farlow) cium or other fertilizer elements and, per- haps, the removal of zinc by the crops. Analyses of plant tissues for zinc content should shed some light on this point. It also appears that on noncropped areas zinc levels are somewhat higher un- der perennial plants than they are under adjacent annual plants. This difference may reflect the reduced erosion of soils associated with perennial plants. Erosion generally increases as the distance from the smelter decreases. Edwards plans to continue his investi- gations to determine to what extent and in what ways zinc concentrations in soils af- fect plants and wildlife. Predicting Black Cutworm Development A number of researchers from such widely separated parts of the world as the USSR, Israel, Canada, Japan, and else- where have reported on the biology and development of the black cutworm, Agrotis ipsilon (Hufnagel). This insect does a great deal of damage to corn in the United States. However, little is known about its early season occurrence, and no criteria are available for predicting rates of infes- tation and damage. Survey economic ento- mologists W. H. Luckmann, J. T. Shaw, D. W. Sherrod, and W. G. Ruesink con- ducted experiments to determine the rate of development and the developmental threshold of the black cutworm. They then compared and combined their data with data previously published to calculate tem- perature guidelines that would be useful in predicting the field development of this pest. The entomologists gathered eggs newly laid by black cutworm adults that had been collected in fields near Urbana- Champaign. The eggs were individually placed in containers of pinto-bean diet and were incubated in controlled environ- mental cabinets at 18.3°, 21.1°, 23.9°, 26.7°, and 29.4° C. When the eggs hatched, each newly emerged larva was placed in a diet cup and incubated at the same tem- perature as that at which the egg had The Illinots NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 been incubated. Daily records of growth and development were obtained for each larva. These data were brought together, and the cumulative number of days required for 50 percent of each black cutworm group to reach a given developmental stage was determined for each temperature. The black cutworm goes through six (and oc- casionally seven) molt stages and a pupa stage before the adult insect emerges. Us- ing these data, the entomologists deter- mined a theoretical developmental thresh- old temperature for each growth stage. Such a temperature is the minimum tem- perature at which development from one stage to another occurs. Their calculated average developmental threshold tempera- ture for the black cutworm is 10.4° C. As a means of presenting their findings in a manner useful to agriculturists, the researchers converted their data to centi- grade degree-days. One centigrade degree- day is accumulated when the mean daily -temperature is 1 degree above a specified threshold temperature. Using 10.4° C as the developmental threshold, the entomol- ogists computed the number of degree- days required for an individual cutworm to reach a given life stage, and then they determined the range and median number of centigrade degree-days needed for the development of each life stage. In every step along the way, their findings agreed closely with those of other researchers who had published data similar though not as complete. These data can be used in field predic- tion and research. A researcher can take field-collected black cutworm larvae and, by determining the number of accumulated degree-days for the collection site, can ob- tain a good indication of the date of egg laying of the new generation of black cut- worms and the dates when each stage of development will be reached. November 1976, No, 161, Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinois NATURAL Sulfur Licks or Salt Licks? In a forthcoming book, “The Biogeo- chemistry of Blue, Snow and Ross’ Geese,” soon to be released by the Southern Illinois University Press, Carbondale, the authors, Survey wildlife biologist Harold C. Hanson and Robert L. Jones of the University of Illinois Department of Agronomy, have appended a chapter on the relevance of sulfur in the ecosystem. In brief their dis- cussion relates higher productivity of plants and animals (biomass) to relatively higher levels of sulfates in natural environments. Previous experimental research also indi- cates this relationship, but a close associa- tion has never been postulated. While preparing the sulfur chapter for their book, Hanson and Jones questioned the chemical nature of mineral or salt licks used by deer and other ungulate big game animals. Not too surprisingly, it was found that sulfur or sulfurous odors (hydrogen sulfide) was associated with licks that had been studied and reported in the literature. However, quantitative data on sulfur in licks has never been available. All atten- tion had been focused on the cations, par- ticularly calcium, sodium and phosphorus. HISTORY REPORTS But consideration of these cations and the trace elements failed to provide any consis- tent picture or rationale for the use of licks by big game animals. Completely overlooked has been the role of inorganic sulfur in providing bacteria, plants, fungi and the bacteria of the rumen of big game animals the necessary element to form the indispensable amino acids cysteine and methonine. This factor can be better appreciated when it is realized that the total amount of protein leaving the stomach of a deer is one and one-half to three times the amount ingested in the browse. The increment is synthesized by the bacteria of the rumen. If sulfur is in short supply the ungulates will obviously need to eat a larger amount of food to insure that a balanced amino acid mix will be available. The stimulated Hanson and Jones to solicit soil samples from mineral licks of big game on a continent-wide basis. As of November 15, about 180 samples have been received and 100 additional samples are expected. Find- ings will provide a better understanding of assessment of the role of sulfur big game population densities and also pro- Fig. 1. Mountain caribou at a mineral lick east of Prince George, British Columbia. (Photograph courtesy of K. K. Fugino, British Columbia De- partment of Recreation and Travel Industry) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. vide the basis for the development of an idealized salt block for use on big game ranges as well as for domestic livestock. A few examples of returns from this continental search are given below in order to indicate the type of response received by Hanson and Jones. From Quebec: “...in the above two licks mentioned, the odor of rotting eggs (H.S) is very evident . . . there are over fifty known licks in the Matane Preserve — this region, approximately 100-125 square miles, has one of the highest population densities of moose in Quebec.” From Michigan: “For what it’s worth, the air around some of the Isle Royale licks smells ‘sulfurous’.” From Virginia: “The information con- tained in your letter explains the observa- tions we have made of the heavy use by deer of sulfur springs here in the moun- tains.” Cocoons, Parasites, and Insecticides The alfalfa weevil is the most important alfalfa pest in Illinois. One of the methods of managing populations of this pest is to protect parasites such as Bathyplectis cur- culionis (a wasp which parasitizes the lar- vae of the alfalfa weevil). In pest control the application of insecticides to alfalfa can affect both the pest and its parasites. These small hymenopterous parasites spin small sliken cocoons within which the pupal stage is passed, or within which the insect enters into an inactive state called diapause in order to overwinter. Reports in the liter- ature have suggested that application of insecticides in the fall and/or spring have no apparent effect on the diapausing B. curculionis. Survey entomologists D. P. Bartell, J. R. Sanborn, and K. A. Wood have investi- gated the effects of direct treatment of cocoons of diapausing and nondiapausing B. curculionis with several insecticides (carbofuran, methoxychlor, methyl para- thion, Imidan and radioactive carbofuran ) to determine if cocoons were susceptible to insecticide penetration. Cocoons of diapausing individuals were impervious to all materials and dosages tested. Cocoons of nondiapausing individ- uals did not inhibit penetration of lethal dosages of any insecticide or dosage used. This work indicates that insecticides may cause significant mortality of nondiapaus- ing B. curculionis individuals in the field and supports the observations that applica- tions of insecticides in the fall or spring does not affect the diapausing individuals. Fortunately, most of the parasites are the diapausing strain, so fall and early spring applications of insecticides have little im- pact on B. curculionis. It has been ob- served that diapausing individuals require more time to spin their cocoons than do the nondiapausing individuals. The addi- ‘tional spinning time evidently results in a cocoon which effectively inhibits insecticide penetration. Interesting questions are raised by these results, such as: (1) what influence the physiological state of the parasite has on penetration; (2) how time (newly formed cocoons vs. older cocoons) affects the ability- of the cocoon to inhibit insecticide pene- tration; (3) whether or not the suscepti- bility of nondiapausing cocoons prevails under field conditions. Questions such as these need to be answered to determine the impact of insecticides on populations of B. curculionis and illustrates the impor- tance of intelligent use of insecticides in alfalfa pest management schemes. Stoneroller Populations Among the 55 native species of minnows in Illinois there are two superficially simi- lar and often captured together, even in the same seine haul. The taxonomic and distributional status of these two stone- rollers, so-called because of their habit of turning stones while scraping off algae for food, was the subject of a study recently published in a technical journal by Survey ichthyologists B. M. Burr and P. W. Smith. Copies of this publication may be obtained free by writing to the Chief, Illinois Natu- ral History Survey. The largescale stoneroller, Campostoma oligolepis, was found to differ from the more abundant common stoneroller, Cam- postoma anomalum, in several important ba nf yee 4) ARE y Jeet BREN WLS oy acne morphological features. Chief among these were countable characters such as number of scales around the body, number of gill rakers, and differences in breeding colora- tion and tubercle pattern. Prior to this study, the largescale stoneroller was known only from Wisconsin and the Ozarks of Missouri and Arkansas, but it is now known to occur, or to have once occurred, in parts of Illinois, Iowa, and Minnesota as well. The common stoneroller, on the other hand, is widely distributed in central United States. Although the two species are often found together, the common stoneroller is by far the more abundant and widespread species in Illinois. However, this has not always been the case. Reidentification of the speci- mens Stephen A. Forbes and his associates collected prior to 1908 revealed a much wider distribution for the largescale stone- roller than that indicated by a recent ich- thyological survey of Illinois. In fact, the largescale stoneroller was often the only species present in the old collections or was by far the more abundant of the two species. The rather drastic change in the range of this Illinois fish species is similar to what has been found for other fishes in Illinois, Iowa, and Ohio. The decimation of these native populations is presumed to be the result of siltation, general stream me es Fig. 2. The largescale stone- roller (upper) and the com- mon stoneroller. (Drawings by Mrs. Alice Ann Prickett) deterioration, and also in the case of the largescale stoneroller the construction of reservoirs on rivers where it was formerly common. The largescale stoneroller is still common in the Ozarks where agriculture has had less effect upon streams. The com- mon stoneroller is more ecologically toler- ant and is still common in the [Illinois streams it once shared with the largescale stoneroller. Watershed Ecology During June 1975 the Illinois Natural History Survey began a series of investiga- tions of selected Illinois watersheds as coop- erative studies with the U.S. Department of Agriculture, Soil Conservation Service. The purpose of these studies is to provide basic information regarding the aquatic and riparian animals and to determine the physical, chemical, and bacteriological quality of the surface water of each water- shed. These data are needed by the Soil Conservation Service for the planning and implementation of water resource develop- ment projects. Typical watershed projects include land treatment measures to reduce soil loss by erosion, stream channel im- provements, and structural measures such as flood-water retarding structures and multiple-purpose (flood prevention, water supply, and recreation) impoundments. Because of the multidisciplinary nature of The Illinots NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 these studies, a research team from two sections was assembled: L. M. Page, P. W. Smith, and J. D. Unzicker and D. W. Webb of the Section of Faunistic Surveys and Insect Identification and A. R. Brig- ham and W. U. Brigham (Project Coor- dinator) of the Section of Aquatic Biology. Work has been completed on three of the six watershed studies and work is un- derway on the remaining three of the original study. Results of the faunistic in- ventory of Bay Creek in southern Illinois indicated a diverse community of inverte- brates, fishes, amphibians, and reptiles. An unusual population of the cypress darter, Etheostoma proeliare, was discovered in Max Creek, a tributary of Bay Creek and the site of a proposed impoundment. Be- cause of the threatened status of this fish, the Survey recommended additional study to determine the status of this species in Illinois and to examine particularly the utilization of Max Creek by these fishes. Additional funding has been received and this new study is underway. Subsequent sampling in Max Creek has revealed the presence of yet another threatened species, the spring cavefish, Chologaster agassizt. Little Cache Creek and Dutchman Creek, also in southern Illinois, were in- vestigated physically, chemically, and bio- logically. Water quality was found to be poor, mostly due to the poor quality of wastewater treatment in Vienna. A newly created recreational impoundment in the headwaters of Dutchman Creek, however, was found to be free from pollution. Faun- istic investigation did not reveal the pres- ence of threatened or endangered animals which would be affected adversely by the - proposed channel improvement project. Rather, it is felt that the proposed modifi- cations would increase significantly habitat diversity and environmental quality and would benefit the aquatic community in the stream. Since its inception, four additional proj- ects have been added to this cooperative investigation: the study of the cypress darter mentioned above, a fishery and lower vertebrate inventory of Coal and Crane Creeks in west-central Illinois, a faunistic inventory of Sevenmile Creek in southeastern Illinois, and a physical, chem- ical, and biological inventory of the North Fork of the Embarras River in east-central Illinois. Studies such as these fulfill a prin- cipal function of the Survey: The conduct of research in methods of utilizing and pre- serving the renewable natural resources of Illinois. December 1976. No. 162. Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL HISTORY REPORTS Aquatic Lawnmowers habitats, yet they have been one of the Since the invention of the microscope, Aa aed BODES Bs Liscis 288 eae one group of aquatic microorganisms has streams. From the arctic i the tropics, been the object of study by both amateur these animals are common in the largest Rants. : ahs . : lakes and the smallest rain puddles, and, and professional biologists. Little known : eae ts ALFA. FF being one of the few groups originating feemest people, these creatures, called |" © - “¢ . smug aL ts - from fresh water, they have become rotifers, are a major constituent of the aah By: BE pb =f tS sol . abundant and diversified. freshwater zooplankton, providing an im- : ; i 3a ee aay, wh Current studies by Survey invertebrate portant link in aquatic food chains. Ronn ce ie Wa; i. are : : . zoologist Stephen Waite are investigations Members of the phylum Rotatoria, roti- eT eaS : ie ce 5 { CE a distrey. : i of (1) the taxonomy of rotifers in central fers are the single taxonomic category ei: é ; ’ ethage ci ct - 1 ~~, and southern Illinois reservoirs and (2) most characteristic of all inland freshwate1 : : the importance of these tiny animals as Two rotifers common to central Illinois reservoirs (left) Platyias quadricornis and (right) Brachionus quad- ridentatus with egg. These organisms are about 0.3 mm long, but the majority of rotifer species range from 0.04 mm to 2.5 mm (1/1000 to 1/100 inch). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey fish-food organisms in a lake receiving thermal effluents (Lake Sangchris). Eco- logically, rotifers function as aquatic graz- ers (similar to cattle grazing in a pasture) ; like lawnmowers, they keep the aquatic grasses (algae) mowed and, in turn, pro- vide a substantial energy source for larval fishes. Preliminary data from Lake Sang- chris reveal that a substantial rise of fish- food energy in May and June may have been beneficial to larval shad and sunfish, which feed primarily on zooplankters dur- ing most of their early life. Thermal effluents also affect rotifer re- production in Lake Sangchris. During most of the year, most females produce eggs which develop without fertilization into young females. At certain times, in re- sponse to adverse environmental condi- tions, these eggs develop into females which eventually produce eggs that can be fer- tilized. Some of these eggs develop into males. Others are fertilized by these males and become resting eggs, which remain dormant for a time before hatching. Some evidence exists of resting egg production during the summer at Lake Sangchris when water temperatures exceeded those of nearby reservoirs. In addition to studies of the taxonomy and ecology of rotifers, various other phases of their existence present interesting problems for research. All species lack cell reproduction and thus lack the capacity to repair injuries. The processes which de- termine whether eggs can or cannot be fertilized are still not understood. The ability of rotifers to survive desiccation poses problems in the physiology of reduced metabolism. Some species can survive 3 to 4 years in dry conditions, and when water becomes available, they become active in a few minutes. The development of mech- anisms providing resistance to desicca- tion has permitted some species to become semi-terrestrial, living in mosses, lichens, and tree bark. Cell Walls Broken Down By Plant Physiologist Claus Grunwald, Survey plant physiol- ogist, hasn’t been in jail, but he is in- terested in cells. The cell, often referred to as the building block of plants and animals, is surrounded by a plasma or membrane. This membrane is the living outer bound- ary of all cells. Plant cells, however, gen- erally have an additional wall outside of the cell membrane which gives support to the cell and the organism. Living cells generally contain a number of organelles, such as chloroplasts and mitochondria, usually also bound by a membrane. Plasma and organelle membranes are not easily seen under the light microscope, but the electron microscope usually reveals a dou- ble-layered structure, as shown in the pic- ture. It is generally accepted that the double-layered appearance is caused by a ‘bimolecular layer of lipids sandwiched be- tween two protein layers, and this is re- ferred to simply as the “bimolecular leaflet model.” Basically, plant membranes, like mem- branes of other organisms, are composed of lipids and proteins; however, exact chemical characterization is often diffi-. cult because of contaminating components. Because of the importance of membranes in the bioenergetics and development of plants, plant physiologists in recent years have become interested in the lipid physi- ology of membranes. Grunwald has turned his attention to the sterol component of plant membranes. Sterols are classified as lipids and are an important constituent of membranes. Cholesterol is the sterol component of mammalian membranes; however, in plant membranes a number of sterols are-found, all closely related in chemical structure to cholesterol. Cholesterol has been found as a membrane component in a number of plant species, but the most commonly found sterols in plant membranes are sito- sterol, stigmasterol, and campesterol. One important function of a membrane is its semipermeability; i.e., it permits the passage of some molecules but not others. It has been found that sterols serve an important function in controlling perme- ability, and if this lipid component is ex- perimentally removed from membranes, the membranes become leaky. The various plant sterols differ in structure only Vy Nae nat Sn rs ~ +S Electron micrograph of specially prepared chloroplasis. The membrane structure is clearly visible. The line at the lower left-center represents a micron, equal to one thousandth of a millimeter, or about 0.000039 inch. slightly, but it has been shown that these small differences have definite effects on membrane behavior. The qualitative and quantitative sterol makeup of plant membranes is controlled by environmental factors, such as light and photooxidants. Grunwald has studies un- der way to correlate changes in sterol composition with plant aging as_ this process is influenced by light intensity and photoperiod. Flight Characteristics of Ducks Different species of ducks exhibit dif- ferent characteristics of flight speed, wing beat, and wing arc. In an effort to dis- cover the underlying reasons for these differences, wildlife specialist Frank Bell- rose has been studying the wing conforma- tion and wing load of several species of ducks that have distinctive flight behavior. The area of the wing surface was ob- tained by age and sex classes for almost 200 individuals of five species: mallard, black duck, gadwall, wood duck, and can- vasback. The weights by age and sex class of many thousands of ducks have been published previously. A comparison of the surface area of the wing with the weight provides data on the wing load. The wing loads for these species are: mallard, 1.49 grams per square centimeter; black duck, 1.31:1; gadwall, 1.35:1; wood duck, 1.23: 1; and canvasback, 2.09: 1. Thus, among the five species studied, the wood duck has the lowest wing load and the canvasback, the greatest. The canvas- back has the shortest, narrowest wing in this group of species. Field observations indicate that the canvasback flies the fast- est and has the most rapid wing stroke. On the other hand, the wood duck is slower than other species but is more adept at quickly altering its line of flight. A comparison of the length to the breadth of the wing for the five species re- veals that wings of all but the canvasback are at least-half as wide as they are long. The wing of the canvasback is 42 percent as wide as it is long; the wood duck’s wing, at the other extreme, is 56 percent as wide as it is long. The next step in studying the aerody- namics of waterfowl flight will be to use motion pictures of ducks in flight to deter- mine the wing beat and depth of wing stroke in relation to the wing load and other wing characteristics. More Knowledge Needed About Insect Pests According to entomologists Gilbert Waldbauer, University of Illinois, and Marcos Kogan, Illinois Natural History Survey, a great deal of fundamental bi- ological information is still needed about insect pests of agricultural crops. In de- fending this point of view, the entomol- The Illinots NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 ogists examined bean leaf beetles of the genus Cerotoma in relation to the soybean crop and the ecosystem of which the soy- bean crop is a part. Studies of the species Cerotoma trifur- cata are under way at Louisiana State Uni- versity, the University of Illinois, and the Illinois Natural History Survey, but the most recent comprehensive studies of this insect were published 45 years ago. Wald- bauer and Kogan say that this situation is far from unique. “When we look at the literature of almost any pest, we find that our biological knowledge is not sufficient to provide a rational basis for deciding whether pest control is needed or choosing control tactics.” They emphasize, how- ever, that in the last few years much re- search has been done on basic insect bi- ology and on control tactics and strategies. The entomologists point out that the kinds of information needed about insect pests are (1) complete descriptions of the insect at all stages of development; (2) the host plants that the insect feeds upon or otherwise attacks; (3) biological character- istics, such as in what developmental stage and where the insect overwinters, when and where it lays eggs and how much January 1977. No. 163. Published monthly except time elapses between egg laying and hatch- ing, the duration of each developmental stage and where it occurs, and the num- ber of generations of the insect that are hatched in a given geographical region each year; (4) the patterns of the insect’s populations and geographical distribution: and (5) the nature of the damage caused by the insect. Early economic entomologists, Kogan and Waldbauer point out, generally agreed that workable insect controls must be based on a thorough knowledge of the biology of a pest. “This point of view was all but submerged by our reliance on synthetic organic insecticides. These are highly effi- cient killers of insects — a property which, unfortunately, we confused with efficient control of insect injury to crops. “We have now come more than full circle and, in espousing the concept of pest management, have recognized that eco- nomic entomology is really a form of ap- plied ecology. Obviously, we cannot make rational attempts to manipulate an agro- ecosystem for our benefit unless we have a thorough and sophisticated knowledge of the organisms in that ecosystem.” in July and August by the Natural History Survey, a divi sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation Prepared by Robert M. Zewadski with the collaboration of the Survey Staff Second-class postage paid at Urbana, Illinois Office of publication: 175 Natural Resources Building, Urbana Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR CHIEF, ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 The Illinois Of Clams and Ducks The Keokuk Pool is a 46-mile section of the main channel of the Mississippi River which is backed up behind a dam which extends across the Mississippi from Ham- ilton on the Illinois side to Keokuk on the lowa The Pool ereatest concentration of diving ducks in the Mis- side. hosts the WISCONSIN nf ASK Y 8 ureer R tg Bean MISSISSIPPI Rie Bex yi KENTUCKY-TENNESSEE-MISSISSIPPI G) Map showing the geographic areas used for analyses of Illinois populations of gray squirrels. The black dots indicate localities from which most of the speci- mens were collected within a river drainage. FEBRUARY 1977, NO. 164 sissippi Flyway during Spring and Fall migrations, and historically has been one of the most productive pools of the entire Upper Mississippi River in terms of game and commercial fishes. The heavy utiliza- tion of the Pool by ducks and the high production of fish are both based on an unusual abundance of benthic food organ- isms, primarily fingernail clams. Survey aquatic biologists Richard E. Sparks and Carl M. Thompson have been investigating the population dynamics of the benthic organisms since 1973. Their most recent samples, which were taken from a specially-rigged boat in October and November and through the ice in December, show that the fingernail clam populations are only 5-10 of what they were in the Fall and Winter last year. Not only are there fewer clams, but the remain- ing adult clams are small in size. Utiliza- tion of the Pool by diving ducks appears to have declined as a result of the reduction in the population of fingernail clams, upon which the ducks feed. Survey wildlife biol- Frank C._ Bellrose Robert Crompton have censused the waterfowl ogists and utilizing the Pool, in conjunction with the weekly aerial census of waterfowl in the state during the Spring and Fall migra- tions. The peak numbers of canvasbacks and lesser scaup ducks using two major clam beds in the Pool ranged from 212,000 to 244,000 in the period 1973-1975, but de- clined to 117,000 in 1976. The low clam populations appear to be related to an extremely low amount of water flowing in the river this year as a consequence of a drought in the Upper Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey Mississippi Basin. Since the volume of effluents discharged from cities and indus- tries is relatively constant from year to year, a reduction in river flow results in a reduction in waste dilution. The water quality requirements of fingernail clams are unknown, so that the specific factors responsible for the decline of the clam populations cannot be identified as yet. Richard Sparks and Kevin B. Anderson, a graduate research assistant from Western Illinois University, are currently conduct- ing bioassays with fingernail clams to iden- tify their water quality requirements. One beneficial effect of the drought, from an aesthetic point of view, is that the Mississippi is considerably clearer this year than it has been for a number of years, because of the reduction of runoff and the amount of sediment entering the river as a result of erosion. Sparks and Thompson are hopeful that the reduction in fingernail clam popula- tions is a temporary problem which will be alleviated when rainfall in the Upper Mississippi Basin returns to normal levels, and not a persistent problem such as the die-off of fingernail clams which occurred in the Illinois River in 1955. Fingernail clams have failed to recolonize the areas in the [linois River where they died out, and utilization of the river by diving ducks and the condition factor of bottom-feeding fish have declined as a result. Gray Squirrels in Illinois Mammalogists report the presence of two subspecies or races of gray squirrels, the southern subspecies (Sczwrus carolin- ensis Gmelin) and the northern subspecies (S. c. pennsylvanicus Ord), in Illinois. The northern and southern subspecies of gray squirrels differ in body size and pelage characteristics. The northern subspecies has (1) larger external and cranial dimen- sions, (2) a whitish-gray winter pelage with clear white patches behind the ears and definite ear tufts, in the northern portion of the range, and (3) a melanistic phase or various degrees of intergradation between gray and black phases often with reddish-brown coloration on the belly. However, controversy exists not only con- cerning the ranges of these two races of gray squirrels in Illinois, but also if there are enough differences between distant populations of gray squirrels to distinguish them as different subspecies or races. Wildlife researchers S. P. Havera and C. M. Nixon collected information from over 500 gray squirrel specimens from throughout Illinois in an attempt to define the geographic variation existing among Illinois gray squirrel populations in rela- tion to reference populations of the sup- posed northern subspecies from Wisconsin and southern subspecies from Kentucky, Tennessee, and Mississippi. Illinois speci- mens were examined from 12 of the river “systems shown in the figure. A series of cranial measurements, an indicator of body size, were used for the multivariate sta- tistical comparison of the various gray squirrel populations. Variations in pelage coloration and some electrophoretic anal- yses on blood and body tissues were also considered. The results of the study disclosed signifi- cant variations among Illinois gray squirrel populations. Although biochemical differ- ences among selected populations were not detected by electrophoresis, results from pelage and cranial investigations were similar. Instances of melanistic character- istics in pelage coloration were common in Wisconsin (A), and the upper Mississippi (B), Rock River (C), and upper Illinois (D) river basins. The cranial dimensions of the gray squirrels varied somewhat clin- ally in size from small in the south to large in the north. Northern Illinois gray squir- rels from the upper Mississippi (B) and the Rock River (C) areas statistically re- semble the northern (S. c. pennsylvanicus) reference specimens from southern and central Wisconsin (A). Gray squirrels from the upper Illinois (D) and lower Illinois (E) river systems statistically appear to be intermediate between the group consisting of the northern reference sample (A), the upper Mississippi River (B), and the Rock River (C), and specimens from the re- maining Illinois watersheds. From the results of this study, we believe that the gray squirrels in the upper Missis- sippi River (B), the Rock River (C), and Sampling fingernail clams from the bottom of the Mississippi River with a dredge. The muck is strained in the box to the right of the dredge. (Photo by Survey Photographer Larry Farlow.) the upper Illinois River (D) watersheds are most closely associated genetically with gray squirrels from southern and central Wisconsin (A) designated by taxonomists as the northern subspecies S$. c. pennsylvan- icus. An area of intergradation between the large specimens from the southern part of Illinois apparently occurs in the lower Illinois River drainage (E) and at the northern extremity of the middle Missis- sippi River (F). In the central and eastern portions of Illinois, the northern and southern IIlinois gray squirrel populations are separated by their scarcity or absence where suitable habitat does not occur in the heavily cul- tivated prairie areas of the Sangamon, Iroquois, Vermilion, and upper Illinois river systems. Gray squirrels from the re- maining Illinois drainages (F-M) more closely resemble the specimens from Ken- tucky, Tennessee, and Mississippi (N) known as the southern subspecies S$. c. carolinensis. The Measure of Diversity One measure of a community’s diversity is simply the number of species it contains. A major problem in ecological research dealing with species diversity of terrestrial soil invertebrates is the lack of accurate sampling techniques. Two basic methods have been used to sample invertebrates which wander freely over the soil surface (cursorial) : quadrat sampling and pitfall trapping. Quadrat sampling involves re- moval of all animals in a given surface area (e.g., one square meter). Pitfall trap- ping utilizes a container, such as a metal can, which is buried flush with the soil surface and traps animals moving over the ground. Quadrat sampling should provide an absolute density measure, but is influ- enced by the activity of animals during the brief span of time when the sample is taken. Results are also influenced by the presence of the investigator since many invertebrates are disturbed by his presence and move out of the sampling area. Pitfall trapping provides a continuous sample over time, but is influenced by the activity levels and movements of the animals. In a recent article Survey entomologist John Unzicker and George Uetz of the Department of Ecology, Ethology and Evolution of the University of Illinois, compared quadrat sampling and _ pitfall trapping in order to determine the effec- tiveness of each method. They surveyed the scientific literature for studies of a wide range of communities using both quadrats and pitfalls and used this data in addition to data from two separate The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 studies of their own of deciduous forest litter spiders (an Oak-Hickory forest in Illinois and an Oak-Tulip-Maple forest in Delaware) to compare the methods. As- suming that the two methods together sample the total number of species in an area, one can evaluate the estimates made by each method alone. The total number of species taken was compared with the number collected by each method. The pitfall trapping results are highly corre- lated, whereas the quadrat sampling re- sults show a nonlinear relationship with the total number of species. The quadrat technique adds very few species to a com- munity list beyond those compiled by pit- fall trapping alone. In almost all cases there were a larger number of species ab- sent from quadrat samples and present in pitfalls than vice versa. Moreover, quadrat sampling does not sample a constant frac- tion of species present, but takes a dispro- portionately larger fraction in more diverse communities. These data suggest that pit- fall trapping gives a closer estimate of the total species in a community, and would be more useful in studies of species diversity. Whether or not either method is accept- able for ecological research will depend on the degree of reliability with which it samples the relative abundance of species. Neither of the two methods is without bias in this regard, and it seems that a truly accurate means of assessing relative numbers is yet to be found. Quadrat sam- pling is an acceptable method for slow moving or nonmotile species in soil and litter, and provides accurate estimates of density. Pitfall trapping is only suitable as a means of sampling cursorial forms, and appears to be the best available at present for this purpose. Sources of error in pitfall trapping usu- ally can be placed in one of two categories: error resulting from dispersion or place- ment of traps and error resulting from as- pects of trap design. Problems have arisen in previous studies when too many or too few traps are used, and when traps are placed too close or too far apart. Unzicker and Uetz suggest that the particular sam- pling regime chosen for a study should depend upon the patchiness of the habitat to be sampled, the size of the area, the size of the traps and the type of information being sought. They also describe a pitfall trap which has several advantages over traps used by other investigators. This trap uses a screen roof to exclude debris, has drainage to prevent flooding, uses a re- moveable funnel to direct organisms into an interchangeable collecting cap, and has a collar which prevents gaps from occur- ring between the trap and the adjacent soil. February 1977. No. 164. Published monthly except in July and August by the Natural History Survey, a divi sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. La Berge with the collaboration of the Survey Staff Second-class postage paid at Urbana, Illinois. Office of publication 175 Natural Resources Building, Urbana Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR CHIEF ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 The Illinots NATURAL HISTORY REPORTS Sore Stems Spring is on the way (we hope!). Soon it will be time to start gardens and put in those new trees and shrubs we have been dreaming about all winter. Unfortunately, we must also think about how to control the disease and insect pests that may attack our new plants. Plant diseases, particularly stem cankers and diebacks, often appear on trees and shrubs following transplanting, when the plants are in a weakened condition due to ‘ transplanting “shock.” Like humans, plants weakened or under stress may become sus- ceptible to attack by pathogens that may be present in or on a plant but do not cause disease if the plant is vigorous and strong. The many deaths associated with the great flu epidemic early in this century were caused by pneumonia bacteria, nor- mally present in the human body, that only attacked those persons severely weakened by the influenza virus. The same is true with stem canker fungi, which are often present on dead twigs and branch stubs of healthy woody plants. When trees or shrubs are transplanted, either bare rooted or with a root ball, a considerable portion of the root system 1s lost. Woody plants often retain as little as half of their original root system after transplanting. This root loss can have many adverse effects on the plant. Food reserves stored in the roots are reduced, open wounds are numerous, and the rela- tive capacity of the plant to take up water and nutrients is reduced. Which of these or other effects is involved in increased dis- Material in this publication may be reprinted if credit is given ease susceptibility in transplanted plants has not been thoroughly investigated. To gain some insight into what stress o1 stresses associated with transplanting in- fluence susceptibility to stem canker fungi, Survey plant pathologists D. F. Schoene- Stem cankers arising from infected branch stubs on a recently transplanted willow. (Photo by D. F. Schoeneweiss) to the Illinois Natural History Survey weiss and E. G. Wene recently conducted a study on a stem canker disease of Euro- _ pean white birch. Container-grown plants were inoculated with a canker fungus known to attack birch weakened by ex- posure to environmental stresses. The in- oculated plants were removed from the containers and approximately half of each root system was removed to simulate root pruning accompanying transplanting. ‘The root-pruned plants were immediately re- potted and placed in a growth chamber, where they were kept well watered and under high humidity to prevent water stress. After 2 weeks no infection had oc- curred. Half of the root-pruned plants plus several inoculated unpruned plants were then subjected to water stress by withhold- ing irrigation until the plants began to wilt. Stem cankers appeared at the inocula- tion points of all wilted plants. These results indicate that water stress due to reduced water uptake in transplants is probably the main stress factor involved in increased susceptibility to stem canker fungi. There are several ways to help prevent water stress in newly planted trees and shrubs. They should be planted in a porous, well drained fertile soil to promote rapid growth of new roots. The soil should be kept moist but not flooded during the first growing season. Top pruning or thin- ning of branches, if this was not done prior to transplanting, will help reduce water loss and lessen the demand placed on the reduced root system. Keeping trees and shrubs vigorous is the best way to avoid damage caused by stem canker diseases. Growth of Young Largemouth Bass in Heated Water Lake Sangchris, located in central Illi- nois, is a 2,165-acre impoundment used for cooling purposes by Commonwealth Edi- son’s 1,230-megawatt Kincaid Power Plant. The lake consists of three long narrow arms which converge near the dam. The thermal effluent of the power plant is cir- culated through two of these arms, creating a temperature gradient. The third arm is relatively unaffected by the thermal ef- fluent and serves as a control area for investigations. This rather unusual form makes Lake Sangchris ideal for studying the effects of increased water temperatures upon aquatic organisms. Largemouth bass from Lake Sangchris were studied by aquatic biologist Michael Sule to determine the effects of thermal discharge on the first-year growth of bass. Young-of-the-year bass were collected throughout the 1975 and 1976 growing seasons from the unheated and _ heated arms of the lake and were analyzed for length, weight, physical condition, and feeding habits. In all collections, bass from the heated arm were larger than bass collected at the same time from the un- heated arm of the lake (see figure). The difference in size was probably established by an earlier spawn of bass in the heated arm, giving the warm-water fish a head start on the others. Growth rates of the two groups were similar throughout most of the growing _ season, except near the end of the normal growing season, when bass from the heated arm grew somewhat faster than those from the unheated arm. Bass from both arms exhibited similar condition factors. The feeding habits of bass from the two areas were similar and were determined more by the size of each bass than by its residence in the heated or unheated arm of the lake. Bass changed from a diet of mainly zooplankton to aquatic insects with increase in fish length. As bass reached a total length of about 90 mm, other fish be- came an increasingly important food re- source. The elevated temperatures of the heated arm seem to have been advantageous to bass inhabiting that area. The extended growing season in that arm allowed more bass to reach a total length that is asso- ciated with the more efficient fish-eating habits. The possible detrimental effects of long- term exposure to elevated temperatures may well outweigh the apparent first-year- growth advantage indicated by this study. Depressed fecundity, higher mortality, and shorter life span are all possible alterations 160 140 ——— ———- = JD. SCHARGE = INTAKE MEAN TOTAL LENGTH (mm) AUGUST SEPTEMBER MAY JUNE JULY OCTOBER which should be considered before any general conclusions are drawn concerning the effects of heated water on largemouth bass. Pheasants Compete with Prairie Chickens The greater prairie chicken has been supplanted as a game bird over much of its former range by the ring-necked pheasant. All the north-central states closed their hunting seasons on prairie chickens, at least temporarily, during the first 20 years of this century. The same period saw these states initiate and expand pheasant stock- ing programs. In Illinois the remnant flocks of prairie chickens in Jasper, Marion, Clay, Washing- ton, and Wayne counties are now outside the contiguous range of the pheasant. However, a small population of pheasants persists in southwestern Jasper County on and near the prairie chicken sanctuaries. This small population of pheasants prob- ably originated from, and is at least par- tially maintained by, releases made by local sportsmen. Survey biologists R. L. Westemeier and D. R. Vance have documented the com- petition between pheasants and_ prairie chickens during their studies of the nest ecology of prairie chickens. The competi- tion most often observed by Westemeier and Vance has been the aggressive harass- ment of prairie chickens on booming Growth in length of young-of-the- year largemouth bass collected from the heated (discharge) arm and the unheated (intake) arm of Lake Sangchris, May 29 to December lI, 1975 and in July (small 6A and B13) and September (small A75 and B69) 1976. Each point represents the average length of the fish ex- amined, and the number of fish examined is shown at each point. NOVEMBER DECEMBER grounds by cock pheasants. Although such ageressive behavior has been observed dur- ing every month that prairie chickens occupy the booming grounds (late Sep- tember to June), most harassment appar- ently occurs in March and April. These 2 months cover the peak booming and breed- ing season of prairie chickens in Illinois and also the beginning of the establishment of crowing territories by cock pheasants. No pheasants were seen on booming grounds prior to 1970. During March and April 1970-1976, biologists spent 440 ob- server-mornings on booming grounds. Pheasants were observed on the grounds on 77 occasions. On 33 of these occasions, some interspecies conflict was noted. In 25 of the 33 encounters between cock pheasants and prairie chickens, the pheas- ant dominated one or more prairie chickens. Aggressive behavior by cock pheasants usually consisted of chasing one or more prairie chicken cocks off the booming ground. Frequently, the pheasant pursued the prairie chicken in flight. On a few occasions, the cock pheasant performed the courtship display before a hen prairie chicken. In every case, a single cock pheas- ant was responsible for all harassment. On the six occasions that prairie chickens proved dominant over a pheasant, the pheasant initiated the conflict with a domi- nant prairie chicken cock and was chased to the edge of the booming ground by two The Illinots NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 or more prairie chicken cocks. At no time did prairie chickens pursue pheasants off the booming ground. Evaluating the impact of this harass- ment by cock pheasants is difficult. How- ever, no benefit to prairie chickens 1s apparent. Conceivably, such aggression could delay or even prevent successful breeding by prairie chickens on a partic- ular booming ground. At its worst, aggres- sive behavior by pheasants could result in sterile hybrid offspring, thus reducing the reproductive potential of the largest rem- nant flock of prairie chickens in Illinois. Pheasant-prairie chicken hybrids have been reported in other states. In addition to the harassment of prairie chickens on booming grounds by cock pheasants, hen pheasants also interfere with the nesting of hen prairie chickens. Since 1969, pheasants have laid eggs (parasitized) in 17 of a total of 463 prairie chicken nests. Four of these 17 nests were successful. Eleven of the nests were de- stroyed and two were abandoned (76 per- cent unsuccessful). In contrast, of the 446 nonparasitized prairie chicken nests, 219 (49 percent) were successful. No parasitized prairie chicken nests were found prior to 1970. In 1970-1972 one parasitized nest was found each year. Fourteen parasitized nests have been found in the past four years (4 in 1973, 2 in 1974, 4 in 1975, and 4 in 1976). As the number of parasitized nests increases, they con- stitute a growing proportion (8.9 percent in 1976) of the declining number of prairie chicken nests. The Survey biologists believe there is cause for concern about this parasitism. The incidence of parasitism is apparently increasing, as is the pheasant population in the area. Parasitized nests are markedly less successful than nonparasitized nests. Consequently, parasitism of prairie chicken nests by hen pheasants has and will prob- ably continue to limit, to some extent, the production of young prairie chickens. March 1977. No. 165. Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by. Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 61801 The Illinozs NATURAL HISTORY REPORTS Men, Birds, and Libraries Recently the Illinois Natural History Survey received, as a gift from Mrs. T. E. (Mary) Musselman, the library and _ pa- pers of Dr. T. E. the nowned Illinois naturalist from Quincy. Musselman, re- The papers include his notes on a variety of natural history subjects, but with special emphasis on birds. The notes span 60 years, beginning in 1910, and provide data mainly on western Illinois, particularly Adams County. The great enthusiasm which Dr. Mus- (he was known far and wide as TE) brought to his studies of natural his- tory, carried through to his lectures, and to selman the thousands of students who were fortu- nate enough to hear him and know him. Among that number was the Survey’s own Dr. Robert A. Evers, who once worked with TE in evaluating Botanist emeritus, the use of nest boxes by bluebirds. TE took a special interest in the bluebird, when he noticed the once vigorous popula- tions badly depleted. With characteristic energy TE placed thousands of nest boxes along the roads of west-central Illinois, and encouraged similar programs through- out the country. The response was grati- fying, as the beautiful birds once again be- came common in the areas. So successful was the campaign that one who thinks of bluebirds automatically remembers TE. It is an epitaph unlikely to be challenged. In the past, the Survey has also been the recipient of other historically impor- tant papers from Benjamin T. Gault the birds of Du Page, Cook, and Lake on Material in this publication may be reprinted if credit is given counties, 1884-1927; from John J. Schafer on the birds of Rock Island County, 1913- OSE Smith his students on the birds of Champaign County, 1903- 1923: and Alfred O. Gross on the birds of many counties, 1905-1909. Frank and These papers, individually and _ collec- tively, are priceless for the picture they provide of natural habitats and their popu- lations at specific times and _ localities. From such data and present-day observa- Dr. T. E. Musselman in his later years. (Photographer unknown) to the Illinois Natural History Survey tions, we can perceive how this part of the world is changing and the rate at which it - is changing, important data to have for the conservation of species. Included in the collections of Dr. Musselman and Dr. Gross are photographs which augment the value of the field notes. All of the notes contain some quanti- tative data on bird populations, but the field notes of Alfred O. Gross are probably unique in the world as a quantitative rec- ord of the habitats and bird life of a large area — perhaps as much as 30,000 acres in Illinois. Some of Dr. Gross’ study was re- peated in 1956-58 by Wildlife Specialists Jean and Richard Graber, who hope to be able to repeat virtually the entire original census in the next few years. ; It is important that the census be re- peated as a benchmark to the rates of faunal and habitat changes, particularly as there have been greater changes in the acreage of certain agricultural habitats since 1960 than in the previous fifty years. It also seems important that the censuses be carried out by the Grabers, who bene- fited directly from the instructions of Dr. Gross on the precise methods of the origi- nal census. Aquatic Ecosystem Model A cooling lake ecosystem model (CLEM) based on studies of Lake Sang- chris is being constructed by John McNur- ney and Don Halffield with the coopera- tion of the other Survey aquatic biologists. The model will consist of functional sub- models describing the physical and_bio- logical components of a cooling lake in the littoral and pelagic zones of each of four lake sections. The lake sections in- clude an area directly influenced by the power plant discharge, a transition area, an ambient area of the cooling loop, and an ambient area outside the cooling loop. A mathematical model is a condensed representation of a real system which uses equations as building blocks. Each equa- tion is the modeler’s approximation of a functional relationship existing in the real system in a form which can be conve- niently programmed on a computer. While each expression is relatively simple by it- self, the combined interactions of all the expressions describing a system can be extremely complex. While a man cannot consider all the aspects of a complex sys- tem at once, a modern computer can as- similate a nearly infinite number of equa- tions describing a system, consider all the interactions simultaneously, and produce a summary output in a matter of seconds. The computer simulation of a system’s function is limited by the integrity of the model and the cost of its operation. The optimum structure of a model is, therefore. one which represents the system as simply as possible while maintaining the accuracy necessary for reliable operation. The modeling process begins with iden- tification of the phenomenon to be mod- eled. The functional relationship of each component part must then be described and defined mathematically. The param- eters of each equation must be determined directly by experimentation or indirectly - through a literature search. The com- puterized model is then run under con- ditions comparable to those of a known real system in a process called validation. The model is refined by adjustment of the descriptive equations and/or parameters until the model results agree with those of the real system. Preliminary submodels for Lake Sang- chris, which consists of original work or modifications of existing models, are com- pleted for water temperature, phytoplank- ton, zooplankton, periphyton, macrophytes, benthos, and fish. The fish, which are most emphasized in the model because of their recreational value, will be further divided by species and size classes. Once CLEM has been validated it can be used, by manipulation of input param- eters, to estimate the effects of extreme weather conditions or unusual power plant operation on the biota of Lake Sangchris. Proposed management practices could be evaluated in much the same manner. By adjusting certain physical constraints the model could also be used to predict the biological potential of cooling lake sites in the Midwest prior to construction of new power plants. Stripetail Darters In 1856 early Illinois naturalist Major Robert Kennicott discovered some speci- mens of a new kind of small fish in a rocky brook in Union County. His specimens were darters with boldly striped tails somewhat like those of Plymouth rock chickens. The new species was formally described and named Catonotus kennicotti in his honor by Frederick Putnam of Har- vard University in 1863. Twenty years later a similar but larger stripetail darter was described from the headwaters of the Cumberland River in Kentucky and named Etheostoma cumberlandicum by David Starr Jordan and Joseph Swain. During the next 110 years, specimens of the stripetail darter were found in locali- ties geographically intermediate between southern Illinois and eastern Kentucky. Recently Survey ichthyologists L. M. Page and P. W. Smith studied all avail- able museum specimens of these darters and analyzed variation and distribution among them. In a newly published study, they concluded that specimens from most parts of Kentucky and Tennessee are in- termediate in their characters and size at- tained between the species called kenni- cottt and that called cumberlandicum. Since the diagnostic characters of one spe- cies grade into those of the other, these workers recommended that use of the name cumberlandicum be discontinued and that the earlier name kennicotti be applied to all populations of stripetail darters. The authors were able to show that the stripetail darter originated above Cum- berland Falls in eastern Kentucky and dis- persed westward to southern Illinois before the last glacial advance. It was able to get into Illinois then because the Ohio River Adult male stripetail darter, Etheostoma kennicotti. In Il- linois the species is seldom more than two inches in length. at that time occupied the ancient Cache River channel farther north than it flows at present. The scientists also demon- strated that size attained and general abundance of the various populations are controlled by competition with closely re- lated species. They pointed out that the stripetail darter upstream from Cumber- land Falls has no coinhabiting close com- petitor, and it grows to a larger size and is very common. Elsewhere in Kentucky and Tennessee, the stripetail may occur with as many as three competing relatives, and it is quite rare and dwarfed in size. How- ever, in southern IIlinois the Ohio River is presently a barrier to closely related spe- cies, and with only one close competitor the stripetail darter is abundant and inter- mediate in size. This is a classic example of how competition may affect animal spe- cies. Since the study was published, evi- dence has continued to mount that distri- bution, abundance, and size in this group of darters are strongly influenced by the number of closely related species that oc- cur together in a stream drainage. Microsporidian Methodology Microsporidia are an important group of microorganisms which occur as parasites in nearly all major animal groups, but are extremely common in invertebrates such as insects and crustaceans. In 1947 there were about 215 species of microsporidia. Today about 525 species are recognized and another 200 unnamed ones have been reported. This phenomenal growth in the number of microsporidian species, along with a renewed interest in these organisms as biological control agents, prompted the publication of a two volume treatise deal- ing with the biology of the microsporidia. These are published as volumes 1 and 2 of Comparative Pathobiology, a new series The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 published by Plenum Press. The treatise, edited by Jiri Vavra of the Czechoslovak Academy of Sciences and Victor Sprague of the University of Maryland, provides~a convenient general reference work that will facilitate the efforts of both students and researchers who are pursuing an in- terest in microsporidia. One of the chapters in this treatise, “Methods in Microsporidiology,’ was au- thored by Jiri Vavra of the Czechoslovak Academy of Sciences and J. V. Maddox of the Illinois Natural History Survey. This chapter covers methods most com- monly used by microsporidiologists. In addition to those used for years, more sophisticated techniques are increasingly being employed in these studies. Vavra and Maddox have attempted to compile the methods most commonly used in mi- crosporidian research into a single source. Such topics are covered as making field collections of animals suspected of having microsporidian infections, examining ani- mals for the presence of infections, induc- ing experimental infections, maintaining infections in cultures of animals, elimi- nating unwanted infections from animal cultures, and storing viable microsporidian spores. Various physiological, immunolog- ical, and cytological techniques are in- cluded along with the more commonly used techniques of measuring, staining, and photographing microsporidian spores -and developmental forms. In order to conduct dosage mortality and biological control studies, micro- sporidian spores must be extracted from infested hosts, purified and quantified. Methods for these operations are discussed. Electron microscopy has become an in- valuable tool in studying microsporidia, — especially in differentiating the organisms at the species level. Although Vavra and Maddox could not possibly cover all as- pects of electron microscopy used, they describe those techniques proved most suc- cessful in preparing microsporidia for ul- trastructural observation. In an area of biological research which is developing as rapidly as the field of microsporidiology, old methods are con- stantly being modified and new methods developed. Consequently, Vavra and Mad- dox view this chapter on methods as a be- ginning rather than a conclusion to an ac- cepted methodology within the field of microsporidian research. They hope that the chapter will serve to standardize many of the diverse methods currently being used and acquaint researchers with some innovative methods they have not previ- ously considered using in the fascinating field of microsporidiology. April 1977. No. 166. Published monthly except in July and August by the Natural History Survey, a divi sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS é ] The Illinovs NATURAL SURVEY Warning to Farmers: Corn Rootworm Damage May Be Severe in 1977 Entomologists of the Natural History Survey and the University of []lh- Illinois nois College of Agriculture Cooperative Extension Service are viewing the 1977 corn rootworm situation with deep concern. The unusually large populations of western and northern corn rootworm beetles found in Illinois last August indicate that heavy infestations of corn rootworms may be ex- pected in 1977 in cornfields that were planted in corn last year. Entomologists D. E. Kuhlman, J. L. Wed- berg, J. T. Shaw, and K. Black warn that moderate to severe rootworm damage is expected in many fields of corn following corn in the area north of a line from Pittsfield through Decatur to Danville (see map). Light to moderate damage is ex- pected in fields in south-central counties north of a line from Collinsville to Paris. The potential for rootworm damage south of this line is low. In a survey made in August 1976, west- ern and northern rootworm beetle populations in the northern two-thirds of Illinois were at the highest levels observed corn during the 10 years that beetle numbers have been monitored. Corn growers in the problem areas should base the decision to use or not use a rootworm soil insecticide on the number of rootworm beetles ob- served in their fields last year. An average of one or more beetles per plant in August 1976 indicates potential for damage, and a soil insecticide should be used if a field is Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. HISTORY MAY 1977, NO. 167 replanted to corn this year. Lodging or elbowing of corn during July and August are also indicators of rootworm damage. If beetle counts were not made in 1976, corn growers in the moderate to severe root- worm damage areas should plan to use a corn rootworm soil insecticide in 1977. The large corn rootworm populations in 1976 resulted from the good survival rate of the larvae due to the early corn planting that generally occurred last spring. Western and posit eggs (as many as 1,000 per female; northern corn rootworm beetles de- probable average about 400) in the soil at the base of the corn plant or between rows in August and September, and the eggs overwinter in the soil. The eggs begin hatching in early June, and hatching usu- ally takes place over 3 to 5 weeks. Larval and pupal development requires about | month. Consequently, all stages of the corn egg, larva, pupa, and adult - rootworm may be found in a field at one time in early July. Rootworm larvae feed on corn plant roots, and most damage occurs dur- ing June and July. In spite of the severe weather conditions experienced in Illinois during the 1976- 1977 winter, preliminary surveys conducted this spring show that most corn rootworm eggs have survived. Thus, a great potential for rootworm damage in 1977 still exists. In 1976 some corn growers experienced control failures with soil insecticides ap- plied at planting in early to mid-April. It is likely that the insecticides had lost some of their potency by June, when rootworm eggs were hatching, and many of the larvae 40 OMNES STEPHENSON WINNEBAGO [BOONE] MeneWRY [LAKE } | 433 178 =| | CARROLL. [OGLE cai SESE TCOOR Average number of 517 lies oe 4 rootworm beetles per | 166| WHITESIOE =N2/) | 100 plants, August, LEE | 1976 300 237 OU PAGE WENOALL) WILL HENRY | BUREAU Jena | ROCK ISLAND _ rae | 244 Femamor MERCER Sal : > 268 (eet a rom 3 IL KNOX L — _ { LIVINGSTON MARSHALL WOOOFORO 96 165 234 27 MCLEAN R72 ae 62 Moderate to — PEORIA iROQUOIS severe 201 Light to moderate EFFINGHAM KANMAKEE JASPER ae CRAWFORD RICHLAND | LAWRENCE pe sow ROOTWORM POPULATIONS Areas of Illinois where corn root- worm damage is expected to be severe, moderate, or noneconomic in 1977. The numbers within some counties are the average numbers of rootworm beetles found per 100 plants in August 1976. BY DISTRICTS AUGUST, 1976 Noneconomic Average number of bee- tles per 100 plants survived to become adults and lay more eggs. Insect resistance to the organic phos- phate and carbamate insecticides in Illinois has not been conclusively demonstrated by research, and resistance does not appear to have been a factor in control failures in 1976. However, the entomologists antici- pate that rootworm resistance to soil in- secticides may occur within the next few years, since a high percentage of Illinois corn is treated annually with such insecti- cides. Corn rootworms have already devel- oped resistance to the insecticides aldrin and heptachlor. In addition to the use of soil insecticides to control corn rootworms, several cultural practices can be employed. Crop rotation is the most effective method of preventing corn rootworm damage. If practical, do not grow corn 2 years in succession in the same field. Select a corn variety that has Northwest........- 348 No~theds tapeerierlelate 196 VWeESEoocogoccoonco oly) Gentrall scree. cpaterele 168 Has tetereteteneloherstenstetar= 84 West-southwest.... 43 East-southeast.... 18 Southwest.....-.... 0 Southeast.......-. 0 good standability and root regeneration capability. Finally, plant last those fields that had high rootworm beetle populations in August of last year. Late planting will help to minimize the breakdown of soil in- secticides before rootworm eggs begin hatching. Ridge Lake Research and Fishing Ridge Lake is a 16-acre lake in Fox Ridge State Park, 7 miles south of Charles- ton on Illinois Route 130. Dr. George W. Bennett, former head of the Aquatic Biol- ogy Section of the Survey, conducted sport fisheries research in this lake from 1941 to 1974. The primary objectives of his re- search were to devise and evaluate methods of producing optimum fish populations for sport fishermen and to evaluate state fish- ing regulations pertaining to open seasons, length limits, and creel limits. Dr. Bennett retired in 1974 because of poor health, and we are sorry to inform our readers of his death on March 18, 1977. His many publi- cations and his book, Management of Lakes and Ponds, stand as evidence of the im- portance of his work. His many colleagues and friends will long remember him not only as a scientist, but also for his warm human understanding of the people he came in contact with. In 1970 Dr. Bennett initiated a study at Ridge Lake to evaluate the effects of 14-inch length limit on largemouth bass and channel catfish. effects of supplemental feeding on_ fish production in the lake. This study terminated in April 1976, when the lake was drained and a complete census of the fish population was made. Data from this 6-year study are now being analyzed, and the results will be submitted for publica- tion during 1977. Aquatic biologists W. F. Childers and G. W. Lewis have begun a new research program in Ridge Lake. The lake was re- stocked in May 1976 with adult large- mouth bass, adult channel catfish, and fingerling green sunfish x bluegill F, hy- brids. Public fishing (by permit only) was permitted from June 2 to August 30. Dur- ing these 3 months fishermen harvested about 55 percent of the adult bass and 13 percent of the channel catfish. The large- mouth bass produced a large 1976 brood, and additional 10-inch channel catfish were stocked in the lake during August. During 1977 public fishing (by permit only) will be permitted from May 21 to ae 28. Daily fishing hours will be from 00 AM to 10:00 AM and from 3:00 PM to 8:00 PM (Central Daylight Time). The lake will be closed to fishing on Mondays and ‘Tuesdays. No bank fish- ing will be permitted, but boats are pro- vided free of Fishermen can make boat reservations for the opening days by sending a postcard to Mr. George W. Illinois Natural History Survey, 137 Natural Resources Studies Annex, Urbana, Illinois 61801. Fishermen living more than 30 miles from Charleston may fish during both the morning and afternoon fishing periods. Fishermen living less than 30 miles from Charleston may request either the He also studied the was Saving charge. Lewis, Mee® - a. April 1976 draining census of Ridge Lake fishes. Fish were collected in a weir and were rapidly sorted to keep as many bass and channel catfish as possible alive for restocking the lake. morning or afternoon session but not both. Fishermen should state their first second choice for a fishing date. A drawing for reservations for the opening days will be held on May 6, and permits to fish will be mailed to fishermen. After opening day, reservations can be made by writing to the Illinois Natural History Survey, Fox Ridge State Park, Charleston, Illinois 61920, or by calling 217-345-6490 during the daily fishing hours. The 1977 fishing regulations are: 1. All inches total length must be returned to the lake. All channel catfish less than 14 inches total length must be returned to the lake. 3. All hybrid sunfish less than 6 inches total length must be returned to the lake. 4. Each have a 1977 Illinois fishing license and must check and largemouth bass less than 18 fisherman must with the creel clerk for boat assignment. Prune Out Dutch Elm Disease If you are fortunate enough to have one or more healthy elm trees on your property, you will be interested in the results of a re- search project conducted by plant pathol- The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 ogist E. B. Himelick and Evanston mu- nicipal arborist D. W. Ceplecha. They found that about two of three Dutch-elm- disease-infected trees can be saved if the infected branches are pruned soon after wilt symptoms become apparent. In their 4-year study Himelick and Ceplecha worked with personnel of the Evanston Forestry Section, who visually surveyed from the ground the entire city elm population every 2 weeks throughout the growing season. Each elm exhibiting Dutch elm disease leaf-wilt symptoms was tagged, and twig samples were sent to an Illinois Natural History Survey laboratory for confirmation of the presence of the dis- ease. Most trees that show Dutch elm disease symptoms in early June were infected in the preceding growing season or have been infected through root-graft transmission of the disease. Therefore, trees showing symp- toms in early June usually cannot be saved by pruning. In Evanston pruning was be- gun in the third or fourth week of June. Pruning and painting of the wound were completed within 1 to 5 days after each infected tree on city property was located. Infected trees on private property were re- ported to the property owners, and most such trees were pruned by commercial tree companies within | to 4 weeks after dis- ease detection. May 1977. No. 167. Published monthly except in July and August by the Natural History Survey, The results show that 62 percent of the infected trees on public land were saved and that 32 percent of the privately owned trees survived. Himelick and Ceplecha point out that for pruning to be successful, all of the fungus growth must be removed from the tree. A pruning cut must be made far enough below the point of fungus invasion in a branch so that the invasion of other branches and of the trunk will be pre- vented. Consequently, the researchers’ © recommendations are that diseased elms be pruned as soon as possible after wilt symp- toms appear and that infected branches be trimmed back at least 10 to 15 feet from the point where the sapwood is discolored. The study further showed that the cost of pruning diseased branches averaged $57 per tree. The cost to Evanston for remov- ing diseased elms on public property was $190 per tree. Another $30 was paid for stump removal, and the cost of planting and maintaining a new tree was- $125, bringing the total average cost to $345 per diseased elm. If about 62 percent of the pruned elms survive, the savings clearly justify an intensive scouting and pruning program for any city. The homeowner must also consider the esthetic value of a mature elm versus that of a small replace- ment tree. a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR. CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 61801 The Illinovs NATURAL HISTORY REPORTS Glenn, the Moth Man A valuable collection of almost 20,000 specimens, including 1,325 different species of microlepidoptera (small been presented to the Illinois Natural His- tory Survey. The gift was made recently by ing recorded for the Survey’s permanent files, and the specimens are being incorpo- rated into the Survey’s insect collection. s _ Because the new acquisition is so complete, moths) has. : , it may prove useful as baseline data for monitoring the effects of a changing en- ~~ ; Sec vironment on animal life in Illinois. Wal- Murray O. Glenn of Henry, Illinois, and ‘ ‘ : : Eps ¢ . lace E. La Berge, Survey taxonomist, notes represents 46 years of work and study in Putnam County. For its scientific value, the gift is the that the collection is extremely valuable be- cause it was started before pesticides were - widely used. most important collection of Lepidoptera ever entrusted to the Survey, according to George L. Godfrey of the Section of Fau- nistic Surveys and Insect Identification. The collection is virtually a complete record of all the small moths for a defined area of the state and reveals many new host plant associations. Specimens from the Glenn collection have been used by several scientists in the descriptions of 28 new species. Eighteen of these species were orig- inally Putnam County, and three were named glenni in honor of the collector. collected by Glenn in Many of the species represented in the Glenn collection are pests on farm, garden, and fruit crops plus ornamental yard plants. The immediate value of the gift is the aid it will give to the insect identifica- tion services offered by the Survey to [lh- nois residents and various research pro- erams. Accurate recognition of an insect is the first step in determining whether it actually may create a serious problem and how it may be controlled. s The locality, date of collection, and host & plant association for all the specimens of each species in the Glenn collection is be- some of his ex- Godfrey) Mr. Murray O. Glenn examining tensive collection of moths. (Photo by G. L. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey Glenn became interested in collecting in- sects as a high school student. After gradu- _ ating in 1911, he studied agriculture at the University of Illinois for three years, but a death in the family made it necessary for him to leave before graduating. His serious collecting adventures began in 1931. During his “spare” time, Glenn farmed over 600 acres with his brother near Henry in north-central Illinois. After retiring from the farm, he found more time to devote to his avocation. Professional sci- entists from several universities, the I]li- nois Natural History Survey, and the Smithsonian Institution soon became aware of Glenn’s activities and his col- lection. They consulted with him profes- sionally many times through the years. _ The Survey is delighted to have been se- lected by Murray Glenn as the institu- tion to care for his extensive collection. This collection is one of the most impor- tant acquisitions that the Survey has made during the past 25 years. Alfalfa Weevil Management The most serious pest threatening alfalfa in Illinois is the alfalfa weevil. Larvae of the alfalfa weevil feed on alfalfa plants for three or four weeks in the spring. When full grown, they spin silken cocoons on the plants, in fallen or dead leaves, or in the litter on the ground. In one or two weeks adults emerge from the cocoons. In the spring the adults feed for a short time, then fly to protected areas and enter a rest- ing period. In Illinois, most of the adult weevils return to the alfalfa fields in late summer and early fall. Egg-laying by the weevils may be in fall, winter or spring in southern [llinois, but chiefly in the spring in northern alfalfa fields. Control of the alfalfa weevil depends upon three primary methods. Chemical control with insecticides is the most widely used method. Timing of the first harvest in the spring can be manipulated to help reduce weevil populations and control damage by the weevils. ‘The third method involves biological control agents, such as predators and parasites. One of the most successful biocontrol agents in Illinois is a small parasitic wasp, Bathyplectes curcu- lionis, which lays eggs inside young weevil larvae. The three control methods are interre- lated. For example, insecticides kill para- sites and predators, as well as alfalfa weevils. Harvesting alfalfa when many weevil larvae are parasitized will reduce the parasite population as well as the weevil population. To help understand how the three methods of control work together, a computer-based mathematical model was developed by Survey entomol- ogists. This model simulated field condi- tions and analysis of the model, operating under differing conditions and tested by extensive field trials, has resulted in a pest ‘management program for control of alfalfa weevils in Illinois. Circular 1136 of the Cooperative Ex- tension Service, College of Agriculture, University of [linois, authored by entomol- ogists John L. Wedberg, W. G. Ruesink, E. J. Armbrust and D. P. Bartell, was pub- lished in April, 1977, and is available from - County Extension Advisors in Illinois. This circular offers a program which should help in deciding when to spray for alfalfa weevils or whether other control methods are sufficient. The program is a continuing program which will receive further testing, revision, and refinement in the future. Dr. George W. Bennett Dr. George W. Bennett, for many years head of the Aquatic Biology Section of the Illinois Natural History Survey, died at 6:30 a.m., Friday, March 18, 19/7, in Mercy Hospital, Urbana. He had retired January 1974 after 36 years of outstanding service. He joined the staff January 1938, and was appointed head of the Aquatic Biology Section in November WES George was trained as a limnologist at the University of Wisconsin, where he re- ceived a Ph.D. degree in 1939. Very early in his career he recognized the need and the potential for manipulating the density and composition of fish populations as a means of increasing the yield to anglers. He developed new concepts for the manage- ment of his favored combination of large- mouth bass and bluegills, and through his Dr. George W. Bennett. (Photo by Survey Photog- rapher, Larry Farlow) classic studies of the use of water level manipulations (drawdowns) at Ridge Lake, he achieved new levels of success in fisheries management and influenced an entire generation of fisheries scientists. His more than 30 years of research produced many important scientific publications. Much of his knowledge and _ philosophy was brought together in his widely used book, “Management of Artificial Lakes and Ponds,” first published in 1963, and revised for a second release in 1971. Perhaps of equal importance to his own research were his contributions as an effi- cient, kindly, and unselfish administrator. His quiet but effective leadership, excep- tional personal qualities, and high stan- dards of achievement were a great source of inspiration to his stag and co-workers, and his warm and gentle personality will not be forgotten by those who had the privilege of knowing George and working with him. Severe Winter and Pheasants Illinois pheasants are fortunate because corn and soybeans (the principal food source during winter months) are widely scattered each fall during the harvest. In addition, the pheasant can survive periods of extended fasting and has the ability to recover weight losses rapidly when food intake is resumed. Biologists in the 1940’s found no evidence of nutritional stress for the Illinois pheasant, and winter mortality in Illinois was not of the magnitude ex- perienced in northern and plains states, in part because temperature and precipitation patterns were typically milder. During the past 30 years, intensified corn and soybean production and_ associated farming practices have resulted in a sharp reduction in the cover commonly used by pheasants in the winter months. Hay and oat stubble fields and grassy areas (princi- pal cover for roosting) , woody and shrubby vegetation (used by the ringneck primarily for loafing during mid-day), and corn and soybean stubble (feeding areas) have al- most been eliminated in the prime pheas- ant region of Illinois. At present, nearly all row-crop stubble fields are plowed in the fall, burying a substantial portion of the grain scattered at harvest. Because of the dramatic changes in land use in I]linois, biologists have renewed their concern over the well-being of pheasant populations during winter. The unusually severe weather conditions experienced in east-central Illinois in December and Janu- ary 1976-1977 enabled wildlife biologist Richard E. Warner to evaluate the survival of the pheasant population under winter stress. Severe weather on January 27-29, 1977, including moderate snow, 50 mph wind gusts, and temperatures below — 20° F, re- sulted in severe wind-chill factors. Follow- ing this weather, Warner and _ biologists from the Department of Conservation col- lected 49 pheasants found frozen in selected areas of study in Ford, McLean, and Iro- quois counties. Weights of the 38 hens col- lected (17 juveniles) averaged 957.5 grams, and the 11 1,293.4 grams. These weights do not repre- cocks (7 juveniles) averaged sent a significant departure from the normal weights of winter pheasant populations in most midwestern states. Thirty-nine of the 49 collected specimens were found to have The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 substantial fat reserves, and 40 had food in their crops. In general, the pheasants were determined to be in good condition up to the time of death, with no evidence of nutritional stress. Nearly all of the speci- mens were found to have deposits of ice in their throats and beaks, and in some cases the entire head was packed with ice or snow. These are signs that the pheas- ants succumbed from exposure to extreme winter conditions. Even if shrubby, woody cover had been available, the deaths of some pheasants in the January storm may not have been prevented. The ringneck is associated with protective shrubby and woody vegetation primarily during mid-day hours, feeding occurs in the surrounding plowed or stubble fields, and night roosts are located in the low cover of hay or oat stubble fields and grass. Thus, when severe storms hit during periods of roosting or feeding, the relative inflexibility of the ringneck’s behavior works against the bird’s well-being. There is no evidence that changes in land use practices in Illinois have created a significant nutrition-related stress for this species. Some speculation is possible as to the ex- tent and range of the storm-related mor- tality. The Department of Conservation has received letters describing late January losses of pheasants from individuals located in many portions of Illinois’ pheasant range, and biologists in some areas confirm such storm-related mortality. Thus, the ef- fects of the storm appear wide-spread. On — one 16-square-mile area, the Ford County Management Unit (FCMU), Warner esti- mates that perhaps 25 to 50 percent of the pheasants in this area may have succumbed during the January storm. This estimate may be representative of the pheasant mor- tality occurring in the prime pheasant range. When spring census activities are conducted in May, biologists will be able to define more clearly the effects of this highly unusual winter on pheasant popula- tions in Illinois. June 1977. No. 168. Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois Office of publication 175 Natural Resources Building, Urbana Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 61801 The Illinois NATURAL SURVEY Studies of Vegetation on Bluffs and Ravines The land north of Chicago along Lake Michigan rises rapidly, forming high bluffs (40-88 feet) along the lakefront. From Glencoe northward the bluffs and _ table- lands above them are dissected by more than 30 deep ravines. The lands adjacent to the lake are glacial moraines and are composed of highly erodible glacial till. Ten large ravine systems occur in High- land Park. This area is largely residential, and several hundred properties could lose structures and land to erosion in the ra- vines. The city has funded a project with the Natural History Survey to study the vegetation in the ravines and make recom- mendations on how vegetation can be most effectively used to retard erosion. Drs. Kenneth Robertson and Eugene Himelick, Section of Botany and Plant Pathology, have completed a report, which will be printed and distributed by the city. The ravines are unique ecological habi- tats in Illinois and are vestiges of natural areas within a large city. They are heavily wooded and contain an abundance of wild flowers. Most of the plants that occur in the ravines have been identified, including about 50 species of trees, shrubs, and woody vines and about 80 species of herba- ceous plants. American beech grows in two of the ravines, the only places in northern Illinois where this species occurs naturally. The bluffs facing Lake Michigan in Illi- nois are also subject to severe erosion. The Illinois Coastal Zone Management Pro- gram is sponsoring a publication that will HISTORY SEPTEMBER 1977, NO. 169 help to protect lakefront properties. Part of this publication will explain how to use vegetation for bluff stabilization, and this part is being prepared at the Survey. Dr. Warren U. Brigham, Section of Aquatic Biology, 1s project coordinator, and Dr. Robertson has written the publication. The three primary forces causing erosion of the bluffs are direct wave action at the toe, slumping of the crest due to seepage of excess groundwater, and surface water runoff over the slope itself. Vegetation is useful only against runoff, and the toe and crest of a bluff must be made stable by structural means before any attempt is made to establish vegetation on the slopes. (The Army Corps of Engineers and the U.S.D.A. Soil Conservation Service are preparing guidelines on stabilizing the toe and crest.) Most previous work on the use of vegetation for erosion control has been done for slopes along highways and for construction sites. Evidently no experi- A severely eroded bluff at Lake Forest, Illinois, near the site of the former McCormick estate. (Photo by Dr. Kenneth Robertson) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. mental test plots have been used to deter- mine which plants and planting techniques. are best suited to bluffs. Dr. Robertson has examined existing vegetation on slopes that are stable. From this work and from a re- view of the literature on erosion control, he has developed guidelines for the suc- cessful establishment of vegetation on un- stable slopes. Robertson found that the paper birch is common in these bluff woods although it is rare in the state. White pine and arbor- vitae, also rare in Illinois, occur occasion- ally along the bluff, and buffalo-berry is known in Illinois only from a few sites along the lakefront. The Natural History Survey and Illinois River Research “Yes, we did lots of business some sea- sons, shipping one, two, and three [rail- road] cars of chilled and live fish to East- ern markets every week.” — “Uncle Billy” LeTissier of Bath, Illinois, interviewed in The Mason County Democrat (Havana) August 29, 1941. The River Research Laboratory of the Illinois Natural History Survey, on Quiver Creek north of Havana, is investigating the effects of the 9-foot barge channel on the Illinois River and its fish, waterfowl, clams, turtles, and other wildlife. Drs. Frank C. Bellrose, wildlife specialist, and Richard E. Sparks, aquatic biologist, are directing the study, paid for by the Chicago District, U.S. Army Corps of Engineers. These studies build on a long tradition. The Natural History Survey is one of the few agencies in the country which have long-term records of biological changes in major rivers. The first chief of the Survey, Dr. Stephen A. Forbes, established a field station on the Illinois River at Havana in 1894, where studies on the food relation- ships between the plankton, bottom-dwell- ing organisms, and fishes were carried out. Forbes intended that these studies should determine the reasons for the remarkable productivity of the Illinois River and its bottomland lakes so that the river could be managed wisely. After 1900, when the Chicago Sanitary and Ship Canal began to carry sewage and industrial wastes into the upper Illinois River, the purpose of the research was changed. Forbes and Robert Richardson documented the ad- verse effects of low dissolved-oxygen levels in the water and putrescent conditions in the bottom muds on food organisms and fish. Following Richardson, Dr. D. H. Thompson made extensive surveys of fish populations and their condition. Early in this century, the backwater lakes of the Illinois River achieved national fame as waterfowl hunting areas. Natural History Survey studies of waterfowl habi- tat and populations in the valley com- menced in 1938 with the employment of Dr. Bellrose and Arthur S. Hawkins. To facilitate their studies, a small build- ing — still in use — was built in 1939 on the Chautauqua National Wildlife Refuge in cooperation with the U.S. Fish and Wildlife Service. Early studies included the ecological requirements of aquatic, marsh, and moist-soil plants; the food habits of waterfowl; and the abundance and migra-- tion habits of waterfowl. In 1949 Dr. William C. Starrett was assigned to the laboratory to investigate the fishes and other aquatic organisms of the river and its bottomland lakes. His fishery investigations filled a gap which had existed since Dr. Thompson had left in 1942. The passing of Dr. Starrett in December 1971 brought a temporary cessa- tion in aquatic research until Dr. Sparks assumed this responsibility in July 1972. The locks and dams and the 9-foot navigation channel went into operation in the Illinois River in 1938. Since then freight tonnage on the [Illinois has in- creased at least 10 times. Several proposed construction projects —a new lock and dam at Alton, duplicate locks along the river, or a 12-foot channel — would fur- ther increase barge traffic on the Illinois. By looking at effects of the existing 9-foot channel and current barge traffic, research- ers hope to learn what more traffic might mean for the river, its backwater lakes, and the plants and animals that depend on both. Valuable old research results gathered in the 1930’s and 1940’s on Illinois River fishing — long thought to have been lost The sloughs, backwaters, and bottomland lakes of the Illinois River were once highly productive of fish and wildlife. Now fish and duck food organisms, such as fingernail clams and mayflies, are gone; aquatic vege- tation has disappeared; and sloughs like Babbs (on the right) and Big Meadow (left) are rapidly filling with sediment. The main channel of the Illinois River meanders through the left center of the picture. From bluff to bluff the river valley is 2% miles wide here. (Photo by former Survey Phctographer W. D. Zehr) —have been recovered. These data are being compared with what is known of today’s fish and their condition. In addi- tion, researchers are interviewing commer- cial fishermen and fish market owners. Their memories and records provide an- other basis for historical comparisons. A long-term increase in the rate of sedi- mentation in the Illinois River has been documented. The depths of Senachwine, Sawmill, Billsbach, Sparland, Whitman, Upper Peoria, and Rice lakes and Babbs Slough have been measured to determine how fast they are being filled with soil. In a recent cooperative study, using depth measurements taken by the Natural His- tory Survey, the Illinois State Water Sur- vey found that, at the present rate of siltation, Lake Chautauqua near Havana will be dry land by the year 2068. What has happened to duck-food plants and turtles over the last 40 years and the effects of barge traffic on fish are among other subjects being considered at the Havana Laboratory. The Illinois River hasn’t always been as it is today. When the Natural History Sur- vey completes its analysis of the old in- formation, we will know a great deal more about what has happened to fishing, hunt- ing, and clamming as a result of the dam- ming and dredging for a 9-foot barge channel. Current studies will show how aquatic organisms and wildlife are re- sponding to the pollution-control measures being taken in the Illinois valley. In short, we will be in a better position to judge whether future changes in the Illinois River — and other rivers — will be for the better or the worse. Pesticides in Fox Squirrels Twenty-eight fox squirrels were shot by hunters during the 1975 season on three adjacent large areas of timber in Fayette County in south-central Illinois. Fayette County is moderately cultivated — corn, soybeans, and wheat are the major crops. Areas of timber and pasture are still com- mon. The fox squirrels collected were analyzed for pesticides in the laboratory of the Section of Wildlife Research by Ron Duzan. Survey biologists Chuck Nixon and Steve Havera separated this sample of squirrels The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 into five groups: lactating adult females, nonlactating adult females, adult males, subadult females, and subadult males. The squirrels were analyzed for DDE, dieldrin, PCB’s, and other pesticides. - The concentrations of pesticides found in the specimens were low. Only DDE (a residue of DDT) and dieldrin were de- tected. Only 3 of the 28 squirrels contained dieldrin. The range of dieldrin concentra- tions was 0.0005 to 0.0023 ppm (parts per million). However, a surprising number (25) of the 28 specimens contained DDE residues. The DDE concentrations ranged from 0.0008 to 0.0195 ppm, with an aver- age of 0.0037 ppm for the 25 squirrels in which DDE was detected. The highest concentration of DDE was found in lactat- ing adult females, which had an average value of 0.0053 ppm, whereas the nonlac- tating adult females had the lowest average concentration, 0.0023 ppm. The remaining groups had levels near the average for all squirrels — 0.0037 ppm of DDE. The probable method of the uptake of DDE and dieldrin by fox squirrels is through their diet. Pesticides wash from agricultural fields into small creeks and streams. Mast-producing trees probably absorb water containing the pesticides. The trees may store the pesticides in their seeds, where they become available to squirrels. Because the lactating adult females had the highest concentration of DDE, it is possible that nursing female squirrels pass pesticides through their milk to their young. Nixon and Havera conclude that DDE and dieldrin are apparently so wide- spread throughout the environment that they even occur in fox squirrels living in areas less intensively cultivated than east- central and other parts of Illinois. September 1977. No. 169. Published monthly except in July and August by the Natural History Survey, a division of the state Department of Registration and Education, operating under the Board of Natural Re sources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois Office of publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to sEORGE SPRUGEL CHIEF LLINOIS NATURAL HISTORY SURVE URBANA LLINOIS 61801 The Illinots NATURAL SURVEY Weevils, Crucifers and Men Horseradish is a crucifer grown for its fleshy pungent roots. Since the 1890's it has been produced commercially in Illinois in Madison and St. Clair counties near East St. Louis in an area called the ““Amer- ican Bottoms.” Half to two-thirds of all horseradish in the U.S. is produced in this area on roughly 1,000 acres by about 30 growers. Horseradish is propagated from thin side roots or “sets” trimmed from the main root at harvest and stored in coolers or under- ground pits through the winter. Planting is done in the spring with harvest of the large marketable main roots in October- November; a portion may be left for a spring harvest. In 1976 a program was begun by the Economic Entomology Section of the Nat- ural History Survey and the Department HISTORY of Plant Pathology, University of Illinois, to catalog the insects on horseradish and to determine possible vectors of brittleroot, a serious virus-like disease. In May, 1977 Survey researcher Dan Sherrod and exten- sion horticultural adviser Chris Doll found dark-blue weevils feeding on horseradish crowns and larvae damaging the roots (Figs. 1 and 2). Survey entomologist John Bouseman tentatively determined the wee- vil to be Baris lepidii Germar, an insect heretofore known to occur only in Europe and the U.S.S.R. Identifications of adults and larvae were confirmed by D. R. White- head and D. M. Anderson, USDA-ARS Systematic Entomology Laboratory, U.S. National Museum, Washington, D.C. In Europe B. lepidit is a pest of such crucifers as turnip, cabbage, cauliflower, and horseradish. Because of its threat to horseradish and other commercial cruci- Figs. 1 and 2. Adult (left) and larva (right) of Baris lepidii in horseradish roots. (Photo by Brian Melin, Survey entomologist) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. fers, the Illinois Vegetable Growers Asso- ciation successfully petitioned the state leg- islature to pass a special appropriation for research on the weevil. A team of Survey staff — entomologists Dan Sherrod, Cathy Eastman, John Bouseman, Roscoe Randell, and Clarence White with librarian Bonnie Irwin — has been organized to gather his- torical and biological information on the weevil, determine extent of its threat to horseradish, and develop cultural and chemical means of control. To date 90 percent of the horseradish acreage has been surveyed. The weevil sit- uation now appears to be more serious than was originally anticipated. Moderate to heavy infestations have been found in ~ 30 percent of the fields. While adult feed- ing on crowns is negligible, larval damage to roots can be severe. Larvae tunnel un- derneath the root surface and sometimes down to the heart. While some roots are killed by larval feeding, the primary result is reduction of root quality. Insecticide screening in laboratory and small-plot field trials has revealed two ma- terials that provide partial control of wee- vil adults. One, toxaphene, is already reg- istered for use on horseradish. Through the efforts of W. H. Luckmann, head of the Survey's Economic Entomology Section, an emergency exemption has been granted for use of another material—_ M+M, a commercial preparation of malathion and methoxychlor. High-gallonage applications (100* gal/A) have produced the best con- trol. The adults feed in the crown of the root, often below the soil surface making control with insecticides difficult. Examination of adults indicates that only a very small percentage can fly. ‘This information, together with observations made during the survey, may indicate that weevil infestations are most often a result of the planting of infested sets and the presence of weevil populations in vol- unteer horseradish in rotation crops rather than a result of inter-field movements of adults. Much remains to be learned about B. lepidu and its impact on Illinois crucifers. Research this winter will include determi- nation of the weevil’s life cycle in Illinois, evaluation of other crucifers as potential hosts, and development of a treatment of sets for destruction of eggs and larvae prior to spring planting. Flies: Who’s Who During the past year Survey entomol- ogist Donald Webb has been involved in systematic studies on the aquatic and semi- aquatic flies of the suborder Brachycera. As part of a world-wide revision of the family Athericidae, Webb has revised the two Nearctic genera Atherix and Suragina. This family of flies was recently erected by B. Stuckenberg of the Natal Museum to include several genera of flies throughout the world. This study involved borrowing speci- mens from some fifty museums and uni- versities, in addition to private collections. Over 1,500 adult and immature specimens were examined, involving three species of Atherix and three species of Suragina. The genus Atherix is common through- out Canada and the United States with numerous females collected as they aggre- gate in masses to lay eggs. Eggs are laid on stones or vegetation along streams into which the newly hatched larvae crawl. The larvae are aquatic and commonly col- lected in shallow stream rifles and vege- tation. ‘They are predacious and feed on a variety of stream organisms, in particu- lar caddisfly larvae. Before pupation the larvae migrate into the sand or debris along the shore to pupate. Adults emerge and can be collected from May through August. The genus Suragina occurs in south- western Texas and Mexico, south into the tropics. Adults are collected infrequently, although the females require a blood meal and impart a severe bite. The immature stages are unknown for the Nearctic re- gion. This study has involved the description of one new species of Atherix and the re- moval of two names to other genera of flies. Descriptions, keys, illustration of mor- phological characters, and the distribution of each species was presented. The study, appearing in an Entomological Journal this month, is one segment of an overall Fig. 3. Pileated woodpecker at nest entrance. (Photo by Richard Graber, Survey ornithologist) study to examine the phylogenetic relation- ships of several genera of lower bachycer- ous flies. Woodpeckers and Old Forest As various human activities reduce or alter natural habitats in one way or an- other, it becomes increasingly important from a conservation standpoint to under- stand more precisely the habitat require- ments of all populations. A study of Illinois woodpeckers (now in press) by Drs. Jean W. and Richard R. Graber includes anal- yses of the vegetation, habitat structure, and terrain used by these species in sum- mer and winter. Knowledge of seasonal variation in habitat requirements is essen- tial to the preservation of populations. In cases where the habitat of a given popu- lation differs from summer to winter, sur- vival of that population obviously depends upon some realistic balance in availability of the habitat requirements of each season. Perhaps the most striking example of seasonal habitat change among [Illinois woodpeckers is found in the red-headed woodpecker, which occupies primarily for- est-edge, savannah habitats in summer and mature bottomland oak forests in winter. Besides the habitat shift, there is also a geographic shift southward which brings large numbers of red-heads to southern [linois in winter. This population shows an interesting alternate-year cycle of highs and lows with especially high levels in the odd-numbered years (for example, Janu- ary 1975 and 1977). These large popula- tions are concentrated in bottomland (es- pecially pin oak) forest, which produces quantities of acorns on which the birds feed. Red-head populations are at least four times as dense in bottomland as in upland forest, and other woodpeckers also favor the bottoms. Pileated woodpeckers are at least three times more numerous in bottomland forest than in upland forest, and flickers and downy woodpeckers at least two times higher in bottomland for- ests. Only the hairy woodpecker had roughly comparable densities in bottom- land and upland, but the hairy still fa- vored old forest in both places. This habitat preference of the wood- peckers puts them at odds with human foresters, whose long-standing policy has been to cut old forest stands. The old bottomland forest stands are being deci- mated not only by foresters, but by farmers and reservoir builders. Only two old bot- tomland forest areas — Beall Woods in Wabash County, and Heron Pond-Little Black Slough in Johnson County — have been preserved in southern Illinois. Serious consideration should be given to the estab- lishment of similar forest preserves on all of the major Illinois streams. Such pre- serves would be important not only to the nesting and wintering populations but to the large numbers of transients that pass through the area in migration, spring and fall. Underlying these observations is an im- portant philosophical question on inter- national and national conservation. The question, simply put, is: “Does the legal owner (federal, state, and other) of a resource have a special obligation to the resource?” Consider the long-standing re- lationship of the red-headed woodpecker with the bottomlands of southern Illinois. The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 Much of that population comes from breeding areas outside of Illinois, but the birds are no less dependent upon their Illinois winter range. If we use waterfowl management as a precedent, the answer would seem to be that Illinois —its citi- zens — should protect the species’ Illinois habitats. However, nongame species have October 1977. No. 170. Published monthly except not received the same considerations as game species. Official policy on such questions should be established soon because of the present rapid pace of change. In addition, the pragmatic questions of costs and the im- portant biological questions about size and spacing of preserves need be answered. in July and August by the Natural History Survey, a division of the state Department of Registration and Education, operating under the Board of Natural Re sources and Conservation. Prepared by Dr. W. E, LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinors NATURAL HISTORY SURVEY Cristulariella Leaf Spot of Black Walnut The eastern black walnut is one of the most valuable hardwood trees in North America. Black walnut is valued not only for its wood but for other products. Since the 1960’s an expanded export market has increased the demand for walnut logs. In response to the greater market value of black walnut, the number of walnut plan- tations has increased in many parts of the U.S. Most of these plantings are pure stands of black walnut. From an economic viewpoint such practices are desirable: however, growing trees in monocultures greatly intensifies disease problems, which can easily reach epidemic proportions. In 1976 Survey plant pathologist Dan Neely and coworkers from the USDA Forest Service reported the association of Cristulariella pyramidalis, a leaf-spotting fungus, with the defoliation of black wal- nut plantations in southern Illinois in 1973 and 1975. This was the first reported occurrence of C. pyramidalis on black wal- nut. Neely and Robert Evers, former Sur- vey botanist, reported the occurrence of Cristulariella leaf spot on 20 species of herbaceous plants not previously reported as susceptible. The plants were native un- derstory vegetation in the black walnut plantations defoliated by C. pyramidalis. The fungus is known to have a wide host range. This disease is apparently sporadic, ap- pearing in mid-summer to fall. Cool, moist periods seem to favor disease development. In Illinois when the disease was reported on walnut, the mean daily temperature from mid-July through mid-August aver- aged about 75° F in 1973 and 1975, and extensive rainy periods occurred during these times. With these extended periods of rainfall and high humidity, complete defoliation of the walnut trees occurred within 4 weeks. The symptoms on infected walnut leaf- lets appear as round necrotic lesions. In- fected leaflets may have many ranging in diameter from | to 10 mm. The lesions often coalesce over large surface areas. ‘The small lesions are mostly white, and the larger lesions are brown with raised white concentric rings, giving the appearance of a bull’s-eye. Lesions along the veins tend to be wedge shaped. The asexual fruiting structure of the fungus is often seen on the lower leaf surface. The fruiting or pyra- mid shaped, resembling miniature white Christmas trees. Their shape is readily vis- ible with a hand lens. Since limited concerning this fungus, graduate student lesions. structures are cone information is available Molly Niedbalski initiated an investigation Leaf spots caused by Cristulariella pyramidalis on a black walnut leaflet. (Photo by Survey Photographer Larry Farlow) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. of the organism and its disease develop- ment on black walnut. The effects of medium, temperature, and light on the growth of the fungus in culture were tested. Greenhouse-grown black walnut seedlings were used in dis- ease-development studies conducted in lab- oratory growth chambers. An isolate of the fungus from naturally infected leaves was used to inoculate the seedlings. The effects of light, temperature, relative hu- midity, and free moisture were tested on lesion development and fungal sporula- tion. The unusual nature of the asexual fruiting stucture was also studied with the aid of Lee Crane, Survey mycologist. It appears that the entire asexual fruiting structure serves as the inoculum source in nature. When these studies are concluded, they will contribute to the understanding of the fungus and the conditions favorable to dis- ease development. Waterfowl Foods and Water Levels A 28-year study of the relationship of water levels to waterfowl food plants, and of these, in turn, to waterfowl populations is nearing completion. Low-water condi- tions during the summer months produce extensive mud flats in the backwater lakes of the Illinois River. Many moist-soil plants develop on the mud flats when the growing season is adequate. Studies by Frank C. Bellrose and his associates at Havana reveal that there is a significant linear correlation between the date when mud flats are exposed, the area exposed, and the growth of moist-soil plants. For maximum plant growth, water levels must decline enough to expose mud flats by June 15. After August 15 there is little germination of these plants and even less opportunity for them to produce seeds before frost. Because the reduction of the water level of the Illinois River was found to corre- late with the production of moist-soil plants, an evaluation was made of water levels and waterfowl abundance. ‘There was little correlation, none significant, be- tween the abundance of various species of ducks in the lakes of the upper Illinois River (above Peoria) and the summer de- cline of water levels from 1949 to 1976. This lack of significant correlation is understandable, because mud flats have begun to reappear in this region only in the last few years. The Peoria lock and dam raised the water levels of the upper Illinois River from 1939 onward, immers- ing mud flats previously exposed during low water. A high sedimentation rate has resulted in the increasing re-emergence of mud flats, so that by the summer of 1976 they were approximately as extensive as they were before 1939. However, in the river lakes below Pe- oria mud flats were not submerged by the ‘La Grange lock and dam (operational in 1939) to the same extent as were those above Peoria. Consequently, there is a sig- nificant correlation (linear regression) be- tween the degree of low water and the fall abundance of certain ducks. The abun- dance of the pintail showed the most in- fluence from the prolonged exposure of - mud flats in summer, followed by the green-winged teal, blue-winged teal, and wigeon. Other species failed to show a significant linear correlation between fall abundance and summer water levels. The mallard, the most abundant duck in Illinois, failed to show a linear corre- lation between fall population and sum- mer low water for two reasons: (1) yearly changes in continental mallard abundance and (2) waste corn in harvested fields that provides an important source of food. A partial correlation of the three vari- ables (mallard abundance in the lower II- linois Valley, low-water conditions, and fall continental mallard population) dis- closed that the size of the continental pop- ulation was more important than water conditions in determining the abundance of mallards in the Illinois Valley. How- ever, with the variable of continental mallard population changes weighted, sum- mer (low) water levels became a signifi- cant factor in affecting the fall abundance of mallards in the Illinois Valley. The lesser scaup, canvasback, ring- necked duck, and other diving ducks ap- parently rely so greatly upon animal life for food that their populations are not . ae —vy MR? ar, & Wigeons resting at a private sanctuary a few miles east of the Illinois River near Manito. The wigeon is one of the dabbling ducks whose fall populations in the Illinois River Valley are influenced by summer water levels in the river and the resulting exposure of mud flats and growth of moist-soil plants. (Photo by former Survey Photographer W. D. Zehr) significantly influenced by summer low water and the concomitant development of moist-soil plants. Thus, summer water conditions play an important role in the abundance of dabbling duck populations in the fall but have little or no effect upon the abundance of diving ducks in the backwater lakes of the lower Illinois River. Insect Movie in Production With the aid of a grant from a private foundation and in cooperation with the Morton Arboretum, economic entomolo- gist James Appleby is producing a 25- minute color motion picture on insects and mites that attack trees and shrubs in Illi- nois. Work on the movie was begun during the summer of 1976 and is progressing well. The film will depict insects feeding on trees and shrubs, providing action shots of their various developmental stages. Thus far, life stages of the cottony ma- ple scale, euonymus scale, lecanium scale, eastern spruce gall, Zimmerman pine moth, several cynipid galls on oaks, bronze birch borer, and birch and oak leafminers have been filmed. The work will be continued through 1978, with completion of the film scheduled for early 1979. The movie will be made available to public television sta- tions, garden clubs, nurserymen, and others. Kankakee River Studies Aquatic biologists from the Illinois Nat- ural History Survey have begun a four- year study of the Kankakee River and Horse Creek The purpose of the study is to obtain bio- near Custer Park, Illinois. logical, physical, and chemical data which will be used to evaluate any effects of the construction and operation of Common- wealth Edison Company’s Braidwood Nu- The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 clear Power Station and its associated cool- ing lake on animals, plants, and water quality of the Kankakee River and Horse Creek. Specifically, the study involves the col- lection of samples from a stretch of river located from about one mile above to one mile below the mouth of Horse Creek. R. Weldon Larimore is principal investi- gator, with Michael Sule coordinating field and laboratory operations in addition to studying fish populations along with Don Myrick and Jodie Smith. Other principal biologists include Larry Coutant and Carl Alde (periphyton), Steve Swadener and Gary Warren (benthos), Harry Bergmann and Jeff Hutton (fish eggs and larvae), Allison Brigham (general chemical param- eters and bacteria), and Ken Smith (heavy metals and pesticides) . Preliminary data have indicated diverse benthic and fish communities. ‘The benthic study has incorporated a variety of tech- niques (dredge samples, artificial sub- strates, invertebrate drift collections, light trap collections, and a rearing program) to examine the dynamics of the river-bot- tom invertebrate community. Dredge sam- ples taken in April 1977 revealed 65 in- vertebrate taxa, including 27 genera of Chironomidae. ‘The predominant organ- isms have been mayflies, caddisflies, riffle beetles, and midge larvae. The fish study also involves various col- lection methods, including electrofishing, seining, and hoop net sets, to insure ade- _quate sampling of the fish population. Sampling has already indicated a great variety of species and good populations of sport fishes. Populations of such fishes as walleye, northern pike, smallmouth bass, rock bass, and the northern longear sun- fish offer an opportunity to study the life histories and population dynamics of sev- eral fish species not common to many parts of the state. Several aspects of the ecology of the Kankakee River have already become ap- parent even though the study covers only a restricted part of the river. The Kanka- kee River is one of the finest flowing-water environments in Illinois and supports di- verse populations of vertebrate and inver- tebrate species. The fine water quality and unusual and diversified habitats present in the river system are responsible for the overall excellent rating which this river has received in the past. The contract be- tween Commonwealth Edison Company and the Survey will make it possible for the Natural History Survey to study the dynamics of this distinctive midwestern river and to gather data which will help determine the effects of the establishment of a nuclear power plant in the watershed. November 1977. No. 171. Published monthly except in July and August by the Natural History Survey, a division of the state Department of Registration and Education, operating under the Board of Natural Re- sources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 | The Illinois NATURAL HISTORY REPORTS Illinois Natural Areas A recent report “Some Unusual Natural Areas in Illinois,” published by the Survey as Biological Notes No. 100, is an expanded revision of a 1963 publication. The earlier work, authored by Survey botanist R. A. Evers, botanical and scenic features of natural areas in Illinois. For the new publication, Evers was joined by Survey zoologist L. M. Page, and un- usual animals as well as plants and scenic was a report on characteristics are discussed. The revision includes descriptions of 33 natural areas. Among the areas discussed in the revision that were not included in the original report are Chain O’Lakes State Park, Iroquois County Conservation Area, Middle Fork of Vermilion River, Embarras River, Illinois Caverns, and Big Creek. Chain O’Lakes State Park and Conser- vation Area in Lake County encompasses an area composed of glacial lakes, marshes, disturbed oak woodland, and wet prairie. The Illinois where black ferns and long billed marsh area is one of the few in wrens can be observed. Among the un- usual fishes found in the glacial lakes are the pugnose banded killifish, brown bullhead, and Iowa darter. Rare or uncommon plants include shiner, blackchin — shiner, the beaked spike rush, tufted bulrush, pitcher plant, twig rush and grass of Par- nassus. Iroquois County Conservation Area is adjacent to the Willow Slough Wildlife Refuge in Newton County, Indiana, en- hancing the area as a biological refuge. In and near the area are small to medium- sized streams with sandy bottoms, masses View of Big Creek in Hardin County, a rocky spring-fed stream. (Photo by Survey zoologist Larry Page) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. of submerged vegetation, and headwater marshes. In these streams are fishes pe-_ culiar to sand areas, including the iron- color shiner and weed shiner, and other uncommon fishes such as the lake chub- sucker, starhead topminnow, and _ least darter. Sand-inhabiting reptiles found here but normally more western in distribution are the bullsnake, ornate box turtle, and six-lined racerunner. Among the unusual plants in the forest and prairie are colic- root, white-bract hymenopappus, and nod- ding ladies’-tresses. Middle Fork of the Vermilion River in Vermilion County is a high-gradient river with many boulder riffles, clear pools, and extensive raceways over gravel and sand. Many of the raceways are bordered by emergent vegetation. The river has a large variety of aquatic animals that are unusual in Illinois, and the floodplain and bluffs harbor a great diversity of plants and wild- life. The bluebreast darter, a small and brightly colored fish, is found in Illinois only in the Middle Fork, and the rare and unusual salamander, Ambystoma platineum, occurs in Illinois only in wooded areas along the Middle Fork. The Embarras River from Greenup to Newton, in Cumberland and Jasper coun- ties, is unpolluted and mostly unmodified and represents one of the finest aquatic natural areas in Illinois. The river and its environs are sufficiently wild to sup- port populations of the timber rattlesnake and a small fish, the harlequin darter, known to occur nowhere else in Illinois. Illinois Caverns, in Monroe County, is also known as Mammoth Cave of Illinois, Eckert’s Cave, and Burksville Cave. The cave has a number of interesting and un- usual animals including one scud, Gam- marus acherondytes, known only from caves in Monroe and Randolph counties, Illinois. Also found in the cave are cave- adapted (often white and eyeless) milli- pedes. Big Creek is a beautiful, clear, rocky, spring-fed stream in Hardin County that is a near facsimile of some of the Ap- palachian streams of Kentucky and Ten- nessee. The stream has populations of three rare crayfishes, relict populations of “was northern fishes, and several other fishes with very limited distributions in Illinois. These organisms inhabit Big Creek because of its large influx of spring water and pre- ponderance of rocky substrates. A historic attraction on the watershed is Illinois Furnace, the site of an early iron works in Iilinois. Bantam Sunfish in Illinois Of the seventeen sunfishes occurring in Illinois, eight are members of the genus Lepomis which includes several species fa- miliar to local fishermen and naturalists. One species, the bantam sunfish, Lepomis symmetricus, is very rare in Illinois and formerly poorly known even to ichthyologists. The taxonomy, distribution, and life history of this species were the subjects of a study recently published by former Survey ichthyologist B. M. Burr. Copies of this publication, Ilinois Natural History Survey Bulletin 31, article 10, may be obtained free by writing to the Chief, . Illinois Natural History Survey. The bantam sunfish was first discovered near Pekin, Illinois, and was later de- scribed by Stephen A. Forbes, former chief of the Survey. The species is found in len- tic waters characterized by submerged logs, standing timber, and rich vegetation and presently occupies the Coastal Plain prov- ince in the mid to lower Mississippi River valley. The life history portion of the study involved two years of field and labo- ratory observations made on a population in Wolf Lake, Union County, Illinois. The bantam sunfish was found to occupy vege- tated margins of the lake, to live a maxi- mum of 3.4 years, to grow to a maximum length of 76 mm, and to feed primarily on gastropods, crustaceans, and immature aquatic insects. At one year of age and a minimum of 34 mm, the bantam sunfish spawns in nest depressions formed by the male. Up to 1600 eggs may be laid by a single female. Males are aggressive during courtship and sometimes cause the death of their female partners. Examination of museum specimens re- vealed that the bantam sunfish shows lit- tle morphological variation throughout its range. In some countable characters popu- size lations along the Gulf Coast have lower average values than those in southern IIli- nois. The bantam sunfish was at one time known from the Illinois and Wabash Rivers but has not been taken in these waters since the 1880's. A reduction in aquatic vegetation, the draining of natural lakes and the stocking of non-native sun- fishes are presumed causes for the decima- tion of the species in Illinois. Because of the limited habitat now available to the bantam sunfish in Illinois, it has been placed in a threatened category in Illinois’ latest list of endangered and threatened species. The study on the bantam sunfish was the eighth life history study on Illinois fishes completed at the Survey. Detailed life history studies provide information to persons conducting environmental studies and contribute to our knowledge of the lesser known non-game fishes. Fox Squirrel and Winter Food Fox squirrels eat a wide variety of foods. In the fall, early spring months, however, tree seed or mast is their winter, and primary source of nutrition. In sparsely timbered areas, fox squirrels will often eat corn, soybeans, and osage orange seeds during the critical winter months. From December through March, 1975 to 1977, wildlife biologist Stephen P. Havera fed nine diets to adult female fox squirrels housed in an_ environmental chamber programmed for average Janu- The bantam sunfish, Lepomis symmetricus. (Photo by Sur- vey photographer Larry Far- low) ary conditions of east-central Illinois. The diets tested of black, white and bur oaks; nuts of shagbark and mockernut and black walnut: and corn and soybeans. The amount of food consumed, feces and urine excreted, and changes in body weight were moni- tored during the experiments. were acorns red, hickories The average weight change per day of the squirrels on the various diets somewhat paralleled the amount of energy metabo- lized on each diet. White oak, which had the highest amount of energy metabolized per day, also resulted in the largest in- crease in weight of the squirrels. Squirrels fed mockernut hickory metabolized the second highest amount of energy per day and showed the second largest average in- crease in weight. Squirrels fed red oak and corn germ diets had the lowest amount of energy metabolized per day and were the only groups to have average weight losses during the feeding trials. These that the signifi- cantly higher assimilation coefficients and higher caloric values for shagbark and mockernut hickory nuts require that adult female fox squirrels eat about 59 percent more black oak than hickory nuts to attain a similar level of metabolized energy. All of the acorns had results reveal white, bur. and acorns assimilation coefh- oak drastically from the other oaks in the about the same cients; however, red acorns differed amount of energy metabolized per day. Correspondingly, the red oak diet was the The Illinots NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 only oak diet on which the squirrels showed an average weight loss. Red oak acorns are apparently less palatable to fox squirrels than white, bur, or black oak acorns. 2 Because fox squirrels ate more white oak acorns, metabolized more energy from them, and gained more weight than on any other acorn diet, white oak acorns are apparently highly palatable to fox squir- rels, as they are to other wildlife species. Fox squirrels do not acquire as much energy per day, or extract energy as effi- ciently, from grain crops of corn and soy- beans as they do from mast crops with the exception of red oak acorns. December 1977. No. 172. Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. La Berge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots NATURAL HISTORY REPORTS More on Herons Wildlife specialists Jean and Richard Graber are presently analyzing data on Illinois herons, including a survey begun in 1973 of major colonies of the two larg- est Illinois species — the great blue heron and the great egret. As reported earlier, the available historical data strongly sug- gested that breeding populations of these Illinois. Other possible interpretations were that two species were declining in the colonies were moving about or that the populations were fluctuating up and down (as natural populations do), and that the data for recent years happened to represent low years. That still exists, but the knowledge gained from extensive air and possibility ground searches of much of the state’s suitable habitat for herons is not reassur- ing. Few new colonies have been found Although some colonies show the expected pattern to make up for colonies lost. of annual gains and losses, the over-all state population shows a progressive yearly decline of between 12 and 18 percent from 1973 to 1977 for the great blue heron and an average annual loss of 25 percent for Fig. 1. The Great Blue Heron. (Photo by former Survey bi- ologist George Bennett) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. the egret, including a 55 percent loss be- tween 1975 and 1976. The situation ap- pears very serious and calls for special measures of protection. Recoveries of great blue herons banded in Illinois (especially those banded by Kar] Bartel of Blue Island) show the high cost to great blues of unwariness. About two- thirds of the fledged young are lost in the first year, most in the first six months, after which their chances of survival im- prove. The most common cause of death cited is shooting. In earlier years, the pop- ulation could apparently sustain such losses and survive, but this is not true now, and hunters should be apprised of the harm being done. Unfortunately, the problem extends all the way to Central America, where some IlIlinois-raised great blue her- ons winter. We do not know whether mor- tality from illegal shooting is increasing, but even at the rate the herons have been killed in the past, it would take a produc- tivity rate of about 2.8 young per adult pair to sustain the population. The very best average of young per nest observed by the Grabers was 2.5 young, not count- ing nests that failed completely. Better information is needed on produc- tion of young and on the entire nesting cycle; however, one cannot study a colony without disturbing it, and disturbance in- creases food loss to young and perhaps nest- ling mortality. Yet, without such studies, we cannot hope to learn how to preserve the populations. Careful studies by respon- sible students should be encouraged, and every effort should be made to reduce hu- man traffic in the vicinity of colonies, roosts, and the heron fisheries. The fisheries are generally located within six miles of the colony, often within a mile, and need to be protected as rigidly as the colony site itself, preferably closed to human traffic from March to September. The question of whether the heron’s problems are related to pollution has re- ceived little attention. Because great blue herons nest so high, gaining access to their nests involves great disturbance to the col- ony. Thus, there are no data on hatching success as a possible clue to pesticide in- toxication, and no historical perspective on hatching and fledging rates from which to judge whether these rates are changing. At present the knowledge, if it is obtained, may come too late. Although herons com- prise a tiny fraction of the Illinois fauna, for most groups of organisms we do not even know whether the population is changing, let alone why. The Sam A. Parr Fisheries Research Center The INHS field station near Kinmundy is one of the many fruitful results of a life- span of friendship and cooperation be- tween Sam A. Parr and George W. Ben- nett. Sam was for many years the Assistant -Director and chief mover and shaker in the Illinois Department of Conservation, and George was the distinguished Head of the Section of Aquatic Biology in the INHS from November, 1943 until his re- tirement in January, 1974. Both are now deceased and have become legendary fig- ures in conservation circles in I[]linois. The station was established in 1963 as the Mar- ion County Fisheries Research Center. Fol- lowing Sam’s death in November, 1966, George officially dedicated the station as the Sam A. Parr Fisheries Research Center in recognition of Sam’s many contribu- tions to the sportsmen of [llinois, and be- cause of his long friendship with the Sur- vey. The Station sits as an adjunct to the Stephen A. Forbes State Park in order to tap the park’s 237-ha reservoir as a water supply for the experimental ponds. Origi- nal construction included 9 drainable 1- acre ponds completed in 1963. Five addi- tional smaller ponds were added in 1965. Original station personnel included Homer Buck, Charles F. Thoits, III, and Russell Rose. Thoits left the Survey in 1969 and was replaced by R. J. Baur. The small original staff shared the office of the park ranger in 1964-1965 and later occupied a renovated chicken house until the present quarters were completed in the spring of 1967. The present laboratory comprises about 2,700 square feet, containing an of- fice, fish lab, limnological lab, dark room, large tank room, and a combination li- brary and conference room. Additional fa- cilities include two storage and_ service buildings and an outdoor array of 3-meter diameter experimental pools. The first major project at this new sta- tion was to assess the time-honored but untested concept that individual ponds will have inherent productive potentials that will cause them to rank high, low or intermediate on a rather permanent basis. The 4-year study revealed a startling and previously unconceived range of variations, not only from pond to contiguous pond, but by individual ponds in consecutive years. The conclusion was that whether a pond ranked high or low in a particular year was largely due to chance. The major element of chance was believed to be the differences in rates at which, or pathways by which, available nutrients were cycled through the systems. The published results brought the authors an award for the most significant paper published in the Trans- actions of the American Fisheries Society in the year 1970. Because of the surge of interest in chan- nel catfish farming, a series of studies were initiated in 1968 to evaluate the potential and problems surrounding the production and/or management of the channel cat- fish in Illinois, and the interrelationships with such associated species as largemouth bass, bluegills, and golden shiners. Experi- ments were conducted in pools, ponds, cages and raceways, and the results have been published. In 1972 a series of studies were initiated to compare the life histories and produc- tivities of the largemouth and smallmouth basses, first as single species, later in asso- ciation with bluegill, channel catfish and grass carp. Specific evaluations also were made of the influence of both the bluegill and the grass carp on bass production, and of the efficiency of the grass carp as a biological control of aquatic weeds. Ad- ditional projects now in progress involve (1) the production of sport fishes in ponds enriched with swine manure, and (2) the use of Chinese carps in the recycling of organic wastes. The studies are yielding useful information in such critical areas as waste management, water quality con- trol, and the production of protein. New Aquatic Fungi It is difficult to characterize an aquatic fungus or even define the aquatic environ- ment itself. Nearly any fungus that can be grown in submerged shake culture is po- tentially aquatic. Furthermore, there are micro-aquatic habitats such as the aqueous phase between soil particles, slime fluxes of trees, nectaries of flowers, and films of sugar solution on the surface of ripe fruit each of which has a fungal flora. The work of Survey botanist, J. Leland Crane, is presently limited to large volumes of fresh water such as swamps, streams, riv- ers, ponds, and lakes, and an aquatic fungus is regarded as any fungus that is normally completely submerged in these habitats for some period of its life cycle. Aquatic Ascomycetes are abundant in freshwaters, their richest source being sub- merged, dead stalks of reed swamp plants and submerged wood in the form of water- logged sticks of various kinds of trees. This submerged aquatic Ascomycete flora is large and poorly known, and many species remain to be described. There is also a large flora of the asexual stages of fungi such as aquatic Hyphomycetes found grow- ing on submerged decaying leaves and twigs of broad-leaved trees and shrubs in well-aerated water or aquatic Sphaeropsi- dales which are also not uncommon on submerged, dead, reed swamp plants. The taxonomy of both these groups is in need of careful study. Fig. 2. Scanning electron micrograph of Trichocladium on submerged balsa wood (XI,020). (Photo by J. Leland Crane) The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 Recently, in research leading to the identification of the fungi encountered in these aquatic habitats, Lee Crane found a new species belonging to the genus T’r1- chocladium Harz. This species was col- lected from a cypress swamp in southern Illinois containing large quantities of de- caying vegetation consisting mostly of sub- merged and floating aquatic plants and litter from cypress and tupelo trees. ‘The swamp becomes extremely anaerobic in the summer and in the winter when it is covered with ice. However, oxygen con- centrations are high in the spring due to photosynthesis of aquatic flowering plants and algae before light is limited by leafing- out of the canopy of trees. ‘The new species of Trichocladium is characterized by soli- tary or aggregated conidia with 3-4 septa that are of two distinct morphological types. This Trichocladium species is marked by the reticulate ridges on the surface of the spores as in the figure. The fungi of aquatic habitats is so poorly known because mycologists have traditionally devoted most of their time to the study of terrestrial fungi. In re- cent years, aquatic fungi have received increased attention largely due to man’s concern with environmental aspects of aquatic ecology. Pollution of our streams, rivers, and lakes is common; therefore, knowledge of the kinds, frequency, dis- tribution, and role of aquatic fungi in these situations is important. Custom Spray Operator’s School The Thirtieth Custom Spray Operator's Training School was held January 3-5, 1978, at the University of Illinois. The Ground Sprayer’s Association and Aerial Applicator’s Association held a program January 3 at the Ramada Inn, Cham- paign, directed at those persons in custom pesticide application. The formal program was held at the Illini Union on January 4 and 5. Speakers from the University of Illinois, and several invited speakers from outside the University, presented talks on the many facets of agricultural pesticides. The Custom Spray School began in 1949, the brainchild of H. B. Petty, then Extension Entomologist. Even at that early date it addressed problems in application, safety, laws and regulations, and effective pest control. Attendance has grown steadily over the years to a record of 1,705 in 1977. Now under the leadership of Steve Moore, Extension Entomologist at the University of Illinois and the Illinois Nat- ural History Survey, the Custom Spray School has become renowned throughout the Midwest drawing people from as far away as California, Kansas, and Ohio. January 1978, No. 173. Published monthly except in July and August by the Natural History Survey, a divi sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. Office of publication 175 Natural Resources Building, Urbana Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 61801 The Illinots NATURAL SURVEY” Sulfur and Ecosystem Productivity In recent years, society has been con- cerned with adverse effects of acid com- pounds of sulfur circulating in our atmo- sphere, primarily as the result of burning fossil fuels and smelting of ores. These concerns relate to human health, deteriora- tion of man-made structures, and the gen- eral health of our ecosystems. Adverse effects are particularly apparent where ecosystems have developed on rock and geologic materials that are inherently acid or of low buffering capacity. In an appendix in their newest book, The Biogeochemistry of Blue, Snow and Ross’ Geese, Harold C. Hanson and Robert L. Jones have presented examples of the asso- ciation of high biomass production (partic- ularly animals) with high concentrations of Virginia or white-tailed deer. (Photo from the Wis- consin Department of Conservation) Material in this publication may be reprinted if credit is given HISTORY sulfate in saline environments. For example, the western prairies are rich in sulfates of calcium, magnesium and sodium. Because rainfall doesn’t exceed evapotranspiration, these nutrients are retained in the upper soil horizons rather than being leached or lost to surface runoff. The capacity of the high plains to sustain huge numbers of ungulates, particularly buffalo downwards (bison), can be related not only to protein rich grasses, but also to a Juxury consump- tion of minerals thereby permitting bac- teria and protozoa of the rumens of the animals to synthesize additional proteins and particularly to use sulfates present in the environment. One has only to read Audubon’s journal from his travels of the upper Missouri River to appreciate the wealth of wildlife produced on the prairies. But what of the wood buffalo of the coniferous forest zone of northern Alberta? A review of the en- vironment of these northern buffalo reveals that large portions of their range south of Great Slave Lake is strata of calcium sulfate underlain by gypsif- . An area north of the western portion of Great erous rocks Slave Lake is characterized by alkali (sul- fate) encrusted botoms of dried out ponds. A desolate and seemingly unproductive appearing area, but buffalo, reintroduced to their former range, thrive there. Anal- ogous to this mineral encrusted environ- ment is the former range of the buffalo in a part of Wyoming where the vegetation was mineral encrusted, but the area never- theless produced the best buffalo in respect to carcass condition, according to a frontier trapper J. Osborne Russel. to the Illinois Natural History Survey. The range of the buffalo extended into the eastern and southeastern states, but _ early accounts indicate the relatively small scattered herds of his region were greatly dependent on mineral licks for their nutri- tional welfare and possibly survival. One early writer refers to “the sulphur or salt springs” at one of the famous lick sites in Kentucky. The thesis that sulfur-rich en- vironments nutritionally benefit ruminants is also supported by a study which showed that sulfate-supplemented feeds given cat- tle and sheep increased the amino acids in the rumen by nine to twenty times. Do these observed associations of wild ruminants with high-sulfur environments have any implications for the present-day livestock industry? In recent weeks, the news media have featured the experience of three Georgia farmers who obtained greatly improved growth from steers fed kiln dust produced by cement manufactur- ing plants. These findings have been con- firmed by feeding experiments by U.S.D.A. scientists at Beltsville, Maryland. The sci- entists were unable to provide a rationale for the gains they found in feeding samples of the cement dust. Hanson and Jones hypothesized on the basis of their studies of sulfur in the environment that part of the gains relate directly to the sulfur content of the dust. Cement, apparently by design, con- tains 4-5 percent gypsum. The kiln dust fed the experimental steers contained 2.33 per- cent sulfur. Thus, the microflora of the rumen had an abundance of readily avail- able sulfur for the synthesis of sulfur- containing amino acids. Proteins cannot be synthesized unless all the amino acid build- ing blocks are simultaneously available. The microflora of the rumen synthesize the amino acids that the cow and all other mammals cannot synthesize by virtue of their physiology. ‘The protein increment ab- sorbed above dietary intake is obtained from the bacteria and protozoa in the ru- men. This manufactured protein passes into the digestive tract for digestion and absorption. Jones and Hanson are currently studying the composition of mineral licks of wild ungulates across the continent. Among the elements of physiological importance, sul- fur and/or calcium are consistently abun- dant in these samples. In light of these find- ings and the news releases regarding the virtues of feeding cattle kiln dust produced in manufacturing cement, the following notation which accompanied a “lick” sample furnished by R. E. Keiss, a game biologist with the Colorado Division of Wildlife, is particularly meaningful: “This material is from an area where ready- mixed concrete trucks are washed. Bighorn sheep have started using this area and are specifically seeking out this material.” When wet, soils of the alkaline country of the West became anaerobic due to bacteria which reduce sulfates to sulfides. ‘The soils then appear to be conducive to the proliferation of the bacterium Clos- tridium botulinum Type C which produces toxins deadly to waterfowl and other birds. If an association of Clostridium with high sulfate soils seems suspect, how do we ex- plain the fact that the only site in Wiscon- sin where botulism outbreaks occur with . any regularity is at the mouth of the Fox River at the south end of Green Bay? It is significant that 17 paper companies south of Green Bay have dumped sulfite liquors into the Fox River for many years and that Type E phase of the botulism orga- nism has been found in fishes in Green Bay. Is the source of these infections — to which fish are apparently immune — also related to sulfur-rich sediments that pre- sumably characterize the bottom of the south end of Green Bay? Can the massive die-offs of loons from botulism that have occurred in the fall on Lake Michigan have their origins in the sulfate pollution of Green Bay waters? The hypothesis that sulfur compounds are primary constituents of both “salt licks’ and wet soils associated with botu- lism outbreaks came full circle with the finding of a report on a lick heavily used by deer in southern Ohio. Sulfate was one of the major constituent ions found in this lick, and it had to be fenced off, for the deer using it were dying of botulism! Nevertheless, in an aerobic situation, sulfate-rich waters of the prairie are highly productive of invertebrates which in turn form the base of the notable duck produc- ss ape eae’ ~ oh tion on the pot-hole sections of the western plains. It is significant that the largest fairy shrimp known, Branchinecta gigas, is found in the “salt and soda sloughs” of southeastern Alberta. A recent irruption of “supershrimp” (Axius serratus) occurred in the Straits of Canso, Nova Scotia. Once thought to be extremely rare, these bur- rowing shrimp established dense popula- tions in a highly polluted section of the straits. What were the polluting industries? A gypsum dry wall plant and a pulp and paper mill discharge wastes to these waters. Sulfates and sulfites as well as organic wastes would be major components of such waste discharges. Perhaps a capstone to the hypothesis of Hanson and Jones that an abundance of available sulfur has a pro- found effect on biomass production is the dramatic recent discovery of a rich oasis of invertebrate life found off the Galapagos Islands and attributed to a food chain that has hydrogen sulfide as its base (National Geographic Magazine, October 1977). A mineral lick in Pennsyl- vania. Soil around rocks has been mined and eaten by deer. (Photo by J. S. Jordan, U.S. Forest Service, Warren, Pennsylvania) Numerous other examples have been located by Hanson and Jones, but in es- sence the investigators believe that the role of sulfur in ecological productivity is neither adequately understood nor ap- preciated. Alfalfa Weevil Parasite Production Many species of parasitic hymenoptera have been imported and released in the U.S. and Canada to help regulate popula- tions of the alfalfa weevil, Hypera postica (Gyllenhal). One of the most important and successful species to be introduced is Bathyplectes curculionis (Thomson), an endoparasite of alfalfa weevil larvae. Through initial releases in 1911, subse- quent releases, and natural dispersal, cur- culionis is now established throughout the range of its host. Dynamic models of the alfalfa weevil’s life system are being developed by Survey entomologist W. G. Ruesink for use in pest management programs. Since curculionts is The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 such an important natural enemy, it is essential that these models include its effect on the weevil. Among the more important processes in the parasitism submodel are: 1) egg production and deposition by the parasite, and 2) distribution of those eggs among available hosts. Writing equations to describe these processes is relatively simple once the biological relations are described quantitatively. Although there is an abundance of literature pertaining to curculionis, only a few researchers have dealt with quantitative aspects of the host/parasite interactions, or with the effect of these interactions on the popula- tion dynamics of the alfalfa weevil. Survey entomologists R. J. Barney and D. P. Bartell used several laboratory ex- periments to determine the effect of host density, temperature, and parasite age on the reproductive potential of curculionis. They found that nearly 100% of the host larvae were parasitized at very low host densities, while at very high host densities each parasite would attack about 30 hosts per day. In the laboratory, this parasite did not differentiate between unparasitized hosts and those already parasitized ; instead it laid its eggs at random among all avail- able hosts, even though only a single para- site can succesfully mature in one host. Temperatures ranging from 10° to 30° did not affect the number of hosts para- sitized. This means that curculionis can find and attack alfalfa weevil larvae suc- cessfully over the range of temperatures normally encountered in Illinois alfalfa fields. The age of the adult parasite strongly controls its ability to parasitize hosts. Dur- ing the first day of its life, each adult laid an average of 5 eggs, while on days 2, 3, and 4, averaged about 15 eggs per day. After the 4th day, very few eggs were laid, and the average age at death was 4.8 days. Equations have been written to fit these findings, and the equations have been in- corporated into the alfalfa weevil model. This is an example of the interaction be- tween biological research and population modeling that frequently occurs: in devel- oping a model for whatever purpose, gaps in our understanding are revealed and re- search must be performed to provide the needed information. February 1978. No. 174, Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation Prepared by W. E, La Berge with the collaboration of the Survey staff. postage paid at Urbana, Illinois, es Building Second-class Office of publication: 175 Natural Resourc Urbana Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 | | The Illinozs NATURAL HISTORY REPORTS Research on Urban Tree and Shrub Problems For several years, [linois municipalities have invested considerable sums of money for trees to replace American elms killed by Dutch elm disease. These investments have generally improved the physical environ- ment of municipalities and have increased the aesthetic value of both private and public property. However, due to various ecological, horticultural, and pathological problems, many of the replacement trees have not survived or produced satisfactory growth. Consequently, plant pathologist Gene Himelick has initiated an extensive research effort to determine specific causes for poor survival and growth rates and to develop practical transplanting and other cultural practices that will contribute to increased plant survival and improved vigor. The research effort will give a basis for amending and expanding the specifications for species selection, planting, and mainte- Elms arching above an urban street. This photograph was taken in a city which has an effective disease control program, but in many cities the elms have died and are being replaced with other tree species. (Photo by Gene Himelick) Dutch elm Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. nance, and it will result in such tangible benefits as a shorter establishment period and fewer replacements following planting. Not only will this research offer the poten- tial for reduced establishment and mainte- nance costs in the future, for both the private homeowner and the municipality, but it will also contribute substantially to the improvement of the physical-aesthetic quality of urban areas. Several municipalities have been ap- proached to assist in financing this research, and grant support has been received re- cently from four major cities. The research is divided into three major phases. To complete each phase will re- quire a minimum of 3 years of field work. Phase I involves the surveying of several thousands of recently transplanted trees to measure and record data on existing woody plants along municipal parkways and streets in various municipalities in Illinois. Phase II will involve identification and measurement of causes of decline in estab- lished trees in several randomly selected municipalities. In phase II the researchers will also attempt to determine which tree species, varieties, and clones do well under urban growing conditions. Tree clones showing disease and insect resistance and outstanding form and growth character- istics in the field surveys will be propagated for future evaluation and recommendation for commercial nursery production. Phase III will include intensive studies to mea- sure the effects of various horticultural and transplanting practices as they relate to mechanical root injury, root regeneration, and diseases of tree roots which develop after transplanting. Read Any Good Books Lately? The library of the Illinois Natural His- tory Survey was founded at the first meet- ing of the Natural History Society of Illi- nois in 1858 and has always had an official librarian, a professional since 1906. The original collection consisted mainly of re- prints received by the members of the society and publications received through an exchange program. In 1861 the society received its charter from the state legislature and was located at Normal. It became the Illinois State Laboratory of Natural History in 1877. It was transferred to Urbana in 1885 so that the laboratory director, Stephen A. Forbes, could also serve as professor of zoology and entomology at the Illinois Industrial Uni- versity. Dr. Forbes brought the library with him, and in 1928 it became a part of the Uni- versity of Illinois Library, with the collec- tion kept separate but made available to university students and faculty. The Nat- ural Resources Building, which houses both the Illinois Natural History Survey and the Illinois State Geological Survey, was built in 1940. At that time the Natural History ‘Survey Library became a full departmental library of the University of Illinois Library. An agreement was reached between T. H. Frison, Chief of the Survey, and C. M. White, Director of the University Librar- les, providing that the Survey would pro- vide the building, furniture, and staff for the library and the University Library. would provide a budget for the purchase of books and serials and do the technical processing. The library is arranged according to the Dewey Decimal System and contains about 32,000 volumes. The collection is about 80 percent serials and 20 percent monographs. A few items are on either microfilm or microfiche, and the library has a reader for each. The exchange program, which began in the 1800’s, has been maintained and ex- panded to the extent that about two-thirds of the library’s serials come from exchange partners. The Survey sends its publications to over 550 institutions throughout the world, and in return receives their publica- tions for the library collection. The subjects covered in the collection reflect the research projects done by the Survey staff through the years. Entomology is the area covered most thoroughly, but there are extensive works also in botany, ichthyology, ornithology, wildlife, aquatic biology, and economic entomology. The library is open to the public as well as University of Illinois students and fac- ulty and Natural History Survey staff members, and the librarian is available to Ha Illinois Natural History Survey Technical Librarian Doris Sublette reviews periodicals for articles that may be of interest to Survey staff members. (Photo by Survey photographer Larry Farlow) help in locating books and articles and in making a search for literature relevant to subjects in the area of natural history. Only members of the Survey staff may check materials out of the library, but the library has a copying machine for the use of its patrons. As a part of the University of Illinois Library, the Natural History Survey Li- brary participates in the extensive inter- library loan system, making its materials available to libraries worldwide. The INHS Library is an affiliate library of the Lincoln Trail Library System and is a member of an informal group called IPAHGEIS (Inter-Professional Ad Hoc Group for Environmental Information Sharing). Release Cutting for Hickories Hickory seed is a primary food of Illinois squirrels, particularly during the fall and early winter, when both gray and fox squirrels are rapidly gaining weight and storing body fat. hickories have slow growth, generally poor form, and low market value, Because foresters usually have ignored them in their silvicultural studies of midwestern hardwoods. Hickories are relatively toler- ant of shade and seem to increase best under light cutting, where the canopy re- mains intact and the faster growing trees that are intolerant of shade are unable to take over in the understory. The recent switch from selection cutting to clear-cut- ting threatens to reduce the amount of hickory in future stands. Survey wildlife biologists Charles Nixon and Lonnie Hansen are investigating a number of methods for insuring that at least a few hickories reach seed bearing size in these hardwood clear-cuts. One approach involves release cutting around selected hickory stems in 7- and 15-year-old clear-cuts, where all competing stems are removed from around a suppressed hickory. The investigators selected 2+ pairs of hickory sprouts in a 7-year clear-cut and 40 pairs in a 15-year clear-cut. Stems were paired by species, total height, and stem diameter at | meter, and one stem of each pair, selected by coin flip, was re- leased by cutting out all competing stems. after Three growing seasons release, The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 stems of pignut, mockernut, and shagbark hickories averaged larger stem diameters and shorter heights than the control stems. Released stems of 15-year-old mockernut hickories were significantly larger in diam- eter and significantly shorter in height than comparable control stems. Stem diameter and height growth of released stems did not differ significantly from their paired controls for either shagbark or pignut hickories at 7 and 15 years. The reduction in height growth shown by released hickories is apparently a normal response to sudden release from competi- tion. Such a response has been reported for released stems of red oak, tulip tree, black cherry, and yellow birch. However, basing their conclusion on the results of release cutting for these species, the Survey biologists expect their released hickory stems to grow at a faster rate than the controls during the next few growing seasons. They plan to remeasure all stems after five growing seasons, at which time they hope to be able to determine if a single release cutting is a feasible means of — insuring that some hickories will reach seed bearing size in clear-cuts. March 1978. No. 175, Published monthly except in July and August by the Natural History Survey, a divi sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation Prepared by Robert M, Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois Office of publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to SEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 61801 The Illinots NATURAL HISTORY REPORTS Winter Feeding of Squirrels Winter is considered a critical period for fox squirrels (Sciwrus niger), and it is a breeding season for both fox and gray squirrels (S. carolinensis). The winter sur- vival of potential breeding squirrels and their reproduction depend mainly on the size of the fall tree seed crop (mast) and on the severity of the winter. In winters of low mast and severe weather, squirrel populations may suffer. Fox squirrels readily eat corn during the winter months. Gray squirrels may not eat corn as readily as fox squirrels, but it may be part of their diet. Some biologists be- lieve that under certain conditions, winter feeding may be of value to squirrels. Shelled corn has been used in winter feed- ing of fox squirrels and gray squirrels, but Material in this publication may be reprinted if credit is given to the Illinois Natura the results of these supplemental feeding studies have been inconclusive. Wildlife specialists Stephen P. and Charles M. Nixon designed a study to Havera determine the effects of supplemental corn supplied in winter to populations of gray and fox squirrels in mature and in pole- sized (average dbh 25.4 cm) mixed hard- wood forests. Populations of fox and gray squirrels were provided with shelled corn (Zea mays) for three winters in a mature mixed hardwood forest and for two win- ters in an even-aged 40-to-50-year-old oak-hickory forest in central Illinois. Ha- vera and Nixon found that corn provided no obvious benefits to squirrels in the mature mixed hardwood forest with re- spect to reproduction, population density, survival, physical parameters, or reduction in disease. In the even-aged timber, the Fox squirrel. (Photo by former Survey photog- rapher, W. E. Clark) numbers and survival of squirrels were higher where corn was provided, but un-_ authorized squirrel hunting on one of the study areas may have influenced this result. To evaluate the use of unharvested grain as a method of supplemental feeding for squirrels, standing corn and soybeans (Glycine max) were left unharvested dur- ing the fall of 1975 approximately 10 m from timber. Six rows of standing corn were left unharvested in two fields in Mc- Lean County. Four rows of soybeans were left unharvested adjacent to a mature oak- hickory stand in Shelby County. Squirrels made little use of unharvested corn and soybeans left in fields adjacent to wood- lands, but use of corn increased somewhat in March. Havera and Nixon concluded that corn apparently is not a nutritionally adequate supplemental food for squirrels. They also do not believe that winter feeding with corn or soybeans is justified during most winters in the Midwest. The natural com- position and diversity of the hardwood forests in the Midwest insures, except in extreme mast failures, that squirrels will find adequate nutrition. Havera and Nixon found that fox squirrels collected through- out Illinois in early spring were in just as good physical condition as those collected in the fall, and that fall-to-spring survival of squirrels on their study areas was higher than spring-to-fall survival. Perhaps winter is not as critical a period for squirrels as it is often considered to be. Lake Shelbyville Mercury In 1974, wildlife specialist William L. Anderson and analytical chemist Kenneth E. Smith found that muscle tissues of largemouth bass in Lake Shelbyville con- tained concentrations of mercury which exceeded the 0.5-part-per-million (ppm) limit set by the U.S. Food and Drug Ad- ministration. Subsequent collections and comparative analysis by several labora- tories confirmed these levels in both large- mouth bass and walleyes. These fishes are near the top of the aquatic food chain, and the appearances of high mercury concen- trations in their tissues is indicative of ‘will mercury contamination at lower trophic levels and quite probably in the lake it- self. Because Lake Shelbyville and _ its watershed are in a prime agricultural set- ting with little industrialization, these ex- cessive mercury concentrations are par- ticularly distressing. Attempts to support further research met with success in October 1977, when the Illinois Institute for Environmental Quality and the Illinois Natural History Survey funded the current project to in- vestigate the occurrence, distribution, and accumulation of mercury in Lake Shelby- ville and its biota. Planned as a 2-year study under Smith’s direction, this study sample the water, soil, sediment, aquatic and terrestrial plants, benthic or- ganisms, plankton, and fishes of the lake for mercury analysis. Results of these analyses will hopefully answer the question of the origin of the mercury in the lake, its overall distribution, and how com- pletely it has infiltrated the food web of. the lake. It is also hoped that the results may allow the avoidance of similar prob- lems in other lakes in mid-America. To date, samples of lake sediment and monthly water samples from Lake Shelby- ville have been analyzed for mercury by cold-vapor atomic absorption spectropho- tometry. Of the water samples, only the October samples showed values above 0.1- part-per-billion (ppb), the detection limit of the procedure, and ranged from 0.1 to 9.4 ppb. The samples collected during No- vember and December were uniformly at 0.1 ppb detection limit. It’s possible that the November samples were abnormally high, or that water from the lake contains much lower mercury concentrations than do autumn waters. Spring and summer samples should resolve this question dur- ing the coming year. The analysis of the sediment samples gave wide ranging values from <1 to 230 ppb without any apparent pattern among the samples. Interpretation is complicated by the varying particle sizes in the sedi- ment samples. Experiments are in progress to relate the particle size to the amount of mercury that can be absorbed by the sedi- ments. These data should allow for better interpretation of the mercury in sediment data from Lake Shelbyville. Black Cutworm Trapping The life history of the black cutworm, Agrotis ipsilon, is not fully known for the north-central United States where the destructive larval stage attacks seedling corn during May and early June. The origin of these larvae has been the subject of debate. Did they overwinter as larvae, or did they arise from eggs laid early in the spring? A study by entomologists Lynn Pautler, William G. Ruesink, Hans Hummel and William H. Luckmann was undertaken to develop and test a method for early season detection of adults in Champaign County, Illinois. A sticky trap baited with virgin female black cutworm moths reared in the laboratory along with a blacklight trap was evaluated to determine which method was the better indicator of adult black cutworm presence and density. The virgin female black cutworm produces a pheror- mone which attracts male moths and the blacklight trap attracts both sexes of gv’ inp aL Ee ’ 4 Pherormone trap for black cutworm baited with virgin female. (Photo by entomologist Brian Melin) moths. The traps were all located in an abandoned orchard converted into a tree nursery in Urbana, Illinois. The earliest black cutworm moths trapped were two males, one taken on March 14 and the other on March 15, 1977, in the sticky trap baited with virgin female moths. Additional male moths were caught in the sticky traps on March 27 (two) and on March 28 (14). During this period (March 15 through March 31) the blacklight traps caught three males and one female moth. Seedling corn damaged by third and fourth instar black cutworm larvae was found in a field near the study area on May 11, 1977. The centigrade-degree-day accumulation from April 1 to May 11 was 210, an amount sufficient for develop- ment from oviposition to third and fourth instar larvae. It seems likely, then, that the larvae damaging corn in Champaign County in May developed from eggs laid by moths flying in early spring, rather than having overwintered as early instar larvae. For the entire season 2.6 times more males were captured by the traps baited The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 with virgin female moths than by the blackhght traps. More importantly, the baited traps attracted 6 times more males during March through May than did the blacklight traps, and the blacklight traps failed to detect the early moths (mid- March) caught in the baited traps. More Flies — the Genus Dialysis As part of an ongoing systematic study of lower brachycerous flies, Survey ento- mologist Donald Webb has recently re- vised the genus Dvalysis. This study in- volved borrowing specimens from some fifty museums and universities, in addition to private collections. Over 1,000 speci- mens were examined, involving nine species. The genus Dialysis is widely distributed in the United States, occurring from Cal- April 1978. No. 176 sion of th tate and Conservation Prepared by Dr, W. E. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Res Published monthly except in July and August by the Natural History Department of Registration and Education surces Building, Urbana ifornia to the Canadian border east to southern New Brunswick and northern Georgia. Three of the nine species occur in Illinois. Adults can be collected on herbaceous vegetation in wooded lowlands from April to August. The immature stages of this genus are unknown in North America, and little of their adult biology has been determined. The study has involved descriptions of two new species and the synonymy of two species names with previously known spe- — cies. Descriptions, keys, illustrations of morphological characters, and the distri- bution of each species were presented. This study is another segment of an overall study to examine the phylogenetic rela- tionships of several genera of lower brachy- cerous flies and is preliminary to a faunal study of the flies of Illinois. Survey, a divi operating under the Board of Natural Resources LaBerge with the collaboration of the Survey staff Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61 The Illinots NATURAL Green Slime and the Gizzard Shad Several unflattering names, such as pond scum, green slime, and even frog spittle, have been used for plants properly known as algae. Most people are aware of algae as the green scum that floats on ponds and lakes in mid to late summer, but few real- ize that certain kinds of algae are also sus- pended in the water column and are at- tached to the sediments under the water and along the shore. Examples of phyto- plankton (algae suspended in the water) and periphyton (algae attached to the lake bottom or to objects in the water) illus- trating their beauty and uniqueness of shape are Pediastrum duplex var. reticula- tum and Gomphonema acuminatum also known appropriately as the “naked lady.” Algae constitute a major part of the or- ganisms that convert sunlight into organic matter in most waters, and algae are re- sponsible for the production of a large per- centage of the atmospheric oxygen. These plants also provide food for zooplankton (weakly swimming microscopic animals), which in turn are consumed by certain fishes. Some fish are even directly depen- dent on algae for food; one of these is the gizzard shad. Although the gizzard shad is not a fish sought by fishermen, it is probably the most important forage fish found in midwestern lakes and reservoirs. The gizzard shad is therefore a direct link between algae and the game fishes. The successful spawning and growth of the gizzard shad are impor- tant for the success of many game fish, especially the largemouth bass, which is HISTORY REPORTS strongly dependent on the shad for food. It is therefore important to understand the reproduction, growth, and feeding habits of the gizzard shad. Understanding the im- portance of periphyton and phytoplankton abundance to the success of the gizzard shad could lead to better fish management in the future. In relation to gizzard shad feeding hab- its, phycologist Larry Coutant has studied the dependency of gizzard shad on algae for food in two Illinois lakes during 1975 and 1976. The two lakes studied were Lake Sangchris, a power plant cooling lake, and Lake Shelbyville, a river reservoir. Anal- yses were carried out in part to determine gizzard shad food sources and_ possible power plant influences on shad diet and feeding behavior. Gizzard contents of shad from 40 to 340 mm in length from different areas of the Pediastrum duplex var. reticulatum, an alga common in phytoplankton. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. ‘ Gomphonema acuminatum, the common in periphyton. ‘naked lady,” an alga two lakes contained primarily algae, par- ticularly pennate diatoms, a special group of algae common to most waters. Blue- green algae, pigmented protozoans, and zoo- plankton were also present in gizzard con- tents but were less common than diatoms. Certain groups of algae are found pri- marily in the phytoplankton, and other groups of algae (including certain pennate diatoms) are found primarily in the peri- phyton. Therefore, it is possible to deter- mine from the algae found in their gizzards where gizzard shad of different lengths were feeding. Smaller gizzard shad ate more phyto- plankton than did the larger gizzard shad, which apparently ingested more periphy- ton. ‘This trend was less apparent in shad from Lake Sangchris, but some evidence of this relationship was found there as well as in Lake Shelbyville. Another interesting result was that the highest concentrations of organisms were found in shad taken from the power plant intake arm ot Lake Sangchris, while the lowest organism concentrations were found in shad from the discharge arm of Lake Sangchris. Shad from two locations in Lake Shelbyville produced results intermediate between the values obtained from Lake Sangchris. These results may be due to the availability of algae in the locations where shad were feeding. Certain minimum algal populations may even prove to be of major importance for adequate maintenance of gizzard shad populations. Studies of gizzard shad feeding habits have greatly increased our understanding of the importance of fish-food organisms in fisheries. The monitoring of many fish- food organisms, including periphyton and phytoplankton, may prove to be more and more valuable to the proper management of bass and other game fish in the future. Computer Storage of Soybean-Pest Literature Since 1969 the Illinois Natural History Survey and the University of Illinois have been studying arthropods associated with soybeans. Because of the economic impor- _ tance of this crop, this program has cre- ated two service-oriented units that sup- port its research projects. One of these units is the Soybean Insect Research Information Center (SIRIC), which operates a computerized information storage and retrieval system on the litera- ture of insects and mites associated with soybeans. Initially, Jenny Kogan and her associ- ates at SIRIC used a manual system, but with the rapid increase, beginning in the late 1960's, in the number of papers pub- lished on soybean pests, a computerized system was required. The objectives of SIRIC are: 1. To compile literature on soybean-re- lated insects and mites and to establish a data bank for this literature To organize a collection of relevant doc- uments (journal articles, book chapters, reports, etc.), using code word descrip- tors for input and computerized re- trieval To compile and publish bibliographies of key soybean pests ihe) oo 4. To help soybean researchers, extension and others with their infor- mation needs workers, The SIRIC literature collection now ap- proaches 17,000 documents with about 16,- 600 documents fully processed and stored on magnetic tapes. Copies of the docu- ments are filed by accession number. Biblio- graphic references to these documents are ‘stored in a computerized file for retrieval on the Cyber 175 computer of the Univer- sity of Illinois. To select items to be included in the data base, SIRIC researchers check stan- dard abstracting and indexing journals or their computerized data bases. ‘They care- fully check all documents that are added to the system for additional references. In addition, they correspond with researchers in the USA and abroad to obtain relevant documents. These articles are often pub- lished in foreign journals not easily located in U.S. libraries, making SIRIC a valuable depository of foreign soybean entomology literature. The criteria adopted for selection of rel- evant documents are: (a) papers that deal with soybeans and with soybean-associated insects or mites, including their natural enemies; and (b) papers that deal with a list of selected soybean pests and their important natural enemies. The literature of these species is surveyed independently of their plant associations. For this reason SIRIC contains many documents on crops other than soybeans, such as corn, cotton, and alfalfa. Requests for service are received from researchers, extension workers, students, and other interested persons working with soybean insects here and abroad. Computer searches reflect the information needs of users and the subject contents of docu- ments in the data base. A key component of the system is its controlled vocabulary. A Hierarchical Code Descriptors (HCD) thesaurus, specially compiled for SIRIC, is used in input and output operations. Bibliographies compiled and_ published within the framework of SIRIC have been widely distributed to interested researchers. Four bibliographies have been published in the series on the literature of arthropods associated with soybeans, and a fifth bibli- ography is in its final stages of preparation. It is a compilation of the literature of two species, Heliothis zea and H. virescens, con- sidered the number-one agricultural pest complex in the USA. This bibliography will contain about 5,800 references and a complete subject index as a preliminary key to this huge literature. SIRIC is housed in the Ilinois Natural History Survey and is sponsored in part by INTSOY, the University of Illinois Inter- national Soybean Program; the Office of International Agriculture of the Univer- sity of Illinois; and the Illinois Agricultural Experiment Station. New Method of Estimating Wildlife Abundance from Livetrapping Data Viable population estimates or indices of abundance are essential to many eco- logical investigations. Most wildlife species can not be counted directly because of their secretive behavior. Capture-recap- ture methods have long been used to esti- mate the abundance of such species as cottontails, squirrels, and other small mam- mals. Numerous estimators have been pro- posed for use with livetrapping data, most of which assume some combination of ran- dom, uniform, or constant probability of capture. Wildlife specialist William R. Ed- wards has used 22 years of data from cot- tontails livetrapped at Allerton Park to evaluate methods of estimating abundance from capture-recapture data. He rejected the usual methods of population estimation because probability of capture is not ran- dom, uniform, or constant. Frequency of capture typically follows the geometric, and frequently the negative, binomial distributions. Edwards’ current study demonstrates that past difficulties with the geometric and negative binomial estimators have been caused by sampling intensity bias. Higher rates of capture than are typically obtained are needed to mini- mize that bias. Edwards found that two of the geomet- ric estimators had biases that tend to offset each other when the estimators are com- bined. He has proposed a combined esti- mator as the “best” with livetrapping data, provided the data ap- proximate the geometric distribution. Be- one for use The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 cause livetrapping data usually do ap- proximate that distribution, the combined estimator should be very useful in popu- lation studies of rabbits and other small mammals. r Edwards cautions that in any livetrap- ping study what is being estimated is the number of animals that have had a posi- tive probability of capture at some time during the trapping period. This estimate is not necessarily an estimate of the num- ber of individuals on the area at any given time or even of the number whose centers of activity fall within the study area. It is not legitimate to relate population esti- mates to the area trapped in order to esti- mate the population density of animals on the area trapped. Livetrapping can only estimate the individuals that used the area during trapping. The reasons for rejecting estimators often used in wildlife population studies also hold for estimates based on visual observations of color-marked or tagged animals, because those animals do not have the required random, uniform, - or constant probabilities of observation. May 1978. No. 177. Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois, Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 | The Illinois NATURAL HISTORY SURVEY The Spring Cavefish The cavefishes make up a family of only six known species, all occurring in the eastern half of the United States. All but two of them are eyeless, unpigmented, small fishes confined to streams in the deep recesses of caves and known to visitors of commercialized caves. The exceptions are two species in the genus Chologaster (meaning mutilated belly in reference to the absence of pelvic fins). One of them is pigmented, eyed, and lives in surface waters on the Costal Plain of the South- east. The other is intermediate in almost every way between surface-dwelling fishes and the true cavefishes. It is known from a few springs and caves in Tennessee, Ken- tucky, southern Illinois, and extreme south- western Missouri. It is the subject of a new Survey publication entitled “A summary of the life history and distribution of the spring cavefish, Chologaster agassizi Put- nam, with population estimates for the species in southern Illinois.” The paper was written by Survey ichthyologist P. W. Smith and N. M. Welch, a physician on the staff of a Dallas, Texas, hospital. Copies are available upon request to this agency. oN Pg: ¥ = Since this three-inch, semi-translucent fish bridges the gap between an existence above ground and in subterranean waters, it is a curlosity often sought by collectors. Several state conservation departments and the U.S. Department of Agriculture Forest Service became concerned that its numbers might be seriously depleted from over col- lecting. The Forest Service in 1973 em- ployed Dr. Welch to census the numbers of this fish in several springs in the LaRue- Pine Hills Ecological Area of Union Co., Illinois. This he did by dipnetting speci- mens at night in springs and marking them with an injection of tattooing ink. Then by using a mathematical formula called the Petersen Index, he could calculate the probable number of individuals present based on the proportion of marked to un- marked fish taken on each visit. He found that in eight springs studied the number of fish ranged from one to 302 individuals for a probable overall total of 785 + 314 fish — thus fewer than 1,000 individuals in the gene pool. All known aspects of the life history of the species were summarized in the report. It was found that breeding occurs under- ground in winter, that the 80 to 285 eggs An adult spring cavefish from a spring along Big Creek, Hardin Co., Illinois. (Photo by L. M. Page) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. produced by one female are almost two mm in diameter, that the fish grows on_ an average of 10 to 20 mm per year, that it rarely attains an age of three years, and that in springs it feeds primarily on one kind of amphipod but in caves is strongly cannibalistic (caves have a very limited food supply). Many facets of its reproduc- tive cycle are still unknown. It emerges into springs at dusk but usually retreats underground just before daylight. It is most often found when springs have heavy outputs such as after rains. Its eyes are so poorly developed that it relies on smell and touch to discern its food. It has evolved an ability to withstand without acclimation higher water temperatures, which offers some protection to a little fish sometimes swept into warm surface water by copious spring flow. The spring cavefish is superbly well adapted to a very difficult way of life. Turfgrass Insect Problems Insects infesting home lawns have usu- ally been either the sod webworm, Crambus trisectus or the annual white grub, Cyclocephla immaculata. The sod webworm occasionally is a serious prob- lem in late July and August especially in the central and northern areas of the state. The buff-colored moths lay eggs while in flight on the best fertilized and watered lawns in an area. The first generation ap- pears in June and there is never enough of a population to cause damage. The sec- ond generation in late summer can be damaging. The larvae damage the grass by cutting shoots off about % inch above the crown rather than 1% to 2 inches as recom- mended for proper mowing of a lawn. Annual white grubs are increasing in both numbers of lawns infested and the area of Illinois in which it is being com- monly found. The grubs are white with brown heads and C-shaped, and feed on the roots of bluegrass causing the sod to be severed from the soil surface. Counts of 12 to 50 grubs per square foot can be found in most lawn areas from about In- terstate 70 on the south to Interstate 80 on the north across the state from east to west. Tan, half-inch long, adult beetles emerge in June from the sod and soon lay eggs. The eggs hatch in July and damage can be observed, if grubs are pres- ent, after mid-August until early Novem- ber. The grubs overwinter below the frost- line deep in the soil. Two insects which were found in dam- aging numbers in golf course turfgrass during 1977 included a sod webworm, Crambus teterrellus commonly called blue- grass webworm and a small grub, Ataenius spretulus. The bluegrass webworm was severely damaging the bentgrass golf greens by feeding on the roots as a soil insect. The A. spretulus has been observed during the past four years feeding on the roots of bentgrass and annual bluegrass commonly ‘found in the fairways. Numbers of both bluegrass webworm and A. spretulus were very high on some golf courses. As many as 200 or more webworms per square foot were found under bentgrass sod in western Illinois. Ataenius grubs numbering over 300 per square foot were found in the Chicago area. Chemical control evaluations continue to be done for control of grubs and web- worms. There are many labeled and effec- tive sod webworm control insecticides for use by the home lawn owner and managers of other turfgrass areas. Many insecticides are very effective for grub control if ap- plied in late summer or fall. But only two are labeled at the present time with one, diazinon, being the only one available in garden centers and other stores selling pesticides to homeowners. Illinois Mollusks In May Professor Emeritus Max R. Matteson of the University of Illinois de- posited his personal collection of naiad mollusk shells in the permanent research collections of the Illinois Natural History Survey. His specimens, described by sev- eral biologists as the finest state collection of mussels in existence, is being put in order by one of his former students, Mrs. Liane Suloway. His material will be re- ferred to as “The Max R. Matteson Mol- lusk Collection.” Dr. Matteson joined the Zoology faculty in 1947 and soon thereafter embarked on a quantitative survey of the mussel fauna Dr. Max R. Matteson. (Photo by Gliessman Studios, Champaign) of the inland rivers of Illinois. ‘Throughout the 1950’s and well into the 1960's, he and a research assistant conducted transects of streams at three, seven, and 15-mile inter- vals on 22 different streams in the state. The collecting sites were randomly selected on quadrangle maps the night before each visit, but the precise transect made at places judged typical for the stream with access and a riffle or raceway shallow enough to be worked from one bank to the other. Sight from above the water, snorkeling, and groping were employed, depending on which method was appro- priate. Dr. Matteson and assistant worked steadily at each site for three hours before moving to another so that the number of each clam species could be expressed in man-hours of effort. Since dead shells could be transported downstream by cakes of floating ice, only living animals were taken. Each had to be boiled, fleshed, and thoroughly scrubbed. The dried shells were subsequently sorted and identified. Meticulous field notes were recorded, and a sketch of each site drawn. If no shells were found after three hours, the station was still recorded, and the reasons for the absence of mollusks noted. The field notes list numbers of each species found at every station. The sites. The []linois River was, of course, too stream collections represent 225 deep to be worked from one bank to the other, and another river in southwestern Illinois was avoided because Dr. Matteson didn’t like snakes! Collections are available from several stations now inundated by large reservoirs such as Shelbyville and Carlyle, and all of them were made before the peak of the crisis. Environmental degradation was rela- present environmental tively minor in many parts of the state in the 1950’s. Other samples are present from ponds in Illinois and streams in Indiana and Michigan. The collection is of enor- mous value in providing quantitative base- line data that enable native habitats and their degree of deterio- ration at that time. It will provide priceless information for environmental impact statements and will be an important re- source for future ecological studies of our aquatic environments. reconstruction of Wandering Weevils The detection in Illinois in May 1977, of the imported crucifer weevil, Baris lepidu, was unusual in the sense that the insect was first found established in the Western Hemisphere in I]linois. It was not the first time that an immigrant species of weevil has found its way to the state. Since the period of the Civil War, at least one species per decade on the average, of these wandering weevils has become established in Illinois and many are of concern to agri- culturalists of the state. The cabbage curculio, Ceutorhynchus rapae, another European pest of crucif- erous crops, including cabbage and horse- radish, was first detected in the United States in New England in 1855. A speci- men in the Illinois Natural History Survey was collected in the central Illinois city of Bloomington on May 15, 1882. Also from Europe are three species of Otiorhynchus, O. ovatus, the strawberry root weevil, O. weevil, and O. rugosostriatus, the rough strawberry root weevil. These damaging weevils feed as sulcatus, the black vine The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 larvae on the roots of a variety of culti- vated plants and they are frequently re- ceived at the Illinois Natural History Survey for identification and for recom- mendation for control measures. Several-of the Otiorhynchus species were detected along the eastern shore of the United States from 1835 to 1876, and one of them, the strawberry root weevil, was taken at Urbana as early as 1891. Perhaps the most damaging European import has been the alfalfa weevil, Hypera postica. The eastern strain of the alfalfa weevil was detected in Maryland in 1952. By 1964 it had entered Illinois, and it is now well established throughout the state. Pest management of the alfalfa weevil is a matter of serious concern to growers of alfalfa in Illinois. Japan has also been a source of pest species. Since 1940, three such Oriental weevils, Calomycterus setarius, the im- ported longhorned weevil, Cyrtepistomus castaneus, the Asiatic oak weevil, and Pseudocneorhinus bifasciatus, the Japanese weevil have become established in Illinois. The most recent of these to arrive in the state, the Japanese weevil, was identified . by Survey entomologist, John K. Bouseman, upon its detection at Murphysboro in the southern part of the state in 1976. In addi- tion to feeding as adults on the foliage of a wide variety of cultivated plants, the im- ported longhorned weevil and the Asiatic oak weevil frequently enter households in large numbers, thus giving them status as a general nuisance, and are very frequently received at the Illinois Natural History Survey for identification. With the advent of rapid air transporta- tion, we may expect to see more of these unbidden guests arrive in the state. For- merly such tramp species had to undergo the quarantine of a long voyage. Now they can travel long distances in a few hours. The presence of a large reference collection at the Illinois Natural History Survey helps to insure that any such future immigrant will be quickly identified after its detection in Illinois. June 1978. No. 178. Published monthly except in July and August by the Natural History Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinois NATURAL HISTORY REPORTS Cooling Lake Study The Illinois Natural History Survey has signed a research contract with Central I]- linois Public Service Company (CIPS) to investigate the environmental effects of the CIPS Coffeen Power Station on Coffeen Lake, located 8 miles southeast of Hills- boro. The 3-year study will include coor- dinated physical, chemical, and biological aspects of this power plant cooling lake. Individual re- investigations of the search projects included within this study will be investigations of water quality, aquatic macrophytes, phytoplankton, zoo- plankton, benthos, fish, and trace metals in the biota. Drs. John Tranquilli and R. Weldon Larimore, principal investigators of the said that the signed to determine whether Coffeen Lake study, investigation is de- and Shoal Creek, its receiving stream, are environmentally acceptable in terms of supporting shellfish, fish and wildlife, and consistent with good recreational uses = - ee a as : —— —_— — a * <: x Sa = <= mn ~ —— <> ae wan. -- <, = * } ta Central Illinois Public Service Company power plant on Coffeen Lake. This cooling lake is to be the subject of a 3-year study. Material in this publication may be reprinted if credit is given to the Illinois Natura! History Survey management practices. Jim Buckler will be the project leader and will be stationed at the field laboratory, located in Taylor Springs, Illinois. It is hoped that, at the end of this 3-year study, recreational facilities may be devel- oped through the cooperation of CIPS and the Illinois Department of Conservation. Effects of Drought on Plant Membranes The membrane is an essential part of all living cells, and the plant cell is no ex- ception. The membrane (plasmalemma ) forms the major barrier between the inte- rior of the cell (protoplasm) and the exter- nal environment. The biological membrane is semipermeable (it permits the passage of some molecules but not others), allow- ing water to enter the cell at a faster rate than most solutes can enter. In the root system, the membranes control the uptake of water and nutrients, and only through the action of a semipermeable membrane can the proper water status be maintained. Within the plant, membranes also control the movement of solutes and water, and without this control mechanism the plant could not survive. A plant is composed of 80-90 percent water. The movement of water from the roots to the leaves is extremely important, because the nutrients for proper plant growth are carried along in the water. Most of the water that is taken up by the plant is lost through the leaves by trans- piration. The water status of the plant is a function of water uptake and water loss, and certain environmental factors influ- ence this ratio by changing the behavior of membranes. Claus Grunwald, plant physiologist at the Survey, is studying the effects of water stress (drought) on plant membranes, especially as the stress factor might change the chemical makeup of membranes. Bio- logical membranes are composed of pro- teins and lipids at about a 1:1 ratio. A number of environmental factors produce small changes in the lipid component of membranes, and it is believed that these slight changes have a significant influence on the behavior of membranes. For example, low temperatures reduce the uptake of water, and this reduction is due to a decrease in membrane perme- ability. It is thought that a change in sterol composition and fatty acid satura- tion occurs as the growing temperature is changed. Whether similar changes cccur under drought conditions is presently not known, but many cellular activities are very similar under water and temperature stresses. An understanding of any changes in plant membrane behavior or chemical composition resulting from drought could help us in minimizing the effects of drought on field crops and other plants. The Gray Squirrel in Illinois The flora and fauna present in Illinois when the first white settlers moved north and westward across the Ohio River have undergone drastic changes during the past 175 years. This change is particularly true for the gray squirrel, a species adapted to large expanses of old-growth hardwood forests. Extensive clearing of the virgin forests following white settlement led to the virtual disappearance of gray squirrels in many of the central and northern coun- ties early in this century. Survey wildlife biologists C. M. Nixon, S. P. Havera, and R. E. Greenberg have documented these changes in gray squirrel abundance in a new publication, “Distri- bution and Relative Abundance of the Gray Squirrel in Illinois,” published by the Survey as Biological Notes No. 105. Copies of this publication may be obtained free by writing to the Chief, Illinois Natural His- tory Survey. To determine the present status of the gray squirrel, Nixon and his co-workers divided Illinois into 14 watersheds (see map) and in each watershed contacted cooperators thought to have knowledge of gray squirrel abundance. Cooperators were requested to indicate the townships pres- ently “occupied” by gray squirrels and to indicate their relative abundance as: Com- mon — frequently shot or seen, Scarce — shot or seen every year but only in low numbers, are — shot or seen infrequently (every 2 or 3 years), or Absent. Super- visors of urban parks were also contacted in all the major cities of Illinois to de- UPPER sok MISSISSIPPI <4 py ng | 1 Py ae a bats pata 3 4 u Geter oo comm Ie SAN GAMON. MIDDLE MISSISSIPPI The major watersheds of Illinois, used to delineate the present distribulion and relative abundance of the gray squirrel. termine the urban distribution of squirrels. Gray squirrels were found to be gen- erally distributed throughout the Shawnee Hills, Saline River, and Big Muddy water- sheds, and to be common in the southern portions of the Kaskaskia, Little Wabash, and Embarras basins. In the remaining watersheds, however, gray squirrels were found to be widely scattered, with large areas of unoccupied range in each water- shed. Why has the gray squirrel fared so poorly in this century while the fox squirrel has increased in abundance during the same period? The answer lies in the differ- ing habitat requirements of each species. Gray squirrels favor extensive forests of mature hardwoods, while fox squirrels are adapted to woodlots, hedgerows, and rela- tively young and open forests. Thus, the transformation of Illinois from a wilder- ness to a modern technological society has favored the fox squirrel, because much of the forest cover present in I]linois in 1800 gray has been destroyed (declining from 15.25 million acres to the present 3.7 million acres or less). There is a significant re- lationship between the percentages of gray squirrels killed in each county and the per- centage of each county that is forested. What does the future hold for the gray squirrel in Illinois? The human population of the state is predicted to increase from the present 11 million to nearly 14.5 mil- lion by 1990. This increase in human pop- ulation will place even more pressure on the already distressed forest ecosystems. Gray squirrels are expected to continue to decline in numbers in the Upper Mis- sissippi, Rock River, Upper Illinois, San- gamon, Vermilion, and Iroquois drainage basins. They are also expected to experi- ence further declines in the upper reaches of the Kaskaskia, Little Wabash, and Em- barras basins if stream channelization and conversion of forests to tillable land con- tinue at the present rates. Gray squirrels should be relatively secure in the lowe1 portions of these basins as well as in the Big Muddy basin, the Shawnee Hills, and portions of the Saline River basin. How- ever, as new water impoundments are created, more acres are strip mined for coal, and towns and cities expand, gray squirrels will become locally scarce or ab- sent even in these extensively forested basins. Progress Report on Introduced Lady Beetles A large population of the seven-spotted lady beetle, not native to North America but found throughout much of Europe, Asia, and India, was located in New Jersey in 1974. In 1975 Survey entomologist Clar- ence White began receiving shipments of these ladybugs from the U.S. Department of Agriculture, and he traveled to New Jersey to collect beetles. Like most species of lady beetles, these feed on other insects and their eggs and help to control insects that are harmful to agricultural crops and ornamental plants. These beetles, however, are about twice the size of the native lady- bugs, and they feed heavily on aphids. White has released thousands of these lady beetles at several locations in Cham- The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 paign County in 1975, 1976, and 1977. Last November, 13,000 adult beetles were placed in overwintering cages in the for- estry plantation south of Urbana. The cages have openings which allow the in- sects to disperse naturally in the spring. Searches of the 1975 and 1976 release sites have not revealed any evidence that the beetles are reproducing and _ estab- lishing a permanent population here. How- ever, White did find evidence of repro- duction in 1977 near a release site in the Salt Fork River Forest Preserve near Homer and at another site near Mayview. September 1978. No The fact that larvae were observed in the summer and adults in the fall is encourag- ing, but is not proof that they have estab- lished a population here. By conducting a selective-breeding pro- gram in the laboratory, White has ob- tained, in nine generations of beetles, a strain that produces not one but several generations each year. This lady beetle breeding and release program is only one of many on-going attempts by Survey re- searchers to find natural, in addition to chemical, means of controlling harmful insects. 179, Published monthly except in July and August by the Natural Histery Survey, a divi- sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M, Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinots ATURAL SURVEY Soybean Spiders Spiders are receiving considerable atten- tion as potentially important predators of arthropod pests of agricultural crops be- cause of increased interest in the develop- ment and use of integrated pest-manage- ment systems. However, reports quantifying spider populations, showing colonization rates, and listing prey preferences of the dominant spider species in row crops are lacking. Entomologists C. D. LeSar and Locations of the 12 most abundant spider species on soybeans during the 1100-1400 time period with percentages of each species present. (Diagram by Lloyd LeMere, Survey artist) HISTORY J. D. Unzicker, with support from the Section of Economic Entomology and the [llinois Agricultural Experiment Station, undertook a study of spider species compo- sition, population densities, and vertical distribution in soybeans in order to provide information on these predators in soybean fields. Over 4,100 spiders, representing 77 species, were collected in five fields during two seasons. Colonization of the fields be- gan in mid-June, after insect colonization had continued until August. Early colonizing spiders during 1975 suffered high mortality rates because the small soybean plants offered little pro- tection from heavy rains. Only 13 of the 77 species collected during the 1975-76 grow- ing seasons became firmly established on the soybean plants. The data fields and/or years were analyzed and com- pared for species diversity. Diversity was higher in 1975, when a very wet growing begun, and mid- from three combinations of season suppressed the dominant species, Tetragnatha laboriosa, causing a greater evenness of distribution among the remain- ing species in the population. In 1976, when a relatively dry summer allowed the build-up of the dominant spider, the spider species in the total sample became uneven in their abundance, causing the diversity to decline. Spider diversity was high when adjacent fields sampled in different years were compared, while widely separated fields sampled the same year had similar This that differences in habitats adjacent to the soybean fields values. suggests (e.g., woodland versus native grasses played a major role in species composition. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. Species diversity was greatest after the soybean plants matured and the foliage provided the greatest number of niches for the spiders and prey. Population densities peaked during early September and then fell rapidly as the soybean plants reached senescence. The soybean plant was divided into four vertical zones of about 250 mm each for stratified sampling. Sampling showed that two-thirds of the entire spider population was located on the lower one-half (Zones A and B) of the plant during any time period of the day. There was a great deal of species shifting which is likely deter- mined by heat and humidity stress, as well as availability of prey. A two-way analysis of variance indicated that the six most common species had significant differences in location of the population between zones and/or the different time periods of the day. The locations of the 12 most abun- dant spider species on soybean plants be- tween the hours of 11:00 am. and 2:00 p.m. is shown in figure. Spiders are indiscriminate predators which feed on beneficial as well as insect pest species and, with the exception of T. laboriosa, do not reproduce in soybean fields. Thus the spider population in a given field cannot respond numerically to increases in prey densities. However, there may be a functional response to changes in prey densities in which additional spiders are recruited from areas adjacent to the fields. The authors recommend additional research to explore the role of these preda- tors in agrosystems including: (1) deter- mination of spider species commonly found in major agricultural crops, (2) studies on the migration and dispersal patterns of the major spider species, and (3) laboratory feeding studies to determine the potential impact on insect pest species. Lake Michigan Diversion Ever since the turn of the century, a major part of the water in the Illinois River has come from Lake Michigan. Cur- rently, lake water is diverted into the Illinois Waterway at Chicago at an aver- age rate of 3,200 cubic feet per second (cfs). By comparison, the average flow of the Illinois River at Kingston Mines (182 miles downstream) is 9,000 cfs or less during half the year. Now much more water may be on the way and the Natural History Survey will help evaluate the effects. Congress has authorized a temporary one-year tripling of the Lake Michigan diversion rate to 10,000 cfs, in order to determine how in- creased diversion would affect the levels of the Great Lakes and water quality and flooding in the Illinois Waterway. The Chicago District of the U.S. Army Corps of Engineers has asked the Aquatic Biology and Wildlife Research Sections of the Natural History Survey: (1) to pro- ‘ vide a preliminary assessment by Decem- ber, 1978, of the expected effects of in- creased diversion on fish, wildlife, and vegetation in and along the Illinois River: (2) to conduct a baseline survey of existing biological conditions in and along the Illinois River; and (3) to monitor the biological effects of the temporarily in- creased diversion, which is scheduled to begin in the fall of 1979. Aquatic biology staff, under the supervision of Richard E. Sparks and Kenneth S. Lubinski, are re- viewing available literature and are also computerizing and analyzing previously unpublished data for the preliminary assessment. Between 1931 and 1972 D. H. Thomp- son and W. C. Starrett conducted fish pop- ulation surveys in the Illinois River and its bottomland lakes. Their surveys spanned a period in which Lake Michigan diversion varied and in which there were several floods and droughts in the river basin. Present survey staff are continuing and replicating these studies. Information about relationships between fish popula- tions, water levels, and river flow should make it possible to predict some of the effects of increased diversion on fish. Wildlife biologists Frank Bellrose and Stephen Havera are supervising studies of vegetation and wildlife along the Illinois River, including water level tolerances of several species. Inventories of ducks, geese, swans, eagles, herons, egrets, shorebirds, beaver, and muskrats are being expanded and updated. Aerial photo showing some of the multiple uses of the Illinois River: scenic bluffs to the left are part of Starved Rock State Park, barges and a tug approach the Starved Rock lock and dam from downstream. (Photo by former Survey photographer, W. D. Zehr) Wildlife researchers are also measuring the contours of the bottomland lakes and sampling and mapping the plants which grow in bottomland forests and mud flats along the river. A lake’s contours influence the degree to which increased diversion will flood the adjacent forests and mud flats. Deer, squirrels, raccoons, and other valuable game animals inhabit the bottom- land forests, along with ecologically im- portant nongame species. Mud flats pro- vide moist soil food plants for migratory shorebirds and waterfowl, such as pintails, widgeon, gadwall, and teals. What happens in the Illinois valley is important to the entire state. Natural re- sources in the river valley include a com- mercial fishery, bottomland forest, prime farmland, private duck clubs (about 60,000 acres), private goose hunt- ing clubs, nature preserves, natural areas, hunting state parks, conservation areas, and federal wildlife areas. A complete and accurate evaluation of the effects of increased diver- sion is both economically and environ- mentally essential to [lhnois. The data now being gathered and analyzed should make this evaluation possible. Soybean Mosaic Virus Soybean mosaic virus (SMV) _ occurs wherever soybeans are grown and, from a global perspective, is probably the most common and important virus attacking soybeans. The impact of SMV on soybean yield varies depending on locality, soybean cultivar, and particular strain of the virus. The time of inoculation is directly and positively correlated with yield quality and quantity. Survey entomologist, Michael E. Irwin, and University of Illinois virologist, Robert M. Goodman, both of whom hold joint appointments and postdoctoral fellow, G. A. Schultz, have recently found large The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 yield reductions and decreased seed quality in soybeans inoculated with a severe strain of SMV soon after emergence. Later in- oculations produced less drastic results. SMV is transmited from generation to generation through the seed and is spread within and between fields by winged aphids. The only important field sources of SMV are soybean plants grown from infected seed, and the percentage of SMV infected seed in seed lots in central Illinois is very low. Therefore, the amount of primary inoculum available for spread is currently minimal. Timing and abundance of alate aphids is a critical factor in the spread of SMV. Irwin, and Susan E. Halbert, a graduate student, have found more than 60 species of aphids landing in central Illinois soy- bean fields each year. Since aphids do not colonize soybeans in Illinois, insecticide sprays are ineffective against field spread of SMV. Only about six of the more abundant species are important as vectors of SMV in Illinois. Irwin has monitored aphid flight activity in soybeans for the past four years. Each year the temporal pattern was distinct and abundances shifted between years. Because SMV reduces yields and lowers seed quality most severely when it infects soybean plants during early vegetative stages, late spring to early summer flights of aphid vectors are very important to SMV spread. Although SMV is a limiting factor in soybean production in some areas of the world, it is not currently an important disease of soybean in central Illinois be- cause seed lots have a very low percentage of SMV infected seeds and aphid flights - have been sporadic. If aphid flights become heavy and timely for several seasons in a row, this disease could become increasingly more important in central Illinois. Monitor- ing aphid flight activity and insisting on a minimum standard of acceptance for SMV infected seed in certified seed lots are two ways of helping to predict and prevent possible SMV epidemics in the future. The work undertaken by this team of re- searchers has been supported by the Inter- national Soybean Program (INTSOY) through the Agency for International De- velopment, an Illinois Agricultural Exper- iment Station competitive Hatch grant, and the Illinois Natural History Survey. October 1978. No. 180. Published monthly except in July and August by the Natural History Survey, a division of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinovs NATURAL HISTORY REPORTS Fall Freezing Affects Plant Disease The past two winters in the Midwest set new records for severity. Are we in for will we be spared such hardship this year? Unfortu- nately, the weather in Illinois is unpredict- able, regardless of the Farmer’s Almanac and the color bands on the “wooly bear” caterpillars! another bitter cold winter or the record snow, ice, and low temperatures became apparent during the past two springs in the form of crumbling highways, burst and lines, cracked masonry, etc. A more subtle type of winter damage that few people recognize, how- ever, occurred on many of the trees and shrubs in Illinois. This damage can be seen Much of the damage caused by water sewer as an increase in the frequency of certain types of plant disease. Fall in 1976 decreased steadily to very low levels and the extreme cold persisted into mid-February. Extreme low temperatures, such as the —20° to —30° F readings recorded in January of 1977, caused the death of fruit buds, trunk cracks on sugar maple and london plane temperatures trees, and the death of stems on woody species not native to the area and on those on the northern edge of their natural range, such as sweet gum trees in central Illinois. Most of this damage was due to actual freezing and physical injury caused by ice crystal formation in plant cells. The injury was apparent at the time of new growth in the spring of 1977. The winter of 1977-1978 was quite different, as was the effect on woody plants. Temperatures were below normal for most Material in this publication may be reprinted if credit is given of the fall, winter, and spring but did not reach the extremes of the previous year. However, plant damage was often more severe. The main cause of this extensive damage was a hard freeze to near zero in early December 1977 after an extended period of relatively mild weather. ‘Trees slowly falling temperatures and, when fully and shrubs cold harden under hardened, may withstand record low tem- peratures without injury. If hardening is delayed by mild weather, a severe drop in -_ : : j% as tallhedge weakened by freezing. (Photo by Dr. D. F. Schoeneweiss) fruiting bodies of Basal canker with of fungus Tubercularia on stems to the Illinois Natural History Survey. temperature to below freezing can result in frost collars, bark splitting, and dieback of_ stems. Even if tissues are not killed, freez- ing temperatures can weaken stem tissues and cause normally resistant plants to be- come susceptible to attack by many stem- infecting canker fungi. A sizable increase in the appearance of stem cankers on several tree and shrub species this past spring reflected the freezing stress that occurred from the hard freeze last De- cember. The dramatic influence of sublethal freezing stress on disease susceptibility of dormant but not fully cold hardened woody stems has been reproduced arti- ficially in controlled freezing experiments by Survey plant pathologist D. F. Schoe- neweiss. Plants frozen and inoculated with stem canker fungi that do not attack non- stressed plants showed disease symptoms typical of those observed under field con- ditions. Unfrozen inoculated plants and plants frozen but not inoculated remained healthy and were indistinguishable from untreated plants. These results confirm the relationship between freezing stress and many common stem canker diseases and help explain the sudden outbreak of certain diseases, such as basal stem cankers on upright euonymus, tallhedge buckthorn, and red-twig dog- wood, that occurred this year. Unfortunately, little can be done to pre- vent this type of damage except to plant sensitive species in sites protected from extreme exposure and to avoid practices such as late-season watering and fertilizing or the use of outdoor lighting, which may delay the hardening of woody ornamentals. The appearance of stem canker damage on many woody species should be considered symptoms of stress conditions rather than plant diseases that can be controlled with fungicide sprays. The Heron Report The most recently published paper in the Survey’s series on Illinois bird popula- tions is Illinois Birds: Ciconiformes. It covers the herons and related species and presents the histories of the Illinois popula- tions, so far as they are known, as well as recent population figures for the various species. The paper also contains quantita- tive information on migration, nesting, and feeding habits of herons in Illinois. As with all the papers in this series, this one is based on a bibliography of about 7,000 titles, previously unpublished data from numer- ous contributors, and the field work of Jean and Richard Graber, who compiled the data. Between 1973 and 1976 an effort was made to locate all the major heron colonies in the state in order to see how well the populations were surviving. Though histor- ical records were fragmentary, the recent census data indicated that heron popula- ‘tions have undergone two kinds of change — (1) a relatively slow long-term decline and (2) a much more rapid recent decline, particularly noticeable in southern Illinois. Possible causes of the population declines are discussed, and areas of further study are recommended in the report. A serious problem for students of natural. populations, and one very pertinent to the herons, is the general lack of information on “normal” fluctuations to be expected from one year to the next. That kind of information is becoming more and more difficult to acquire because the general environment has become so unstable. That instability is exemplified by habitats that are available one year and gone the next, and by food sources clean and dependable in one decade, but in a few short years, dangerously polluted. There is some evidence that at least the great blue heron and great egret in IIlinois are being harassed by hydrocarbon pollu- tion. Egg shells from two colonies on the Mississippi River were very thin by com- parison with those of pre-1940 eggs. An important next step in research on Illinois herons would be comparative studies of the pesticide relationships and productivity of herons in northern Illinois (where populations are surviving better) with those in the south. Single copies of Illinois Birds: Ciconi- iformes, Biological Notes No. 109, are avail- able on request. Write to the Chief, Illinois Natural History Survey, 172 Natural Re- sources Building, Urbana, Illinois 61801. Pelleted Baits for the Black Cutworm The black cutworm, Agrotis ipsilon, is a serious pest in Illinois cornfields, and its attack results in an average of 58-percent loss of plants and a 42-percent loss of yield in some fields. Survey entomologist Ralph Sechriest had found that insecticides in the form of pelleted baits were as effective as sprays in controlling black cutworms in greenhouse and small-plot field experi- ments. Consequently, he and entomologist Dan Sherrod investigated the effectiveness of pelleted baits under different soil mois- ture conditions in the greenhouse and as emergency treatments for the control of black cutworm larvae in large field ex- periments. Illinois cornfields with natural infesta- tions of third- and fourth-instar black cut- worms were selected for the experiments. Commercial formulations of pelleted baits, consisting of standard carrier mixtures of apple pomace, cornmeal, wheat bran, and molasses combined with an_ insecticide, were used. Baits were broadcast by hand in late May or early June on plots measuring 31x31 meters. Pesticide performance was evaluated by comparing the original stand of healthy plants with the number of Adult yellow-crowned night heron, from a drawing by Beverly Sander- son. This bird has a bluish gray body and is about 50 cm tall. plants remaining 3 weeks after treatment. Each experiment was replicated three times. Within the center of each plot, five 15- meter rows, each separated from the others by a row on each side, were staked so that a known number of plants in each plot could be compared. Natural infestations of black cutworm larvae varied greatly, as did plant stand counts, from one plot to another. Thus, comparisons were made be- tween the plant stand counts in the staked corn rows when the treatments were ap- plied and at 1, 2, and 3 weeks after treat- ment. The effects of two levels of soil moisture on black cutworm control with pelleted baits and granules were examined in the greenhouse by using wooden flats (plots) with 20 corn plants in each. Treatments equivalent to 1.12 kg of active ingredient per hectare were applied to three replicates of each experiment at the time of planting. Some flats were watered so that the soil surface was always moist, while others were watered only enough to keep the seedlings from wilting. Three fourth-instar black cutworms were released in each flat 3 weeks after planting, and 1 week later two The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 fourth- and three fifth-instar cutworms were released in each plot. Counts of healthy seedlings were made at the time of each infestation and 1 week later. Sechriest and Sherrod found that in the field the standard control practice of ap- plying toxaphene spray as a band over the row was less effective than the broadcast fonofos bait. Carbaryl 5-percent bait and biothion 2-percent bait broadcast at the rate of 0.56 ke of active ingredient per hectare protected corn seedlings as well as the same baits broadcast at double that rate. Biothion 2-percent, carbaryl 5-percent, chlorpyrifos 2-percent, fonofos 4-percent, methomyl 1-percent, and trichlorofon 5- percent baits provided good control of the black cutworm larvae in 3 years of field experiments. Soil moisture affects the control efficacy of pelleted baits under field conditions. Carbaryl 5-percent bait was found not to have as good residual effectiveness on moist soil as on dry soil in the greenhouse experiments. Some moisture must be pres- ent to make the dry pelleted bait accept- able to the larvae, but generally the humid- ity in the air or a slight dew was sufficient to soften the pellets. In addition, the carriers tend to attract moisture. Since black cutworm larvae typically feed and rest only in moist soil, during extremely dry conditions larvae remain 5—8 cm deep in the soil and may not respond to the pelleted baits. Conversely, moist soil with larvae at or near the soil surface appears to aid control with such baits. This moist soil condition is typical of most Illinois fields when corn seedlings are emerging, and excellent control can be expected under these circumstances. Damage to seedling corn in the field can range from slight to extensive, and the cut- ting of 30-50 percent of the plants in a cornfield by black cutworm larvae is com- mon. However, as much as 40-percent re- covery or regrowth of cut plants is possible. The closer to the time of seedling emer- gence the treatments were applied, the greater was the protection provided. The preferred control recommendation by Nat- ural History Survey and University of Illinois extension entomologists is carbaryl 5-percent pelleted bait, and good control of black cutworm larvae has been achieved by Illinois farmers except under very dry conditions. November 1978. No. 181. Published monthly except in July and August by the Natural History Survey, a division of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. Office of publication 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 61801 The Illinovs NATURAL HISTORY REPORTS Mail Carrier Pheasant Census One method employed by biologists to monitor the relative abundance and distri- bution of pheasants in Illinois is that of soliciting volunteer assistance of the rural letter carriers in recording pheasants ob- served while delivering mail. The first Rural Mail Carrier Census (RMCC) was conducted in Illinois during five consecu- tive days in April in 1958 and has been repeated at five-year intervals. Wildlife bi- ologist Richard E. Warner has recently released data from the 1978 RMCC which encompassed the 74 northernmost counties of the state. Self-maintaining populations of pheasants in Illinois are known only in these counties. Eighty-eight percent of the 1,178 census cards mailed to rural letter carriers in 1978 were returned and found usable (89 per- cent were returned and found usable in 1973). A total of 366,005 miles were tallied in 1978, about 15,000 miles more than in the previous count. The number of pheas- ants observed per 100 miles of driving av- eraged 0.8 in 1978, compared with 4.9 in 1973, 5.5 in 1968, 9.9 in 1963, and 7.6 in 1958. Thus, the number of pheasants re- corded in 1978 represents a decline of 83 percent over the five year period since 1973. Counties that were among the top 15 in 1973 but are not on this list in 1978 in- clude Macon, McLean, Iroquois, Moultrie, DeWitt, Kankakee, Vermilion, Champaign, Piatt, and Douglass. The northernmost two tiers of counties, broadly classified as a mixed livestock and dairy region, pres- ently rank among the highest with respect to numbers of pheasants counted, a posi- tion that has been held in recent decades by the east-central cash grain belt. The top Cock pheasant in road- side habitat. (Photo by Larry M. David, Depart- ment of Conservation) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. ten counties are now Macon, Winnebago, Carroll, Lee, Stephenson, Kendall, Wood- ford, DeKalb, Will, and Ogle. Declines in pheasants observed over the past five years were evident for all of the top 15 counties censused in the 1978 RMCC. Two factors which have most contrib- uted to the depletion of populations of pheasants from 1973 to 1978 in Illinois have been the continued expansion of row crop farming, resulting in less prime habi- tat for reproduction, and severe winter weather, particularly where protective cover on the winter landscape is scarce. The RMCC indicated declines of 80 to 96 per- cent since 1973 in Champaign, Ford, Mc- Lean, and Iroquois counties. Declines of this magnitude have been directly attrib- uted to severe winter storms in 1976-77 and 1977-78 on areas in these counties that are monitored as a part of ongoing investigations. Evidence of this sort, in con- junction with the fact that the ringneck presently appears in greatest numbers where protective winter cover is most abundant, as in the northernmost tier of counties, suggests that the decline since 1973 is largely the result of severe storms during the previous two winters. Malaysian Prawns in Illinois Aquatic scientists at the INHS and the Urbana campus of the University of Ilhi- nois recently were honored by a visit from Dr. Shoa-wen Ling, one of the world’s foremost aquaculturists. Following a long and distinguished career in Asia, Dr. Ling is now adjunct professor in the School of Marine and Atmospheric Science at the University of Miami. Dr. Ling is best known as the first scientist to control the life cycle of Macrobrachium rosenbergit, the giant Malaysian freshwater prawn, for which he is affectionately acclaimed by his colleagues as the “father” of freshwater prawn culture. The development has great commercial as well as scientific importance because the freshwater prawn has the gour- met qualities of the finest marine shrimp but, once past the larval stage, can be cul- tured in fresh water. Dr. Ling’s visit to Illinois was prompted in part by his inter- est in the use being made of the prawn at the Kinmundy field station of the INHS, the Sam A. Parr Fisheries Research Center. The work is being conducted in coopera- tion with the Prawn Aquaculture Program of the State of Hawaii, and the University of Hawaii. In studies by D. H. Buck, R. J. Baur and associates at Kinmundy the prawns have been incorporated into a polyculture of Asian fishes whose specialized feeding habits are being exploited in the recycling of swine manure. The prawns provide an additional consumer for the uptake of nu- trients, the control of eutrophication, the management of wastes, and an additional source of high quality protein. While pro- ‘duction of this tropical Asian species will be limited by the short growing season in temperate I]linois, the results at Kinmundy have exceeded expectations. Following an escorted flight from Hawau, 35,000 of the translucent, inch-long (0.09 gram) prawns were stocked on June 1, 1978, in four ex- perimental ponds. At Kinmundy they re-- ceived no food beyond that produced in the manure-enriched ponds. Following a period of 131 days, survivors had attained weights averaging 12.7 grams for all ponds, 17.6 grams for the most productive pond. In this best pond 20 percent of the prawns had attained lengths of 4 inches (9.6 cm) or larger as measured from the eye to the tip of the tail, which is market size in many areas where prawns are sold. It was a pleasure to learn, however, that even the smallest of the Kinmundy prawns were a gourmet’s delight. The total production of prawns was at rates of from 250 to 400 pounds per acre in addition to a production of more than one ton of fish per acre. Such high rates of production in temperate waters, with no supplemental feed, and against the compe- tition of native crayfish, suggests the pres- ence of compensating factors. The enrich- ment by the fresh manure and_ the abundance of partially-digested plankton (primarily algae) rained down on the prawns in the feces of a large population of filter-feeding fishes must create a milieu rich in organic detritus and both micro- and macro-organisms that is both tasty and nutritious to the omnivorous prawns. The Cypress Darter Of the 23 species of darters presently known to occur in Illinois, two are mem- bers of the subgenus Microperca (meaning small perch) and are among the smallest fishes in the United States. One of these, the cypress darter, Etheostoma proeliare, reaching a maximum adult size in Illinois of only 36 mm (1.5 inches) in length, was the subject of a life history study recently published by former Survey ichthyologist B. M. Burr and Survey ichthyologist L. M. Page. Copies of this publication, Biological Notes No. 106, are available upon request to this agency. The cypress darter is found in leaf-laden and/or vegetated sluggish streams and margins of lakes and is distributed through- out the Coastal Plain province in the lower Mississippi River valley. One year of field and laboratory observations were made on a population in Max Creek, Johnson County, Illinois. In contrast to other darter species that have been the subjects of life history studies in Illinois, the cypress darter is shorter-lived (maximum of 18 months), much smaller in size, and has indented eggs that are in the shape of half-donuts rather than being spherical. At one year of age the cypress darter spawns in vegetated or debris-laden pools. One to three eggs are laid at a time on leaves of aquatic plants, on algae, or on the sides of rocks. Laying eggs on leaves, un- dersides of rocks, etc. requires that the spawning pair assume vertical and inverted ig MOLD. Z, 4 Breeding male (upper) and breeding female (lower) of the cypress darter. (Drawings by Allice A. Prickett) positions. The male mounts the female and expanded cuplike webs of skin on his pelvic fins allow him to grasp and hold onto the back of the female during spawning. Eggs are left unguarded by the parents and hatch in about nine days at 20°C. Growth is rapid during the first eight weeks. The cypress darter feeds principally on small crustaceans and immature aquatic insects. Life history studies contribute greatly to our knowledge of a species and its overall place in the environment and often reveal information useful in determining relation- ships to other species. The indented, half- donut shaped eggs and the pelvic-fin flaps found on breeding males are unusual, highly derived attributes of the cypress darter and indicate that the species is among the most highly specialized of all darters. Future studies at INHS will con- tinue to concentrate on poorly known fishes for which information is much in demand by persons conducting environmental stud- ies, students, and naturalists. Dimorphic Protozoans One of the many problems facing biolo- gists involved in the classification of ani- mals or plants is the occurrence of mor- phologically or biochemically different forms within a single species. Unless the dimorphic or polymorphic nature of the species is understood, the different forms are often described as several different species while these are, in fact, only vari- ants of a single dimorphic or polymorphic species. Such dimorphic species of microsporidia were the topic of a recent paper by Survey entomologists, J. V. Maddox and R. K. Sprenkel. Microsporidia are tiny Protozoan parasites primarily of insects. They are ob- ligate parasites which infect the insect hosts either orally by ingestion of the resistant spores or transovarially via the eggs. Sev- eral hundred species of microsporidia rep- resenting 38 genera have been described from insects. Most of these microsporidia form only one type of spore depending on the genus to which they belong. However, some of the microsporidia studied by Mad- dox and Sprenkel produced two spore forms; one having characteristics of the The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 genus Nosema and another having charac- teristics of the genus Thelohania. If the insect host is reared at 32°C or higher only Nosema-type spores are produced, but at lower temperatures both Thelohania-type and Nosema-type spores are produced. Both the Nosema-type and Thelohania- type forms were previously described as two separate species. Among the methods used to prove that these forms were dimorphic forms of the same species, Maddox and Sprenkel used a density gradient technique to mechanically separate the two forms. When fed to sus- ceptible hosts the Thelohania-type spores produced only Nosema-type at 32°C, while the Nosema-type spores produced both Nosema-type and Thelohania-type spores at lower temperatures. Maddox and Spren- kel also theorized that, since only Nosema- type forms are found at 32°C, if this were a mixture of two species, continuous pas- ‘sage through susceptible hosts at that tem- perature should eliminate the Thelohania- type form. However, the percentage of Thelohania-forms remained relatively con- stant during passage through eight hosts at yaa OF Most of the Thelohania species described from lepidoptera occurred as mixed infec- tions with Nosema sp. and many of these are probably single dimorphic species. These findings suggest that dimorphism may be common among the microsporidia infect- ing lepidoptera and extreme care should be exercised before mixed infections are described as two separate species. December 1978. No. 182. Published monthly except in July and August by the Natural History Survey, a divi sion of the state Department of Registration and Education, operating under the Board of Natural Resources and Conservation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. Office of publication 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 | The Ilinois NATURAL SURVEY Weed-Eating Insects as Biological Control Agents The purslane sawfly has been observed to cause considerable destruction to com- mon purslane and was thought to be a possible biological control agent for this weed. Survey extension entomologist Ros- coe Randell and University of Illinois De- partment of Horticulture researchers S. F. Gorske and H. J. Hopen conducted tests to determine whether the purslane sawfly feeds exclusively on common purslane and what effects some commonly used pesti- cides have on the purslane sawfly. Common purslane is a weed that is not destroyed by normal cultivation practices. Once uprooted, purslane is capable of sending out adventitious roots and reestab- lishing itself. Some purslane sawfly larvae mine out the contents of the leaf; another race feeds externally on the leaves. One characteristic of an effective biolog- ical control agent is that it feeds only on the organism that it helps to control. If the weed plant is not present, the insect that helps to control it must not feed on other plants of economic importance. Before a proper field management pro- gram can be established, it is necessary to know which pesticides are toxic to the control-agent insect under study. Several pesticides commonly used in Illinois vege- table fields were selected for tests on the purslane sawfly. In the field studies, screen wire cages were placed around each weed to be tested and were set 5 centimeters deep into the soil to prevent the escape of the larvae. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. HISTORY JANUARY 1979, NO Larvae of the externally feeding and leaf mining types were collected, and three larvae of each type were placed in each cage. In each test, each experiment was replicated several times. The testing of various plants as possible food sources of the purslane sawfly was also carried out in the greenhouse. Each plant to be tested was placed in a pot. Three larvae of each of the two feeding types were placed in each pot and a screen wire cage was placed over the pot. Of the 17 plant species tested in the field, the purslane sawfly larvae fed only on common purslane. Greenhouse studies of closely related plants showed a broader range of host plants. The purslane sawfly deposited eggs and fed on common purslane, and it de- veloped normally on winter purslane. When seedlings of winter purslane were grown in the greenhouse, adult purslane sawfly females flew in through an open vent and deposited eggs on the leaves. The eggs and larvae developed normally, and the larvae fed only on the winter purslane. Eight pesticides were selected for tests, including three insecticides, carbaryl, mal- athion, and Bacillus thuringiensis; three DCPA, fen; and two fungicides, chlorothalonil and herbicides, trifluralin, and _nitro- maneb. Externally feeding larvae were col- lected for this study, and 10 larvae and five purslane leaves were placed in a petri dish for each test. Each pesticide was ap- plied to the leaves and larvae at one-tenth of the recommended rate for field use, at the recommended rate, and at 10 times the recommended rate. A plain water spray was used as a control test. Carbaryl and malathion caused almost immediate and complete mortality of the sawfly larvae at all application rates. Of the sawfly larvae feeding on common purs- lane treated with Bacillus thuringiensis, 50 percent died from the recommended field rate, and the higher rate gave complete mortality. Direct application of the herbi- cides DCPA, trifluralin, and nitrofen at the recommended field rate or higher killed all of the larvae. The fungicides chlorothalonil and maneb produced little or no mortality at or below the recommended application rate. The highest rate of application resulted in 100 percent and 95 percent mortality rates, respectively. In the tests involving pesticides applied to the soil, purslane plants were planted singly in pots to which 10 larvae of the externally feeding type were added. A screen wire cage was placed over each pot. Three days after the sawfly larvae pupated, the herbicides DCPA and tri- fluralin were applied to the soil at the same three rates used in the foliar appli- cation tests. After the herbicides were ap- plied, water was used to wash the herbi- cide into the soil. The herbicides applied to the soil had no effect on the sawfly pupae, the cocoons preventing the herbicides from making contact with the pupae. Other researchers have found that bio- logical control of weeds is best accom- plished by the use of insects on perennial weeds in range lands or other areas not under cultivation. Common purslane, an annual weed growing in intensively culti- vated areas, does not fit that model. The Survey and University researchers con- cluded that the purslane sawfly has the potential of providing good control of purs- lane late in the growing season in culti- vated areas and complete control earlier in the season in areas not under heavy cultivation or pesticide application. Con- trol by the sawfly should be part of an integrated control program in which the major compcnents are the use of selective herbicides and cultivation. Pesticides to control other pests might best be applied lying during the period when the sawflies are pupating. Yellow-wood: A Forgotten Tree Yellow-wood, Cladrastis lutea, a mem- ber of the bean family (Leguminosae), is native to the eastern United States and is one of our rarest trees. Survey botanist Ken Robertson recently published a review of the yellow-wood (single copies available on request). The species occurs in 12 states, primarily in the southern Appalachian highlands (Great Smokey Mountains, Cum- berland Mountains, Cumberland Plateau) and the Ozark Plateau (Boston and Oua- chita mountains) with a number of out- populations, including Alexander County, Illinois; Brown County, Indiana; Brown County, Ohio; and Aiken County, South Carolina. Nowhere is the tree com- mon. Wild yellow-woods usually are found on cliffs along river systems or in openings of moist coves in hardwood or hemlock forests. Because of its scarcity (there are _ fewer than 100 wild yellow-woods in IIli- nois), it is being considered for the official lists of threatened and endangered species of the United States and of Illinois. Yellow-wood is one of the most beauti- ful flowering trees native to eastern North America. The tree is hardy throughout much of eastern North America, including most of Illinois, and is sometimes culti- vated in parks, on campuses, in botanical gardens, and less often, in yards. In win- ter, the tree is attractive because of its gray, beech-like bark. In late spring, a yel- low-wood tree in full flower is truly spec- tacular. In summer, the rounded crown, medium textured foliage, and short trunk make the yellow-wood a nice landscape tree. In autumn, the foliage turns a beau- tiful yellow. However, yellow-wood should probably not be used for mass planting, but is best suited to the patient gardener, since the species takes 10 to 20 years to flower from seed. Individual trees flower heavily only every second or third year, and the species is difficult to purchase from commercial nurseries. A number of fine specimens of yellow-wood are in cultivation on the Uni- versity of Illinois campus, in the Morton Yellow-wood tree in summer. (Photo by K. R. Robert- son) Arboretum at Lisle, in the Missouri Bo- tanical Garden in St. Louis, and in the Chicago Horticultural Society Botanical Garden. The genus Cladrastis is of interest to botanists because of its distribution, with C. lutea in the eastern United States and four additional species in eastern Asia. This type of distribution indicates that the genus is an old one and once had a much broader distribution. As a result of the periods of glaciation, the genus was locally extermi- nated over much of its range, leaving relict populations only in eastern Asia and east- ern North America. The present distribu- tion of C. lutea reflects this history. Plant geographers theorize that the species oc- curred over much of North America during the Mesozoic but survived the Pleistocene glaciations only in areas that escaped inun- dation by glaciers or shallow seas. Follow- ing glaciation, the species expanded its range somewhat, particularly along certain major river systems, such as the Kentucky and White rivers. For some reason, how- ever, the species has not been able to migrate into areas once covered by glaciers. Since the only Illinois population of yellow- wood occurs in an area that was not glaci- ated, it is possible that it represents a pop- ulation that survived the glaciers. Yellow-wood trees in cultivation are gen- erally not troubled by diseases or insect pests. The branches are rather brittle and the crotch of the trunk is weak, making yellow-woods, particularly old ones, sus- Trunk and main branches of yellow-wood tree in winter. (Photo by K. R. Robertson) ceptible to wind and ice damage. Although the cultivated yellow-woods in Illinois are generally healthy, the wild trees are not, and many of them have dead or dying branches. The reason for this decline is not known, but may be due to diseases or in- sect pests, to the inability of the species to compete or persist under the present en- vironmental conditions, or to past distur- bances in the forest. Further studies are needed to ascertain the nature of this problem. Trends in Cottontail Abundance In November 1978 Survey biologists con- ducted roadside censuses of cottontails in the vicinity of Sibley, Ford County, and Neoga, Cumberland County, that further document the decline of cottontails in prime agricultural areas. These censuses followed the routes and procedures used by Survey biologist William R. Edwards for a similar census in November 1962. In 1962 on the Sibley area, cottontails were counted on six evenings along 552 miles of rural roads, with 268 rabbits ob- served — 48.6 per 100 miles of driving. At The Illinois NATURAL HISTORY SURVEY : NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 Neoga in 1962 a total of 269 rabbits was seen on seven evenings along 545 miles of roads — 49.4 per 100 miles. During the 1978 census at Sibley, cottontails were counted on five nights along 450 miles- of roadside, with only seven rabbits observed —1.6 per 100 miles. This density repre- sents a decline of almost 97 percent in the number of rabbits seen at Sibley between 1962 and 1978. At Neoga in 1978 cotton- tails were censused on six evenings over a total of 468 miles, with 29 rabbits sighted —6.2 per 100 miles. This density repre- sents a decline of about 87 percent in the number of cottontails observed at Neoga. By comparison, counts of cottontails ob- served on summer roadside pheasant brood censuses at Sibley by Richard Warner and his predecessors at the Survey show 26.9 cottontails observed per 100 miles in 1962 compared with 2.2 rabbits observed in 1978 — a decline of 92 percent. Previously, Survey biologist D. Russel Vance (1976) reported a decline of cottontails from 5.1 flushed per 100 hectares censused on the Hunt Area in Jasper County in 1939 to 0.2 flushed in 1974 —a decline of 96 percent. Vance associated the decline of cottontails to drastic changes in habitat and land use at Hunt. There can be little doubt that popula- tions of cottontails in Illinois, particularly in prime agricultural areas, have been . drastically reduced over the past 20-30 years. Allerton Park, Piatt County, represents a situation where habitat has been rela- tively stable and minimally affected by changes in agriculture. Cottontails have been censused on the 4-H Area at Aller- ton Park in late October or early Novem- ber for the past 23 years. Trapping in November 1978 indicated a population of 136 cottontails using the 4-H Area. Al- though the 1978 estimate was well below the estimate of 259 for 1977 and the peak estimate of 358 obtained in 1976, it was well above the estimate of 97 obtained by Edwards in 1962 and the mean estimate of 104 for the 4 years, 1962-1965. The 23- year mean estimate for the 4-H Area is 206 cottontails, with a range from 88 in 1965 to 358 in 1976. The drastic long-term decline of cotton- tails in agricultural areas apparently is due in part to changes in land use and farming practices. In contrast, the cottontail popu- lation in the undisturbed habitat at Aller- ton Park appears to have remained rela- tively stable. January 1979. No. 183. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. ‘US PS 258-220" Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinors NATURAL SURVEY: Fishes of Illinois Among the responsibilities assigned by law to the Illinois Natural History Survey are “to conduct a natural history survey of the state” and “to publish, from time to time, reports covering the... zoology and botany of the state.” The most recent of such reports is a book released in January entitled The Fishes of Illinois by Survey ichthyologist P. W. Smith. This report, which has superb color illustrations of 34 species, was published, and will be distrib- uted solely, by the University of Illinois Press, 54 East Gregory Drive, Champaign, Illinois 61820. The post-publication price is $20.00, but it is available to readers of the Illinois Natural History Survey Reports at a 20 percent discount, making the total cost $16 plus a $1 postage and handling charge and 5 percent sales tax for Illinois residents. Smith and his associates spent 11 years collecting in various aquatic habitats throughout Illinois and in adjacent areas of bordering states. Some six years were spent in office research, writing the text, and preparing the illustrations. The paint- ings were done by Mrs. Alice Ann Prickett of the University’s School of Life Sciences and usually depict males in breeding colors made from living but anaesthetized fishes. The fish book treats the 199 species that occur, or did occur, in the state. A sepa- rate chapter for each family headed by the common and scientific names describes the family, its relationships, and economic im- portance. A key to genera follows with a paragraph briefly mentioning the content of each genus and how many of its species HISTORY FEBRUARY 1979, NO. 184 occur in Illinois. Each species account con- tains the common and scientific name, a synonymy of the names used in the Illinois literature, a diagnosis, a discussion of vari- ation and subspecies, a summary of the ecology of the species, and a statement of its former and present distribution. There are 185 black and white illustra- tions and 196 distribution maps. Each map indicates the distribution of the species prior to 1908 and, by a different type sym- bol, that at the present time. For the many species whose status has changed during the 75-year interval, the probable reasons for the changes are identified. The book also contains illustrated keys for identifying all Illinois species, a discussion of the his- tory of ichthyological research in the state, ( THE FISHES ¢ OF-ILLINOIS New fish book. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. an extensive literature cited section, and a glossary. It has been anxiously awaited by biologists for more than 10 years. Seventy Years Later It is now more than 20 years since the second series of statewide censuses of bird populations was conducted in Illinois. The first censuses, conceived by Stephen A. Forbes in recognition of the need for quan- titative data to understand ecological rela- tionships, were started in 1905 by Alfred O. Gross with the help of fellow student Howard Ray, under Forbes’ direction. The study was carried on intensively through 1909 and provided a population record probably unmatched anywhere in_ the world. Part of the data were published by Forbes and Gross between 1907 and 1923, and Gross left all of his original field notes at the Survey for further evaluation. Alfred Gross later became a renowned professor of biology at Bowdoin College. With his encouragement and advice and the Sur- vey’s support, Survey biologists Drs. Jean and Richard Graber carried out a similar series of censuses from 1956 through 1958. In the 50 years between the censuses some interesting changes occurred, but overall the Illinois avifauna had remained remarkably intact. It was fortuitous that the second series of censuses came when they did, on the brink of enormously rapid change in the habitats of Illinois. Included among the changes were vastly increased use of insecticides and herbicides and great changes in habitat availability. Illinois has changed more in the past 20 years than it did in the previous 50 years. Although the Grabers have been censusing forest areas the past 5 years using the Forbes-Gross technique, in 1978 they started work on other habitats, the ultimate goal being to determine what is happening to bird popu- lations in these times of such rapid change. Even though the same technique can be used, one important change has been forced upon the census takers. The earlier censuses covered the various habitats in a random sequence as they were encountered on cross-country transects. Ample samples of most of the habitats were eventually acquired in this way, including even the Yellowheaded blackbird on cattails Illinois marsh (photo by Jean Graber). in a northern ’ rarer habitats such as marsh and ungrazed grassland. Now, random transects would be unlikely to encounter the rarer habitats and the investigators must seek out such habitats in the few places they still exist. That change complicates the interpreta- tion of the data, because there is no way to determine whether the surviving tracts of habitat differ in important ways from the habitat in general. The investigators have no choice in the matter. If any data are collected on certain habitats, such as marsh, the investigators must census what is left. Herbert H. Ross Dr. Herbert H. Ross, former principal scientist, assistant chief, and head of the Section of Faunistics and Insect Identifica- tion, died in Athens, Georgia in Novem- ber, 1978, at the age of 70. Dr. Ross re- tired from the Survey in 1969 after more than 40 years of service. He took a teach- ing position at the University of Georgia from which he retired in 1975. One of the most respected scientists in North America, Dr. Ross published 220 Herbert Holdsworth Ross. scientific works, including 7 books and chapters in 6 other books. He was active in several scientific organizations and served as president of the Entomological Society of America (1954-55), the Society for the Study of Evolution (1966-67), and the Society of Systematic Zoology (1973- 74). A memorial fund has been established in Dr. Ross’s name to support systematic research in entomology at the University of Illinois and the Illinois Natural History Survey. Readers who knew Herb Ross and would like to provide a lasting tribute to his memory can make a contribution to this fund. Checks should be made payable to the University of Illinois and marked for the Herbert H. Ross Memorial Fund. Please send contributions to the University of Illinois Foundation, 224 Illini Union, Urbana, Illinois 61801. Crop Pests of 1978 Extension entomologists in the University of Illinois and the Natural History Survey and other extension specialists held the thirty-first annual Custom Spray Operators Training School at the University on Jan- 10, and 11. Black and Gary Braness presented infor- 1978 insecticide usage, and also on the outlook uary 9, Entomologists Kevin mation on the insect situation and for insect conditions in 1979. Much of the information regarding the ranking of the insects and estimation of insecticide usage in Illinois was compiled from reports sub- mitted by county extension advisers. Of the field crops in the state only corn rootworms de- common insect pests of clined significantly. This decline was caused by late planting of corn, a factor which helped promote black cutworm problems. Black cutworms were ranked by county extension advisers as being second only to European corn borers in terms of damage, amount of pesticides applied, and numbers of calls for assistance or informa- tion which were received in the county offices. Grasshoppers were ranked by ad- visers as the third worst insect pest in Illi- nois. Grasshopper populations have been steadily increasing over the past few years and many fields of both corn and soybeans were damaged in 1978. Other agricultural insects which were considered especially bad this past year in- cluded corn earworms, bean leaf beetles, stored grain insects, rootworm beetles, and fall armyworms. Alfalfa weevil problems were reported from occasional fields of al- falfa in northern Illinois, an unusual situ- ation since damage from this insect nor- mally occurs only as far north as Peoria. Another unusual situation was a corn borer infestation in a field of first-trifoliate-stage soybeans in Jasper County. Prediction of insect problems for 1979 is difficult at best. Black cutworm infestations are highly dependent upon spring weather, weed conditions, planting date and other factors. Likewise, European corn borer in- festations are highly weather dependent. The amount and type of fall and spring tillage, as well as planting date, greatly affect resulting populations of borers. Be- cause of the tremendously high fall gen- eration of corn borer populations in I]linois in 1978, conditions for 1979 should be re- garded as threatening. Grasshoppers are also likely to be a problem again in 1979 if The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 weather during the early summer egg hatch is relatively dry. Cool wet weather during the egg hatch could greatly reduce grasshopper damage potential. Rootworm populations, greatly reduced between 1977 and 1978, are likely to remain relatively stable. The number of rootworm beetles laying eggs in 1978 suggests no large increase in popula- tions for 1979. Populations of other insects which were such as alfalfa weevils, corn earworms, fall armyworms, etc. are nearly impossible to predict. Growers can greatly improve their chances of getting maximum yields if they will frequently inspect their crops for de- veloping insect problems. Should problems or questions arise, the entomologists of the University Extension Service and Natural History Survey are always willing to help. February 1979. No. 184, Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation, Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinows Alfalfa Weevil Hunt Attempts to control the alfalfa weevil with fall insecticide applications have not always been successful. Alfalfa weevils go into aestivation, a torpid or dormant state induced by the heat and dryness of sum- mer. Economic entomologists R. J. Barney, Seeiest.oberts, R. D. Pausch, and E. J. Armbrust recognized the need for informa- tion about when alfalfa weevil aestivation ends, when the weevils return to alfalfa fields, and the timing of their dispersal and subsequent egg laying throughout the fields. It is believed that some alfalfa weevils aestivate in woods bordering alfalfa fields. Therefore, the entomologists con- ducted a study in Washington County in southern Illinois, where many wooded field borders serve as aestivation sites for alfalfa weevils. The study site was a 24-acre alfalfa field bounded on the north by soybeans, on the south by corn, on the west by a road and corn, and on the east by woods. Four al- falfa weevil sampling methods were used: emergence traps, flight traps, sweeping with nets, and collecting egg samples. Each emergence trap covered an area of 1 square foot, and they were designed so that any insect or other active organism emerging beneath the trap was collected in a jar. The six emergence traps were placed in the woods along the border of the alfalfa field. Each trap was checked peri- odically, and any alfalfa weevils were re- moved and recorded. Each flight trap was a rectangular box supported by a metal pipe. A sheet of clear Plexiglas was positioned 30 degrees for- ward of vertical above the box to deflect any flying organisms into ethylene glycol contained in the box. Four flight traps were placed in the alfalfa field 40 feet from the woods and facing the woods. During peri- odic checks any alfalfa weevils were re- moved with an aquarium dip net and re- corded. A standard 15-inch-diameter sweep net was swung across the tops of alfalfa plants to locate weevils within the field. Five sets of 50 sweeps were made at five evenly spaced intervals across the field, the first set near the wooded east border of the field and the fifth set near the west side. The The termination of alfalfa weevil aestivation and the patiern of reentry into a field have been studied by Survey entomologists. (Photo by former Survey photographer W. D. Zehr) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. number of adult alfalfa weevils was re- corded for each set of sweeps on every sampling date. Each egg sample consisted of a one- quarter square foot area of alfalfa removed with a knife and placed in a plastic bag. The alfalfa was ground in a blender and washed through a series of screens to re- veal the alfalfa weevil eggs. Five egg samples were collected at each of the five locations where net sweeps were made. Ege samples were collected until the aver- age daily temperature was below the threshold of development for the alfalfa weevil (48° F.). The entomologists found that not all al- falfa weevils ended their aestivation at the - same time. The emergence traps revealed two peaks of activity. A small group of weevils appeared in the traps in early September, while the majority were found in mid- to late October. More than 300 acres of alfalfa were in the area surround- ing the study field, and some growers were forced to cut alfalfa before the optimum time. Other researchers have suggested that cutting alfalfa earlier than usual in the spring, which results in much higher ground temperatures than would other- wise be encountered, may initiate alfalfa weevil migration from the alfalfa to aesti- vation sites. This early initiation of aestiva- tion by a minority of weevils may result in an early termination of aestivation by these same weevils, perhaps explaining the emer- gence in early September. The flight trap catches showed that al- falfa weevils moved into the field about a week after emerging from their aestivation sites. However, the flight traps caught only a small number of weevils, possibly indicat- ing that more flight traps should have been ated or that hey were placed at an incor- rect height or distance from the field bor- der. Another explanation may be that wee- vils reentered the field by short flights or simply by walking, which would not be detected by the flight traps. The sweep-net data revealed a large adult weevil population in the field 3 weeks after their emergence at aestivation sites. Once the weevils end their aestivation and begin to reenter the alfalfa field, a feeding period at the edge of the field may be necessary before they disperse through- out the field. Sweeping the field at five locations showed that field reentry was a gradual process, beginning at the wooded field border. In late October more than 50 percent of the alfalfa weevils were located near the wooded border. By mid-November the weevil population was well dispersed throughout the field. The data from the egg samples demon- strated the same gradual field dispersal. On 1 November almost 60 percent of the wee- vil eggs were found along the wooded edge of ne field. By mid-November egg densi was uniform throughout the field. The termination of alfalfa weevil aesti- vation and the pattern of reentry into a field may be different for various areas be- cause of the availability of aestivation sites, the timing of spring alfalfa cutting, and climatic conditions. Data will have to be gathered for local areas to predict accu- rately the best time for fall application of insecticides as a part of an integrated pest management program. Fingernail Clam Bioassays Before 1955 fingernail clams were abun- dant in the Illinois River. In that year, for some reason still unknown, fingernail clams died out in the Illinois, and they have never recolonized the areas where they for- merly lived. These clams are used for food by diving ducks, such as the canvasback and lesser scaup, and by some bottom-feed- ing fish. The use of the river by diving ducks and the condition of bottom-feeding fish have declined as a result of the finger- nail clam die-off. The demise of the finger- nail clam in the Illinois River contributed to the decline of the commercial fishery there, and the remaining commercial fish- eries on the Mississippi River are depen- dent on fishes that feed on fingernail clams. Research has been in progress for some time at the Survey's Illinois River Labora- tory, using an apparatus which exposes fingernail clams collected from the Missis- sippi River to raw Illinois River water treated to remove suspected toxicants. Sur- vey aquatic biologists Richard Sparks and Michael Sandusky expect to learn, by a process of elimination, which factors in Illi- nois River water prevent fingernail clams from recolonizing the river. The results of this research could also be used to prevent the die-off of fingernail clams in the Mississippi. Testing has been impeded because of equipment failures, contamination of IIli- nois River water by metals leaching from the intake system, and the failure of some batches of fingernail clams to grow well or survive under laboratory conditions. How- ever, steps have been taken to solve these problems, and research progress is being made. Culture tests have shown that after 4 weeks the survival of fingernail clams in petri dishes containing silt is much better than it is in petri dishes without silt. The growth rate of clams is also slightly better in silt. Therefore, fingernail clams will be maintained in silt during subsequent bio- assays. Some of the mortality in fingernail clam cultures maintained in the laboratory is at- tributable to leeches that prey on the clams. These leeches are introduced in the sedi- ment which accompanies the clams when they are collected from the Mississippi River. Consequently, the clams may have to be handpicked from the sediment be- fore they are placed in culture tanks, and the sediment used as a substrate in the tanks may have to be sterilized by heating. These experiments may eventually un- lock the secret of why fingernail clams died Fingernail clams, formerly abundant in the Illinois River, died out there in 1955 and have never returned. They are an important food source for diving ducks and some fish. (From a color transparency by Dr. R. E. Sparks) out in the Illinois River, and they may also point the way to cleaning up the water so that fingernail clam populations can be re- established in the Illinois. Sandhill Crane Migration In cooperation with the University of Wisconsin and the U.S. Fish and Wildlife Service, Survey wildlife biologists William W. Cochran and Arlo Raim studied the fall migration of sandhill cranes from the interlake region north of Winnepeg, Mani- toba, where these birds breed, to their win- tering grounds on the Texas coast. Raim devised two radio transmitter designs for mounting on the leg band normally used by wildlife researchers for marking this spe- cies. One of the designs was conventional, being powered by batteries for a predicted life of 1 year. The other used photocells to provide an indefinite period of opera- tion. A total of 12 transmitters was con- structed. The Canadian Wildlife Service placed the transmitters on nestlings in late July. Personnel from the University of Wis- consin and the Canadian Wildlife Service monitored the birds as they dispersed from their breeding area to southern Manitoba and North Dakota, where they spent the last part of August and all of September. Cochran went to North Dakota in early October, prior to the migration of the sandhill cranes, to instruct personnel from the University of Wisconsin in the tech- niques used for following migrants. One The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 bird, in a flock of about 500, was followed to a wintering area for the species south- west of Houston, Texas. These birds turned out to be easy to fol- . low because they travel slowly and make their migratory flights during the same pe- riod each day (from 1100 to 1730 hours). Cochran’s interest was in the possibility for observing the homing phase of this mi- gration during which the birds were ex- pected to alter their generally southward course to seek out their specific wintering areas. It was expected that a rather abrupt change would be noted about the time the birds reached the latitude of their goal. The cranes’ flight was almost due south for the first 800 miles (this took 4 days) after which the flight distance covered per day was reduced to about 80 miles and the flight direction became rather unpredict- able. Flight was generally to the southeast, south, or southwest, seemingly dependent upon wind direction. However, during the last half hour to hour of flight each day, the direction shifted to almost straight east or west. During this period, the flock size (the number of birds with the radio- equipped bird) was reduced gradually to about 200 birds and, finally, to about 70 birds. These observations suggest that experi- enced members of the flock search out fa- miliar landmarks during the latter portion of the migration, with flock breakup due to differing goals. If this is the case, this species is a poor one for definitive studies of orientation and navigation mechanisms. The principal objectives of the study were to evaluate habitat use during migra- tion and to field test the technique and train personnel for a follow-up study of the endangered whooping crane in 1979- 1980. The study will be continued with the spring migration of the sandhill cranes al- ready radio tagged (and later, the whoop- ing cranes) by researchers from the Uni- versity of Wisconsin. March 1979, No. 185. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation. Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinovs NATURAL SURVEY Bee Systematics — Melandrena The genus of bees known as Andrena includes nearly 500 species in North Amer- ica and as many or more in the Old World. Many of these bees are important pollinators of fruit crops such as straw- berries, blueberries, apples, pears, plums, cherries, and native plants such as sun- flowers. Survey entomologist W. E. LaBerge and several associates have been studying the systematics of the North American species of Andrena for several years. These studies are being supported in part by funds from the National Science Founda- tion, and they are a prelude to a faunal study of the bees of Illinois. Systematic studies have several purposes among which are: to known the different kinds of organisms, to make known their valid scientific name, to name forms that have not been named, to pro- vide illustrations and keys so that other scientists can identify the species, to de- make scribe their variation, geographical distri- adits HISTORY APRIL 1979. N¢ Ré bution and habits when known. It is fre- quently of practical importance to be able to accurately identify species. For instance, if a scientist were studying pollination of apple trees in northern Illinois, he would have to be able to recognize Andrena thas- pu, a bee important in apple pollination. However, there are three or four other species of Andrena which may be active in northern Illinois at the same time as Andrena thaspu and which are very simi- lar in appearance to thaspi. These other species do not visit apple tree blooms or do so only infrequently. Without a care- fully constructed key, illustrations, and descriptions, no one would be able to make the critical distinctions between these spe- cies of Andrena, and the scientist may effort wrong species. Also, the valid scientific spend considerable studying the name of a species is the indispensable key to all previously published information re- garding that species. The ninth part of the revision of the Andrena (Melandrena) carlini rest- ing on flowers of toothwart (Photo by Joseph Laury Luth). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. bees of the genus Andrena, describing a group of species known collectively as the subgenus Melandrena, was recently com- pleted by Survey entomologists John A. Bouseman and Wallace E. LaBerge. This study was based upon over 12,000 speci- mens which segregate into 22 species. The species of Melandrena are spring or early summer bees, and several are important pollinators of fruit trees and berries. One common fruit tree visitor, previously with- out a name, was named Andrena illini by Bouseman and LaBerge because it is com- mon throughout the state of Illinois. Coal Conversion Wastes With the shrinking of the world’s petro- - leum resources, energy planners are taking afresh look at the nation’s energy sources, especially coal which represents a large percentage of our energy resources. Coal gasification and liquefaction are two meth- ods by which coal can be converted to synthetic gaseous and liquid fuels. How- ever, the conversion of coal is not without environmental impact. The amount of solid waste produced by a single coal gasi- fication plant over 20 years is estimated to occupy 1,250 acres to a depth of 10 feet. The disposal of these huge amounts of waste is unprecedented and successful com- mercial production of these fuels will par- tially depend on the “safe” disposal of their wastes. Survey aquatic biologists John J. Suloway and William F. Childers in conjunction with members of the Illinois State Geological Survey have been investi- gating the impact of leachates generated from coal conversion wastes on the aquatic environment in a study funded by the federal Environmental Protection Agency. The four phases of the project included examining the mineralogy of the coal solid wastes, the solubility of chemical consti- tuents of the waste, the attenuation of leachates by the soil, and the toxicity of leachates generated from coal conversion wastes to aquatic organisms. Suloway and Childers were primarily involved with the toxicity testing. The primary objectives of the toxicity tests were to determine: a) if coal conversion waste leachates were acutely toxic to young fathead minnows, b) how much dilution was necessary to eliminate mortality caused by a leachate during a 96-hour test and c) which water soluble chemical constituents were responsible for the toxicity. Ninety-six hour static bioassays of the leachates were conducted with one to six- day-old minnows, Pimephales promelas. Small, young fish were used since it was occasionally difficult to obtain large quan- tities of solid waste from which leachates could be generated. For example, Illinois coal had to be shipped overseas to be pro- cessed at a power plant in Scotland in order to obtain coal gasification ashes. The bioassays were conducted under controlled conditions in an environmental chamber where the temperature was maintained at 21 (+ 1)C and there was a constant pho- toperiod. Approximately 14,000 minnows were utilized in bioassays of 88 leachates. Approximately half of the natural leach- ates were acutely toxic to young fathead minnows under laboratory conditions. Sev- eral acidified leachates were very toxic and required large amounts of dilution (> 1:100) to ensure survival during a 96- hour bioassay. The extent of a leachate’s toxicity and the amount of dilution neces- sary to ensure survival during a 96-hour bioassay were largely a function of acidity and total ion concentration. Some of the leachates contained potentially hazardous concentrations of aluminum, chromium, copper, magnesium, nickel and zinc. Sulo- way and Childers plan to continue this research in order to study long-term effects of these leachates and the effects of these leachates on other aquatic organisms. Illinois River Timber Several hundred acres of bottomland forest exist in the floodplain of the Illinois River on islands and along the shorelines of the river and its associated backwater lakes. The majority of the bottomland tim- ber occurs along the lower two-thirds of the river from the Great Bend, near Hen- nepin, to Grafton. One aspect of the Lake Michigan Diversion Project was to assess the effects of increased water levels on the Bottomland forest, chiefly silver maple, near Rice Lake, Illinois (Photo by Steven P. Havera). floral and faunal species comprising the bottomland forest community of the Ilh- nois River. During the fall of 1978, wildlife biologist Stephen P. Havera and associates Donald Steffeck, Fred Paveglio, and Kathleen Archer sampled 15 tracts of bottomland timber between Hennepin and Grafton, and gathered such data as species composi- tion, basal area, density, tree size (DBH), and the monetary lumber value of the tim- ber. By combining these field inventories of the bottomland tree species with their tol- erances to various water conditions as reported in the literature, the possible effects of levels timber of the Illinois River can be assessed. A total of 18 tree species were tallied in the timber cruises. Silver maple, cotton- wood, and species of ash were found in all 15 tracts of timber sampled; elm species in 14 of the tracts; willow, hackberry, pe- can, and sycamore in about half of the increased water on the study areas. Box elder, river birch, honey locust, red mulberry, basswood, hawthorn, pin oak, persimmon, sugarberry, and swamp privet were found in 25 percent or less of the tracts. The basal area of the bottomland tim- ber stands sampled varied from 95 to 173 sq. ft. per acre. In all of the 15 stands, silver maple accounted for the majority of the basal area, with an average of 64 per- cent of the total basal area for all 15 areas. The density of bottomland trees varied from 95 to 304 trees per acre among the study areas. The area with the smallest density of trees (95 per acre) was near Meredosia. This tract also had the largest trees inventoried with an average diameter at breast height (DBH) of 25.8 inches. The remaining timber stands had average DBH values between 12.2 and 17.9 inches. The number of board feet was calculated from the number of sawlogs tallied for each tree species on the study areas. Utiliz- ing the most recent Illinois timber prices, an estimated value of the lumber could be derived. The value for sawtimber in bot- tomland stands sampled varied between $254 and $595 per acre. These estimates should be considered as maximum amounts. The stand with the highest sawlog value The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 per acre was in Sanganois State Park at the confluence of the Sangamon and IIli- nois rivers. Perhaps the most impressive timber stand sampled was at Godar’s Swamp sear Kampsville. Here large pecan trees ac- counted for 30 percent of the basal area. Some of these pecan trees had DBH’s of 36 inches. A good population of large cot- tonwood trees and a fair number of pin oaks were also present. Timber from four of the 15 tracts sam- pled had been harvested within the last 5 years. Because of selective timber cutting and agricultural encroachment upon bot- tomland areas, pecan and pin oak stands once prevalent along the southern reach of the Illinois River are being transformed to stands dominated by silver maple. Insect/Plant Relationships The practical implications of how insects select plants upon which to feed and how plants evolve to avoid being eaten justify research efforts in this field. Recently, en- tomologist Marcos Kogan published a paper summarizing information on insect/ plant chemical interactions in which he suggests several basic models in the host- selection processes followed by various in- sects. About half of all known species of insects are more or less dependent on plant hosts. Generalized feeding, or polyphagy, seems to be a primitive stage in insect/plant in- teractions and oligophagy (few plant hosts) the rule among plant-eating insects. The information available on _host-selection processes is based on few insect/plant rela- tionships. Only 18 plant families out of about 320 existing families of higher plants have had representative species investigated in this way. As these studies expand to include other plants and insects, additional models will be recognized. These insect/plant associations involve sensorial, physiological, and ecological pro- cesses mediated by many factors. There is little doubt, however, that plant allelo- chemics are the key factor in the establish- ment of the associations. The identification of the chemical bases of host-plant selec- tion by insects and of host-plant resistance to insects can greatly improve the efficiency of programs for breeding resistant varieties of plants. It can also open new avenues for the manipulation of insect’s behavior for use in pest management programs. Although the practical aspects of in- sect/plant asociation studies are obvious, the scientific knowledge to be gained on the interdependence of organisms and their harmonic coevolution makes such studies especially exciting and attractive. April 1979. No. 186. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation, Prepared by Dr. W. E, LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA, ILLINOIS 61801 The Illinovs NATURAL SURVEY The Persistence of Benomyl On Walnut Fruit The severity of anthracnose leaf spot on black walnut, a major disease of this tree species, Causing premature defoliation, re- duced growth, malformed nut meats, and possible tree death, has recently been found to be reduced by applications of the fungi- cide benomyl. Successful treatments have been made through leaf spray and soil in- jection methods. The ability of this fungi- cide to control many other pathogens has been well documented since its introduc- tion in 1967. Benomy] is a systemic fungi- cide that moves through a tree’s vascular system from one part to others. Researchers have shown that MBC, the stable product formed when benomy] is suspended in a water-based medium, can have long-lasting effects on disease devel- opment for up to several years after soil application. Foliar applications have also resulted in MBC residue accumulation in the xylem tissue, but its movement to other Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. HISTORY plant parts is slow and for the most part restricted to areas about the point of application. In both leaf spray and soil treatments, the prime site for MBC accumulation is in the foliage. Scientists elsewhere applied benomyl sprays to the external surfaces of oranges and detected residues in the juice for up to 84 days after treatment. The per- sistence of benomyl on exterior surfaces, acting as a reservoir for its subsequent sys- temic movement into the plant over long periods of time, is an obvious asset to its use in curbing disease. Because of the systemic nature of be- nomyl and the uncertainty of its move- ment, particularly into floral parts and fruits, plant pathologists Dan Neely and Steven Cline decided to determine the per- sistence of benomyl on and in walnut fruit when applied as foliar sprays, as trunk in- fusions, and by soil injection. The ability of benomyl to persist on nut hulls was found to be a function of its con- Black walnut trees are now a plantation crop. The tree in the center has been extensively de- foliated by anthracnose. centration. The spray concentration nor- mally used on walnut plantations lasted about 5 weeks, when more than one-half of the inhibitory effectiveness was lost, as measured by bioassays. Spray treatments two and four times the normal concentra- tion lasted longer, but all foliar spray treat- ments were 97-98 percent ineffective at inhibiting the test fungus 22 months after treatment. Soil and trunk injection results sug- gested the possible uptake and transloca- tion of benomyl (MBC) to nut hulls when some of the bioassays displayed sensitivity after 48 days. These data, however, do not appear significant and require additional testing. Correlations between benomyl residue persistence on nut hulls and amounts of precipitation, both in the field and under simulated rainfall in the laboratory, indi- cated an interaction. At test sites at Ur- bana, Carbondale, and Fisher, rainfall of 5-7 inches accompanied a decrease in benomyl effectiveness of 80-90 percent. At the Martinsville test site, however, more than 5 inches of precipitation fell, but no marked change in bioassay results ap- peared. Laboratory rain bioassay experi- ments demonstrated the ability of benomyl to remain effective after 24 inches of pre- cipitation. These results indicate that other factors may be involved in the ability of benomy] to persist on nut hulls. Nut meat tests resulted in a lack of de- tectable benomyl! residue. A more sensitive testing method is now being sought for the detection of smaller fungicide amounts than can be detected through bioassays. Abundance and Migration of Woodcocks The date of arrival of woodcocks in central [llinois in 1978 is not known. How- ever, on March 15 Survey Biologist Charles M. Nixon observed a male exhibiting what is believed to be territory-establishing be- havior, called “displaying,’ on snow- covered ground along the Vermilion River south of Danville. Wildlife Specialist William R. Edwards and his associates are studying the wood- cock to learn more about how to manage it as a living natural resource. They estimated that 38 woodcock territories were active through May on the Forest Glen Nature Preserve, also along the Vermilion River, and on lands immediately adjoining the preserve. Peak numbers of woodcocks were observed during June at Forest Glen, but woodcock sightings declined in July and August. Woodcocks were observed almost every evening, but in much reduced num- bers, in late August, September, October, and early November. Where 15—20 birds might be seen on an evening in June, only 2-4 might be seen in late summer. Single birds were seen on November 17 and 21, the last to be observed at Forest Glen in 1978. On November 11, the opening day of the 1978 upland game hunting season in Illinois, hunters reported flushing unusu- ally large numbers of woodcocks over much of central Illinois. Examination of weather data indicated the southeasterly passage of a frontal system through Wis- - consin on November 5 and through Illinois on November 6. Rainfall was quite general in Illinois on November 6 behind the front. Following the passage of the front in Wis- consin, the barometer was relatively high, temperatures were low, and winds were out of the north and northwest — condi- tions basically favorable to woodcock mi- gration. The investigators concluded that probably there was a major woodcock migration out of Wisconsin on the evening of November 6 and that migration ended when the birds caught up to the rain in central Illinois. As a result, large numbers of woodcocks were present in Illinois on November 7. On the assumption that southward mi- grations proceed on the basis of high pres- sure systems and southerly or southeasterly movements of air following the passage of frontal systems, the next weather condi- tions favorable for a major migration of woodcocks out of Illinois took place during the period of November 19-21. No wood- cocks were observed at Forest Glen after November 21. Weather in Illinois in January and February 1979 was much colder than normal, and snowfall was much above Survey wildlife specialists are studying the abundance and migration of the woodcock in Illinois. The bird shown here was injured when it flew against a large piciure window. normal. The passage of the first major warm front of 1979 occurred on March 2. Temperatures in the 50’s occurred on March 3-4. Rainfall was general in IIli- nois on March 4 with winds out of the south. On March 4 Nixon again observed a woodcock near the Vermilion River, and Ms. Marilyn Campbell, naturalist for the Forest Glen area, reported a woodcock that was seen on March 4 in nearby West- ville. On the evening of March 5 the Forest Glen area was censused for the first time in 1979, and woodcocks were found displaying on or near all territorial sites visited that had been occupied in 1978 and in several locations that were not regularly used in 1978. Here again was a pattern of woodcock migration associated with the passage of a frontal system followed by a wind favor- able to the direction of migration and ap- parently terminating with rainfall. The northward migration was associated with a warm front, whereas the southward mi- grations of November 1978 were associated with cold fronts. In their continuing in- vestigations the researchers expect to learn more about woodcock abundance and mi- gration patterns. Even the Bugs Have Bugs The alfalfa ecosystem, unlike many other field crops, represents a relatively long lasting, well-established perennial system. Thus, it serves as a natural nursery for many predators, parasites, and pest spe- cies which may eventually migrate to neighboring annual crop systems, such as soybeans. Many pests of the order Lepi- doptera, whose larval forms are caterpil- lars, are commonly found on soybeans and alfalfa, and some are serious pests of both crops. To control insect pests of field crops through integrated pest management pro- grams, it is necessary to know which para- site species occur naturally in pest species at each stage of their lives. Entomologists Stephen Roberts, W. K. Mellors, and Ed- ward Armbrust decided to research the relationships of parasites and lepidopter- ous larvae in soybeans and alfalfa to un- derstand more fully the importance of parasites as biological control agents. In the first growing season of this study, 10 soybean and 5 alfalfa fields were sam- pled, and in the next season, 1+ soybean and 8 alfalfa fields. Larvae were collected with a standard 15-inch sweep net; the entomologists made 200 sweeps per field The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 at about 1-week intervals. The larvae that were collected were reared on suitable ar- tificial diets or on fresh alfalfa leaves. The rearing continued until adult Lepidoptera emerged, parasites emerged, or the larvae died from unknown causes. The percent- age of parasitism was calculated for pest species. Ten species of lepidopterous larvae were collected in Champaign County in the two growing seasons. These species, with the percentages (in parentheses) that were at- tacked by parasites in alfalfa and soybeans, were the green cloverworm, Plathypena scabra (43.3 and 32.4) ; the celery looper, Anagrapha falcifera (38.2 and 37.9) ; Au- tographa precationis (no common name) (the population was too small to deter- mine percentages of parasitism) ; the var- iegated cutworm, Peridroma saucia (34.1 and 46.7); the alfalfa caterpillar, Colias eurytheme, and the clouded sulphur, Co- lias philodice (these two species were not separated because of the possibility that they may hybridize and because it is diffi- cult to identify species of larvae in the genus Colias) (47.0 and 47.0) ; the forage looper, Caenurgina erechtea (9.7, and the population in soybeans was too small to May 1979. No. determine the percentage of parasitism) ; the yellowstriped armyworm, Spodoptera ornithogalli (36.0 and 40.6); the army- worm, Pseudaletia unipuncta (21.4 and 52.8); and the yellow woollybear, Dia- crista virginica (24.0, and the population in soybeans was too small to determine the percentage of parasitism) . All of these species of lepidopterous lar- vae were collected in both alfalfa and soy- beans in both growing seasons, except for A. precationis, which was not collected in ~ soybeans in the second season. A total of 27 parasites, including two hyperparasites that attacked some of the parasites, were found in the host species. All parasites and hyperparasites were identified as to genus, and all but two were identified to species. Possibly as a result of the influence of pathogens and parasites or both in combi- nation with other factors, the seasonal av- erages of most of the lepidopterous larvae collected were less than one per 100 sweeps of the collecting net for both years in both crops. Only the green cloverworm and the Colias species had averages of more than one per 100 sweeps in one or both crops. Undoubtedly the parasites played a part in controlling these pest populations. 187. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation, Prepared by Robert M. Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 6180) The Illinors NATURAL HISTORY REPORTS Squirrel Nests Both gray and fox squirrels use tree holes for shelter or construct nests of leaves and twigs in trees. A nest in a tree cavity should be warmer and more protected than one made of leaves or twigs and, likewise, nest boxes ought to be comparable to tree holes. If this hypothesis is correct, squirrels wintering in nest boxes should be in rela- tively better physical condition than those wintering in leaf nests. Survey wildlife biologists C. M. Nixon and L. Hansen compared the percentage of carcass fat for male fox squirrels col- lected from nest boxes with male fox squirrels from leaf nests in late February 1978 in Vermilion County, Illinois. These biologists also evaluated the use of nest boxes by fox squirrels by collecting data on the physical environment surrounding each nest box. Some 27 variables such as height of box from ground, tree species, numbe1 of escape trees, and direction of box en- trance were used in an analysis of their effect on the use or non—use of nest boxes. Nixon that fox squirrels from nest boxes did not have and Hansen found male significantly more fat than those from leaf nests. Only two physical factors were found to be important to the use of nest boxes by fox squirrels. There was a positive relation- ship between box height above ground and box use and a negative relationship be- tween number of existing tree holes in the nest box tree and squirrel use of that box. Thus, to maximize use of a nest box by fox squirrels, nest boxes should be placed as high in a tree as possible and should not be put in a tree with an existing cavity. Another method of enhancing squirrel populations is by retaining some large trees when timber is harvested. with cavities Gray squirrel (Photo by Larry Farlow, former Survey photographer). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey Wildlife biologists Nixon and Hansen counted all trees with a diameter at breast height (dbh) of 5 inches or greater on 63.5 acres of forest to determine which species of trees produced most tree cavities and in what size of tree were these cavities most likely to be found. Three species of trees — sugar maple, basswood, and beech — con- tained significantly more cavities than ex- pected, and white and black oaks and hickories contained fewer cavities than ex- pected from their abundance in the forest. A majority of trees with cavities were larger than 12 inches dbh. The retention of 2 to 4 maples, basswood or beech trees per acre during selective harvesting of trmber in a hardwood forest should pro- vide squirrels and other cavity nesting wildlife with sufficient nesting sites with little loss of valuable timber. Collections and Collectors An extremely valuable resource at the Natural History Survey is the systematic collections of plants and animals. Many scientists are well aware of them and make almost constant use of them, but the gen- eral public may not have given much thought to the value of collections that date back a century or more ago. They have been used primarily for research and reference (direct comparison for identi- fication purposes) rather than for public display, but today with the intense interest in baseline data for environmental impact statements they are proving to be a gold- mine of information on environments of the past. They provide a picture of what Illinois habitats were like at almost any given period during the past 100 years, what organisms were present, and even something about the relative abundance of these plants and animals. While serious studies of plants in the State predate those of animals, the mate- rial collected and reported upon was not deposited at the Survey. The earliest speci- men in any of the collections is a remark- ably well-preserved sturgeon collected in the Ural River of Russia by a Dr. Lew- zerow in 1862 and apparently sent to Sur- vey scientists in a specimen exchange. A few fish and insect collections made in Illinois during the 1870’s are extant, and many specimens of fishes, various kinds of insects, amphibians, and reptiles, taken in the 1880's, are in remarkably good con- dition. Most of the study specimens in the Survey’s collections were made by staff members, who in a sense were monitoring the environment by their collecting pro- grams over the years. As the fame of the collections grew, it was inevitable that private collections would be donated to the Survey for safe keeping. Among the animal groups more than 50 major collections have been deposited here. The earliest for which we have a record consists of approx- imately 6,000 beetles and bees given to the Survey in 1881. The most recent were last year when a private collection of 20,800 mussels from Illinois rivers was presented: some 10,000 vials of caddisflies, ants, and scorpion flies were bequeathed, and more than a quarter of a million pinned insects were transferred to us on permanent loan _ by the University of Illinois. All study specimens have complete collecting data. The outstanding collections at the Sur- vey are those of insects with over four million specimens and fishes with about a half-million, but other small collections represent fungi, flowering plants, mollusks, spiders, and other vertebrate groups. A special collection consists of soybean-asso- ciated arthropods from all parts of the world where soybeans are grown. It and some of the other noninsect groups are being computerized in order to facilitate rapid retrieval of valuable data. The refer- ence material is the official State collection, and one of the responsibilities of this agency is the proper maintenance of the collections. Thrips in Soybeans The soybean thrips, Sericothrips vart- abilis, is commonly found in soybean fields throughout the Midwest and it approached pest status in Illinois for the first time in 1975 when numbers reached epidemic pro- portions. The stress exerted by thrips on soybean seedlings, especially in the southern third of the state, was compounded by stress caused by herbicide injury. As leaves of seedlings curled and dropped, farmers became concerned and began treating with insecticides. Within the major zone of in- festation about 1.5 million ha (hectares) of soybeans were planted. Of those, over 50,000 ha were treated with insecticide to control soybean thrips. At the time of the outbreak, little was known about the soy- bean thrips and their impact on soybean quality and yield. Some species of thrips are known to be involved in the transmis- sion of bud blight disease of soybeans, caused by tobacco ringspot virus. This dis- ease can dramatically reduce soybean seed quantity and quality. Survey entomologist M. E. Irwin began a study of thrips in soybean fields in 1975 and has discovered some facts that could lead to an improved understanding of the role of thrips in soy- bean production in Illinois. Under laboratory conditions Irwin and S. E. Halbert, a graduate student, have shown that the soybean thrips is probably incapable of spreading bud blight disease to soybeans. A study was initiated between Irwin of the Illinois Natural History Sur- vey and the University of Illinois, K. V. Yeargan, University of Kentucky, and N. L. Marston, United States Department of Agriculture, Missouri, to determine the species composition and the spatial and temporal distribution patterns of thrips in soybean fields in the Midwest. Two species of phytophagous thrips — the soybean thrips, Sericothrips variabilis, and the flower thrips, Frankliniella tritici —colonized soybean plants in the area. Numbers of thrips were similar no matter which part of the fields were sampled. However, both species were unevenly dis- tributed on the soybean plants. Larvae and adults of the flower thrips were concen- trated in terminal buds and_ blossoms. Adults of the soybean thrips were found most commonly on the uppermost fully expanded leaf or on the leaf immediately below it. Larvae of the soybean thrips were generally concentrated on the 3rd—6th leaves below the terminal. Both species occurred in soybean fields throughout the growing season. Populations of the flower thrips peaked earlier than did those of the soybean thrips. Early season population densities of both species were higher, and rates of population buildup and decline were more pronounced in Kentucky than in either Illinois or Missouri. Moderate infestations of certain species of thrips early in the growing season may be economically beneficial. Preliminary re- sults strongly suggest that the density of Orius insidiosus, an important general insect predator, in soybean fields is directly correlated with buildup of colonizing thrips. After thrips population levels are suppressed by the predator, O. insidiosus seems to act as a buffer to the buildup of other soybean pest species because it preys on their eggs and small larvae. Irwin is currently studying the interaction of thrips and Orius in soybeans with the thought that a better understanding of these two major groups of insects in soybean fields could be used to help reduce pest problems throughout the growing season. Computers at the Library LCS is the new acronym being used at the University of Illinois Library. It stands for the Library Circulation System, which is now computerized. As a departmental library of the University of Illinois, the INHS Library has a computer terminal that is wired directly to the data base con- taining the shelf list of the entire U. of I. Library. It can be searched by author, title, author-title or call number. If the work being searched is located in the library system, the terminal prints out its call number, author, title, place and date of publication, location, circulation period, and whether it is charged out, has saves on it or is on the shelf ready to circulate. If the book a researcher needs is located in the main library or another depart- mental library, it can be charged out to him/her remotely on the INHS Library terminal. The book can then reach the researcher in one of three ways: (1) the researcher can wait a few hours and go pick it up at its location, where it will be waiting; (2) it can be sent to the INHS Library through the shipping department of the U. of I. Library; or (3) it can be mailed to the researcher through campus mail. The Illinows NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 The INHS Library computer terminal is also wired to be used with an acoustic coupler to reach literature data bases through long-distance telephone lines. The University of Illinois Library subsidizes searching on BRS) Bibliographic Retrieval System), which contains data bases such as Biosis Previews (publishers of Biological Abstracts and Bioresearch Index), Agri- cola or Cain (National Agriculture Li- brary), Dissertation Abstracts, Pollution Abstracts and National Technical Informa- tion Service. These data bases can be searched very reasonably with the U. of I. Library subsidization. Royalty data bases cost $10 per half-hour on-line and non— royalty data bases are only $3 per half— hour on—line. Back files can be searched off—line at night when the data bases are unavailable for on—line use..‘The citations retrieved in this way can be printed on— line the next day at the on-line rate or mailed to the Library at the rate of 16¢ per page. Most of the data bases contain citations to literature from about 1970 to the present. This makes them very valu- able as a fast literature search for fairly current citations in many subject areas. BRS is a relatively new vendor and has at this time fourteen data bases for search- ing. ‘Iwo of the data bases useful to INHS researchers that are not offered by BRS are Commonwealth Agriculture Bureaux and Aquatic Sciences and Fisheries Abstracts. Consequently, the INHS Library also has a password and account number with ‘DIALOG, the Lockheed Information Sys- tem. In the near future the University of IIli- nois Library will be closing its card catalog and replacing it with a full-bibliographic record on-line. This record will be search- able by every access point, if not more, as the current card catalog, i.e., author, title, - subjects, junior authors, series, corporate affiliations. This data base will be search- able in each departmental library, includ- ing INHS, as well as many libraries throughout the state. Computers are great aids in getting the right material to the right person at the right time, and will most likely become more so in the future. With the cost of printing on paper increasing so rapidly, we may find publishers of both primary liter- ature and secondary literature (abstracting and indexing services, bibliographies) mak- ing more use of on-line services and less use of printed products. In twenty to twenty-five years we may find scientific research institutions, such as INHS, par- ticipating in what Dr. F. W. Lancaster of the U. of I. School of Library Science calls “the paperless society.” June 1979. No. 188, Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation, Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 6180) The Illnovs NATURAL SURVEY A Newly Discovered Fungus During an investigation of the fungi that gather on plant debris in cypress swamps in Illinois, a new fungus of the class Asco- mycetes was found by mycologists J. L. Crane of the Illinois Natural History Sur- vey and C. A. Shearer of the University of Illinois. This fungus has a closed spore- structure two-celled, brown, butterfly-shaped (papil- ionaceous) spores, called ascospores, con- tained in asci, or spore sacs. It is referred to as CS-470. The mycologists will describe this new species in a new genus in the sub- bearing (cleistothecium) and class Loculoascomycetes. The fruiting bodies, which spores, are solitary and lie on or near the surface of the material on which the fun- produce HISTORY gus lives, or are embedded in or sunk be- low the surface, and are globose. The asci are bitunicate (two-walled), globose to somewhat globose, and stalked and lack a subapical chamber. The papilionaceous, two-celled, brown, smooth-walled asco- spores uniquely characterize this species. Of the Ascomycetes with bitunicate asci, CS-470 fits best in the Order Pleosporales because of its middle-sized pseudothecia, persistent pseudoparaphyses, septate brown spores, and occurrence on dead twigs. CS-470 appears to be a rare species that occurs in warm seasons. It was found only once in collections made monthly from three cypress swamps over a 2-year period, and this occurrence was in August 1974. It was collected again in August 1977 in Newly discovered fungus, CS-470. At the left is the bitunicate (two-walled) ascus (spore sac) magnified 793 limes. At the right is the mature butterfly-shaped ascospore magnified 1,833 times. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey the same cypress swamp from which it had been collected originally. ; Although CS-470 was collected from submerged wood, fruiting bodies developed on the wood after it was incubated in a moist chamber. In addition, submersion of the fungus culture was not necessary to induce fruiting. Even though this behavior is typical of a number of freshwater, estu- arine, and marine Ascomycetes, more in- formation is needed about the distribution of this species before it can be character- ized as a freshwater Ascomycete. Managing Waterfowl Habitat Along the Illinois River The Illinois River valley is one of the nation’s most important areas for migrat- ing waterfowl. Long ago, hunters recog- nized the abundance of waterfowl in the bottomland lakes of the valley, and in the 1890’s sportsmen began to acquire bottom- land property for the purpose of forming “duck clubs.’’ However, the prohibition of baiting in the mid—1930’s greatly reduced the duck kill by private clubs in the []linois Valley. Although the navigation dams built on the Illinois River in the late 1930's increased the natural food resources for waterfowl, it became necessary for duck clubs to control water levels on their prop- erties to maintain high quality hunting. Water levels are now manipulated by many private duck club and public waterfowl areas. Water manipulation permits duck food plants to be sown or to volunteer on mud flats during the summer and then allows them to be flooded with water during the fall to attract migrating waterfowl. By 1941, 432 (55 percent) of the 792 duck clubs in Illinois were located in the IIli- -nois Valley. During the late 1950’s and early 1960’s, thousands of acres of aquatic duck food plants were lost in the valley as increasing sedimentation and turbidity filled shallow productive areas and clouded the waters of the bottomland lakes. As a result of this degradation, the management of water levels by duck clubs and state and. federal agencies is now almost mandatory if high quality hunting is to be enjoyed. Aerial view of land belonging to a private duck club north of Spring Bay, Illinois. Naturally occurring moist- soil plants are grown in the irregularly shaped area in the center foreground. Corn is grown in the other fields. The annual harvest of ducks in the Illinois Valley ranges between 50,000 and 100,000. The number of waterfowl hunting areas along the Illinois River, their sizes, and management practices were investigated by wildlife specialists Frank Bellrose and Stephen Havera and other members of the Wildlife Research Section at the Ha- vana Laboratory as part of the Lake Michigan Diversion Project that proposes to increase the amount of Lake Michigan water that is diverted into the Illinois River. The Illinois Department of Conserva- tion issued licenses to 272 duck hunting clubs that managed land along the Illinois River during 1977. In September 1978, a questionnaire was sent to 219 duck clubs that owned 40 acres or more along the Illinois River. A total of 160 (73.1 per- cent) of the clubs responded, representing 77.3 percent (51,405 acres) of the total area managed by licensed duck clubs in the Illinois Valley. Water levels could be controlled on almost 32 percent (16,315 acres) of the total area managed by the clubs responding to the questionnaire. The U.S. Fish and Wildlife Service and the Illinois Department of Conservation own 50,478 acres containing 24,344 acres of water in the IIlinois River valley. Water levels can be managed on 14.6 percent (7,388 acres) of the total area. In addition to impoundments where water levels can be controlled, thousands of acres of publicly and privately owned waterfowl areas rely on naturally occurring low water levels during the summer for the establishment of moist-soil vegetation (such as smartweeds, rice cutgrass, wild millet, and beggar ticks) and the planting of agricultural duck foods. Also, sections of federal, state, and private duck-hunting lands are refuge areas where no hunting and little disturbance is permitted during the waterfowl] season. Of the private clubs that responded to the questionnaire and that control water levels, 18 percent managed exclusively for natural moist-soil food plants, whereas 24 percent managed for agricultural crops. Both natural and agricultural food man- agement occurred on 58 percent of the private clubs with water level control. Jap- anese millet was the most common agricul- tural crop planted by private duck clubs (59 percent) followed by buckwheat (58 percent), corn (46 percent), soybeans (2 percent), rice (1 percent), and milo (1 per- cent). State and federal agencies planted primarily Japanese millet, corn, and buck- wheat. State, federal, and private areas control 90,829 acres that are used primarily for waterfowl hunting and management, rep- resenting approximately 43.2 percent of the 210,000 acres of nonleveed floodplain in the Illinois Valley. The remaining 190,- 000 acres of the floodplain are in levee and drainage districts primarily for agri- cultural purposes. New Concepts on Black Cutworm Field Biology The black cutworm, Agrotis ipsilon, is a cosmopolitan insect that attacks at least 49 species of field and vegetable crops. The larval or worm stage of this insect is dark brown to black and is approximately 2 inches long and about pencil thick. The larvae cause damage by severing seedling plants or chewing into stalks, roots, bulbs, and tubers. These worms are especially damaging to corn throughout Illinois dur- ing May and early June. The complete life history of this insect is not known for the north-central region of the United States, and no criteria have been available for predicting infestation and damage. During the growing seasons of 1974 chickweed found beneath a plant in a field before crop planting time. Black cutworm larva The Illinois NATURAL HISTORY SURVEY) NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 through 1977 a total of 38 corn fields dam- aged by the black cutworm were inten- sively studied by economic entomologists Dan Sherrod, John Shaw, and W. H. Luckmann. Two new concepts concerning the field biology of this insect resulted from these studies. The first concept is that black cutworm larvae damaging seedling corn in May and June originate from eggs oviposited in the field in the spring before the corn is planted. By collecting and sizing larvae from the study fields and applying predictive techniques based on tempera- ture data, they determined a theoretical oviposition date. In almost every case the predicted oviposition date preceded the planting date for each field. These larvae that hatch prior to corn emergence must have some source of food until the corn is available. They found that spring weed plants growing in the field could fill this need. This point forms the second concept: agronomic practices which encourage the establishment of weeds, especially winter annual and perennial weeds, increase the potential for the presence of the black cut- worm. In 1976-1977 fields that had a his- tory of problems with black cutworms were monitored by regularly visiting the fields from February through May in an attempt to detect infestations before corn planting time. Larvae were observed in April and May around clumps of common chick- weed, Stellaria media, and mouse-eared chickweed, Cerastium vulgatum vulgatum. Usually, one or more larvae could be re- covered by digging in the soil around the base of a chickweed plant. In Illinois chickweed is classified as a winter annual which germinates and establishes itself in the fall. It grows during the winter and flowers in late February and in March. Chickweed and other winter annuals are most likely to occur in fields where soy-~ beans were grown in the previous year and where the soil has not been disturbed or has been disturbed in a minimal way through conservation tillage. The proposed concepts are based on the best data currently available. The black cutworm is a difficult pest to predict, and considerable additional information on cut- worm biology and behavior and on field ecology will be needed before good detec- tion and control programs can be refined. The concept on the significance of weeds is very applicable to conservation tillage sys- tems often used for corn following soy- beans. Weediness also increases in the spring due to extended periods of rainfall when fields cannot be timely prepared and planted. The concept that the larvae that damage seedling corn are in the field be- fore the seed is planted reflects the reality of field observations and field problems. September 1979. No. 189. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR CHIEF, ILLINOIS NATURAL H STORY SURVEY URBANA, ILLINOIS 6 The Illinozs NATURAL Stinging Caterpillars The concern of people when they en- counter caterpillars feeding on plants, trees, and field crops primarily garden focuses on the economic or aesthetic dam- age that the caterpillars may cause. They rarely are considered as potentially and directly hazardous to human comfort. The vast majority of caterpillars brought to the Illinois Natural History Survey for identification are various species of cut- worms and armyworms. These can be safely picked up with bare fingers, and the most that the handler may anticipate is being nipped by the caterpillar’s man- dibles. Unfortunately the same cannot be said of stinging or urticating caterpillars Stinging rose caterpillar (Parasa indetermina) on a leaf (Photo by Les Woodrum, Survey Photographer). RE ee a ee a HISTORY Po LS. that can cause reactions ranging from mild itching and stinging sensations to a variety of more serious symptoms, for example in- flammation of lymphatic tissue, that may be accompanied by considerable pain and swelling of extremities. Several species of urticating caterpillars occur in Illinois. Examples of them include (Automeris io O per- the larva of the io moth the puss caterpillar (Megalopyge cularis) and about 20 species of slug cater- pillars. Many urticating caterpillars feed on a variety of cultivated shrubs and trees, but frequently go undetected. The ones most likely to attract the attention of the curious gardener or horticulturist are some of the slug caterpillars because of their bright, gaudy coloration. Slug caterpillars belong to the lepi- dopterous family Limacodidae. Their slug- like appearance is caused by a retracted and partially concealed head, inconspicu- ous thoracic legs, and abdominal prolegs that are vestigial or absent. As a result slug caterpillars seem to glide rather than walk. Some of the species are smooth and lack tubercles or spines while others such as the rather common saddleback caterpil- and the stinging lar (Szbine stimulea rose caterpillar (Parasa indetermina) beat prominent fleshy tubercles that are cov- ered with numerous spines. Neither the relative toxicity of each species of slug caterpillar nor the nature of the toxin has been documented ade- quately. It is known that the spines on the body of slug caterpillars contain a sub- stance that is released when the spines pierce and break the skin of an unsuspect- ing person. Not all reactions are chemi- Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey cally caused because some species of urti- cating caterpillars bear types of setae or hairs that contain no toxin but instead are minutely barbed and can mechanically cause irritations. There is no reported outbreak of slug caterpillars and other urticating caterpil- lars in Illinois. However, because they may be found in a variety of outdoor and crop situations, persons finding slug caterpillars should handle them cautiously with twee- zers or forceps. Anyone needing identifica- tions of troublesome caterpillars may send or bring them in vials of alcohol to George L. Godfrey, Section of Faunistic Surveys and Insect Identification, Illinois Natural History Survey, 172 Natural Resources Building, Urbana, IL 61801. A Leaf Miner in Soybeans Many specimens of small dark red beetles were present in surveys of arthro- pods associated with soybeans made since 1969. ‘These were determined to be Odon- tota horni, hispine beetles whose larvae formed blotch mines in leaves of native legumes such as Amphicarpaea bracteata var. comosa, Desmodium illinoense, Teph- rosia virginiana, and Meibomia rigida. When soybean plants were searched, the blotch mines and larvae were found in the field. Survey entomologist Marcos Kogan and his student assistant, Dan D. Kogan, studied and published on the life cycle and feeding habits of the adults and the larvae of this beetle in Illinois. The adults feed on the leaves leaving the veins intact, thus skeletonizing the leaf. The egg is inserted, usually singly, under the epi- dermis of the leaf usually on the lower surface. The larvae emerge after about six days and feed on the parenchyma near the egg forming a mine between the upper and lower surfaces of the leaf and feeding outwards from the position of the egg in all directions unless a major vein or leaf margin is encountered. The larvae when mature enter a pupal stage in the mine and the three larval and the pupal stage take about 25 days. Two generations per year probably occur in Illinois. The potential of this species to cause economic damage to soybeans in Illinois is slight. However, the beetle may have to be taken into consideration if other more serious pests are also present and ap- proaching the economic injury level. From the viewpoint of the evolution of the arthropod fauna associated with soy- beans in the New World, O. horni exem- plifies a tendency also shown by the Mexi- can bean beetle and the bean leaf beetle. These are all oligophagous (feeding on few hosts) species with host ranges limited to a few genera of the plant family Le- guminosae. O. horni seems to prefer Amphicarpaea and Desmodium as the natural hosts. Since Amphicarpaea is con- . sidered to be the closest New World rela- tive to the soybean, the transition of this beetle would have been predictable. Docu- mentation of a gradual adaptation of na- tive legume fauna to the soybean as it is introduced into new regions has _ both practical and theoretical aspects. Submersible Vacuum Cleaner Taking accurate and reliable samples of aquatic microorganisms has been a _his- torical stumbling block for many aquatic ecologists. Although many types of devices, ranging from simple water bottles to elaborate pump systems, have been de- signed and modified since the mid—1800's, the recent demand for more stringent en- vironmental assessments and answers to specific ecological problems has resulted in the development of improved sampling instruments. : Faced with the need for an apparatus that samples zooplankton with repeatable precision from rivers and power plant cooling lakes, as well as most other aquatic habitats, aquatic biologists Stephen W. Waite of the Natural History Survey and Scott O’Grady of the University of Illinois developed a design that combines some of the best features of two major types of zooplankton samplers: the plankton net and the pump sampler. In most cases, pump samplers have been proven superior to other types of equipment for general use. They provide a reliable measure of the water volume sampled and are pro- ficient in coves, shallow depths, and tur- bulent waters. Nets, on the other hand, provide a convenient means of reducing the mass of organisms present in large volumes of water to smaller, more easily handled, concentrated samples. Therefore, the priorities for a new ap- paratus included the following objectives: to incorporate and enclose both a battery- operated pump and a high speed plankton net within a single submersible unit, read- ily obtainable materials in the sampler’s construction, and to create a basic design that can be readily modified for a variety of specific sampling requirements. The design of the new apparatus is relatively simple. It consists primarily of a pump assembly, a filtering unit, a box-like struc- ture that provides support for the whole apparatus, and a portable power supply (battery) which is separate and remains with the operator. Prior to operation, the filter-pump ap- paratus is lowered into the water and allowed to fill. The pump is activated with a remote switch and the gear is raised and lowered or held at a specific level in the water depending on the sampling regime. At the end of the required time interval, the apparatus is raised out of the water where the netting is thoroughly rinsed. The sample is retrieved by removing a brass plankton bucket from the rear of the sampler and rinsing the organisms into a bottle containing preservative. Although the original apparatus was de- signed to sample zooplankton, its size and Submersible vacuum pump collecting equipment with battery in boat (Photo by John Barlow, Aquatic Biolo- gist). shape can be easily altered to collect other types of organisms including algae and stream macroinvertebrates. The uses of this sampler are many and vary according to the research needs. Mercury and Lake Shelbyville The analysis for mercury in largemouth bass and walleye collected from Lake Shelbyville in central Illinois in 1974 touched off an investigation of the lake’s level of mercury contamination. Fish col- lected at that time had mercury concen- trations substantially higher than those found in fish collected from other lakes in the same region of the state and several exceeded the 0.5 ppm Food and Drug Administration guideline. Reports of these results, with confirming analysis of the same samples by another laboratory and the collection and analysis of additional samples, caused the Illinois Department of Conservation to issue a warning to fishermen about consuming excessive amounts of these fish. During the next two years, fish from Lake Shelbyville con- tinued to show similarly high mercury con- centrations and the warnings were reissued annually. In 1977, a two year investigation of the lake was begun by Survey analytical chem- ist Kenneth E. Smith and his associate Aaron P. Griffith under joint funding from the Illinois Natural History Survey and the Illinois Institute of Natural Resources. The study was to determine if a point The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 source, or sources, could be found for the mercury contamination and to determine the bioaccumulation occurring in the lake’s aquatic ecosystem. Seventeen sampling sites were estab- lished to cover major tributary streams as well as central areas in each of the three arms of the lake. Water samples were col- lected monthly from each station, as well as samples of bottom sediment, clams (when present), zooplankton, and five spe- cies of fish. For the tributary stations, samples of terrestrial soil were collected 2-3 kilometers upstream from each tributary’s mouth. All samples were analyzed for total mercury and results were interpreted with the aid of statistical tests. The results indicated that there was not a distinguishable point source, or area, which was contributing the mercury con- tamination to Lake Shelbyville. Results of the analysis of the biota collected from the lake also were not indicative of a con- tamination in one area of the lake. The bioaccumulation of mercury in the lake’s food chain was determined from the results of the analysis. Beginning with water as a background value, and con- tinuing through the plankton, clams, and lower trophic level fishes to the major predators, a steady accumulation was found. Normalizing the mean mercury October 1979. N« 190. Published monthly sion of the Illino Institute of Natural Resources vation Prepared by Dr. W. f LaBerg : d at Urbana ond-clas postage pa Illinois Office of publication 175 Natural Resource except in July and Auvaust by the operating under the Board of Natural Resources with the collaboration of (USPS 25% s Building, Urbana, Illinois concentration of the plankton as 1 and expressing the concentrations of the other biological organisms as multiples of this _ factor yield the following bioamplification scheme: plankton (1), clams (2), gizzard shad (7), bluegill (10), carp (21), large- mouth bass (20), and walleye (30). Since 1974, a highly significant corre- lation has existed for the predator species between their size and the concentration of mercury in their tissues. In 1974 this re- gression predicted that bass over 0.5 kg would exceed the FDA 0.5 ppm guideline, while the regression for the bass collected in 1978 predicted this size to be 2.2 kg at the same level of confidence (99% level). The same trend was seen for walleyes, be- ginning at 2.0 kg for the 1975 collection and rising to 3.1 kg for the 1978 collec- tion. This indicates that the level of con- tamination is decreasing and soon may no longer be a problem for the fishermen. A postulated mechanism for the mer- cury’s entrance into the aquatic ecosystem involves methylation of mercury absorbed on soil once the soil is flooded and enters an anaerobic system. As mercury in the now lake-bottom soil is depleted, less mer- cury would be available to the biota of the lake and once methylated, various pathways would be available for removal of mercury from the aquatic environment. Natural History Survey, a divi- b and Conser the Survey staff Persons desiring individual or additional copies of this publication please write to Gt GE sPRU | CHIEF LLIN¢ NATURAL |} sT EY IRBANA, ILLIP The Illinors AL Control of the Imported Crucifer Weevil in Horseradish Planting Stocks In 1977 the imported crucifer weevil, Baris lepidi Germar, was discovered in- festing fields of horseradish in St. Clair and Madison counties. Previously, this in- sect had been considered an occasional pest of crucifers only in central Europe and the USSR. The adults feed on stems and roots and lay eggs in tissues of pri- mary and secondary roots. The white, grublike larva is the most damaging stage because it tunnels in the roots. Horseradish is produced for its fleshy, pungent roots. The method of growing horseradish greatly influences the spread and establishment of this weevil. Horse- radish is vegetatively propagated by plant- ing 30- to 35-cm pieces of pencil-thin secondary roots (“sets”) in early spring. The crop is harvested in late fall and in the succeeding spring. Primary roots are HISTORY \ sold for processing, and sets are stored in underground soil pits or in cool cellars to be used for planting in the spring. Many root pieces remain in the soil following the harvest, producing extensive patches of horseradish in rotation crops in the suc- ceeding year. Horseradish is usually rotated with other crops and is planted on the same land every other year. The imported crucifer weevil overwinters in Illinois as adults, eggs, and larvae in unharvested or volunteer horseradish and as eggs and larvae in stored sets. Infesta- tion of the commercial horseradish crop occurs through the dispersal of weevil adults from infested volunteer horseradish and through the planting of sets contain- ing eggs and larvae. Illinois Natural History Survey economic entomologists R. E. Foster, Dan Sherrod, Cathy Eastman, and Roscoe Randell in- vestigated procedures for reducing field An imported crucifer weevil, Baris lepidii, larva in a typical feeding channel in a horseradish root. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey infestations of the imported crucifer weevil by the destruction of eggs and larvae in horseradish sets. They evaluated tech- niques using hot water dips, fumigants, and insecticide dips. The entomologists sum up their findings in this way. Dichlorvos as a dip or a fumi- gant proved ineffective at killing eggs of the imported crucifer weevil. Hot water treatments showed promise but should be abandoned because of the difficulty of maintaining precise water temperatures for large commercial crates of sets. Fumiga- tion with methyl bromide also appeared promising but would require further re- search to make it usable by growers. Immersing the sets in permethrin was the most useful method tested. While this treatment had little effect on larval sur- vival, egg mortality was high. Eggs were by far the most numerous stage present in sets, and a recent examination of sets showed that few larvae survived the winter, Set sprouting was not affected by treatment with permethrin at concentra- tions of 0.1 to 0.5 percent for exposure times of 30, 60, and 120 minutes, and by the end of the growing season only mini- mal permethrin residues persisted in the roots. Breaker, Breaker. Come in, Good Bassy! For more than 20 years Survey biologists have been tracking all sorts of animals from hawks to squirrels and, more recently, fish. The imagination and engineering skill of William Cochran, wildlife specialist, in developing tiny radios that can be attached to these animals have permitted following them in the air, on the land, and in the water. In 1970, working with fishery bi- ologist Weldon Larimore, Cochran de- signed a radio that could be surgically implanted in the body cavity of a fish. The small radio with its battery and loop antenna resembles a small padlock about 1% inches long. The Survey’s first extensive fish radio- tracking program was in Lake Sangchris, a power-plant cooling lake in central Ilh- nois. The biologists were interested in how largemouth bass moved from day to day through the seasons and how they re- sponded to the warm water being dis- charged into the lake by the power plant. About the same time a companion study was being conducted at Lake Shelbyville, a main-stream impoundment where water levels fluctuate throughout the year. How bass responded to changes in water level was the primary objective of that study. Recently a new and more sophisticated radiotelemetry study has been initiated in the Salt Fork River of east-central Illinois, where Dr. Larimore is following the move- ments of smallmouth bass. Although these small radios developed by the Natural History Survey have been used in cold- -water rivers of the West to follow the ex- tensive movements of salmon and trout, no such work has been done in our more turbid, warmwater streams, and nearly all Illinois streams are of this type. The spe- cific area of the Salt Fork being studied is a 15-mile stretch southwest of Oakwood in Vermilion County. When a smallmouth - bass has been selected for the experiment and the small radio has been surgically implanted in the body cavity, it is given a numbered 2-inch long piece of yellow plastic tubing that is attached to the fish’s back. On this tubing are the fish’s number and a telephone number that can be used if the fish is caught by an angler. Each radio put in a fish is on a different frequency so that the fish can be identified when a biologist picks up a transmitted signal. The actual tracking of the fish, a search for each fish with its distinctive signal, is done through two systems. In one system the biologist simply moves up and down the river “listening” for the radio signal to show the exact location of an experimental fish. The other system is more complicated; it includes a tall fixed re- ceiving antenna that can pick up signals over a mile or so of stream. The signal is then recorded automatically on a chart. What is this research all about? Dr. Larimore is trying to associate the daily activities and seasonal movements of our sport fishes with their breeding and feeding requirements, and to understand their re- sponses to changes in water conditions, such as increased turbidity and water levels during flood periods or drastic drops in water flow during droughts. He will be able to observe the responses of fish to changes in water quality, such as pollution, that might cause the displacement of river fishes. There are many interesting and exciting potentials for this work, and Dr. Larimore is anxious to have the help of fishermen that fish this river. Their cooperation can add tremendously to the research results. It is hoped that these special fish will be released after the fisherman has noted the tag number and the telephone number. A call to the fishery laboratory would then provide valuable information and save the experimental fish. If, however, the fish is accidentally killed by hooking or dies be- fore the tag is noticed, the angler is en- couraged to save the tag from the back and the radio from inside the fish and then report his catch. Because the cooperation of fishermen is so important to this study, they are encouraged to call the Survey at (217) 333-6890 to ask questions or further discuss the work. As this research gresses biologists may be able to tell fisher- men where to look for bass during different times of the year and under different con- ditions. Certainly the biologists should learn more about the habitat requirements of our river fishes and ultimately be able to protect and improve habitats in our IIli- nois rivers. pro- Miniature radio transmitter about to be implanted in the body cavity of an anesthetized bass. Measuring Migrant Bird Populations The large numbers of transient birds that pass through Illinois each year prob- ably have an important influence on the habitats they use, yet absolute measure- ments of these populations are virtually nonexistent. Students of bird populations have concentrated on studies of breeding and, to a lesser extent, winter popula- tions. There are at least two reasons for this choice of seasons: (1) the obvious importance of the breeding cycle (i.e., pro- ductivity) and winter survival on the ecol- ogy of species, and (2) the fact that nesting and winter populations, once estab- lished, are relatively stable from day to day. By contrast, the ephemeral nature of the transient populations has made cen- susing seem impracticable. The transect census technique developed by the Illinois Natural History Survey’s early investigators, Stephen A. Forbes and Alfred O. Gross, is potentially a useful method of measuring transient bird popu- lations. In April and May 1979, ornithol- ogists Richard and Jean Graber applied the technique to measure populations of birds in arboreal habitats in southern and Illinois. The concerned that the numbers of transients central investigators were present on some days would overwhelm their capability to detect and record. Daily censuses in April and May proved the even the highest method workable for The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 populations encountered, and the census will be continued through the fall and next year. The pressure which the transient popu- lations exert on a habitat can be seen in a comparison of the density of the popula- tion in April and May with that of the June breeding population. For example, in a bottomland forest tract with a breeding population of 40 bird species and a density of 266 birds per 40.5 hectares (100 acres), the average daily population of transients was composed of 58 species at a density of 571 birds per 40.5 hectares, i.e., more than twice the breeding population. The pres- sure of these populations on the habitat might be more realistically expressed in terms of biomass or the metabolic require- ments of the animals involved. In either case the comparative pressure of the tran- sients might be somewhat lower than the densities suggest because many of the spe- cies (e.g., warblers) are small. It is also necessary to note that the breeding densities referred to above do not include young that are produced on the area, a component which would definitely swell the importance of the breeding popu- lation (to an unknown, but calculable, level). With just the data from the spring cen- ~ suses, it is already clear that transient bird populations are of great importance to Illinois habitats, and vice-versa. An im- portant practical question that needs con- sideration is whether, and to what extent, the transients affect the resources of the breeding bird populations. November 1979. No. 191, Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana Office of publication 175 Natural Resources Building Illinois. (USPS 258-220) Urbana Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 The Illinois NATURAL Least Darter Biology At the turn of the century, 26 species of darters occurred in the streams and lakes of Illinois; however, only 23 are known to remain. Of these 23, ten have been the subjects of life-history studies conducted by present and past Survey personnel over the last 12 years. The latest study to be com- pleted and published by former Survey ichthyologist B. M. Burr and Survey ich- thyologist L. M. Page concerns a tiny spe- called the least darter, Etheostoma microperca. The least darter has a moder- cies ately large range in eastern North America and reaches its greatest abundance in the Great Lakes region. The population chosen for study was in a small, unnamed tribu- tary of the Iroquois River near Watseka in Iroquois County, Illinois. The tributary was a narrow, shallow creek with grass- covered banks and, during the summer months, thick growths of filamentous algae. HISTORY REPORTS One year of field and laboratory work re- vealed that the least darter has a life his- tory similar to that of the closely related cypress darter. In Illinois the least darte1 reaches a maximum length of 32 mm and lives a maximum of only 20 months. Like the cypress darter, the least darter has a deeply indented egg, an unusual feature among freshwater fishes which generally have spherical eggs. At one year of age and mostly during the month of May, the least darter spawns in filamentous algae close to the edges of the stream. The male mounts the back of the female, grasps her with his large cuplike pelvic fins, and then the two ascend to the site of egg deposition. The spawning pair usually assumes a verti- cal position and one to three eggs are laid at a time. Eggs are left unattended and, at 20°C, hatch in about 7.5 days. Growth is rapid for the first six or seven weeks. By October, the population reaches its peak density with as many as 33 darters per Least darters spawning (Photo by Brooks Burr, Southern II- linois University at Carbon- dale). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. square meter of stream bottom. The diet consists principally of larval midge flies and small crustaceans. Public awareness of the importance of nongame fishes in the overall maintenance of diversity and stability of aquatic eco- systems has made the INHS life-history studies all the more valuable. In fact, the Survey has become established as one of the centers for the study of fish life his- tories. Future proper management and protection of Illinois’ nongame fishes will depend in large part on the rational use of baseline data presented in such life-history studies. Copies of the publication on the least darter, Biological Notes No. 112, are available upon request to the Survey. Wood Duck Populations The wood duck population on _ the Quiver Creek study area rebounded in 1979 after a serious decline in 1978, ac- cording to Survey wildlifer Frank Bellrose. There were 113 nests in 1979 compared with 86 in 1978, and nest success in 1979 was 63.7 percent compared with 31.1 per- cent in 1978. In 1978 only 39 percent (15) of the incubating hens were new ducks, but despite the poor hatch in 1978, 46 percent (34) of the incubating hens were new in 1979: In most instances new hens are yearlings hatched on the area the previous year. Yet there are these incongruities: in 1977, there was a 78 percent hatch of 166 nests, but only 15 new hens turned up in 1978. Of 1,013 ducklings marked in 1977, none was found in 1978 or in 1979. 'To further cloud an understanding of what occurred, 22 incubating hens banded on the nest in 1976 and 1977 appeared in 1979 after failing to put in an appearance in 1978. It appears that a high loss of young oc- curred in 1977 that almost eliminated the return of yearlings. This loss was further compounded by the unprecedented nesting by older hens off the study area in 1978. A study of previous records indicates that in the past 26 years an average of four hens per year nested outside the study area or were not found if they nested on the study anea. Is there a relationship between the hens that were not found nesting in 1978 and the disappearance of hatched young dur- ing the summer of 1977? That summer, 67 sick wood ducks were noted on the study area, by far the largest number of ill ducks ever noticed. Did their behavior alarm other ducks, causing them to nest elsewhere in 1978 but return in 1979? Average survival of nesting wood duck hens over a period of 20 years is 49 per- cent. Between 1976 and 1977 it was 66 percent, between 1977 and 1978 it was 30 percent, and between 1978 and 1979, it was 50 percent. Clearly an unusual mor- tality unrelated to hunting decimated the ‘ Quiver Creek wood duck breeding popu- lation between the 1977 and 1978 nesting seasons. Walnut Caterpillars and Wood Black walnut is the most important tim- ber and nut tree species grown in Illinois.. Because of the increased demand for wal- nut lumber, there has been a drastic re- duction in the natural stands of this tree. In recent years an increased interest in planting walnut trees has occurred. In- sects can often cause problems in such plantings. Of the insects which feed on walnut foliage, the walnut caterpillar is the most serious. When the walnut cater- pillars are abundant, complete defoliation of trees often occurs, thereby weakening the trees and making them more suscep- tible to insect borers which destroy the quality of the wood and can result in the death of the trees. Through a research project funded by the USDA Forest Ser- vice and The Joyce Foundation, Survey en- tomologists, Marion Farris and James Ap- pleby, conducted studies on the life history of the walnut caterpillar. They found that the female moth always deposits its eggs in clusters on the lower leaf surface. Tiny wasps often parasitize such egg masses and during certain years may account for 26 percent of the eggs not hatching. After the eggs hatch the walnut caterpillar larvae are often attacked by predaceous stink bugs and wheel bugs. Certain flies and wasps will sometimes lay their eggs on the On the left is a mature walnut tree defoliated by the walnut caterpillar (Photo by M. E. Farris). On the right is a group of walnut caterpillars on foliage of walnut tree (Photo by J. E. Appleby). caterpillar or insert their eggs within the caterpillar’s body. The parasitic larva de- velops within the caterpillar’s body, even- tually resulting in its death. The adult fly or wasp will emerge the following year and search out other walnut caterpillars to parasitize. The walnut caterpillar is gen- erally controlled by its natural enemies; however, periodically the insect’s natural] controls are ineffective and populations of the walnut caterpillar become epidemic. To prevent such outbreaks growers may have to resort to using insecticide sprays for control. Experiments were conducted at the Dixon Springs Agricultural Center in southern Illinois to find insecticides that would be effective but would not have ad- verse environmental effects. and Appleby found that insecticides such as acephate (Orthene), Bacillus thuringiensis (Dipel), diazinon, and malathion were effective in controlling the caterpillars. Through such studies the walnut grower will now have a better understanding of the walnut caterpillar so that the walnut seedlings of today will eventually grow to maturity and become walnut furniture of the future. Farris Redear Sunfish in I]linois Redear sunfish, Lepomis microlophus, originally were inhabitants of the southeast- ern states. They were introduced into Illi- nois in 1946 to supplement the state’s sport fishery. Reservoirs and ponds throughout the state were stocked with this species, but the deep, warm-water lakes provided the most suitable habitat for the redear. Stocking resulted in self-sustaining popu- lations in most of these lakes, and the fast-growing redear became an established sport fish. The redear populations in some Illinois lakes have recently declined, and in other lakes have totally disappeared. The cause for these changes, whether inherent to the species or its habitat, is not apparent. Survey aquatic biologists Dee A. Mc- Cormick and Warren U. Brigham con- ducted an extensive literature review of published and unpublished works on the life history of the redear sunfish with Din- gell-Johnson funds through the Illinois Department of Conservation. The primary objective of the study was to determine which factors limited redear sunfish in IIli- nois waters. The report concluded that these fish are limited in Illinois primarily The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 by temperature and competition. ‘Temper- ature may limit the species by substan- tially reducing its reproductive success in northern waters. The shorter spawning season in Illinois commonly limits redear to one spawn per year. Redear may spawn throughout the entire summer in southern portions of its range. In addition, juvenile redear may not be able to endure the low temperatures common to northern and central Illinois winters in shallow lakes. Competition for food and space may limit the species in habitats which are less than optimal for redear success. The lakes and ponds of [Illinois which contain stocked redear populations commonly are more turbid than those in which redear naturally occur. The low light penetration in turbid water limits the depths to which aquatic plants grow and may force the redear into weedy shallow water where they must compete with other sunfish for food and space. The effects of temperature and compe- tition on redear have not been studied in detail. Survey aquatic biologists are pro- posing a comprehensive field study to de- termine the nature and degree to which temperature and competition limit redear sunfish populations in the lakes of Illinois. Upon completion of this investigation it | will be possible to formulate an effective management plan for the redear sunfish in Illinois. Such a plan will make it possible to restrict the stocking of redear sunfish to those lakes providing favorable conditions for the species and to enhance its status as a sport fish. December 1979. No. 192, Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE PRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 The Illinors NATURAL SURVEY A Treatment for “Anemic” Trees Yellow foliage (chlorosis), sometimes caused by iron deficiency, and slow growth are typical of many trees planted along streets and around homes where the origi- nal topsoil has been removed or mixed with the subsoil. The average urban soil has relatively poor physical, chemical, and biological characteristics. Tree root de- velopment and penetration are greatly reduced in heavy clay subsoils that lack adequate aeration and water drainage. Ad- ditionally, the amount of available nutrients and organic matter is often critically low. Agronomically, urban soils are usually a conglomerate of rubble. Trees growing under urban conditions frequently exhibit nutrient deficiency symp- toms. When these symptoms occur, they are often difficult to diagnose. However, plant pathologist Gene Himelick has found that correcting the deficiency is inexpen- sive and may be effective for 2, 3, or even + years. If affected trees remain untreated they usually continue to decline, but sys- temic treatment for chlorosis will prolong the life, improve the vigor, and increase the aesthetic value of a tree. Most urban trees manage to survive for at least a few years despite poor soil con- ditions and other environmental stresses. In Illinois, chlorosis is a common problem of pin, red, and white oak; bald cypress; sweet gum; river birch; silver and red maple; and hackberry. Occasionally it oc- curs on American sycamore. In tests begun in 1974, Himelick and his associates tested ferric citrate powde: and commercially prepared capsules ( Med- HISTORY JANUARY 1980, NO. 19 icaps) containing ferric ammonium citrate ; highly soluble nitrogen (N), phosphorus (P), and potassium (K); and a slow-re- lease nitrogen source as possible corrective treatments for chlorosis. Six tree species were used in the tests: pin oak, bald cy- press, red oak, swamp white oak, sweet gum, and American sycamore. The trees were located on the Urbana campus of the University of Illinois and were 6—40 inches in diameter at breast height (dbh). A plastic syringe was used to inject the ferric citrate powder into small holes drilled 4 inches apart around each tree trunk. The commercially prepared gelatin capsules were enclosed in slotted plastic coverings and were driven into holes drilled about 6 inches apart around the trunks of trees to be treated. The ferric citrate treatments were ef- fective on pin oak, cypress, red oak, swamp white oak, and sweet gum. Only slight re- sponse was obtained on American syca- more. In 1977 the test was expanded to in- clude pin oaks and sweet gums growing on parkways in Urbana. In this test, pin oak responded well to all treatments with iron compounds and to combinations of iron and nutrients. ‘The sweet gum response to all treatments was generally not as definite as those obtained on pin oak. Trees treated with ferric ci- trate responded best and, in general, the distribution of the compound appeared better than in other treatments. The com- bination of ferric ammonium citrate and soluble NPK gave slightly better color re- sponse in pin oak than did the use of the iron compound alone. Some response was Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey achieved through the use of soluble NPK in both pin oak and sweet gum, but the use of slow-release N alone gave no mea- surable response. White oaks that had been chlorotic 2—6 years growing on parkways along streets in Highland Park were treated to determine if they would respond to either iron or manganese. The trees (average dbh, 20.8 inches) were treated between May 4 and 8, 1978. Color ratings were made on June 7 and August 1, 1978, and August 23, 1979. The color response at the end of the first and second growing seasons was rela- tively poor. ‘There appeared to be no dif- ference in color response between the use of iron and of manganese. The use of ferric citrate as a powder A pin oak showing ad- vanced symptoms of chloro- sis, or yellowing of the foliage. Systemic treatment with iron compounds gen- erally corrects the iron de- ficiency. or ferric ammonium citrate as Medicaps provides a reasonably effective and eco- nomical way of treating large chlorotic trees. The results of treatment have been more pronounced in trees showing ad- vanced stages of chlorosis than in those exhibiting early stages. However, it is ad- visable to begin treating chlorotic trees be- fore they have advanced to the later stages of chlorosis and decline. Proper timing of the treatment is im- portant in correcting chlorosis. Treatments completed in late summer generally were not effective until the following year, and the treatment lasted only 1—2 years. Late- dormant or April and May treatments have been found to be most effective, and the treatments last for 3—4 years. For specific information on how to treat chlorotic trees, contact the Botany and Plant Pathology Section of the Illinois Natural History Survey. Testing the Toxicity of Ammonia to Illinois Fishes Under the Clean Water Act, a national goal is the attainment of fishable, swim- mable waters, wherever possible, by 1983. To achieve this goal, water quality stan- dards must be set which will limit pollu- tant concentrations to levels that will pro- tect aquatic life. On the other hand, complying with the standards in the treatment of wastewaters discharged into streams may be costly. Thus, the standards should not be more stringent than is neces- sary to protect aquatic life. Most studies on effects of pollutants on fishes have been done with a few species, especially trout, and for exposure times of only 2—4 days. There is a scarcity of in- formation on the water quality require- ments of most Illinois fishes, particularly for exposure times of more than 4 days. Recently Reinbold and Richard Sparks, with their aquatic biologists Keturah associate, Stephen Pescitelli, began a study of the toxicity of ammonia to Illinois fishes with funding from the U.S. Environ- Aquatic biologist Keturah Reinbold makes an adjust- ment on the flow-through system being used to test the toxicity of ammonia to Illinois fishes. The Illinors NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 mental Protection Agency. Ammonia is an important pollutant in Illinois from sewage effluents, feedlot runoff, and urban runoff. The ammonia toxicity tests are being conducted in a continuous-flow system. Several concentrations of the pollutant are tested simultaneously in a series of test chambers, each of which receives a con- stant concentration in a continuous flow of water. This is a better method for toxicity testing than has often been used in previous studies in Illinois. Previously the test material and animals have been placed in static water. The flow-through system more closely resembles conditions in a natural stream. Also a constant concentra- tion of the test material is maintained even for volatile substances such as am- monia, which move out of standing water Prepared by Robert M. Zewadski with the ; postage paid at Urbana Natural Re Illinois Office »f publicatior ources y except in July and August by the Natural History Survey, , Operating under the collaboration of the (USPS 258-220) Building, Urbana, Illinois into the air, and for unstable compounds that break down in standing water. In the Survey study fishes are tested during their early life stages. Since these are usually the most sensitive parts of the fish life cycle, the results are more indica- tive of the tolerance of the species than are tests with adults, which have most often been done in the past. Four fish species will be tested: green sunfish, white sucker, channel catfish, and walleye. The tests begin with fertilized eggs and con- - tinue for 4 weeks after hatching. Effects on egg survival and hatchability as well as on growth and survival of young fishes will be evaluated. The current water qual- ity standards for ammonia are being re- vised in I]linois and in the Midwest region, and information from this study will be used in the revision of the standards. a division Board of Natural Resources and Conser survey staf Persons desiring individual or additional copies of this publication please write to i NATURAL HISTORY Ss URBANA, ILLINOIS 61 l The Illinors NATURAL Red-headed Woodpeckers and Acorns One of the most characteristic sounds of the bottomland forests in winter is the raspy bickering of red-headed woodpeckers defending their food caches. The wood- peckers seemingly chase everything that approaches, from innocuous-looking brown creepers and titmice to squirrels, and from each other. The spectacle of irritated birds flying at one another through the tree tops may be somewhat comical, but it is actu- ally a serious matter of survival. When one sees how hard the birds work to acquire their food stores, the reluctance to share is understandable. A particularly striking ex- ample of such work was observed in mid- October 1978 by Jean and Richard Graber in the course of field work in bottomland forest along the Kaskaskia River west of Vernon, Illinois. Several red-heads were collecting and storing acorns from a cluster of three mature pin oaks (Quercus palus- tris) standing about 100 meters from a large block of forest. Each bird, acting independently, landed in the upper third of a mast tree, picked an acorn, and flew to a storage site in the forest. As many as 12 red-heads could be seen in the air at once. Most were adults, but two were obviously immatures, and the immatures were gleaning acorns exactly as the adults did. One red-head route could be observed took 41 immature whose entire seconds per round trip from his storage tree, a dead cottonwood (Populus deltoides) some 135 meters from the mast trees. Other red- heads had more distant storage sites, but none required more than about 90 seconds HISTORY I REPORTS to complete a trip. Each bird had its own storage tree. There was no strife between birds at the mast tree, but noisy conflicts occurred whenever any bird came neat another’s storage site. Apparently acorns at the harvest site are common property, but once gathered they become _ private property. From the time required per trip, 1t was calculated that the 20-25 birds observed were storing 800-1000 acorns per hour. Such intense activity lasted only a few days from the time the acorns became mature until they fell. Ten days later the mast had nb a 2 - + © 2 * - * e (2 , i . = ¢ 2" oad tw «+E ‘ea a “eg 4. A ‘ | “A Fig. 1. Red-headed woodpecker at nest entrance (Photo by wildlife biologist Dick Graber). Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey fallen and the birds were no longer visit- ing the mast trees. From counts made of acorns under the trees and estimates of canopy area, the mast crop that year was about 500,000 acorns per hectare in that site, a very good crop. Jean and Dick Graber reported this incident in a paper in the Illinois Audubon Bulletin in the spring of 1979. Winter red-headed woodpecker popula- tions in southern Illinois show a strong correlation with the importance of the pin oak in forests and with oaks of acorn- bearing size (Graber et al., 1977, INHS Biological Notes No. 102). Moreover there are annual regional fluctuations in num- bers of winter red-headed woodpeckers which are probably based to a large extent on the mast crop in the winter range, the center of which for the red-head lies in southern Illinois. The population of winter red-heads in southern Illinois tends to show an alternate-year pattern of highs and lows, and acorn production varies greatly from year to year. This poses an interesting question concerning homing, i.e., the return by an individual bird to the same wintering territory every year. Homing is well developed in birds, but must be very different in a temperate-zone mast feeder such as the red-head. Why home to an uncertain food supply? We will never understand fluctuations in Ilh- nois bird populations until we have con- sistent, precise annual measurements of their food resources over wide areas. Such understanding is vital to insure that sufh- cient areas with suitable food plants are provided in order to preserve our wildlife heritage. Havana Lab Welcomes Electronic Assistant First, the good news: the Illinois River has been called the most studied river in the world. Illinois Natural History Survey data on its flora and fauna date back to the 1890’s. Then, the bad news: a con- scientious researcher often has to work full-time for weeks or months just to pick out and tabulate any one aspect of this vast store of biological information. Imag- ine trying to decipher hundreds of 40- year-old note cards on which the lengths and weights of fish were hastily jotted down. Now, the really good news: the Aquatic Biology Section at the Survey’s River Re- search Laboratory near Havana is using a new Tektronix 4051 intelligent graphics terminal, plotter, and hard-copy unit to organize its river data for a variety of re- search needs. Aquatic biologist Ken Lubin- ski is currently teaching the staff how to use the computer to help investigate the river system. Want to know how many spottail shiners Survey biologists minnow seined from the Illinois between 1957 and 1978? Until re- cently, you would have had to dig out files for each of the fourteen available years, check for spottail shiner in up to 260 lists of fish for every year (four hauls at each of as many as sixty-five stations), write the numbers down on another sheet of paper, add them up for each year, and divide by the number of hauls. Even a fast worker with a calculator would prob- ably make some mistakes during this tedi- ous procedure — which could eat up four weeks working time. Havana Lab staff members can now pull the same information out of the com- puter in five minutes or less — leaving them nineteen days, seven hours, and fifty- five minutes for analysis or field work. All one needs do is put the right tape in the terminal and type in genus and species and the years desired. Buzzing and beep- ing, the terminal quickly lists the years, reaches of the river, and numbers of spot- tail shiners taken in each. You can have the list turned into a histogram display. printed on paper by the attached hard- copy unit, or stored for computer plotting as a graph of publishable quality. If you are curious instead about a particular year or area of the river, you can have the data reorganized into a different listing. Once workers complete the initial labor of correctly punching in the data, the in- formation remains handy for all kinds of uses. Minnow seining, electrofishing, and water quality files for the Illinois River are already accessible. Rapid tabulation is only the first step. Yip Tai-sang, survey computer program- mer, has written several programs to analyze, sort and display these files. ‘The computer will also make it easier to ana- lyze relationships between two sets of data, such as fish distribution vs. pollutant con- centrations or habitat conditions. Of course, the size of the computer's mem- ory limits the volume of data it can pro- cess—-but a telephone coupler sidesteps this limitation by allowing the Havana terminal to communicate with larger com- puters when necessary and borrow their larger memory capacities. This technological revolution could not have come at a better time. As biologists struggle to keep abreast of both volumi- nous paperwork and fast-changing natural systems, the computer’s help in reducing errors and saving time and labor is espe- cially welcome. Blueberries and Bees Blueberries are dependent upon native bees for pollination. Without this service, blueberry crops would be nonexistent or inadequate. Honeybees are not good polli- nators of blueberries because these plants bloom at a time of year when honeybee colonies are inactive or small and most blueberry crops are grown in northern Fig. 2. Andrena carlini on flower of toothwort. This is one of the most important native blueberry pollinators (Photo by Joseph Laury Luth). areas where keeping of honeybees is a marginal enterprise. The Canadian province of Nova Scotia produces large crops of blueberries. Re- cent failures of this crop has been attrib- uted to the aerial spraying of insecticides to control spruce budworms and the in- secticide (Fenitrothion) used was highly poisonous to native bees. Dr. Peter Kevin, now located at the University of Colorado in Colorado Springs, in cooperation with Survey entomologist W. E. LaBerge has studied the diversity of bees in blueberry fields in Nova Scotia. They have been able to show a. decrease in diversity correlated with the use of Fenitrothion and corre- lated with decreased blueberry yields. During the six years since Fenitrothion was discontinued in spruce budworm con- trol the diversity of the bee fauna has been carefully monitored. This diversity has been increasing and has about reached the level it was before Fenitrothion was used. Blueberry crop yields have concomitantly increased to normal levels. A report of this project was made to the Sixth Inter- national Symposium on Pollination held at the University of Maryland in 1978 and was published in the Proceedings of that symposium. This work is an example of what can be learned with the cooperation of rather distinct disciplines in biology, in this case The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 an ecologist and a taxonomist. The thou- sands of specimens from the study are deposited in the collections of the Survey. Custom Spray Operators School ‘The Thirty-Second Custom Spray Oper- ators Training School was held January 8-10, 1980 at the University of Illinois. Opening the three day program were tech- nical meetings of the Illinois Ground Sprayers Association and Aerial Applica- tors Association. These meetings were held at the Ramada Inn Convention Center in Champaign. Moving to the Illini Union on Wednesday and Thursday, the formal program included speakers from the U of I, Illinois Natural History Survey, and several invited speakers from across the U.S. Attendance at the 1980 School was il Sigs) The goal of the Spray School is to keep custom pesticide applicators and pesticide dealers aware of new developments in all phases of agricultural pesticide use. In ‘addition, a special section of the formal program this year was on scouting tech- niques for insects, weeds, and plant disease. Delivering the keynote address was Mr. Steven Jellinek, Assistant Administrator of the federal EPA. His topic was on the future direction of federal pesticide regu- latory programs. The Custom Spray Operators School, presented by the Cooperative Extension Service of the University of Illinois and the Illinois Natural History Survey, is con- sidered by many to be the finest school of its type in the nation. During its 32 year history it has kept Illinois agricultural pes- ticide applicators alert to changing tech- nology and pest management practices. February 1980. No. 194. Published monthly except in July and August by the Natural History Survey, a divi sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser vation Prepared by Dr. W, E. LaBerge with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR CHIEF, ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 The Illinots NATURAL Finding Insect Enemies of the Alfalfa Weevil The alfalfa weevil, Hypera postica (Gyl- lenhal), and the clover root curculio, Sitona hispidula (Fabricius), are the most damaging insect pests of alfalfa in the United States. The alfalfa weevil is capa- ble of defoliating an untreated alfalfa field, while the clover root curculio feeds on root nodules, lateral roots, and tap roots. Economic entomologists R. J. Barney, a). Roberts, R. D. Pausch, and E. J. Armbrust undertook this study to find spe- cific predators of these two weevil pests and to measure their relative abundance and activity in the alfalfa field. Pitfall traps were fashioned from gal- vanized metal guttering cut into 1-meter long sections, and caps were attached at both ends. Clear bathtub caulk was used to seal the traps and prevent leaking. The linear traps were aligned parallel to a woods bordering the alfalfa field. The traps were sunk into the soil in a staggered pattern of six rows with seven traps in each row. The rows were so aligned that no trap overlapped another trap as they faced the woods. In this manner any mass movement of predators into or out of the woods could be detected. The 42 pitfalls were partially filled with ethylene glycol to catch and preserve any insect falling into the trap. Every week from 12 September to 15 November the traps were emptied of all insects. The carabid beetles, Harpalus pennsyl- DeGeer, and vanicus Abacidus permundus Say LeConte. and a cricket, Gryllus pennsylvanicus Bur- Evarthrus sodalis HISTORY REPORTS — meister, were the most abundant poten- tial predators found over the 2-month period in the linear pitfall traps. These four species accounted for 94.5 percent of the potential predators caught. Other re- searchers had found that the most com- monly caught carabids are probably the most active and numerous and have the greatest potential for finding and destroy- ing prey that occur on the ground. This 2-month period is also the time of migra- tion by weevils from aestivation sites in the woods back into alfalfa fields. Therefore the weevils are concentrated and suscep- tible to predation during this field reentry process. The three carabids and the cricket species were also the most frequently caught in conventional pitfall traps in al- falfa in an earlier investigation by eco- nomic entomologists R. Cherry and E. J. Armbrust. Cherry and Armbrust recorded the highest catches of predators in Sep- tember and October, which corresponds to the timing of this study, with the trap- ping slowing down in November as cold temperatures restricted insect activity. Live potential predators were collected in a dry pitfall trap. The insects were in- dividually placed in '2-pint cartons con- litter organdy. Each of the potential predators taining some and covered with was supplied with two weevils, which were replaced when and if eaten. Each individ- ual predator was supplied with only one species of weevil before it was discarded. Five repetitions of each predator with each weevil species were run for | week. All four potential predators tested preyed on both the weev1l species. The beetle. Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey H. pennsylvanicus, and the cricket, G. pennsylvanicus, were the most voracious eaters, consuming almost twice as many weevils as the other two. Cherry and Armbrust found the same four species to be predacious on cocoons of Bathyplectes curculionis (Thomson), the primary endoparasite of the alfalfa weevil. Therefore, the four predators many exert more pressure on the beneficial parasite than on the pest. The fact that these gen- eral predators feed on both pests and bene- ficial insects of the alfalfa agroecosystem makes it very difficult to determine their impact on the pest population. Cellular Control of Seed Dormancy and Germination A dried-out seed is a “dormant” (liter- ally sleeping) seed. If the dormant seed falls to the ground, it takes up water and resumes its interrupted growth; this pro- cess is called germination. Different plant seeds often require different treatments to restart their growth process. Some seeds, such as lettuce, need light for germination, while others must be ex- posed to chilling temperatures (a few de- grees below freezing) for a few days in a moist condition. Other seeds, for example, winter wheat, do not require chilling for germination, but chilling is required for early flowering. Yet other seeds need strat- ification; that is, they must be buried in moist soil and maintained for weeks or SEED COAT —q@—_———— ENDOSPERM ene LAYER EMBRYO ——— A barley seed, showing its various parts. (Drawing by Survey Illustrator Lloyd LeMere.) even months at moderately low tempera- ture, say about 42°-50° F. The seed coat of others is water impermeable, and ger- mination does not occur until the coat of the seed is weakened. Many of the legumi- nous trees produce such seeds. It has been reported that the seeds of the East Indian lotus (Nelumbo nucifera) have remained ungerminated but viable in the mud of old ponds for several centuries. Most seeds, however, require only the presence of water for germination. Many agricultural crops, including many cereal grains, belong to this group. The process of germination has been studied in a number of plant species, but probably the best . understood is that of the barley seed, since for centuries the beer industry has used germinated barley in the production of malt. The largest part of a barley seed is its endosperm, which is composed mainly of starchy material and acts as the food re- serve. The endosperm is the major con-. stituent of flour. At one end of the endo- sperm is the embryo, which controls the germination process and uses the endo- sperm as its source of energy. The endo- sperm and embryo are surrounded by a cell layer known as the aleurone layer, which plays an important part in the germina- tion process. During the initial uptake of water by the dry dormant seed, the embryo starts its growth process through the re- lease of a plant hormone known as gibber- ellic acid. The plant hormone diffuses out- ward and enters the aleurone layer where it induces the formation of enzymes re- quired to convert the starchy endosperm to sugars. The conversion of the water-insol- uble starch to water-soluble sugars is a very important sequence, since the embryo of the seed cannot use starch directly to produce the energy required for germination. The key for proper seed germination is the production of hydrolytic enzymes by the aleurone tissue. Much is known about this important process; but the steps lead- ing to the production of enzymes are poorly understood. Plant physiologist Claus Grunwald is studying the formation of the endoplasmic reticulum (ER); this is the cellular mem- brane network responsible for the produc- tion of the hydrolytic enzyme. The ER in a dormant barley seed is poorly developed, but once germination begins, this mem- brane network becomes quite prominent. One of the big questions is whether the cellular constituents needed to form the membranes are present (stored) in the seed or have to be synthesized during the very early stages of germination. This is not an easy question to answer, but it is important in the storage of seeds, not only to preserve a high germination rate, but also in the storage of grain for food purposes. The induction of hydrolytic enzymes during grain storage may greatly decrease the nutritional value of the stored seed. Illinois Raccoon Populations Now that pelts of raccoons have in- creased dramatically in value, especially during the past four seasons — from $1.35 in 1970-1971 to $27.25 in 1978-1979 in Illinois — Illinois and several other mid- western states have suddenly become much interested in the raccoon data that Glen C. Sanderson, Head of the Section of Wildlife Research, has collected for the past 24 seasons. This data has been collected at Perardi Brothers Fur and Wool, Inc., Farmington, Fulton County, Illinois. Dur- ing the 1978-1979 season, Sanderson made five trips to this fur house and examined 472 raccoons. The low average body weights of young- of-the-year raccoons for the past three seasons are probably explained by high pelt prices that cause previously discarded, very small raccoons to be sold and, thus, weighed. In past years, these pelts were “worthless”; they now bring from $4 to $8 each. The high percentage of adult females that had not produced offspring observed in 1978-1979 can probably be explained by adverse weather conditions during the breeding season (February) in 1978. For example, in February 1978 the statewide average temperature was 13.5° F below normal compared with 1.7° F below nor- mal in 1977, and the statewide average snowfall was 7.0 inches in February 1978 i The raccoon population in Illinois is at an all-time high despite the dramatic increase in prices paid for raccoon pelts. (Photograph by former Survey Photog- rapher W. E. Clark.) compared with 3.5 inches in February 1977. These conditions probably restricted movements of raccoons enough so that higher-than-average numbers failed to breed. If the data collected are indices to major changes in the raccoon population, they do not indicate changes in the population in west-central Illinois. However, these data probably would not reflect a major change in the population until the year after the change occurred. The fact that the raccoon harvest in 1978-1979 in- creased by nearly 22 percent over that for 1977-1978 suggests that Illinois raccoon populations had not declined as drastically prior to 1978 as many hunters and trappers reported. The Illinows NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 Body weights of raccoons vary as much as 1.5 pounds from one year to the next because of weather conditions but have shown no trends during the past 24 seasons. A decline in average weights of sexually mature fur seals that accompanied a popu- lation increase was seen as evidence of competition for food. It seems apparent that the present all-time high raccoon pop- ulation in Illinois is not having problems finding adequate food. A charge of groups opposed to the use of the leghold trap is that trappers do not run their traps regularly and leave animals to suffer for prolonged periods. During the 1972-1973 season and from 1974-1975 through 1978-1979, the method of taking raccoons — hunting, trapping, or dead on road (DOR) —was noted. During these years, more than 2,000 raccoons killed by hunters weighed an average of 12.0 Ib each, and nearly 600 raccoons killed by trappers weighed 11.6 lb each. A prelim- inary analysis by age and sex indicates that raccoons taken by trappers did not weigh significantly less than raccoons taken by hunters and killed by cars. Thus, Illinois raccoon trappers run their traps often enough so that trapped raccoons do not lose significant amounts of body weight: however, no attempt has been made to de- termine the length of time required for steel-trapped raccoons to lose a significant _ amount of weight. From 1972-1973, when raccoon pelts were worth an average of $5.37 each in Illinois, to 1978-1979, when they were worth $27.25 each, the percentages of raccoons taken by hunters, trappers, and DOR have changed. In 1972-1973 the percentages were 70.9 killed by hunters, 28.0 taken by trappers, and 1.0 DOR. In 1978-1979 the percentages were 78.6 for hunters, 19.6 for trappers, and 1.7 for DOR. Thus, it appears that increased pelt values have resulted in relatively. more hunting pressure rather than trapping pressure on raccoons in I]linois. March 1980, No, 195, Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation Prepared by Robert M, Zewadski with the collaboration of the Surve y staff second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF, ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 61801 The Illinors NATURAL HISTORY SU REPORTS Hop Vine Borer in Corn Several caterpillars, including the Euro- pean corn borer, black cutworm, common stalk borer, and armyworm, appear almost perennially in Illinois corn and are dealt with rather routinely by growers and ento- mologists. Other catepillars are more spo- radic in their appearance and may cause minor to major yield losses in isolated areas. These sporadic pests occasionally are difficult to identify because of the scarcity of information about them. The hop vine borer, Hydraecia immanis, a caterpillar of the family Noctuidae, is a recent example of such an insect. The hop vine borer feeds in the bases of corn plants during May and June, usually killing the plants in the process. It has be- come a problem to corn growers in the contiguous areas of Illinois, lowa, Minne- sota, and Wisconsin. Multiple reports of its damage to corn in the Midwest can be to the mid-1970’s. The counties in which it has been detected in traced Illinois corn include Boone, Carroll, DeKalb, Ogle, Stark, Stephenson, and Winnebago. The species also has been reported from New York. F hey Nie. oo Zs "he 3 ne >> % 1 eS oo att t = 7 2 uh t gee + oe ; ay fey He aber eee ¥ : a £ Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. The identity of the species became con- fused when a related species, the potato stem borer (Hydraecia micacea), was de- tected by entomologists in New York in 1975. This species is an Old World cater- pillar that inadvertently was introduced into Canada during the late 1890’s. It was confined for 75-80 years to the extreme northeastern United States and the eastern maritime provinces of Canada. Its verified appearance in New York was coupled with a nearly simultaneous report of its occur- rence in Wisconsin and of a possible third species in Minnesota. The Wisconsin and Minnesota reports were based on tentative examinations of the larval stages of the in- volved species. It became apparent that any pest man- agement being for Hydraecia areas would be greatly aided if the exact programs planned in Illinois and surrounding number of species involved were known and if their larvae could be easily recog- nized. Survey entomologist, George L. Godfrey, in cooperation with other ento- mologists at the Survey, Cornell University, Iowa State University, University of Min- nesota, University of Wisconsin, and the ~ Fig. 1. Fully grown larva of ae the hop vine borer, Hydrae- =. » cia immanis (Photo by G. L. “ » ~ a Godfrey). a". ~ a Canadian National Collection began a systematic study to clarify the situation. The efforts established that the hop vine borer is the only Hydraecia species pres- ently attacking corn in the Midwest. The confirming evidence will soon appear as a paper by Godfrey in a INHS Biological Notes. However, it is reasonable to assume that the potato stem borer, the introduced species, will someday appear in Illinois. The descriptions and illustration in God- frey’s forthcoming publication will help promote its detection if the event occurs. IPM — New Employment Opportunities in Illinois Pest scouting is an important tactic in integrated pest management (IPM) and it is currently the most visible activity in IPM. It is providing seasonal and full-time employment for a growing number of people. Pest management consultants, in- cluding pest scouts who offer their services for a fee, is a new industry in Illinois. It is an excellent example of a new program begun in the public sector eight years ago, but which is now being adopted by the private sector. Eight years ago there were no pest man- agement consultants and pest scouts in Illinois. Today there are 18 firms employ- ing 21 full-time pest management consul- tants and approximately 130 seasonal em- ployees. ‘They are serving slightly over 1200 erower-customers in 86 counties in I]linois. The research and education to support this new industry is supplied by scientists and extension specialists in the Illinois Natural History Survey and the University of Ili- nois. Research is needed to provide new in- formation and to continually upgrade existing IPM technology. Educational pro- grams transfer this information and tech- nology to the user. ‘The Sixth Crop Protec- tion Workshop for pest management consultants and scouts was held March 11, 12, and 13. The Workshop attracted 372 in 1980; 102 more than in 1979. The evening training sessions gave participants the opportunity to identify weeds, insects, and diseases, and to study the application of programmable calcula- tors to pest detection and decision making. participants The Field Crop Scout Training Program was offered for the 3rd year on April 2-4, 1980. To support these on-campus workshops and schools, four multi-county training sessions will be held in the field during the 1980 crop growing season. These will provide real-world experience for permanent and seasonal employees in IPM. Information on the date, time, and location of these field training sessions can be obtained by writing extension entomolo- gist Donald Kuhlman, IPM Coordinator, 172 Natural Resources Building, Illinois Natural History Survey, Urbana, Illinois 61801. Illinois growers have developed much ‘interest in integrated pest management and with acreage scouted increasing each year, there is a continuing need for more trained scouts. The major emphasis to date has been on the detection and management of pests in corn and soybeans, but this will undoubtedly expand in the future to in- clude other crops. Daily Aging of Fish The age of fish has been determined by counting the annular marks in their bony parts (scales, vertebrae, opercular bones, spines, otoliths, etc.) or by conducting ex- tensive experiments on marking and re- capturing of fish. Although the age of fish in years is extremely important to fishery biologists, they have been unable to deter- mine the age of fish from tropical climates (annular marks absent), fish under one year, or fish from disturbed environments such as cooling reservoirs where hot water hinders the production of annular marks. Recently, fisheries biologists have deter- mined that the inner ear bones (organs of equilibrium called otoliths) are composed of layer upon layer of daily rings. These layers have been used to determine daily age of fish and to aid in elucidating life history information such as dates of spawn- ing, growing season, and the effects of en- vironmental conditions on growth rates. Survey aquatic biologist Bruce D. Tau- bert studied daily rings in otoliths of fish from North and South America and Africa and has published papers on the technique used to reveal daily rings and the validity 4 afi x dd \ Pal #i, op? . \ ge by x te is ge Sree i ee y v3 e hd \ , N - me N Joy | ‘i o ! S40" ‘ ; : i he. ee V we mae Ne ge N Ls SON ee eal \ By . ge ) oe as Fig. 2. Frontal section of an otolith from a pumpkin- seed sunfish (Lepomis gibbosus) showing daily rings (Photo by Bruce D. Taubert). of daily rings. In general, most fresh water fish produce the first daily ring in their otolith at the time of yok-sac absorption or swim-up. From then on a daily diary is kept in the otolith showing daily growth, changes in growth rates, and cessation of growth. In young fish the determination of daily age is accurate but as the fish grows older events take place that hinder anal- ysis of daily age. Normally, fish stop grow- ing when they spawn, overwinter in temperate climates, or become very old. These events are recorded in the otoliths because daily ring production stops when growth stops. To reveal the record of daily and sea- sonal growth in otoliths is as easy as sec- tioning a rock to look at its inner structure and much of the equipment and methods used in sectioning otoliths was developed by lapidaryists. After removal from the fish an otolith is secured to a glass microscope slide with a drop of lakeside balsam. In small fish this is all of the preparation necessary and the daily rings can be counted with the aid of a microscope. In young, small fish otoliths are about the size of the eye of a sewing needle. In older and larger fish the otoliths become irregularly shaped and thickened and in order to reveal the daily rings the otolith must be sectioned. The otolith is ground against carborundum paper until a thin section through the center of growth or nucleus is produced, then polished and the rings counted. In Illinois, Survey biologists are using otoliths to determine basic life history data of fish from Lake Sangchris, Lake Coffeen, and Lake Shelbyville. In Lake Sangchris Survey aquatic biologists Bruce D. Taubert and John A. Tranquilli have used otoliths to reveal life history information about threadfin shad (Dorosoma petenense) and largemouth bass (Micropterus salmoides). Survey aquatic biologist Ted Stork work- ing on Lake Shelbyville will be using daily rings to determine time of spawning for all species present, and Survey aquatic biol- ogists Lanse Perry and Dennis Newman will be using otoliths to determine previ- ously unavailable information on differ- ences in spawning dates and growth rates of largemouth bass from hot water and ambient areas of Lake Coffeen. These tasks can be accomplished by the otolith method at great savings in time, effort, and equipment. Cottontails and Grassland Natural regulation of the abundance of cottontail rabbits is effected through a complex of interacting mechanisms that relate to environmental conditions and events. ‘Trends in statewide abundance re- flect the general pattern of events occur- ring throughout Illinois. Trends in the abundance of local populations can and do differ from the average statewide trends. Studies of the population dynamics of cottontails conducted since the mid-1950’s by Survey ecologist William R. Edwards demonstrate changing patterns of agricul- tural landuse to be closely associated with changes in cottontail abundance in Illinois. Over the past 25 years the average abun- dance of cottontails has declined at least 70% statewide, and 90 to 95% throughout most of the intensively farmed central and east-central counties. Roughly 80-85°% of The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 the decline in cottontails was associated with the pattern of increased production of row crops, decreased acreages of hay, oats and pasture, larger farm and field sizes, and increased use of herbicides and pesticides. The primary constraints on wildlife abundance clearly relate to land- use phenomena that determine base levels of carrying capacity. Prevailing weather conditions are responsible for short term fluctuations about these base levels. Cottontails on the 4-H Area at Allerton Park have not evidenced the long-term decline demonstrated by the general state- wide pattern of abundance. At Allerton, rabbits were abundant in the late 1950's, scarce in the early 1960's, reached a peak again in 1976, and have declined markedly since. The high in 1976 is considered to reflect unusually good survival related to favorable weather. Numbers present in 1977 indicated average abundance and survival in terms of numbers although the percent survival was down relative to the high population in 1976. Survival was low during the winters of 1977-78 and 1978-79 and was attributed to severe weather, par- ticularly prolonged periods of deep snow and sub-freezing temperatures. The reproductive capacity of the cotton- tail has long been known. Adult females may produce 4-5 litters each year, and early born young may produce one or even two litters their first summer. There is no postage paid at Urbana, Illinois {USPS Office of publication Natural Resources Building evidence that the statewide decline of cottontails is related to a pattern of re- duced reproduction. Predation is recog- nized as a primary cause of mortality but its effect on a population depends on the -security offered by the habitat. Where landuse does not supply an abundance of secure niches, cottontails are not numerous. On a short term basis, severe weather makes habitats relatively less secure. On a statewide basis we can expect to see a continuing pattern of changing cottontail abundance. We should see some. weather related, short term and_ local population increases, but the basic long term decline in cottontail populations in Illinois will continue unless there is a trend toward less intensive agriculture. The world’s need for food, our national need for export commodities, and the current energy related move to grain alcohol as a fuel, preclude any trend to less intensive agriculture. It is important that losses of grassland habitats be viewed in much the same way as we are beginning to appreciate the de- struction of forest and aquatic habitats. wildlife should strive to develop and preserve grass- Conservationists and managers land habitat where possible on public and private lands. The true plight of grassland animals such as the cottontail is only be- ginning to be appreciated. Urbana, Illinoi Persons desiring individual or additional copies of this publication please write to f Fl R CHIEF LLIND VEY } ANA LLINOIS é The Illinois NATURAL SURVEY: Swine Manure and Grass Carp in Bass Ponds Preliminary findings indicate that mod- erate enrichment of fish ponds with swine manure and control of pond weeds by grass carp are beneficial to the growth of bass in their first year of life. So say Survey aquatic biologists Homer Buck and Dick Baur after the first year of a three-year study at the Sam Parr Fisheries Research Center, a field station of the Illinois Nat- ural History Survey near Kinmundy. The swine manure is used as a fertilizer to increase the production of fish foods. The Chinese grass carp is used to reduce excessive growths of pond weeds. However, the grass carp is believed to serve a double function. The Chinese say, “If you feed one grass carp well, you feed three other fishes.” They believe this saying because the grass carp consumes such massive quantities of vegetation that it serves as a swimming manure factory. Thus, the pond is enriched in two ways, by the swine ma- nure and by the carp manure. Such organic enrichment yields divi- dends not provided by inorganic chemicals. In addition to promoting the growth of phytoplankton, it stimulates the produc- tion of heterotrophic bacteria. This pro- duction of bacteria initiates a wave of pro- duction through the entire bacteria to protozoa to zooplankton to benthos, that inevitably must benefit the fishes, both prey and predator species. This research is a companion study to a food web, from separate investigation of the largemouth X smallmouth bass hybrid, the so-called HISTORY While it involves both pure largemouth bass and hybrids, no com- parisons between the largemouth and the hybrid are being made at this time. meanmouth bass. The experimental design involved six one-acre ponds, all of which were stocked with equal numbers of both largemouth and hybrid bass fry and with bluegills and fathead minnows to provide forage for the growing bass. Four of the six ponds each received the wastes from ten fattening pigs distributed as a slurry twice weekly, and two of the four ponds also were stocked with grass carp. The remaining two ponds received neither swine manure nor grass carp and served as controls. All ponds were drained and censused following a 130-day bass growing season. The average fall standing crops of bass (both largemouth and hybrids) were 119 pounds per acre in the ponds which re- ceived both swine manure and grass carp, 84 pounds per acre in those which received only swine manure, and 80 pounds per acre in the control ponds. To Freeze or Not to Freeze... Midwest winters are warm or cold, long or short, wet or dry. Above all, they are highly unpredictable. As climatic tions vary from year to year, the stresses imposed on trees and shrubs by winter weather also vary. Some species show dam- age nearly every while others are rarely affected. condi- year, Woody plants that survive many winters in Illinois must acclimate to temperatures below zero. If they are not acclimated at Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. the time a hard freeze occurs, they may suffer from freezing stress. Severe stress causes bud kill, frost collars and cracks, and stem dieback. Less severe stress may weaken plant tissues without actually kill- ing them and result in increased suscepti- bility to attack by disease organisms. Stem canker and dieback diseases are often as- sociated with freezing stress. Many studies have been conducted on hardiness to freezing injury in woody plants, but until recently little was known about how freezing affects susceptibility to disease. Information was lacking on the level and duration of freezing required to alter disease susceptibility and whether freezing stress on one portion of a plant would cause other portions to become sus- ceptible. To answer these questions, Survey plant pathologists D. F. Schoeneweiss and E. G. Wene devised a method for differen- tially freezing whole plant stems under controlled conditions. Portions of stems were wrapped with insulation and heating cables, and those stem parts were main- tained above freezing, while adjacent ex- posed portions were frozen (see photo). When frozen and unfrozen stem portions were inoculated with canker fungi, only those portions subjected to temperatures below zero became susceptible to attack. The fungi were not able to grow into the portions protected against freezing stress. Apparently freezing stress in woody stems is localized; that is, only stem tissues subjected to freezing temperatures below a critical degree become susceptible to attack by canker fungi. Portions of stems protec- ted by snow cover or mulch may survive hard freezes and not become targets for disease organisms. Since protected stems remain resistant to disease, pruning out ‘ portions with canker and dieback symp- toms is recommended as a control measure. The remaining plant will usually put out new growth and recover from damage caused by stress-related pathogens. In ad- dition, plants that acclimate quickly in the fall are less likely to be stressed by freezing. Therefore, late season pruning and fertilizing, which delay acclimation, should be avoided. Portions of tree stems insu- lated to allow differential freezing (Photo by D. F. Schoeneweiss). Pheasants in Illinois have traditionally been most abundant in the east-central counties (Photo by L. M. David, Ilinois Department of Conservation). Fall Land Use and the Survival of Pheasants The relative abundance of ring-necked pheasants in east-central Illinois is pri- marily related to agricultural land use. Research on the Sibley Study Area (SSA) has shown the importance of forage le- gumes and small grains (particularly oats) for successful nesting and brood rearing by pheasants. However, relatively little work has been directed toward the relationship of fall land use and the survival of pheasants dur- ing the cold season. Trapping and mark- ing studies on the SSA from 1962 through 1965 indicated that the death rate of pheas- ants, October to February, averaged 75 percent of the early fall population; only 25 percent of these deaths were attributed to hunting. Although survival rates may have been less than average for 1962-1965, these findings illustrate that mortality of pheasants is perhaps greatest during fall and early winter. Wildlife biologist Richard E. Warner recently completed a statistical analysis of the relationship between fall land use char- acteristics and the survival of pheasants through late winter on the SSA from 1960 through 1970. The three components of fall land use that were considered in the analysis were acreages of unplowed hay and small grains, unplowed row crop stubble (primarily corn), and plowed farmland. During the 1960’s the amount of land planted to hay and oats declined with the expanded production of corn and soybeans. Fall plowing varied among years in con- junction with weather conditions. Numbers of pheasants on the SSA peaked in the early 1960’s, declined substantially from 1963 through 1965, and were relatively stable from 1966 to 1970. A significant positive relationship was found between acreages of unplowed hay and small grains and densities of pheasants on the SSA in late winter to early spring. However, the correlations do not account for how land use and the reproduction of The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 pheasants during the growing season may interact with fall land use and numbers of pheasants that survive through late winter. Thus, correlations of fall land use charac- teristics with late winter pheasant popula- tions may be primarily a reflection of the importance of a particular cover type to the recruitment of pheasants during the reproductive season. The correlation coefficients resulting from another analysis suggest that (1) the characteristics of fall land use that were considered in the analysis do not directly explain variations in the number of pheas- ants that survived on the SSA through late winter, and (2) the significant correlation of the acres of unplowed hay and small grains with late winter densities of pheas- ants primarily reflects the amounts of hay and oats present during nesting and brood rearing and subsequent recruitment to the fall population. Although fall land use could not be directly linked to pheasant survival in this analysis, there is little doubt that more subtle — thus far unmeasured — charac- teristics of fall land use affect rates of pheasant survival on a year-to-year basis. May 1980. No. 197. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conser- vation Prepared by Robert M, Zewadski with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 175 Natural Resources Building, Urbana, Illinois. Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL, JR., CHIEF ILLINOIS NATURAL HISTORY SURVEY, URBANA ILLINOIS 61801 The Illinots NATURAL Prairie and Prairie Chickens Practically all tillable portions of the 1,641 acres now in prairie chicken sanc- had over a century tuaries in Illinois been cultivated annually for prior to ac- quisition. The one exception, the Walter’s 40-acre tract in Jasper County the mid-1950’s), is 75% by native prairie vegetation and 25% Three prescribed 1979) by wildlife biol- Westemeier and his assistants (unplowed since today covered by woodland. burns (1974, 1976, ogist Ree. have apparently hastened the spread of This tract now contains one of the best stands of little bluestem to be found in the south central counties. and prairie plants over the Walter’s tract. (Andropogon scoparius ) mostly Indian- grass (Sorghastrum nutans), and big blue- native (Panicum Seeded prairie grasses, switchgrass virgatum) , stem (Andropogon gerardi), are now pre- ao, aaa : ied at art i J ence i HISTORY U REPORTS dominant species on about 157 acres of the 1,001 acres of prairie chicken sanctuaries also Jasper County. Prairie grasses are started, on anothe1 99 though not dominant, acres. An additional 143 acres are tenta- tively scheduled for establishment of prairie on erodable slopes, waterways, oO! fields that are not well suited periodic cropping. Thus, the cover on at least 358 acres (over one-third of the sanctuaries) at Bogota will eventually involve restoration of prairie vegetation. Althcugh the prairie grasses were shown in young stands of native previous re- ports to be among the poorest cover for nesting prairie chickens with regard to density of hatched nests and percentage success, there are indications that this situ- ation is changing. Nest success in prairie grasses has increased steadily from 25% in 1972 to 75% 1979 except in 1978 when Male prairie chicken (Photo by former Survey photog- rapher, W. D. Zehr). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. success dropped to 33%. In 1979, the three hatched nests found on the Yeatter Sanc- tuary were all in fields dominated by prairie grasses. In 1979, prairie grass pre- dominated around the bowls of all of the five nests found in fields where prairie grasses were present. From 1966 to 1978, prairie grass predominated around the nest bowls of only 64% of the nests found in fields with prairie grass. The increased use of and success in prairie grass by chickens may be due to gradual maturity of stand and improve- ment in the quality of prairie grass stands. Type of management also appears to be a key factor. Nest densities and nest success were compared in four categories of prairie management: (1) no disturbance, or mow- ing for (2) weed control (mw), seed (ms), or nesting enhancement (mn), (3) haying, and (4) prescribed burn. Although data for all categories are still limited, results for the mowing category (ms, ms, and mn) compare favorably with nonprairie grass areas. Nest density (nests per 10 acres) and nest success were 2.2 and 50.0% respectively. By contrast, comparable fig- ures for the undisturbed, hayed, and fresh burn categories were 0.9, and 27.3%; 0.4, and 25%; and 0.0, and 0%; respectively. This is encouraging as prairie restoration seems axiomatic for prairie chickens; how- ever, more data are necessary to confirm the indicated relationship. It would be de- sirable to try limited grazing with the other approaches to prairie management. The prairie chicken project is a coop- erative project between the Survey and the Department of Conservation, using Pitt- man-Robertson funds. The Kankakee River The Kankakee River, considered to be one of the finest rivers in Illinois, originates near South Bend, Indiana, flows westward into Illinois and joins the Des Plaines River to form the Illinois River. During early settlement of the Kankakee Basin the river was channelized in Indiana to in- crease flow and facilitate drainage of the land. Modification of the river in Indiana resulted in a fast-flowing ditch that slows markedly when it reaches the more natural, meandering river at the Illinois border. Concern exists among Illinois citizens that sediments washed into the Kankakee River in Indiana are deposited as they reach the slower moving Illinois portion of the river, and that these deposits are reducing the diversity and abundance of aquatic life. Because of this concern, the Illinois In- stitute of Natural Resources is funding a study by the State’s three Scientific Surveys on the effects of sedimentation in the IIli- nois portion of the Kankakee River. The Natural History Survey is examining the effects of sedimentation on selected groups of aquatic organisms; emphasis is being placed on fishes, mussels, midges, aquatic - beetles, and caddisflies. Information ob- tained is being compared to available his- torical data and the present and probable future effects of sedimentation in the river are being evaluated. The diversity of fishes in the Kankakee River is higher than in most Illinois rivers, and because of improved collecting tech- niques, is higher now than was indicated in previous studies of the river. Several ex- tremely rare species, most notably the northern brook lamprey, pallid shiner, and river redhorse, still are found in the river. In contrast to the fishes, mussels have undergone a drastic reduction in diversity and abundance in the Kankakee River over the past 70 years. Increased sedimen- tation probably contributes significantly to the reduction, although pollution, over- harvesting, and habitat modifications other than sedimentation also are suspected of causing declines in mussel populations. Data on insects are still being analyzed but the high diversity of aquatic beetles and caddisflies indicate that, as with fishes, the Kankakee River is in better condition than are most rivers in Illinois. The Kan- kakee River supports nearly a third more species of water beetles than does any com- parably sized watershed in Illinois. A dozen species of caddisflies are known in Illinois only from the Kankakee River. Sedimentation in the Kankakee River is a problem and needs to be monitored to prevent further degradation of the river. Among the organisms studied, mussels appear to be the most sensitive to sedimen- y tation, and they may be ideal organisms to study throughout Illinois to determine the environmental conditions of our rivers. Hybrid Carp and Aquatic Weeds As a natural course of events, lakes, ponds and often large reservoirs become heavily infested during warm weather with unsightly growths of aquatic weeds and algae, which ultimately may make waters unsuitable for fishing, swimming, irriga- tion, or other uses. Aquatic scientists have considered three basic techniques for the removal of nuisance vegetation: chemical herbicides, mechanical harvesters, and var- ious forms of biological control. The application of chemical herbicides probably has been the most effective and widely used short-term alternative but, since fossil fuels are used in their manufac- ture, the use of aquatic herbicides are be- coming cost prohibitive. In addition, aquatic scientists are uncertain and fearful of specific after-effects of various chemicals on non-target species (both plant and ani- mal). Although considerable work and re- search has been conducted on mechanical harvesters for aquatic plants, this type of control is also proving costly, and it has not been sufficiently developed for use in cer- tain types of habitats, such as small ponds. In view of the disadvantages of chemical and mechanical control strategies, the potential for a certain biological agent ap- pears to be very promising. In recent months, the grass carp or white amur (Ctenopharyngodon idella) has received a great deal of attention. Presently the introduction or use of the white amur is illegal in 32 states, including ee “Nae Pe . Se Foe Hybrid grass carp or white amur (Photo by Survey aquatic biologist, Homer Buck). Illinois, due primarily to the paucity of information regarding the fish’s natural history, ecology, and its potential impact on wetlands utilized by waterfowl and naturally occurring fish species. Fortu- nately, recent genetic research in Hungary and the Soviet Union has produced a reportedly sterile carp hybrid which re- tains the feeding characteristics of the grass carp. That these new fish are in- capable of reproducing provides some in- teresting ramifications for aquatic weed control. The opportunity to investigate the effi- cacy of the hybrid carp as a biological weed control agent for aquatic systems is now at hand for a large multidisciplinary team of aquatic scientists at the Illinois Natural History Survey. The research strategy is designed to compare the hybrid carp and chemical methods as effective means of controlling aquatic vegetation. Following one preliminary year of obtain- ing baseline data and perfecting methodol- ogies, the. team will define a 3-year experi- mental period of specific effects of the two approaches on the microbial, plankton, benthos, and aquatic plant communities, and on the sport fishery. The study con- tinues one step further by assessing perti- nent water physics and chemistry param- eters and by determining the functional processes of plant decomposition, the cycl- ing of important nutrients, and the flow of energy moving into and from each com- ponent group of the ecosystem. Data gathered from these studies will provide a basis for predictive management practices for both the sport fishery and the hybrid carp. This 4-year project is being sup- ported by Dingell-Johnson funds allocated from the U.S. Fish and Wildlife Service through the Illinois Department of Con- servation. Corn Rootworm Egg Sampling The northern corn rootworm, Diabrotica longicornis (Say), is a pest of corn with the larvae attacking roots and the adults feeding on pollen, silks, and leaves. There is only one generation/year and eggs are laid in the soil during August and Sep- tember. The Illinors NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 The two practical methods of predicting infestations are sampling for adults and for eggs. There are at least four reasons that sampling for eggs would be advantageous over sampling for adults: the egg stage immediately precedes the stage that causes the most important damage; eggs are sta- tionary; eggs are in the field and available for sampling for an extended period of time (September to May) ; and sampling for eggs is not affected by time of day, weather conditions, or plant maturity. Survey entomologists W. G. Ruesink and W. H. Luckmann and research assistant R. E. Foster recently studied the spatial distribution of rootworm eggs and com- pared five methods of sampling. ‘The max- imum depth at which eggs occur was not established since they continued to find them in the deepest samples, but 85% of those found in the upper 20 cm were located in the top 10 cm. Northern corn rootworms show a high degree of prefer- ence for oviposition at the plant base, while in the row between plants is of intermedi- ate preference, and the area between rows is least preferred. Of the five sampling methods only two proved to be reliable. ‘The core method used a sampler similar to a bulb setter. A sample consisted of ten cylindrical cores, 5.4 cm diam and 10 cm deep. These ten June 1980. No. 198 cores were sifted through a screen, mixed, and a standard subsample was removed for processing. These samples consisted of plant-base samples (immediately adjacent to the corn stalks) and between-row samples (midway between two rows of corm). For the frame method all soil was re- moved from a trench perpendicular to the row and exactly the row width long. To make this task easier, a metal frame 10 cm . deep x 10 cm wide x one m long was con- structed. This frame was pushed into the ground at the desired location, and all the soil within the frame as long as the row width was removed with a trowel. All soil taken from within the frame was thor- oughly mixed, and the standard subsample was removed for processing. For any sampling program, one of the important questions is how many samples to take. These two methods produce nearly identical levels of reliability for an equal number of samples, but the frame method requires about a third more time. On the other hand, the core method depends on some assumptions about spatial distribution that the frame method does not. Thus the normal core method would be best if the emphasis were on time, and the frame method would be best whenever a high degree of accuracy is desired. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Con- servation. Prepared by Dr. W. E. LaBerge with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication 175 Natural Resources Building, Urbana, Illinois Persons desiring individual or additional copies of this publication please write to GEORGE SPRUGEL IR CHIEF, ILLINOIS NATURAL HISTORY SURVEY URBANA, ILLINOIS 61801 Th NATURAL Tllinots HISTORY REPORTS Weevil Released to Control Musk Thistle The musk thistle is a prickly, bristly weed that grows in large patches in Illinois fields, permanent pastures, and strip mine areas converted to pastures. In June 1979, Illi- nois Department of Agriculture personnel released about 1,200 adult specimens of the musk thistle weevil, Rhinocyllus conicus, at six locations in our state. The collection, release, and monitoring of the weevils was a joint effort of the Illinois Department of Agriculture, the University of Illinois De- partment of Agronomy, and the [Illinois Natural History Survey. The purpose of these insect releases was this establish permanent populations in Illinois to determine whether weevil could and provide biological control of the musk thistle here. The larvae of this weevil eat the seeds of the musk thistle and thus re- strict the plant’s reproduction. The adults do a relatively small amount of damage by feeding on the thistle leaves. About 200 weevils were released at each of six sites near Shawneetown, Gallatin County; Ware, Union County; Edwards- ville, Madison County; Cuba, Fulton County; Aledo, Mercer County; and Mor- The musk thistle weevil, Rhinocyllus conicus, on a bull thistle leaf in the laboratory. Photo by James Ap- pleby. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. Bill Lewis, Illinois Department of Agriculture, exam- ining a musk thistle for weevil eggs. Photo by Clar- ence White. aine Hills State Park, McHenry County. Natural History Survey Economic Ento- mologist Clarence White has been coop- erating with Department of Agriculture personnel by monitoring weevil establish- ment in the field. Between May 28 and June 17, 1980, Entomologist White visited each release site with the person who had made the release. Their purpose was to determine how successfully the weevils had overwin- tered and the extent of their dispersion and ege laying in the spring. At each site a 10-plant sample was inspected for egg masses and adults. They also inspected thistles around the release site to deter- mine how far the weevils had dispersed. They observed egg masses and adult weevils at five of the six release sites. This- tle plants in their samples had 0-19 egg masses on them, and the averages from the five sites were 4.7-8.3 egg masses per plant. Adult weevils were observed at the re- lease sites and at distances of from % to %4 of a mile from the sites. Only at the Gallatin County site did the researchers find no egg masses or weevils. At that site a herbicide had been used in 1979. Apparently, the weevils’ food supply had been eradicated, and no weevils had survived there. Entomologist White concludes that, with the exception of those released at the Gal- latin County site, the weevils overwintered well, dispersed well in the spring and laid many eggs, and are now well established in Illinois. However, White notes that, if our experience is similar to that of western states, the weevils will disperse widely dur- ing the next 4-5 years before populations develop that are large enough to exert any important control on the musk thistle. White-Tailed Deer in East-Central Illinois White-tailed deer have become abundant in Illinois since their reintroduction in the late 1930’s. Harvests of nearly 20,000 deer by 60,000 hunters have occurred in each of the past 2 years. Little is known about the characteristics of deer habitat. ‘To de- termine these characteristics and to deter- mine how much deer range remains in Illi- nois and where it occurs, Survey Wildlife Biologists Charles Nixon and Lonnie Han- sen and Research Assistant James Chelsvig have begun a cooperative research project with the Department of Conservation deal- ing with deer ecology and management in I}linois. Even though winter in Illinois is usually relatively mild, it is a period of stress. The absence of woody cover limits the winter distribution of deer in Illinois, particularly in the central, east-central, and northern counties. In these counties it has long been known that deer tend to concentrate in localized habitats in winter. In the Rock River watershed, for example, deer moved 10 ‘miles or more to areas along the river in late fall and remained until late March or April, when they returned to their sum- mer range. If such concentrations of deer are found each winter and if the same areas are used each winter, the identifica- tion and description of these areas would be of great value in managing Illinois deer. One area that appears to hold a large winter deer population is Robert Allerton Park in Piatt County. Survey biologists captured 21 deer there in late winter and spring 1980. The deer were captured with a 40- X 50-foot nylon net propelled by rockets, which carry the net over the deer as they feed at a bait pile of corn, apples, and block salt. Most of the deer were marked with collars or ear streamers. Five does were fitted with collars containing small radio transmitters, enabling the biol- ogists to follow the deer and to determine the types of cover deer use at different times of the day. Minimum seasonal home ranges were calculated for the radio-monitored deer, and they range from 275 to 500 acres dur- ing winter and from 75 to 210 acres during summer. During winter, deer were pri- marily found in dense brushy areas in timber during the day and in wheat or alfalfa fields at night. In the summer, deer make extensive use of cornfields during both day and night. It is believed that part of the reason for using cornfields, aside from their providing good cover, is to es- cape from the biting insects that are so common in woods. — A fawn captured and marked after biologists located her radio-collared mother. Photo by James Chelsvig. The distances between winter and sum- mer ranges have been surprising. The ra- dio-monitored deer have moved 4.5-38.0 miles between winter and summer ranges. One yearling buck was seen a mile north of Taylorville, 48.5 miles from where he was marked. The effects of intensified farming on small game populations, particularly pheas- ants and rabbits, have received much at- tention, but there has been less concern about the effects of increased row crop- ping, fall plowing, and more efficient com- bines on the availability of deer foods. Corn and soybeans are important fall, win- ter, and spring foods for deer from central Ohio west to the Great Plains. These high- energy foods are needed for deer to com- bat harsh winters, when cover is scarce and protection from the weather is limited. The intensive land use prevalent in IIli- nois forces deer to adjust their activities to constant disturbance. Understanding how they do this will help the Department of Conservation do a better job of managing Illinois’ only big game animal, the white- tailed deer. New Survey Field Laboratory on Largest U.S. River The Mississippi River will receive close scrutiny from Illinois Natural History Sur- vey biologists and other scientists during the next 2% years in a research program tied to the controversial issue of whether a second lock should be built at the new Alton Lock and Dam. Drs. Kenneth S. Lubinski and H. H. Seagle of the Survey’s Aquatic Biology Section will supervise these studies from the Survey’s newest field laboratory at Grafton, Illinois, where the Illinois and Mississippi rivers flow together. Appropri- ately located on the riverfront, the labora- tory’s two buildings are leased from the Illinois Department of Conservation. Cooperating with the Natural History Survey in the venture are scientists from the Illinois State Water Survey, Illinois State Geological Survey, and Western I[lh- nois University. Dr. Richard E. Sparks of the Aquatic Biology Section will coordinate the work at Grafton with studies being conducted by five other agencies upstream on the Mississippi near La Crosse, Wiscon- sin. The Illinois NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 Biologists and hydrologists will join forces at the Grafton Lab to study ways in which barge and pleasure boat traffic af- fects the Mississippi and the aquatic crea- tures that call it home. Congress has authorized the Upper Mississippi River Basin Commission to fund this study as part of the 1978 compromise that allowed the construction of one replacement lock for barge traffic at Lock and Dam 26 near Alton. Under this law, the decision on whether to add a second lock — thus increasing barge traffic on the river — must wait until a $12 million Master Manage- ment Plan for the river is completed. ‘The plan includes both economic and environ- mental analyses. The budget for the research at Grafton is just over half a million dollars. Sub- stantial amounts of state and federal tax money already go to government agencies responsible for the upper Mississippi River: the Fish and Wildlife Service maintains refuges for fish and wildlife; federal and state environmental protection agencies maintain and upgrade water quality; and 9. Published monthly « xcept Prepared by Robert A. Zewadsk ith the ‘ ynd-clo postag paid at Urbana, Illin Office of publ) tio 75 Nat 1 f{ rce Buildina n July and Auvaust by tl f Natural Resources operating nder th llaboration (USPS 2 the U.S. Army Corps of Engineers de- velops structures for navigation and flood control. Do these agencies — all working for the same taxpayers — sometimes pull in oppo- site directions, perhaps without knowing it? For instance, a second lock at Alton might increase barge traffic enough that — river-bottom sediment would be stirred up in amounts exceeding water quality stan- dards, and these sediments in turn might settle out in a wildlife sanctuary. In such a hypothetical situation, the tax dollars used to improve navigation might then re- quire more tax dollars to be spent to undo the effects of the increased barge traffic. It makes sense to spend some money to make sure that each agency can accomplish its work on the Mississippi River without in- terfering with the work of others. Once the Grafton project and other studies are finished, the Upper Mississippi River Basin Commission will use the re- sults to decide whether there are any such conflicts, and if so, how to resolve them. a divi ona Conser Natural History Survey Board of Natural Resources of the Survey staff cm 990) Z22U) | itl . Urbana inc Persons desiring individual or additional copies of this publication please write to ILLIN JA I Y SURVEY RBANA The Illinors NATURAL HISTORY REPORTS George Sprugel, Jr., Retires Search Underway for New Chief Dr. George Sprugel, Jr., retired August 31 after 14 years as Chief of the Natural History Survey. Some of the major ac- complishments during his tenure were the building and instrumentation of the Natu- ral Resources Annex on the University of Illinois, Urbana-Champaign campus, the development of an extensive grant and contract program, and the expansion of eight field around the state. stations in various locations Sprugel came to the Survey in 1966 from the National Park Service in Wash- ington, D.C., where he was Chief of the Division of Natural Sciences. Prior to that he was Program Director of Environmen- tal Biology at the then newly formed Na- tional Science Foundation in Washington. He was listed in American Men and Women of Science, Who’s Who in Ecol- ogy, and Who’s Who in America, and also is a member of many national and inter- national professional organizations. Most recently he was president of the American Institute of Biological Sciences and active in the American Association for the Ad- vancement of Science, and the American Society of Zoologists. A nationwide search is in select and appoint a new Chief. Dr. Wal- lace E. progress to LaBerge, Head of the Faunistic Surveys and Insect Identification Section was named Acting Chief by the Board of Natural Resources and Conservation until a permanent appointee is selected. LaBerge also is chairman of the Staff Search Com- Dr. George Sprugel, Jr., 1966-1980 (Photo by Larry Farlow, former Survey Photographer). Survey Chief, mittee that is now interviewing five final candidates for the vacancy. Other mem- bers of the committee are Drs. William Childers, William Edwards, Joseph Mad- dox, and Kenneth Robertson, and Mr. Robert Ellis with Mrs. Alice Adams serv- ing as the group’s secretary. The committee will present its recom- mendation on the basis of its activities and solicited input from the entire Survey staff to the Natural Conservation. The Board has the responsi- offic ial Board of Resources and bility of making the final and Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey appointment. It is anticipated that the Board’s announcement will be forthcom- ing in the near future. Mushrooms and Toadstools A mushroom or toadstool is a fleshy structure that consists of a stalk and a cap with plates of tissue called gills on the underside. The surface of the gills is cov- ered by a layer of cells termed basidia that give rise to the reproductive spores. There is no technical difference between a mush- room and a toadstool as both represent the spore-bearing phases of a fungus. The term mushroom traditionally refers to edi- ble species, some highly prized for their delicious flavors and aromas; and the term toadstool is used for poisonous mushrooms that contain toxic compounds that may cause both illness and death. Mushrooms can be found throughout most of the year in lawns, roadsides, for- ests, and prairies. The largest number ap- pear when the first cooling trend of fall is accompanied by rains, usually in Septem- ber. Warm spring rains also bring out the second largest number of mushrooms in- cluding the morels and puffballs. Edible and poisonous species can occur Inedible Russula emetica illustrating the stalk, cap and a portion of the gills. Found on rotten wood and rich humus in coniferous forests and bogs (Photo by Leland Crane, Mycologist). together and can resemble each other. Thus, safe and toxic species can be con- fused by amateurs, and there are no quick tests to distinguish the edible from poison- ous species. Eating wild mushrooms with- out learning something about them is like playing Russian roulette. Most of the time, nothing will happen, unless a poisonous species is ingested. For this reason, only people familiar with the technical identi- fication of mushrooms should collect and eat wild species. Learning to identify accurately the spe- cies that you want to eat as well as those to avoid is the best safeguard. In gathering mushrooms, be careful to collect the entire specimen and keep each kind separate. Collect only fresh specimens for the table: however, young and old specimens may be needed for identification. Once the identity of a collection is es- tablished, check its edibility rating. If the - species is rated as poisonous, most people will be poisoned if they eat it. An edible species is one that, when cooked, can be eaten safely in moderate quantities by people in good health. Do not gorge your- self on mushrooms because most people find them hard to digest due to the chi- tinized walls and the fats and oils in the cells. Eat only cooked mushrooms because certain species are more likely to cause problems when consumed raw than when cooked, and some toxins are inactivated by proper cooking. Do not keep -mush- rooms for an extended period of time be- cause bacterial contamination may cause food poisoning. Finally, when experiment- ing with mushrooms, always keep some intact specimens on hand. They may be needed to aid in identification so that the correct treatment can be given in case of accidental poisoning. Carbofuran in Soils Insecticides are important tools used in integrated pest management programs tor various Illinois crops. Because they are in- herently toxic, it is necessary to under- stand their environmental fate and_be- havior so that pollution of non-target sites and organisms can be avoided. Knowledge about insecticide behavior also can aid in => (T) (D) (C) Relative movement of Counter(R) (T), dieldrin (D) and carbofuran (C) on thin layer of soil as recorded on X-ray film (Photo by Les Woodrum, Survey Photog- rapher). more efficiently controlling the target pest. Studies of the behavior and fate of pesti- cides are called environmental chemody- namics. They are designed to elucidate the relationships between physical and chemi- cal properties of a pesticide and its fate in the environment. One aspect of environmental chemo- dynamics is the potential for movement or leaching of a pesticide in the soil. In the Pesticide Chemistry Lab of the Section of Economic Entomology, Allan Felsot and Jean Wilson have studied the mobility of carbofuran (Furadan®), a widely used corn insecticide applied to soil. The studies were performed in the laboratory using a combination of soil, thin-layer chromatog- raphy, and autoradiography. Briefly, a soil-water slurry was spread across a glass plate and allowed to dry. Radioactive- labeled carbofuran was spotted on the plate near the bottom end. The bottom edge of the plate was placed in water. The water was allowed to move up the plate to a distance of 10 cm. Afterwards, the plate was covered with a piece of X-ray film for a few weeks, and then the film was processed. Wherever the labeled pesti- cide was located on the plate, a dark area appeared on the film. The developed X- ray film thus served as a record of pesti- cide movement under leaching conditions. Because carbofuran has a relatively high- water solubility compared to other widely used soil insecticides (such as dieldrin and Counter®), it has more potential for movement in the soil. Conversely, chemi- cals with very low water solubilities (e.¢., dieldrin) are adsorbed by the soil matrix to a greater extent and would be expected to exhibit a very low leaching potential. It was observed that carbofuran adsorption by soils was generally one hundred times lower than dieldrin adsorption, and carbo- furan consequently was spread across the thin layer of soil while dieldrin was found near the bottom. Thus, as carbofuran ad- sorption decreased, its leaching potential increased. ‘These results help to explain why similar runoff losses of dieldrin and carbofuran from watershed areas have been observed. Dieldrin is mostly associ- ated with runoff sediment, whereas carbo- furan is mostly associated with runoff water. Lake Michigan Diversion Project The 300-mile Illinois River stretches from Chicago to Grafton and is blessed with over 100 bottomland lakes and sloughs. These backwater areas make the river unique and once were a paradise for fish and wildlife, and their decline may be accelerated by the Lake Michigan Diver- sion Project. Stephen P. Havera, Frank C. Bellrose and other wildlife specialists at the Havana Field Station are investigating what effects the proposed, water-diversion project will have on the surface area, vol- ume, and depth of the backwater lakes. A total surface area of 28,600 hectares (70,670 acres) of bottomland lakes pres- ently occurs in the Illinois River Valley when the river level is at tree line. The Peoria Pool (Peoria to Starved Rock) and LaGrange Pool (LaGrange to Peoria) constitute 85 percent of the area. There is little bottomland area above Starved Rock because of the narrow river valley northward. From Grafton to LaGrange numerous bottomland lakes in the Alton Pool eliminated by drainage and leveeing for agricultural purposes. The volume of the bottomland lakes is approximately 144,000 acre-feet. The av- erage depth of the lakes is currently and despairingly only 0.62 m (2.04 ft), pri- marily because of the high rate of sedi- mentation from soil erosion on agricultural fields. have been The Illinots NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING URBANA, ILLINOIS 61801 The Lake Michigan Diversion Project will sufficiently increase the surface area and volume of the bottomland lakes in the Illinois River Valley to inundate an un- determinable amount of bottomland tim- ber. Water from Lake Michigan currently is being diverted into the Illinois River at 3,200 cubic feet per second (cfs). The proposed diversion project calls for the rate to be increased to either 6,600 or 10,000 cfs, mainly during the customarily low water periods. However, it is estimated on the basis of a U.S. Army Corps of En- gineers’ computer model that even during these periods the extra diversion water will adversely affect the bottomland habitat even if the 6,600 cfs rate is selected. The increased diversion further accelerate the already extreme rates of sedimentation in the bottomland lakes. The higher water level will allow more sediment to settle in the lakes thereby in- creasing the rate of fill. If diversion was then discontinued, the average depth of will the lakes would be less than if no greater diversion was initiated. The proposed increased diversion will ‘have the least impact upon bottomland forests, mudflats, and storage capacity of the bottomland lakes in the Upper Pools of the Illinois River Valley because of the greater rate of fall and lack of bottomland areas in the Upper Pools than down- stream. The Peoria Pool will be affected the greatest by increased diversion because most of the bottomland lakes are con- nected directly with the river. Therefore, any fluctuations in river levels will im- mediately affect the depth, surface area, and volume of the associated bottomland lakes. In the LaGrange and Alton pools, natural and man-made levees protect bot- tomland areas from some of the fluctua- tions in river levels. Hence, although changes in depth, surface area, and vol- ume would occur, the effect of increased diversion on bottomland areas in these pools should be less than in the Peoria Pool. October 1980. N 200, Published monthly except in July and August by the Natural History Survey, a division of the IIlino Institute of Natural Resources operating under the Board of Natural Resources and Conservation Prepared by Dr. George | Godfrey with the collaboration of the Survey staff ‘ id-clas Postage paid at Urbana, Illinois (USPS 258 220) Office of publication: 172 Natural Resources Building, Urbana, l!linois Persons desiring individual or additional copies of this publication please write to CHIEF LLIh NATURAL HISTORY SURVEY Ut ILLINOIS 61801 The Illinots NATURAL HISTORY REPORTS Underwater Home Movies Within the Aquatic Biology Section, a great deal of the research is aimed directly at solving important and urgent problems. Water pollution, fisheries management, weed control, and many other problems re- ceive the constant attention of Survey aquatic biologists. In addition to these efforts, scientists also study aspects of aquatic biology which, at first glance, ap- pear to have much less potential for prac- tical application. This first glance, how- ever, can be deceiving. For example, aquatic biologist Mike Wiley can occasionally be seen standing in the shallow waters of agricultural ditches and small streams around Champaign ad- justing one or more tripod-mounted 8-mm movie cameras. The cameras are used to make underwater time-lapse movies of various aquatic insects and other inverte- brates. The filming may continue for up to OS 3 oma Sind > Time-lapse movie equipment filming aquatic insect behavior in the Middle Fork of the Vermilion River near Flatville. (Photo by Mike Wiley) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. 3 days, as attached strobe lights fire at 10— 30-second intervals, casting a _ strange, bright, pulsing light on stream banks and adjacent fields at night. By carefully ana- lyzing the films, Wiley can examine the many events and behaviors that together constitute the daily lives of these small aquatic animals. Why are state-supported scientists en- gaged in such seemingly peculiar studies? Just as a mechanic who doesn’t under- stand how an engine works cannot do a good job of diagnosing and repairing it, aquatic biologists cannot provide informa- tion and guidance on complex environ- mental issues unless they first understand how aquatic organisms and communities function. By studying the behavior ~of aquatic invertebrates, biologists like Mike Wiley find answers to such basic questions as: How do these animals live? What do they eat? How much food is available? From the answers to these basic questions comes an understanding of what deter- mines the size and distribution of various invertebrate populations. The small in- vertebrates living in our creeks and drains provide the food for many larger insects and minnows, which in turn are eaten by sport fish, such as bass and catfish. Im- proving our management of sport fishes, then, depends upon a fairly sophisticated understanding of the insect populations on which the fishes feed. All of the sections of the Natural History Survey maintain programs in basic as well as applied research. They do so because understanding how nature works is an important prerequisite to working with nature and getting nature to work with us. Even though basic research often appears strangely impractical at first glance, it is important to remember that, like under- water home movies of insects, these studies are often essential to our knowledgeable use of our state’s living natural resources. Poisonous Plants The word “poison” is often used with plants when only the word “caution” is warranted. Quite a number of plants can cause discomfort, pain, or illness, but few are lethal. The three types of injuries caused by plants are internal poisoning, dermatitis, and allergy. Although many kinds of mushrooms are perfectly safe to eat, some are extremely toxic, and only a few bites can kill an adult. Some flowering plants also are potentially dangerous. The most important ones found in the wild in Illinois include pokeweed (Phytolacca americana), poison hemlock (Conium maculatum) , water hemlock (C1- cuta maculata), nightshade (Solanum species), and jimson weed (Datura stra- monium). A few garden plants are also toxic, including yew (Taxus species), lily- of-the-valley (Convallaria majalis) , daphne (Daphne mezereum), the leaf blades of - rhubarb (Rheum rhaponticum) , and castor bean (Ricinus communis). Children, because of their inquisitive nature and tendency to put things in their mouths, are especially apt accidentally to ingest plant materials. The most frequent cause of plant-in- duced irritation of the skin is poison ivy (Rhus radicans, also called Toxicodendron radicans), which is abundant throughout Illinois. A few other plants can cause dermatitis, including poison sumac (Rhus vernix), trumpet creeper (Campsis radi- cans), and some spurges and poinsettia (Euphorbia species). Stinging nettle (Ur- tica dioica) and wood nettle (Laportea cordata) have stinging hairs that cause immediate, intense pain; one or both of these plants are found almost anywhere in Illinois. Some plants cause dermatitis in an indirect manner by making a person hyper- sensitive to light. For example, areas of the skin that come into contact with wild parsnip (Pastinaca sativa) and are then exposed to sunlight can develop symptoms similar to those caused by poison ivy. The situation is different with a number of other plants, where hypersensitivity results only when the plant is eaten; this phenom- enon is not well understood, and fortu- nately, few people are affected. A fairly large number of people suffer from allergic reactions to plants. Certain people are allergic to particular plant foods, such as wheat, flour, beans, toma- toes, chocolate, nuts, corn, and peanuts. “Hay fever” is an allergic reaction to Poison ivy, Rhus radicans. Several other plants have similar leaves, but until you learn to distinguish them, abide by the old adage, ‘Leaflets three, let it be.’’ (Photo by Kenneth R. Robertson) microscopic airborne pollen and _ spores. In Illinois, there are three peak seasons for hay fever. In early spring, much pollen is shed by many common trees, such as ash, birch, elm, maple, oak, poplar, and syca- more. Many of the wild, yard, and crop grasses flower in midsummer, causing an- other peak in the pollen count, but the greatest amount occurs in fall when rag- weed and a few other weeds shed tremen- dous quantities of pollen. A great deal of other interesting infor- mation about plants is included in the recently published Illinois Natural History Survey Circular 55, Observing, Photo- graphing, and Collecting Plants, by Ken- neth R. Robertson. A copy may be ob- tained by writing to the Illinois Natural History Survey, Natural Resources Build- ing, Champaign, Illinois 61820. Serendipitous Entomologist Makes Discovery Serendipity is not one of the abilities which scientists must have to be employed at the Natural History Survey. However, the “gift for finding valuable or agreeable things not sought for,” as Webster defines serendipity, is always welcome. A case in point is that of economic entomologist Robert J. Barney, who in the spring of 1979 was studying the migration of the alfalfa weevil and its predators into and out of alfalfa fields. As a part of this study, Barney placed pitfall traps along the edge of an alfalfa field 2 miles south of Lively Grove, Wash- ington County, and 13-17 meters into a woods of oak with some hickory inter- spersed that bordered the field. The traps were made of galvanized metal guttering cut into l-meter lengths and fitted with end caps. The pitfall traps were set in the ground flush with the soil surface and were half filled with ethylene glycol. Any insects that walked up to the traps would fall into them and be preserved there. The trapped insects were regularly removed and iden- tified. Trapping was begun on May 15. Imag- ine Barney’s surprise on June 13 when he discovered that his traps contained speci- mens of a dung beetle, or tumble bug, that had never before been found in Illinois. The Illinois NATURAL HISTORY SURVES ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 This beetle, Deltochilum gibbosum gib- bosum, was previously known from Florida, Georgia, Alabama, Mississippi, Louisiana, North Carolina, South Carolina, Texas, Tennessee, and southeastern Kentucky. Its discovery in southwestern Illinois extended its known range by over 100 miles. More than 70 percent of the beetles trapped were found between June 13 and July 3. The ratio of females to males was mber 1980, No 20] Pub Hline Institute of Natural d by Robert M Sé nd-cla postage paid at ¢ hampaign Office f publ ition: 172 Natural Resour« s Building shed monthly except i: Resources wadski with the collaboration 2 to 1. These beetles were found in both the field-edge and the woods traps, most being found in the woods. The Natural History Survey is charged with the responsibilities of identifying the insects and other animals of the state and publishing reports on them. Usually these kinds of work are very straightforward ac- tivities. But once in a while even scientists like to enjoy a little serendipity. Ilinois. (USPS 258-220) Persons desiring individual or additional copies of this publication please write to CHIEF LLIt ATURA T Y RVEY LLIt Lt G A Y, CHAMPAIGN, ILLING July and Auqust by the Natural History Survey, a operating under the Board of Natural Resources of the Survey staff Champaign Illinois TITUTE OF NATURAL RESOURCES NATURAL RESOURCES The Illinots NATURAL SURVEY? Aquaculture, Potential New Industry for Illinois Aquaculture, the practice of growing aquatic organisms in freshwater systems, appears feasible, practical and potentially profitable in Illinois. Catfish, trout, carp and prawns are some of the organisms that have been grown successfully in the state. A literature study recently completed by Robert Gordon, INHS, and Randy West- gren, University of Illinois Agricultural Economics, and funded by the Institute of Natural has shown that the technology for aquaculture is now well developed for various culture methods in- cluding raceways, silos, cage and pond cul- ture. Farm ponds, reservoirs, strip mining lakes, cooling lakes and streams are suit- Resources able systems for various types of aqua- culture. Types of organisms, stocking rates, types of feed, growth rates, diseases, environ- mental problems, harvesting methods and marketing problems have been or are now Prawn grown in Illinois (Photo by Homer D. Buck, Aquatic Biologist). HISTORY being studied. These results suggest that good aquaculture businesses may expect profits ranging from $625 to $1,250 per hectare per year when raising catfish which sell for $2.80/lb retail. Profits may vary according to the individual system in use. Small operations are less likely to be profit- able than are larger systems due to various fixed costs. Catfish ponds of 20-acre size with multiple ponds are recommended. Costs for construction, personnel, equip- ment, land, advertising and processing have a direct impact on the success of any operation as do disease and wise aquaculture practices. buildings, Our studies suggest that by good man- agement practices, hard work and _ perse- verance, a farmer can show a profit in aquaculture within a few years under cur- rent conditions. As the number of aqua- culture systems and the markets for aqua- culture products increase, the data suggest that greater profits will be realized in aquaculture in Illinois. In Ilinois ca. 100-200 acres of water are currently known to be used for the culture of commercial catfish. Fishout ponds in use may raise this number to 300 acres. By contrast, Arkansas (12,000) and Missis- sippi (25,000) are the leading states in acreage registered for the production of catfish. The largest population centers in Mississippi range from 40,000 to 260,000 while the populations of St. Louis and Chi- cago are approximately 2 and 7 million people respectively. Thus, the market po- tential for aquaculture products in Illinois far surpasses that of the southern states. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey The more rapid growth of catfish in southern climates may be offset by the in- creased costs of transportation of aquacul- ture products to northern markets. Catfish can be grown to marketable size (1.e., 1.5 lb) in Mississippi in 2 growing seasons while 3 seasons are required in I]linois. Overall the prognosis for aquaculture as a viable branch of agriculture in Illinois is good to encouraging. The technology is available now and is improving. With the initiation of a government program to stimulate the development of aquaculture through the U.S.A., coupled with the potential markets in the regions, there are substantial opportunities for investments in aquaculture in Illinois. Sampling Methods in Soybean Entomology A source book entitled Sampling Methods in Soybean Entomology recently was pub- lished under the co-editorship of Marcos Kogan, Section of Economic Entomology, INHS, and Agricultural Entomology, Uni- versity of Illinois, and D. C. Herzog, De- partment of Entomology and Nematology, University of Florida. It is the first syn- thesis of techniques and study results on sampling arthropod populations for a spe- cific crop. The book is designed to promote quality research on soybean-associated ar- thropods and to help integrated pest man- agement (IPM) _ specialists objectively evaluate local insect problems. However, Kogan points out that it is not a control manual. The dramatic increase in the level of soybean production in Illinois and else- where in the world since the 60’s brought with it a need for more entomological re- search. One program that was created to fill this vacuum is the U.S.D.A.-sponsored “Regional Project S-74: Tactics and Man- agement Systems for Arthropod Pests of Soybean.” The Survey and the University of Illinois participate in the project along with several other institutions. Kogan recognized the need to standard- ize the methods being used to sample the populations of soybean arthropods, espe- cially in the research of determining levels at which insects can cause economic dam- age and in evaluating effectiveness of bio- logical control agents. He proposed the idea to the S-74 participants in 1976, emphasizing the necessity of being able to compare the results of research from one state to another. Kogan and Herzog, as co-editors worked with 30 authors from various state, na- tional, and foreign programs in order to comprehensively cover the subject of soy- bean entomology. Authors from the Survey and the University of [Illinois besides Kogan are C. E. Eastman, C. G. Helm, M. E. Irwin, W. G. Ruesink, and G. P. Waldbauer. Besides emphasizing sampling ~ methods, the book is a compilation of in- formation on the distributions, life histories, and nature of damage of commonly en- countered soybean pests. L. D. Newsom points out in his forwarding comments that the book’s coverage is sufficient to make “control procedures possible for most of the world’s major arthropod pests of soy- beans.” Persons interested in copies of Sampling Methods in Soybean Entomology may order them from the publisher, Springer- Verlag, New York. Migrant Warblers and Illinois Forests The people of the United States, by treaty with Canada and Mexico, have agreed to protect nearly all species of migratory birds. In practice the degree of protection varies from country to country and, in the United States at least, from species to species. For species of waterfowl, food and relatively large areas of habitat are provided the birds during their stay in the U.S.A. While hunting of some water- fowl is allowed, the populations are mea- sured each year, and strict limits are placed on the numbers killed to insure sustaining populations of each species. Protection of migratory non-game birds has been limited mainly to making it illegal to purposely kill them, though many thousands are killed accidentally each year on television towers and other structures. The over-all effect of that mortality is un- known. Potentially more serious is the fact that there are no specific habitat refuges for most non-game species and no restric- tions on habitat destruction. Even more serious is the fact that there have been no systematic measurements of migrant song- bird populations, and, except in a very general way, there is little knowledge of habitat and food requirements or food availability for these species. To find out more precisely how many migrant birds are using Illinois forests, Survey ornithol- ogists Jean and Richard Graber began in 1979 to make daily censuses of migrants in four arboreal habitats: bottomland forest, upland forest, shrub and _forest- edge, and pines. Because many migrants are insectivorous, a concurrent study was initiated on food availability in the same habitats. With 2 years of field work com- pleted, the researchers are now analyzing data on the wood warblers (Parulidae), one of the most numerous and most beauti- ful groups of birds in Illinois. At the peak of spring migration the densities of warblers in bottomland forest were about 5 times the breeding popula- tions. How does the forest accommodate such numbers? The answer appears to be 10.0 toatl 0.50 LARVAE ‘= 200 ave 5.0 0.30 2 = Ni 3.0 mm = i 150 5 0.20 Ss \ 2.0 z= a 3 \\ Ss S re 100 T 0,10 i \ 2 I = ~ il = = = 50 0.01 = S = 0 10 20 30 10 2030 9 19 APRIL MAY JUNE SH) 200 ea eto. VAE 0.3 ao : LARVAE ya NT 3.0 a 2 NO, - =< in 150 ~ 0.20 & - a | S$ Aue tee ve 3 z= = < 100 <= 0.10 - a | Co ==) - — = [ = 50 0.01 & S = = = 0 = 10 20 30 10 2030 9 19 APRIL MAY JUNE Numbers of warblers, numbers of insect larvae (Lepidoptera) and biomass of larvae during 1980 spring migration in upland forest (top graph) and bottomland forest (bottom graph) in southern Illinois. that the migrants coordinate their arrival to the time when insects are most abun- dant. The insect censuses revealed that over 96 percent of the invertebrate bio- mass on forest foliage in spring was larvae (mainly Lepidoptera), and virtually every time the Grabers observed a warbler with food, the food item (prey) was a cater- pillar-like larva. The peak of warbler migration coincided with the peaks of both numbers and bio-mass of insect larvae. A similar matching curve (not shown) was found for all species of arboreal foliage gleaners, except the tiny sylviids (kinglets) which peak early in the larvae season, possibly to catch the earliest (smallest) caterpillars. The population of migrant warblers was more than 3 times greater in bottomland than in upland forest. It is perhaps not surprising then that the peak insect larval population in the upland was twice that of the bottomland forest. Although it is tempting to try and draw conclusions about the effect of the warblers on cater- pillar populations, much more study is needed on such questions as annual varia- tion in all populations, on the warblers’ foraging rates and other activity patterns, on the warblers’ particular choice of prey and the particular availability of that prey, the nutritional value of the prey, etc., before doing so. That work is continuing, but for now the data emphasize the impor- tance of bottomland habitats not only to our nesting species but also to the migrants, coming and going. With conventional agri- cultural methods, it is relatively easy to provide grain for visiting waterfowl, but for most of our transient species there is no other way to meet their requirements than to preserve the natural habitats that sus- tain them. Horse Flies and Deer Flies The tabanids or horse and deer flies are well known to dairy farmers and livestock producers as well as to campers, fishermen and outdoor enthusiasts as annoying and often painful inhabitants of most wooded areas in Illinois. These large and persistent flies impart a painful bite and can occur The Illinois NATURAL HISTORY SURVEY ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 in sufficient numbers to make canoeing and hiking virtually impossible. Tabanids are vectors of several diseases of man and animals caused by viruses, bacteria, rickettsia or rickettsia-like orga- nisms, trypanosomes and filarial worms. Although some diseases transmitted by tab- anids occur in Illinois, only anaplasmosis is a reasonably common occurrence in the spring and fall, but basically is found only in southern Illinois. From 1978-1980, a faunal study of the horse and deer flies of Illinois was carried out by survey entomologist Donald W. Webb with field collecting done by Edward A. Lisowski. The study, which is part of an ongoing faunal study of several groups of flies in Illinois, resulted in the collection of over 15,000 specimens. The collecting program concentrated on the peripheral counties, particularly in the marshes and swamps of southern Illinois; sand marshes of Iroquois County, sphag- num bogs, dunes and marshes of Lake and McHenry counties; and along the [linois River and Mississippi lowlands of western and northwestern Illinois. Since female deer flies readily attack man, specimens were easily caught with an aerial net as they swarmed around the collector’s head. Horse flies which are more mobile and 8) mber 1980, N 202 Published monthly Godfrey with the Tage paia t Cnan OF f pub ' , 17/2 Natural Re burces BUIIGING except | Natural Resource slaboration of the ipaign, Illinois. (USPS Champaign attack man less voraciously than deer flies were collected in Malaise traps (8 x 60 ft piece of insect netting strung across paths and fire lanes). Malaise traps were located at special locales in Pope, Mason and Ogle counties to provide information on the seasonal flight patterns of various species. On the basis of the recently collected material and previous holdings of horse and deer flies in the collection of the Sur- vey’s Section of Faunistic Surveys and- Insect Identification, 86 species and sub- species definitely are found in Illinois. An additional 23 species are known to occur in the surrounding states and have a strong likelihood of occurring in Illinois. A manuscript on the adult tabanids of Illinois has been completed in cooperation with Dr. L. L. Pechuman, Cornell Univer- sity. In addition, Dr. H. Teskey of the Bio- systematic Research Institute, Agriculture Canada, has cooperated in providing de- scriptions, illustrations and keys to the larval of Illinois tabanids. The published bulletin on the horse and deer flies will provide keys to the males and females of each species, as well as to the known larvae, and will give descriptions of their diagnostic emergence periods, distributions and biologies. Stages characters, History Survey o Natural July and August by the Natural operating under the Board of Resources y staff la’ 0) Hlinois Persons desiring individual or additional copies of this publication please write to ATUR { T TITUTE OF NATURAL RESOL The Illinois NATURAL Clear-cutting and Gray Squirrels Before 1960, foresters used single-tree or small-group cutting to harvest trees in the hardwood Such cutting did not seriously affect gray squir- eastern forests. limited rels if less than 50 percent of the merchant- able volume of trees was removed. Since 1960. demonstrated that eastern hardwoods cannot be reproduced research has with satisfactory composition by the use of single-tree harvesting. Instead, clear-cut- ting, which completely removes woody inches diameter at breast height (dbh), has been found to produce stands well stocked with com- stems larger than 2 mercially valuable species. Obviously, complete tree removal will also remove tree-dwelling wildlife, includ- ing gray squirrels. Foresters and wildlife biologists need information regarding the constraints on timber harvesting, such as the size of clear-cuttings, that are necessary to perpetuate wildlife species that are ad- versely affected by the practice. Charles M. Nixon and his co-workers in Ohio have just Survey wildlife biologist completed an 8-year investigation of the effects on gray squirrel populations of clear- cutting mature hardwoods, using clear- cuttings varying in size from 5.7 to 32 acres and in age from 0 to 22 years. On two study areas, gray squirrels were trapped and marked for 2 logging to investigate the influence of these years before clear-cut cuttings on squirrel densities, individual movements, and recovery rates. Four addi- tional small clear-cuttings, 7-9, 15-17 (two areas), and 20-22 years old, were used to Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey HISTORY REPORTS | determine squirrel presence and squirrel food production up to 22 years after log- ging. They found that captures of gray squir- rels declined 51.5 percent and estimated densities declined 44 percent in the first year following the clear-cutting of 32 acres of the best hardwoods within a 206-acre study area. Recovery rates for marked adult gray squirrels whose home ranges in- cluded the clear-cutting were lower than rates for adults not exposed to clear-cut- ting. Fewer than 20 percent of the adult squirrels known to be living adjacent to the clear-cut area were captured within the cut area in the first 2 years after cutting. In a companion study of two smaller, (9.4 19.5 acres) on a 188-acre stand of hardwoods, narrower clear-cuttings and no significant changes in squirrel densities, recovery rates, breeding rates, movements, or body weights were observed after clear- cutting. The recovery rate for adult fe- males was significantly higher on this area compared with that of females on the area with the 32-acre cutting. On these cuttings and the older ones studied (7, 15, and 22 years old , squirrels ventured significantly farther into a clear- cutting during winter than after leaves appeared. Clear-cuttings less than 22 years old contained less food for squirrels than did uncut forests. Thus, gray squirrels using cuttings less than 22 years old were considered to be transients, but they did forage significantly farther into 15- and 20-year-old clear-cuttings than into the 7- year cutting. A recent clear-cutting of hardwoods in the Midwest. All woody stems greater than 2 inches in diameter are cut to allow rapid growth of new seedlings and stump sprouts. At least two characteristics may render 1- and 2-year-old clear-cuttings unaccept- able habitat for foraging gray squirrels. First, logging residues and the luxuriant growth of annual forbs restrict the squir- rels’ ability to detect predators. Even in winter squirrels in clear-cuttings traveled mostly on downed tree limbs, rarely ven- turing to the ground. A second reason why squirrels may avoid a recent clear-cutting is the lack of staple foods. No winter-storable foods were pro- duced until 15 years after cutting. Squirrel foods were particularly scarce during the first two growing seasons, when only fungi, flowering dogwood drupes, and grapes were produced in quantity. It was apparent from these studies that large (more than 30 acres) clear-cuttings must be avoided if wildlife species that prefer mature hardwood habitats are to survive. Therefore, in considering a size limita- tion on clear-cuttings, the home range of the adult female gray squirrel was used as a guide toward minimizing the effects of clear-cutting on this species. A mean home range of 5.2 acres was found for adult females livetrapped on three study areas in southeastern Ohio a minimum of eight times during 2 or more years (N = 51). ‘The diameter of a circle encompassing an area of this size is about 530 feet. Clear- cuttings kept narrower than this distance should allow most squirrels to retain some portion of their original home range and should enhance their chances to tolerate. the logging operation. The length of narrow clear-cuttings will be determined by site-class differences, topography, logging constraints, or con- flicts with travel and stream protection zones. If cutting units exceed 20 acres, the wildlife biologists recommend retention of uncut travel lanes of mature trees, 50-100 yards wide, to permit squirrels and other wildlife to cross clear-cuttings. These travel lanes would be required for about 30 years after cutting to allow trees within clear- reach seed-producing age. Travel lanes should be cut selectively, us- ing single-tree or small-group cuttings to perpetuate a stand capable of producing at least 100 pounds of winter-storable food per acre. Recommendations for the amount of shelter necessary to maintain huntable numbers of gray squirrels are not docu- mented, but in Illinois, gray squirrels were not present in stands three tree cavities per acre. Because of extensive cutting between 1890 and 1935 in the eastern hardwoods, most stands are now approaching commer- cial maturity. Foresters and wildlife man- agers thus have an opportunity — one that will not occur again for a whole timber cuttings to with fewer than rotation (80-120 years) —to begin ad- justing timber age-classes in most forests. Yields of both timber and gray squirrels can be maintained through long-term plan- ning of cuttings over large units of forest. Use of small (less than 20 acres), (less than 530 feet), carefully located clear- cuttings in forests where 40-60 percent of the stands are retained in a seed-producing age should not materially reduce gray squirrel populations. narrow Cutting-Rot Susceptibility The propagation of softwood cuttings is an important method for producing many landscape tree and shrub species. A mist propagation technique involves the me- chanical spraying of water over leafy cut- tings to maintain a thin film of water on the plant tissues. The high humidity pro- moted by mist, and its cooling effect on plant foliage, allows the propagator to ex- pose cuttings to full sunlight without fear of leaf wilt. During the mist propagation phase, softwood cuttings are especially sus- ceptible to attack by fungal pathogens. Pythium, Phytophthora, and Rhizoctonia are three genera of pathogens often impli- cated in the cutting-rot problem. Economic losses from pathogen attack during propagation can be considerable, since thousands of adjacent cuttings may be involved. More serious is the problem of diseased rooted cuttings being transferred to the field with latent infections. These plants are likely to decline or die when later exposed to such stresses as transport- ing shock, poor drainage, or unfavorable weather. Very little research has focused on pathogen-host species interactions dur- ing propagation. Mary Ann Smith and Dan Neely, Survey plant pathologists, have completed a study that evaluated the dis- ease reaction of 16 woody host plants to the three pathogens. Results of the screening tests indicated that plant species had markedly different levels of susceptibility to the three cutting- rot pathogens. In 40 percent of the com- binations, severe cutting rot developed. In 15 percent of the combinations the plants exhibited no disease symptoms. In many of the combinations the plant survived in- fections by producing a well developed root system above a basal rot lesion. As shown in the table, smoke tree, deutzia, buckthorn, and sumac were highly susceptible to all three pathogens. Only privet exhibited low susceptibility to all of the pathogens. This research established the ability of fungal isolates from three genera to cause disease on 16 woody plant species. The patterns of development of basal rot, root rot, foliar necrosis, and defoliation were defined. This information will be helpful to propagators and nurserymen in diagnos- ing and treating the disease problems en- countered with mist bed operations. Relative susceptibility of cuttings to inoculation with three genera of fungal pathogens. Cutting Rhizoctonia Phytophthora Pythium Red ozier dogwood High Low Low Smoke tree High High High Cotoneaster Moderate High Low Deutzia High High High Winged evonymus Moderate Low Moderate Forsythia Low Moderate Moderate English ivy Moderate Moderate Low Privet Low Low Low Honeysuckle Moderate Low Low Star magnolia High High Moderate Bayberry High High Low Buckthorn High High High Jetbead Moderate High High Sumac High High High Alpine currant Moderate High Moderate Dwarf cranberry Moderate Low Moderate The Illinows NATURAL HISTORY SURVEY ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 Survey Scientist Participates In International Exchange International exchange of information has become increasingly important in aquatic biology, as foreign fishes, such as the Chinese carps and Nile perch, are brought to this country with little under- standing of the impact they may have on our natural ecosystems. As an example of attempts to extend international contacts with biologists, R. Weldon Larimore of the Survey’s Aquatic Biology Section has recently participated in a Fulbright lecture- ship at the University of Nis, Yugoslavia, where he delivered a series of lectures and worked with a group of graduate engineers on the effects of impounding a small stream in northeastern Yugoslavia. Ex- pected changes in water quality and in the biological communities above, below, and within the impoundment were considered. Larimore and his group formulated a long- range plan for the development of the sport fishery in this area that is intensively used by Yugoslavs for rest and recreation. On his way to Yugoslavia, Larimore spent several days with biologists at the Fishery Research Station, Szarvas, Hun- gary. Scientists at this station are doing January 198] Ne 203 Published advanced work in fish culture, fish genetics, and the use of animal wastes in fish pro- duction. Their work on the grass carp and ‘its hybrids has been of particular interest to American biologists because of the po- tential of this fish for controlling aquatic weeds in this country. Survey aquatic biologists Homer Buck and David Philipp have cooperated with the Hungarian biolo- gists on this work and were pleased to have new information gathered personally by- Larimore. Larimore also visited the Hun- garian Institute of Limnology and dis- cussed with scientists their studies of ex- ploitation of lake fishes and the potential for further commercial production. In western Yugoslavia, Larimore visited several large fish farms and led a discussion at the University of Zagreb concerning environmental laws and their economic impacts in eastern Europe and America. Larimore’s visit to eastern Europe has stimulated further activities between for- eign and Natural History Survey sctentists. Not only are Survey biologists in closer contact with the foreign projects, but in the near future two biologists from Yugo- slavia and one from Hungary will come to Illinois to exchange ideas with Survey scientists. monthly except July and August by the Natural History Survey, oa division of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources ana Conservation Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 2 220) Office of publication: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to CHIEF, ILLINOIS NATURAL HISTORY RVEY TITUTE F NATURAL RESOURCES, NATURAL RESOURCES BUILDING 507 F PEABODY. CHAM The Illinots NATURAL — Caddisfly Egg Toxicity Bioassay What are the effects of insecticide and herbicide runoff from farm fields in Illinois on the embryological development of aquatic insects? To answer this question Illinois Natural History Survey biologists David Belluck and John Unzicker along with University of Illinois graduate Bar- bara Pennington selected the pond dwell- ing caddisfly Triaenodes tardus Milne (Trichoptera: Leptoceridae) as a repre- sentative aquatic insect. A new toxicologi- cal test, the caddisfly egg toxicity bioassay which used the eggs of 7. tardus, was de- veloped to study the effects of pesticides on the egg development of this common IIli- nois caddisfly. I. tardus is widely distributed in North Egg mass of the caddisfly, Triaenodes tardus, used for toxicological bioassay research. HISTORY America. It is transcontinental in Canada and the northern United States and ex- tends north into Alaska. In the central and southern United States it occurs from the east coast west to the Rocky Mountains. The aquatic stages are found in lakes, ponds, marshes and in areas of slow cur- rent and in medium to large rivers where they are always associated with vascular plants from which they construct a case of spirally arranged leaf fragments. During the summers of 1979 and 1980, 40 pesticides were screened for ovicidal activity using the caddisfly egg toxicity bio- assay. ‘lo obtain eggs for this test, gravid females of T. tardus were attracted to an ultraviolet light trap set up within 90 min. of darkness at the Illinois Natural History Survey research ponds. Females were cap- tured with an aspirator and transported to the laboratory where their extruded egg masses were removed with a forceps and placed in a cup of filtered pond water. Egg masses were then placed in prepared solu- tions of pesticides and stored on shelves at a constant temperature of approximately 26°C. An experiment was terminated with the successful hatch or death of the last egg in the egg mass (usually between 2 to 3 weeks after oviposition ) . Analysis of the toxic effects of selected insecticides and herbicides on the egg de- velopment of the caddisfly T. tardus indi- cates that these animals are very sensitive to the presence of pesticides in solution. Toxicity levels varied within and between different classes of insecticides and herbi- cides. Herbicides were found to be toxic to Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. eggs of T. tardus from 1.26 parts per mil- lion to 114.30 parts per trillion, and in- secticides were toxic from 2.90 parts per million to less than 10 parts per trillion. While it is difficult to accurately predict the toxic effects of pesticides to organisms in the field from laboratory derived data, tests such as the caddisfly egg toxicity bio- assay attempt to bridge such gaps. Labo- ratory exposure of field-captured aquatic insect eggs to toxicants can show the po- tential effects of a particular chemical upon those organisms if the chemical was to be applied in the field. Additionally, the low cost and simplicity of the caddisfly egg toxicity bioassay permits organizations with limited budgets and/or staff expertise to conduct toxicity tests on a local basis. Migratory Peregrine Falcons Survey biologists William W. Cochran and Arlo Raim conducted studies of migra- tory peregrine falcons in the spring and fall of 1979. Transient migrants, moni- tored with miniature radio transmitters, spent up to one month in southern Texas (Brownsville area) before continuing their spring migration. During an 8-day winter survey in southern Texas, only one pere- grine was sighted. By contrast, in the April study no fewer than 4 and an average of 7 peregrines were sighted per day over the l-month period. The spring/winter ratio of sightings (56:1) supports the view that the 15-bird spring sample was of transients. The northward headings from southern Texas raised some questions as to the win- tering areas of the observed peregrines be- cause there is relatively little land directly south of Brownsville. Migrant peregrines reaching southern ‘Texas from South America and most of Central America would have to travel considerably north- west, not north. Thus, it may be concluded that a migratory direction change takes place for some peregrines after they reach southern ‘Texas, based on the census data showing only few winter residents of the area. Banding and visual data verify a sig- nificant “turn” in migration for only a few bird species. One example is the whistling swan, which heads NNW from its Chesapeake Bay wintering site to favor- able feeding areas in the Ontario-Michigan (Detroit) region where it spends several weeks. It then departs almost straight west for the Dakotas where it remains for several more weeks before again switching direction significantly to the NNW. For the swan it can be shown that the stops occur where shallow-water habitat is favorable for feeding. Peregrines can prob- ably do well enough anywhere they can find prey species. However, the southern Texas area, and especially the barrier is- lands, have considerably more prey than the comparatively barren areas of western Texas and northeastern New Mexico, .which northwest-bound peregrines would reach if they continued on the course that brought them to southern Texas. Thus, it is a good place to make a turn to the north where prey is available. However, it is not known why the peregrines layover in southern Texas until May. Perhaps the turn is not a “behavioral” change in the “method or cues” for orientation. If the cues are celestial, they must be given time to change. For example, during April the sunset direction is moving quite rapidly clockwise to the north. From April 4 to April 27 this change amounts to 11 degrees, which is in the needed direction but only one-half to one-third the change that the peregrines must make if all the turn is made during this interval and in southern Texas. The fall studies, based on a sample of 10, showed that transient peregrines trapped on Assateague Island continued their magration in a variety of directions from SE to SSW. There is also weak evi- dence that many of these migrants spend up to 2 or perhaps 3 weeks along the coast before proceeding. One of the study birds spent at least 10 days on Assateague be- fore heading south. It is known from band- return information that peregrines reach Assateague from directions ranging from NW to NNE. This virtually precludes any solid comment based on a small sample. Alfalfa Weevil Migration The alfalfa weevil has been the most common and destructive pest of alfalfa in Illinois for nearly two decades. The dam- age is done primarily by the larvae feed- ing on the tender growing tips of the alfalfa plant for three or four weeks in the spring. When the larvae are fully grown they spin silken cocoons on the plants or in the ground litter and pupate. The pupae transform into adults in one or two weeks which, after feeding briefly in the spring, migrate to protected areas (par- ticularly wooded areas) in the vicinity of the alfalfa fields where they enter a resting period called aestivation. In Illinois, most of the adults will return to the alfalfa fields in late summer and early fall. For the past several years, two Survey entomologists, Robert D. Pausch and Ste- phen J. Roberts have been studying the movement of adult alfalfa weevils in and out of alfalfa fields in Washington County in southern Illinois. The studies have re- sulted in a better understanding of this pest of alfalfa and have produced a new concept of pesticide usage. Pausch and Roberts have shown that the migration of the adult weevil into alfalfa fields after leaving their sites of aestivation is first a gradual movement across the soil surface. Flight occurs only after the weevils have been in the field for a considerable length of time and have been able to restore their depleted energy resources by feeding. Be- cause of the delayed flight activity, the ma- jority of the weevil population is concen- trated in a relatively narrow band at the edge of the alfalfa fields and is in a rela- tively immobile state. These conditions argue well for controlling the fall adult weevil population with insecticides. Pausch and Roberts currently have re- search underway to more fully investigate various ways of controlling the alfalfa wee- vil with a fall, adult-control program. Pre- liminary tests in the development of this new concept have been encouraging. Two fields of approximately the same size and with approximately the same size popula- tions of alfalfa weevils were used to test the idea. A 60 ft-wide perimeter band of one field was sprayed with an insecticide at a time when the Survey researchers esti- mated that the majority of the weevil pop- ulation was contained within the band. Study area of alfalfa weevil migration and control in southern Illinois. The second field was left unsprayed and served as a control. Both fields were moni- tored very closely the following spring to follow the development of the weevil lar- vae. In the unsprayed control field, the weevil population developed to the point where the field had to be sprayed for the larvae or else the entire first cutting would have been lost. The larval population in the sprayed test field remained low, and an excellent first cutting of alfalfa was made without applying any additional insecticide. It must be pointed out that although the first trial of this new concept of alfalfa weevil control was encouraging, more re- search needs to be done. To this end, en- tomologists Pausch and Roberts have ex- panded the scope of their research and will be studying the effectiveness of different application rates of selected insecticides, band widths, and timing of application in various areas of the state. Aquatic Biology Training Programs Many on-the-job training experiences are available for college students in the Survey’s Section of Aquatic Biology. These experiences are in field and laboratory work involving fish, aquatic insects, plank- ton, bacteria and habitat analysis. The training programs usually include a variety of technical tasks so the students receive broad exposure to work in the aquatic sciences. Students from several universities and The Illinois NATURAL HISTORY SURVEY ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 colleges have taken advantage of the train- ing opportunities. Some have used their experiences toward requirements for a col- lege degree; others simply to prepare them- selves for a job by applying their college ‘book learning’ to real world problems. From the University of Illinois, graduate and undergraduate students have crossed the Urbana campus to take part in Survey aquatic research. Many have prepared theses under the guidance of Survey sci- entists. More students in recent years have come from Eastern Illinois University than from any other school. In 1972, Dr. Leonard Durham, Director of Life Sci- ences at EIU, established an active En- vironmental Biology Program and the fol- lowing year included in it a requirement that each student must serve a 12-week internship in a professional environmental institution. EIU students have interned in many parts of the country and in many kinds of work with governmental and business agencies. Since the program was ‘begun at EIU 8 years ago, 310 students have taken part in the training opportuni- ties and 124 of these have been associated with the Survey. Many other schools in Illinois and in other states now have simi- lar programs for their students and are sending their interns to work at the Survey. Students are given some financial aid _ for their work at the Survey, but the major benefit, besides the small salary and col- lege credits, is the improved eligibility for employment. Even a few months of profes- sional association in biology make the stu- dent much more attractive to an employer who expects that his/her staff can face and solve present day problems. Interns from the Survey program have enjoyed spectacular job opportunities in many areas of environmental biology. February 1981, No. 204, Published monthly except in July and August by the Natural History Survey, a divisior f the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conservation Prepared by Dr. George L. Godfrey with the collaboraticn of the Survey staff Second iss postage paid at Urbana, Illinois. (USPS 258-220) Office publication: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to CHIEF, ILLING NATURAL HISTORY SURVEY, ILLINOIS INSTITUTE OF NATURAL RESOURCES, NATURAL RESOURCES BUILDING, é E PEABODY, CHAMPAIGN LLINOIS 6182 The Illinors NATURAL HISTORY REPORTS Radar Studies of Bird Migration For every bird which regards Illinois as its home, several others pass through this centrally located region on their way to breeding grounds. However, modern land- use practices seem to be reducing the habi- tats available to birds which depend upon Illinois for resting areas on their annual flights. The bottomland lakes of the Illinois River, once a prime resting and feeding habitat for ducks and other water birds, are being filled with silt eroded off agri- cultural fields (INHS Reports No. 200). While the land area of Illinois is certainly large, suitable habitats for many species of migrant birds are steadily disappearing, as woodlots, hedgerows, and riverbank forests give way to man’s use of the land. Recent investigations by Richard Graber and Jean Graber of the Wildlife Research Section (INHS Reports No. 202) that peak periods of migration may result in a suggest “no-vacancy” situation in which small birds occupy almost all of the available forest habitat during their stopovers. Because most species of migrating birds (the others we see in the daytime constitute the fly at night hawks, swallows, and exceptions rather than the rule), the time- tested methods of the field biologist do not Common nocturnal migrants through Illinois, thrushes of the genus Catharus have been the subject of radio-tracking studies at the Illinois Natural History Survey. The distinc- tive thrush wing pattern may be useful in identifying them in migra- tory flight with radar and the track- ing telescope. (Photograph by R. R. Graber) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. give the full picture of avian migration. A bird seeking a hospitable place to come_ down often does so in the dark hours be- fore dawn, out of reach of the sharp eyes of the field investigator. Thus, researchers have turned to less di- rect methods to document the behavior of migrating birds. Chief among these is radar; even small birds can be electron- ically followed through the night in this way, almost certainly without their know- ing that they are being tracked. In 1981 Ronald Larkin of the Wildlife Research Section will begin studies in Illinois using a radar unit which has been specially modi- fied for use by biologists. Some of the most basic questions about bird migration remain open, including how birds navigate from wintering to breeding grounds and back, distances often measur- ing thousands of miles. Other puzzles in- clude social relations and flocking during migration — birds migrating at night are usually detected flying alone yet are often seen in flocks on stopovers. Much of its potential for helping to answer questions like these is presently lost because radar gives almost no informa- tion on the kind of bird which is being followed. Only its general size and flight speed give clues as to the species. In a new attempt to overcome this limitation, Larkin is testing a tracking telescope and spotlight used in conjunction with radar, for the first time giving the investigator a look at the animal under study. This effort prom- ises to pay large dividends in our basic un- derstanding of bird migration. The possibility that birds flying over Illinois may have difficulty finding grounds for resting and feeding is also the subject of radar investigations. Using the ability of radar to reach out over thousands of yards and track an individual bird, the re- searcher can study birds that are descend- ing at the end of a night’s migration and selecting a place to spend the day. Radar can also be used to count birds coming into an isolated woodlot, in order to assess the size of periodic influxes of migrants into shrinking patches of habitat. Surprising Benefits Possible from Nonchemical Alfalfa Weevil Controls During the past few decades several bio- logical and cultural methods of agricultural insect pest control have been conceived. However, farmers have relied heavily on the use of synthetic chemical pesticides, largely because they achieve satisfactory control at relatively low cost. Unfortu- nately, the extensive use of synthetic or- ganic pesticides has had detrimental effects on the environment. Luis Zavaleta and William Ruesink, Sur- vey economic entomologists, have investi- gated the potential benefits that might arise from the use of biological controls as well as from the introduction of a host plant with added resistance to the alfalfa weevil (Hypera postica). This insect is one of the more important insect pests of alfalfa and can cause significant losses in yield or even the death of the crop. Their study used computerized models previously developed for the alfalfa crop and for the alfalfa weevil. The dynamic computer model of the alfalfa crop mim- icked the daily time path of state vari- ables, such as the biomass of leaves, stems, buds, and total nonstructural carbohy- drates as a function of environmental con- ditions. The model simulated other condi- tions, such as the harvesting of the crop, its regrowth, and new material generated by photosynthesis. The rates of flow be- tween components and the rate of photo- synthesis were modeled as functions of light intensity, day lengths, temperatures, and the values of the state variables. The model assumed adequate moisture, high levels of fertility, and the absence of pest problems other than the alfalfa weevil. Dynamic computer models of the life cycles of the alfalfa weevil and the parasite (Bathy- plectes curculionis, a small parasitic wasp which lays eggs inside weevil larvae) were also established. Both models, the alfalfa plant growth and the insect component, were interfaced through the feeding process. The potential rate of feeding by the weevil was modeled as proportional to the average develop- mental rate per life stage, but this rate a “then media dic —. varied from day to day with temperature variations. The interaction between the parasite and the weevil larvae was modeled through the process denoted attack. Through this process, a certain percentage of the larval population in the second stage was parasitized and remained so during the third and fourth stages, dying during the latter. The beneficial effects of the parasite were obtained through an induced reduc- tion of feeding rates for the larval stages of the weevil and through an increase in its mortality rate. For this analysis, records of 10 years were used for each of four weather sta- tions, selected as representative of major alfalfa growing regions in the eastern United States: Ithaca, New York; Bed- ford, Virginia; Rochester, Minnesota; and Nashville, Illinois. For the period of analy- sis, daily maximum and minimum temper- atures and solar radiation were required. The model was given its initial values and set in motion as of September 1, be- cause at that time most alfalfa weevils are diapausing adults. In the simulation runs for each locality, the initial weevil density was set at ten per square meter, typical of a moderately heavy infestation. In those cases where parasites were included, their initial density was set at two per square meter, a rather low population level for that species. These initial conditions were used in the simulation models to provide results that may be considered conserva- tive. Finally, the model recorded an insecti- cide application whenever the density of third and fourth instar weevil larvae ex- ceeded 400 per square meter, correspond- ing approximately to the economic injury level recommended in Illinois. Changes in yield, insecticide use, and their monetary values were computed by comparing 10-year averages for a norma- tive bench-mark solution, the application of chemicals, to averages obtained for dif- ferent elements integrated in pest man- agement methods. The results thus ob- tained were used to measure the benefits that might be derived from integrating (a) biological and chemical controls and (b) biological, cultural, and chemical practices. The alfalfa significant losses in yield or even the death of the crop. (Photograph by J. S. Ayars) weevil (Hypera postica) can cause The researchers found that the inte- grated approach improved yields by re- ducing the damage, compared with those values reached by chemical control only, and it also reduced the amount of insecti- cide required. When the data were evaluated for the eastern United States, they suggested that the parasite could save about $44 million per year as compared with the bench-mark case. This predicted increase in production represents less than | percent of the total crop, and it would not be expected to in- fluence the market price for alfalfa hay. In addition, this approach could account for a great reduction in pesticide use. About 1,100 fewer tons per year of insecticide would be necessary than when only chemi- cal control is employed. This reduction in pesticide input to the environment deserves attention far beyond its economic value, Zavaleta and Ruesink point out. Another method of pest management is the use of cultural practices. These prac- tices may involve, among others, adjusting the date of harvest and introducing plants that are genetically resistant to the weevil. Presently, however, no commercially avail- able alfalfa varieties have resistance to the alfalfa weevil. Zavaleta’s and Ruesink’s analysis was performed to quantify the value of resistance, and the results should provide plant breeders with the incentive The Illinois NATURAL HISTORY SURVEY ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 to develop varieties with even a small amount of resistance. The type of resistance considered here is known as antibiosis, in which some char- acteristic of the plant causes a reduction in the survival of the pest population. Specifically, 20-, 40-, 60-, and 100-percent additional mortality levels were evaluated. The use of a truly resistant plant — one on which the pest can not (or will not) live, represented here by the 100-percent added mortality case— would increase average yields to a total value of $89 mil- lion per year. At the same time, insecticide use would be reduced to zero. If breeders achieved only 60-percent added larval mortality, insecticide use still would decline to zero, but a small amount of damage to alfalfa would continue to occur. Under these conditions the dam- age is too slight to justify the expense of insecticide application. Thus, 60-percent added mortality would be nearly as bene- ficial as 100 percent. If 40-percent added mortality were at- ‘tained, the value of production would increase by $61 million per year, and in- secticide use would decrease by 3,743 tons annually. In this case, some insecticide would still be used in the Midwest, but the use rate would be 85 percent below the present rate. East of the Allegheny Moun- tains, because of differences in the eastern” and western weevil populations, no in- secticide would be needed. Finally, if only 20-percent mortality were added to the first larval instar, the value of production in the eastern United States could be increased by $30 million per year, and annual insecticide use could decrease by 2,260 tons. Although these figures are far inferior to those of the 40-percent case, producers and environmentalists would welcome this dramatic improvement. rvation Persons desiring individual or additional copies of this publication please write to The Illinots NATURAL HISTORY REPORTS Paul G. Risser, Appointed Chief of the Survey Dr. Paul G. Risser has been appointed Chief of the Natural History Survey by the Board of Natural Resources and Conserva- tion. He currently is Chairman of the De- partment of Botany and Microbiology, University of Oklahoma. Risser officially will assume his new administrative responsi- bilities on June 1, 1981, and will succeed Dr. George Sprugel, Jr., who retired on August 30 last year. During the interim, Dr. Wallace E. LaBerge has served as Act- ing Chief. Risser’s selection by the Board followed a thorough screening process by the Staff Search Committee that examined and in- terviewed qualified applicants from the USA and Canada (see October 1980 issue of Natural History Survey Reports). ‘The formal announcement was made by Di- rector Frank Beal of the Illinois Institute of Natural Board’s chairman. Resources who serves as the The new Chief will bring to the Survey an immense wealth of administrative ex- perience and proven leadership in the areas of environmental research and survey re- lated activities. Prior to the appointment as chairman of his department at the Uni- versity of Oklahoma in 1978, Risser served as Program Director of Ecosystem Studies for the National Science Foundation, Di- rector of the Oklahoma Biological Survey, and Assistant Director of the Oklahoma Biological Station. One of his colleagues remarked that he brought national recog- nition to the Oklahoma Biological Survey Material in this publication may be reprinted if credit is given to Dr. Paul G. Risser, new Survey Chief. (Photo by Les Woodrum, Survey Photographer) by turning it into a viable program for the State of Oklahoma. As a leader in environmental biology and plant ecology he has participated on various national and international com- mittees and delegations. His national asso- the National Science Foundation, Smithsonian Institu- ciations have been with tion, Interagency Federal Committee on Ecological Reserves, and the U.S. Fish and Wildlife been involved with the International Bio- Service. Internationally he has logical Program, a U.S. delegation to the Soviet Union for discussions of biosphere the Illinois Natural History Survey reserves and ecosystem analyses; and vari- ous meetings in France and Switzerland under the auspices of UNESCO, UNEP, and IUCN. Risser is a graduate of the University of Wisconsin where he was awarded a PhD in Botany in 1967. His productive scientific career as a plant ecologist has centered on the analysis of plant communities and the assessment of environmental changes on plant ecoystems. As Chief of the Survey he is planning to maintain an active re- search program in addition to administer- ing the diverse programs of the Survey. This will take considerable effort but as one observer noted, Risser has a great capacity for organization and work. Risser applied for the position of Chief because of the highly regarded national reputation of the Survey and its programs. He considers the Survey to be the finest institution of its type and welcomes the association with it and its high quality re- search endeavors which, he stated, coincide with his own scientific and intellectual interests. The staff of the Survey is very sup- portive of Risser’s appointment as Chief and is anticipating a productive and stimu- lating association with him. Clams of the Vermilion River System The freshwater mussel (clam) fauna in eastern North America is the richest in the world; approximately half of the aot known species of freshwater mussels occur in this defined geographical region. The quantity of mussels found in rivers from Wisconsin to Alabama is equalled almost nowhere else in the world. Mussels are a unique source of commer- cial and aesthetic value. Their shells are used as the basic raw material in the pro- duction of cultured pearls in Japan. Several species are very sensitive to changes in water quality and serve as valuable indicators of environmental changes. In Illinois, a variety of aquatic habitats support a diverse and abundant mussel fauna. However, recent surveys indicate that serious depletions of both numbers of individuals and species of mussels are oc- curring in Illinois. John Suloway, a mem- ber of the Section of Aquatic Biology, and Liane Suloway, a member of the Section of Faunistic Surveys and Insect Identifica- tion, have been contracted by the Illinois Department of Conservation to determine the status of mussels in the Vermilion River system (Wabash River basin) in eastern Illinois. The major objectives of the study are (1) to determine the number of individuals and number of species of mussels at ap- proximately 30 sites in the Vermilion River system, (2) to compare this data with his- torical information, (3) to correlate the changes in mussel communities with changes in substrate and water quality, and (4) to aid the Department of Conserva- Quadrula cylindrica, also called the rabbit's foot, a rare mussel (clam) found in the Vermilion River in eastern Illinois. (Photo by Les Wood- rum, Survey Photographer) tion in the establishment of criteria for natural areas in I[Ilinois. Twenty-two species of mussels were col- lected in 1980. The North Fork at present supports the highest densities and diversi- ties of mussels in the Vermilion River sys- tem. Several species collected in 1980 are uncommon in Illinois, and at least two of these species, Obovaria subrotunda and Quadrula cylindrica, are restricted to the Ohio River basin in Illinois. Quadrula cy- lindrica is considered rare and endangered in the U.S.A. by some experts. Thirty-two species of mussels have been found in the Vermilion River system since the turn of the century. Between 1960 and 1980, the number of species collected de- clined from 25 to 22 with a concurrent 61 percent reduction in number of individuals collected. This investigation will be completed by July 1, 1981. During the spring of 1981, collections will be made at approximately six additional stations. The entire data base of chemical, physical and _ biological results will be analyzed and synthesized in the final report to the Department of Con- servation. Aphid Nose Knows Did you ever wonder exactly how those aphids managed to find your favorite rose bush or get into your house and find that prized plant and what that might have to do with an aphid’s “‘nose”’? Most aphids are rather fussy feeders and to accommodate this fussiness they have evolved some complex behavior and de- velopmental patterns. Let’s look at the common aphid on rose, Macrosiphum rosae. ‘Vhat rose bush in your front yard was completely free of aphids after you sprayed it last year but by mid-June of this year it will be covered with aphids again. Where did they come from and how did they get to your rose? They came from another, perhaps distant, rose somewhere. During the winter months this species sur- vives as eggs laid on the stems of rose bushes. The hatch will be from early April in southern Illinois to late April in the Apterous viviparae (wingless adults that give birth to live nymphs) and nymphs of the rose aphid, Macrosiphum rosae, on cultivated rose. (Photo by David Voegtlin, Assistant Taxonomist) northern part of the state. This genera- tion, called the fundatrices, will mature in about two weeks and almost immediately will begin giving birth to live aphids which will grow and reach maturity in another two weeks. These generations are wingless and confined to the host plant. It doesn’t take long for the original rose plant to become very crowded, especially after two or three generations. Crowding does in- teresting things to aphids and _ plants. Under heavy feeding pressure from the aphids, the plant may become very weak- ened, wilt and die. The aphids can sense this, possibly through the quality of the sap they are sucking from the plant, and they can also detect their crowded living condi- tions. In response to one or both of these stimuli the next generation develops wings. When the winged forms are fully de- veloped, other roses become fair game. These winged aphids leave their crowded, dying home, fly up and are carried away by the wind. They will continue to fly until some physiological demand is satisfied and then toward the ground. The amount of time spent in the will slowly descend air will vary from less than an hour to an entire day. With a moderate wind speed a considerable distance may be covered. As the aphids near the ground they will have a variety of plants to land on. They may in fact have landed in the middle of a The Illinois NATURAI ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 HISTORY SURVEY square mile of corn or soybeans, and our fussy rose aphid absolutely refuses to feed on these plants. How does it know they aren’t roses. The nose — we finally got back to the nose — will tell them. : Aphids can’t see very well, and although they are quite good at colors they seem to rely on close-up taste tests for final judg- ment. After landing from an extended flight, the aphid will place its rostrum (nose) against the plant surface, and from this rostrum tiny stylets will probe the April 1981. No, 206 plant and taste it. There are sensors on the tip of the rostrum and quite possibly some associated with the stylets. Positive or nega- ‘tive stimuli will trigger further responses. If there are negative stimuli our aphid will launch itself again and again until it finds a rose. There is usually a tremendous mor- tality to aphids during this time, but there are always a few who happen to find the preferred host, your rose bush, well fertil- ized, with swollen flower buds and a veri-. table aphid feast. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Dr, George lL. Godfrey with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to CHIEF, ILLINOIS NATURAL HISTORY BUILDING, 607 E, PEABODY SURVEY, CHAMPAIGN, ILLINOIS 6] ILLINOIS INSTITUTE OF NATURAL RESOURCES, NATURAL RESOURCES The Illinozs Pheasant Nest Habitat Along Rural Roads From 1962 to 1977 changes in agricul- tural land use in Illinois pheasant range resulted in the loss of approximately 54 percent (2.4 million acres) of the hay and small-grain acreages and 45 percent (1.8 million acres) of uncultivated farmland to row-crop production. In addition, during this period approximately 2 million acres of farmland were converted to nonagri- cultural uses in the counties that sustain self-maintaining populations of pheasants — the northern two-thirds of Illinois. The loss of habitat for reproduction and the clean farming practices associated with row-crop production have been almost cataclysmic developments for pheasants and native ground-nesting wildlife. Wildlife biologist Richard E. Warner has been evaluating roadside management by the Department of Conservation (DOC) in east-central Illinois as a program that may in part mitigate the loss of nest habi- tat. The Ford County Management Unit (FCMU) was established in 1968; 61 of HEN PHEASANTS PER SQUARE MILE IN LATE WINTER the 65 farmers on the 20-square-mile area allowed the DOC to establish a combina- tion of bromeerass and alfalfa along road- sides and agreed to delay mowing annually until August 1. Nest studies conducted on the FOMU since 1973 have indicated that more than half of the juvenile pheasants recruited into the fall population typically hatch in developed roadside vegetation. Late winter and spring indices of relative abundance suggest that when the roadside vegetation became established after 1970, the numbers of ringnecks on the FOMU increased sub- stantially over those of the premanagement era (1967-1970). since ap- proximately 1971, pheasants have been more abundant on the FOMU than on the reference area near Sibley. Moreover, Although pheasant populations on the FQMU maintained a abundance over those of the reference area, have marein of roadside management has not mitigated the deleterious effects of intensified agri- culture in the 1970’s or the decimation of ON THE SIBLEY STUDY AREA AND FORD COUNTY MANAGEMENT UNIT ™ = AERIAL CENSUS R fo \ FORD COUNTY The \ MANAGEMENT UNIT relative abundance of hen pheasants on the Ford County Management Unit and the nearby Sibley Study Area. 12) 1976 1978 1980 Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. ringneck populations by winter storms in January 1977 and during the winter of 1977-1978. However, censuses conducted in 1980 indicate that recovery from recent storm-related declines may be enhanced by roadside management. Although most research on the FOMU has been directed toward pheasants, nest studies have also encompassed ground- nesting songbirds. Preliminary analyses in- dicate that these species have responded to roadside management in a manner similar to that documented for ringneck popula- tions. Mississippi Navigation Effects on Macroinvertebrates One of the major tasks of a research effort to determine the effects of navigation on the aquatic resources of the Mississippi River got off to an enthusiastic start this past summer. Dick Seagle and Jeff Hutton, Survey aquatic biologists, and Rick Ander- son and Deborah Leibig of Western Illinois University began work to determine the effects of river navigation on the drift of aquatic insects and other small organisms, collectively referred to as macroinverte- brates. The first phase of the study, which began in June, involved selecting repre- sentative sampling sites and testing field methods and gear. Pool 26, located near Alton, Illinois, is where the Illinois River enters the Muissis- sippi. Of the commercial river traffic pass- ing through Pool 26, about 60 percent moves down the Illinois River, and about 40 percent comes down the Mississippi above the Illinois confluence. Thus, Pool 26 offered the unique opportunity to study the effects of different levels of barge traffic on aquatic resources in a single pool. Based on physical similarity, three sites, corre- sponding to the three levels of traffic, were chosen for intensive biological sampling: sites 1 and 2, Mississippi River miles 211.5 and 219.7; site 3, Illinois River mile 3. The second phase of the summer's work was to describe the distribution, abun- dance, and drift rates of aquatic macro- invertebrates at the three sites and to estab- lish a base of information from which to work. Drift, a natural phenomenon, is de- fined as the entry into the water column and the downstream movement of inverte- brates. Most aquatic invertebrates exhibit some sort of drift periodicity, and some groups, e.g., mayflies, flies, and caddisflies, occur in extremely high numbers at night. Drift is important in the aquatic ecosystem because it regulates invertebrate popula- tions, supplies organisms to recolonize stressed areas, and is an important food source for fish and other aquatic species. One of the reasons for including drift re- search in a navigation-effects study is that barges and large pleasure craft can vastly alter water pressure and velocity when they pass a certain point in the river. It has . been hypothesized that these pressure and velocity changes are great enough to dis- lodge organisms from the substrate, thus inducing drift. Induced drift and altered drift rates could seriously affect inverte- brate populations and the species that de- pend on them for food. The macroinvertebrate community was sampled with a ponar dredge, artificial substrates (rock-filled baskets placed on the river bottom), and “bongo” drift nets. Though the usual substrates in the Illinois River (silt-clay) and Mississippi River (sand) are different, ponar samples indi- cated small standing crops of macroinverte- brates and few species in both systems. The average number of specimens per dredge sample for both rivers was generally less than 20, and the average number of species never exceeded five. The macroinverte- brate community in the Mississippi River was dominated by midges, caddisflies, may- flies, and worms. Dominant forms in the Illinois River were worms and midges. Artificial substrates in the Mississippi River were placed on wing dams (sub- merged rock dikes extending into the channel to train the river flow). These areas provide a good substrate for colo- nization, typically exhibit high macroinver- tebrate productivity, and are likely to be affected by water pressure and velocity changes generated by barges. Artificial sub- strates in the Mississippi River had by far the greatest average number of specimens (2,421) and the highest average of species (16) of macroinvertebrates. Illinois River Natural History Survey researchers are attempting to learn how towboats (like this one on the Illinois River at Beardstown) affect the drift of aquatic insects and other small organisms. (Photo from a slide by W. C. Starrett) artificial substrates were subjected to heavy siltation and averaged only 291 animals and six species. The number of species and animals collected per unit of time in drift-net samples was lowest at Mississippi River mile 211.5. The other drift-net sampling sites (Illinois River mile 3 and Mississippi River mile 219.7) produced at least twice the number of animals and more species. Drift-net samples taken off the two types of substrates (sand-silt and rock) were similar in the Illinois River. Phantom midges dominated the samples, and at times net-spinning caddisflies, mayflies, and hydra were common. Drift-net samples off of wing dams at both Mississippi River sites were somewhat similar to one another. Phantom midges, net-spinning caddisflies, mayflies, and hydra were the dominant forms. Sand-silt substrate drift was domi- nated by mayflies, hydra, and phantom midges. Drift densities (number per cubic meter) at all sites were always higher at night than in the day, and highest drift densities were recorded at 1:00 and 4:30 a.m. Air Pollution and Illinois Agriculture Many people are increasingly concerned about the variety, quantity, and pervasive- ness of materials which are added to the environment. These include gases, particu- lates, agricultural chemicals, and radio- active materials added to the atmosphere; sewage and chemicals to water systems; and solid wastes to the land. Environ- mental pollutants, acting individually and together, affect man’s food supply, health, and well-being, sometimes adversely. In- deed, clean air is not the normal environ- ment for plant and animal growth in many locations. Air pollution, or “smog,” is usually identified with large metropolitan areas, such as New York, Chicago, Denver. and Los Angeles. However, scientists are aware of and often disturbed by the ap- parent increase of air pollutants in non- metropolitan and rural areas whose eco- nomic base is frequently agricultural. Growing plants, whether in a garden, ornamental landscape, or agricultural field, exist simultaneously in both air and soil environments and are particularly suscep- tible to environmental pollution. Vegeta- tion is especially important because light energy is captured and transformed to chemical energy by photosynthesis. As a result of this activity, plants are pivotal for food production and the support of food webs. For some time, environmental quality The Illinois NATURAL HISTORY SURVEY) ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 has been a major interest of Natural His- been a subject of study for over a century. tory Survey scientists, who conduct research Most studies have concentrated on injury on the renewable natural resources of the symptoms of leaves, which consist of var- state. The Survey’s participation in en- ‘ ious types of pigmented, chlorotic, or ne- vironmental studies has been broadened to crotic markings. Growth and yield reduc- include plant-air pollution interactions. tions caused by air pollutants have also Anton G. Endress of the Botany and Plant been known for some time and are recog- Pathology Section is constructing a cham- nized as widespread problems. Yield losses ber system to examine the effects of ex- have occurred when leaves showed visible posure to air pollutants on the develop- markings. In the last few years, however, ment, growth, yield, and quality of plants. yield losses from air pollutants have been These studies emphasize the acidic gaseous reported without any visible injury to the pollutants — sulfur dioxide (SO2), nitro- crop. For example, last year scientists from gen oxides (NOx), and hydrogen chloride the Argonne National Laboratory in (HCl) — which are produced by the burn- northern Illinois reported soybean yield ing of coal or refuse for heat and power losses ranging from 5 to 48 percent even needs. There are indications that the con- though no injury symptoms were observed centrations in the air of certain pollutants on the plants. They used SO, in their ex- will increase in the future mainly due to periments, but because these were field the combined pressures for relaxation of — studies, the participation of other unknown air-quality standards and the increased use airborne substances could not be ruled out. of domestic coal. The yield reductions stemmed mainly from Endress and two colleagues, Claus Grun- lower seed weights and fewer seeds per wald and Donald F. Schoeneweiss, are _ plant. currently initiating a study of soybean Botanist Endress and his colleagues are growth and development as it is affected initiating their studies in an attempt to by SO,. Soybeans were chosen because verify the observations of the Argonne Illinois is the U.S. leader in soybean pro- group. They are also concerned with duction, and several studies have shown altered seed quality, which may restrict the that soybeans are sensitive to air quality. dietary or industrial use of soybeans, and The Survey scientists emphasize that in- air pollutant stress, which may reduce soy- jury to vegetation was one of the earliest bean plant vigor, rendering them more manifestations of air pollution and has — susceptible to pathogens. May 1981. No. 207. Publish nonthly except in July and August by the Natural History Survey, a division of the Illinois Institute f Natural Re urces, operating under the Board of Natural Resources and Conservation Prepared by Robert M. Zewadski with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publicatior 172 Natural Resources Buildina, Cl ampaian Illinois Persons desiring individual or additional copies of this publication please write to CHIEF ILLINO! NAT AL HISTORY IRVEY LLIN NSTITUT F NATURAL RES RCES NATURA RESOURCES UILDIN i PEABODY. CHAM The Illinots NATURAL Homer’s Odyssey to China Homer Buck, Survey aquatic biologist, recently returned from the People’s Re- public of China where he served as an in- vited consultant for the development of expanding aquaculture programs. His trip was sponsored by the Food and Agricul- ture Organization of the United Nations (UNFAO). his travels and observations. This article is a summary of One of the great challenges of our age is to increase the production of food in Asia, Africa, and other food most desperately needed by millions of hungry people is animal protein, and one developing areas. ‘The of the most efficient ways to produce the Of the or under de- protein is through aquaculture. programs now in operation, of the promising is the Asian Network of velopment, one newest and most Aqua- culture Centers. UNFAO through its United Nations Development Program (UNDP) cert with host cently has completed centers in India, Thailand, and the Philippines. ters have elaborate facilities, con- various governments, re- These cen- and are well funded and well staffed for two principal (1) to develop and/or improve the technologies that offer greatest poten- tial for the efficient, high-volume produc- tion of fishes, prawns, and other forms of aquatic and. (2), to tech- nologists and potential aquaculturists to purposes: protein: train apply the technologies that are developed. A fourth Asian center, and potentially the most important, is nearing completion at Wuxi (near Shanghai), People’s Republic ‘gh BPORTS.: jee were. Se eye See eee eee ee I HISTORY Dr. Homer Buck, Survey Aquatic Biologist (Photo by Les Woodrum, Survey Photographer). of China. It will be known as the Regional Lead Center for Integrated Fish Its special importance derives from two Farming. auxiliary purposes: (1) the training of technologists from other developing coun- tries and (2) the Chinese technologies on a global basis. extension of The traditional Chinese system involves an almost total integration of agriculture and aquaculture. For example, in areas where fish production is the primary func- tion, the production goals for all other ag- geared to the quota that was established first for fish pro- riculture commodities are duction; and labor, land. water, and other resources are apportioned accordingly. The Chinese system has manures, vegetable tops, green fodder, etc., all entering fish Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey. ponds in either a fresh, fermented or com- posted form; and the organically enriched silt is removed annually from the pond bottoms and returned to the land as fer- tilizer. While this ancient system is un- questionably successful, there has been surprisingly little analysis or documenta- tion of how or why it works, or of which elements of the system are the most im- portant or efficient. It also is recognized that the systems of integration as practiced in China will have to be modified to meet the needs, climate, and resources of other areas. The Chinese system is not unknown in Illinois. Since 1975 the research program at the INHS field station at Kinmundy has included studies of the application of cer- tain Chinese methods to our midwestern agricultural systems. This has been done because we in time will need to maximize the use of our diminishing resources. As a result of the Kinmundy studies, Buck, of the Kinmundy staff, was invited to China to participate in the development of the program of research for the new Chinese center. Additional members of the task force included (1) a second consultant, Gerald L. Schroeder, who has conducted extensive research in manured fish ponds in Israel; (2) T. V.R. Pillay, Chief Admin- istrator of Aquaculture Development in the Rome headquarters of the UNFAO; and (3) Chen Foo-Yan, Project Coordinator for the UNDP Network of Aquaculture Centers in Asia, headquartered in Bangkok. Following initial briefings and a good mea- sure of hospitality from Chinese officials in Peking, the task force travelled by train approximately 1,000 km south of the site of the new center at Wuxi to meet with Chi- nese counterparts. A second flurry of brief- ings and festivities was followed by nine consecutive, very intensive days of discus- sions, writing, and translation, followed by more discussions, writing, etc., broken only by a one-day excursion to two local com- munes. The meetings were extremely cor- dial and stimulating. The final product was a documentary draft outlining 16 specific areas of research to be addressed over an initial 7-year pe- riod. Five of the 16 specific points of in- vestigation are listed as examples. 1. Comparative studies on the effects of fresh and fermented animal manure on fish yields. 2. Comparative studies on the performance of different livestock manures in rela- tion to fish production. 3. Studies on the relative values of green manure and animal manure on fish production. 4. Water quality and pond dynamics stud- ies for establishing an upper limit of manure quantum which could be “safely” added to fish ponds under dif- ferent environmental conditions. 5. Comparative studies on the economics of dual and multiple integration of crops aimed at establishing models for various integrated farming systems. It is believed that critical examination of the Chinese systems and procedures will yield short-term benefits to China and to other developing countries, and will in time prove useful in IIlinois. Putting the Heat on Horseradish Disease Illinois, well noted for its soybean and corn production, is the leader in yet another agricultural crop — horseradish. This cru- cifer, grown for its fleshy pungent roots ground for use as a condiment, is produced on about 1,000 acres in Madison and St. Clair counties near East St. Louis, an area which provides half to two-thirds of the nation’s harvest. Since the mid-1930’s Illinois horseradish periodically has been devastated by out- breaks of brittleroot, a condition resulting in yellowing of the foliage, stunting, oc- casional wilting, reduction in the number of branch roots, discoloration of the root phloem, brittleness of the root, and plant death or severe reduction in quality of har- vested roots. Whether the condition was a result of infection by plant pathogenic organisms, mineral imbalance in the soil, or adverse environmental conditions pre- viously was not known. After a brittleroot epidemic destroyed 60 percent of the Illinois crop in 1979, an in- terdisciplinary team of researchers was put together by W. H. Luckmann of the Eco- nomic Entomology Section of the Illinois Natural History Survey and R. E. Ford of the University of Illinois, Department of Plant Pathology. With support from the Illinois Agricultural Experiment Station and the State of Illinois, this team set out to determine the causal agent(s) of brittle- root and its epidemiology. Natural History Survey and University of Illinois entomolo- gists Jerry Schultz, Cathy Eastman, Mickey McGuire, and Karen O’Hayer joined plant pathologists Jacque Fletcher, Robert Good- man, and Kathy Franklin in this pursuit. Additional expertise was provided by con- sultants in plant pathology, horticulture, and agronomy at the University of Illinois and by research cooperators at the USDA Plant Virology Laboratory in Beltsville, MD, the Division of Biological Sciences at the University of California at Davis, and the USDA Agricultural Research Station in Salinas, CA. Although soil fertility and environmental conditions were possible factors in the de- velopment of brittleroot outbreaks, the working hypothesis receiving the most sup- port was that brittleroot was a result of the infection of previously healthy horseradish with one or more insect-transmitted patho- genic organisms. Since brittleroot epidemics have occurred at highly irregular intervals, some means had to be found to produce a dependable supply of plants with fresh in- fections as a source of experimental ma- terial. Numerous attempts were made early in the project to produce brittleroot-like Patch of brittleroot-affected horse- radish (pale, center plants) (Photo by Survey Entomologist Dan Sher- rod). symptoms in healthy horseradish by con- fining these test plants with selected leaf- hopper and aphid species which had fed previously on diseased horseradish collected from the field during the 1979 outbreak. In two instances brittleroot-like symptoms were produced in test plants, but evalua- tion of these results was hampered by lack of a critical means of determining differ- ences in the organisms present in test versus control plants. A major breakthrough occurred in 1980 with the report from research cooperators at the University of California-Davis that bacteria-like organisms had been seen with the electron microscope in_thin-section samples from a diseased horseradish plant obtained from Illinois but were not present in samples from a healthy plant. With this lead and with the help of plant pathol- ogists at Beltsville, MD, researchers here were able to culture a small helical bac- terium called a spiroplasma and determine that it is Spiroplasma citri, known to cause a serious disease of citrus in California and Arizona. This was indeed a surprise be- cause it was the first documented report of the existence of S. citri in the U.S. east of Arizona. Subsequently the spiroplasma was isolated and cultured from numerous dis- eased horseradish plants collected from the 1980 Illinois horseradish crop but was never present in healthy horseradish plant samples. Armed at last with a reliable method for evaluating laboratory experiments, the re- search team was then able to test the hy- pothesis that S. citri was the primary The Illinois NATURAL HISTORY SURVEY ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 cause of brittleroot. Plant pathogenic spi- roplasmas are known to be transmitted primarily by leafhoppers. The beet leaf- hopper (Circulifer tenellus) was chosen as a test vector because this desert-loving in- sect is known to transmit S. citri to citrus in California and has been collected in Illinois horseradish during some past brit- tleroot epidemics. These leafhoppers were microinjected with small hand-drawn glass needles containing cultured preparations of S. citri previously isolated from diseased horseradish. After the insects were allowed to feed on healthy horseradish some of these horseradish test plants developed brittleroot-like symptoms. S. citri was re- isolated from the test plants and was not present in control plants, which remained symptomless. In separate tests beet leaf- hoppers were able to acquire S. citri natu- rally by feeding on diseased horseradish and to transmit the spiroplasma to healthy test horseradish, which then developed brittleroot-like symptoms. The finding of an association between this spiroplasma and brittleroot of horse- radish is only the second instance in which an important plant disease of unknown etiology has been shown to be caused by S. citri. Horseradish is also a new addition to the list of reported hosts for this organism. Work is underway to develop a control program for brittleroot. Other pathogens, OF especially viruses, known to occur with varying frequency in Illinois horseradish are being checked to determine if they -help or hinder subsequent infection of horseradish with the spiroplasma. Selected plant species reported to be susceptible to California-Arizona isolates of S. citri are being tested for their susceptibility to iso- lates from Illinois horseradish to see if they are similar in pathogenicity; to date the team has succeeded in producing in- fections in periwinkle, turnip, radish, and aster. Weeds, especially crucifers, common in the horseradish production area are also being examined to determine their suscep- tibility to S. citri and, thus, their potential role in brittleroot epidemics. Presently wild mustard, shepherd’s purse, and yellow rocket have been infected experimentally with S. citri. Although Illinois researchers have shown the beet leafhopper to trans- mit the spiroplasm to horseradish under experimental conditions, the field vectors for brittleroot outbreaks have not yet been determined; therefore, other leafhopper species common in Illinois horseradish fields are being examined as well for their ability to transmit S. citri. Research is being done on how quickly and effi- ciently the beet leafhopper can transmit the spiroplasma. This information will be important in determining if insecticides will be sufficient to control the leafhoppers and, thus, brittleroot outbreaks. Persons desiring individual or additional copies of this publication please write to The Illinozs NATURAL SURVEY | i Ke - % Air Traffic Control for Soybean Aphids Air traffic controllers have been much in the news recently, but did you know that it may be possible to use a form of air traffic control of flying aphids to help reduce the spread of soybean mosaic virus? It is known that soybean mosaic virus is spread within fields by flying aphids. Con- sequently, a potential means of reducing the spread of this disease is to modify the landing behavior of the disease-carrying aphids — to make a field unattractive to aphids so that they will not land in it. Survey economic entomologists Susan Halbert and Michael Irwin knew that ear- lier researchers had obtained contradictory and inconclusive evidence as to whether differences in the percentage of ground cover influenced aphid landing behavior. They decided to determine the differences in the numbers and species of aphids that are likely to land in soybean fields planted in narrow or wide rows. The entomologists placed 10 sticky traps designed to catch insects in each of two soybean fields. The distance between rows in one field was 7 inches and in the other it was 30 inches. The experiment was con- ducted for two growing seasons at the Vegetable Crops Experimental Farm of the University of Ilinois. Aphid trapping be- gan on June 11 of the first year and on June 27 in the second year. The leaf can- opy of the narrow-row field was closed after the second week of sampling in both years, and during the entire experiment the narrow planting had a higher percentage of ground cover than had the wide one. HISTORY Mal Aphid trapping was stopped when the can- opy closed over the wide-row field, after 35 days in the first year and after 32 days in the second. The sticky traps were ermine-lime col- ored ceramic tiles. The color was designed to approximate the color of soybean foliage that is attractive to aphids. The tiles were mounted on ring stands that were, in turn, mounted on steel rods driven into the soil. As the soybeans grew, the tiles were raised and were continually maintained at canopy level. The entomologists found no statistically significant difference in the total numbers of aphids trapped in the two fields. However, the flying aphids Aphis citricola and Myzo- callis punctatus were caught in significantly greater numbers on traps in the narrow-row field. The species Capitophorus elaeagni was collected more abundantly on traps in the wide-row field during the first 2 weeks of the season. That trend was apparent during the remainder of the season, but the difference was not statistically significant; the difference for season totals, however, was highly significant. Lipaphis erysimi, Rhopalosiphum and Schizaphis graminum, the three additional species col- matdis, lected in large enough numbers for statis- tical analysis, exhibited no preferences be- tween the open and closed canopies of wide and narrow plantings. Of the three aphid species that showed significant preferences, C. elaeagni and A. citricola have been found capable of trans- mitting soybean mosaic virus. The preference for an open or closed Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. canopy seems to vary among species. There- fore, the possibility of restricting the spread of soybean mosaic virus by adjusting row spacing depends on which species of aphids are locally important. Of the aphids that responded to ground cover variation, A. citricola was collected in greater numbers over continuous cover dur- ing weeks 3-5, while C. elaeagni was collected in greater numbers over wide rows during weeks 1-2 (and probably during weeks 3-5). Thus, response by flying aphids to ground cover depends on species and time of year. Seed transmission of soybean mosaic virus, one of the most important economic aspects of the disease, is more likely if parent plants are infected early — in the growing season. This fact focuses_at- tention on the importance of early season disease-carrying aphids. The early part of the season is also the time when row spac- ing has the greatest effect on ground cover. Row spacing might be used as a means of limiting the spread of soybean mosaic virus that results in seed transmission if the principal spring and early summer aphids were responsive to ground cover variation. The entomologists point out that there is no evidence to indicate that manipulation of the percentage of ground cover would eliminate aphid landings and_ therefore eliminate the spread of soybean mosaic virus. However, depending upon the aphid species involved, it could reduce aphid landings enough to make the practice use- ful as part of an integrated pest manage- ment program to control soybean mosaic virus. Choosing the Transplanting Season Survey plant pathologist E. B. Himelick provides this information about tree and shrub transplanting in various seasons (taken from a manual recently published by the International Society of Aboricul- ture). The time of year in which transplanting must occur is not always in the control of the planter. Economic or weather condi- tions may determine a plant’s availability. Landscaping may be required immediately upon completion of building construction. Unavailable equipment or labor may delay the planting program. Fortunately, ex- perienced plantsmen using properly pre- pared plants can successfully transplant most trees and shrubs in any season. The growing of plants in containers has also helped ease the seasonal requirements for transplanting. This is especially true when small shrubs and trees are used in the land- scape plan. The opinions of qualified nurserymen and arborists vary concerning the most sat- isfactory time for transplanting trees and shrubs. Climatic conditions that vary with locality and year will influence both plant- ing time and planting practices. Plant spe- cies and method of digging will also influ- ence season for transplanting. In general, deciduous plants are prefer- ably planted in the fall after leaf drop and before the soil freezes or in early spring before budbreak. Many tree species may be planted in winter when the soil ball is frozen. The frozen ball must be protected to prevent root damage. Some plant species have a limited tolerance to soil tempera- tures below 25°F. Narrow-leaved ever- greens may be planted in the fall or in the spring before the start of new growth. Broadleaved evergreens are usually trans- planted in the spring. Important factors involved in selecting the planting season are: a) soil moisture and temperature, b) exposure, c) the growth stage of plant, d) plant hardiness, and e) the inherent nature of the species. Fall planting has the advantages of fa- vorable soil temperature, usually adequate moisture, and time for some root regenera- tion before the following spring. Winter planting in cold climates has few advan- tages other than what may be termed oper- ative. It takes advantage of the normal slack period of the plantsman and may per- mit the use of a frozen soil ball, thus re- quiring less time for balling and burlapping. Spring planting has the advantage of ample soil moisture and overcomes the possibility that sufficient roots may not become established before freezing weather. Summer planting has the advantages of timeliness and favorable soil temperature, although soil moisture may need to be sup- plemented through irrigation. Transplant- This large tree spade digs a soil ball 7 feet in diameter weighing about 4 tons, and it is capable of transplant- ing trees with trunks 6—8 inches in diameter. (Photo courtesy of Vermeer Manufacturing Co.) ing should be avoided during spring and summer periods when there is rapid leaf growth. It is essential to wait until after the early rapid spring growth has slowed before moving trees in full leaf. A hardening-off period is frequently given plants before moving to the planting site. This consists of holding plants in a cool, moist place for 1 or 2 days. This will aid in successful late spring and summer transplanting. All plants transplanted in leaf should be moved with a ball of soil. Shipment of plants during the hot summer for long distances can result in severe plant injury. Transplanting operations during the summer should be carried out by exper- ienced arborists, nurserymen, or landscape contractors who will guarantee plant survival. The History of Illinois Valley Lakes Several studies have been undertaken re- cently by the Natural History Survey for the Chicago District, U.S. Army Corps of Engineers. These studies have concerned the effect of the Illinois River’s 9-foot waterway on fish and wildlife and the po- tential effect of a projected increase in water diverted from Lake Michigan. A spin-off of these contract studies was the collection of data on physical parameters of bottomland lakes that relate to their his- tory and to their future for fish and wild- life. The Illinois Valley has been famous for its waterfowl hunting as far back as the 1880’s. During the early 1900’s, its com- mercial fish yield was the largest of any river except the Columbia. The favorable habitat for fish and wildlife was created primarily by bottomland lakes that are as- sociated with the narrow, straight river channel. The bottomland lakes have undergone many changes since 1900. Wildlife special- ists Frank C. Bellrose, Stephen P. Havera, and H. Kathleen Archer are preparing a report about these changes. The first major The Illinois NATURAL HISTORY SURVEY) ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 change occurred in the early 1900's as river levels rose as the result of water diverted from Lake Michigan. The increased water levels resulted in a doubling of the surface area of lakes associated with the Illinois River. Under pristine conditions, there were 33,936 acres of surface area in bot- tomland lakes; this area increased to 67,693 acres as a result of diverted water. Prior to this diversion, only four lakes were over 1,600 acres, mostly in the valley above Beardstown. The surface area of many bottomland sloughs, ponds, and lakes coalesced to form larger areas. Currently, even with drainage and levee districts elim- inating about half of the bottomland lakes, there are 11 lakes of over 1,600 acres. Shortly after the diversion increased lake areas, drainage and levee districts began to whittle away at the area of bottomland lakes in the Illinois Valley. Before the levee-district era ended in the early 1920’s, 184,742 acres of bottomland had been en- closed by levees, eliminating a calculated 21,725 acres of water surface. As demonstrated by studies made by the Natural History Survey and by the State Water Survey, sedimentation of the re- maining water areas in the Illinois Valley provides the gravest threat to their exis- tence. A Natural History Survey Bulletin reported on the sedimentation rate for a Septemb 1981. N 209. Pu i blished monthly Prepared by Robert M ewadski with the Second-class postag paid at Urbana, Illinois (USPS Office of publicatior 17 -have been made. except in July and August by the Natural History 258 number of bottomland lakes (INHS Bulle- tin 32[1]) in the Illinois Valley. Since then, additional studies of sedimentation rates These studies include Clear, Big, Matanzas, and Grand Island lakes in the La Grange Navigation Pool and Swan Lake (near Grafton) in the Alton Navigation Pool. The later findings on sedimentation rates substantiate those made earlier. In the earlier report it was pointed out that sedimentation rates varied linearly with water depth, the deep areas filling much more rapidly than shallow ones. As a consequence, the basins of most bottom- land lakes are saucer shaped and shallow. The mean water depth of all sampled lakes was 2 feet. Upper Peoria Lake is the deep- est, with a mean depth of 3.2 feet. At the 1-meter (1.1 yards) water depth, bottomland lakes are filling with sediment at rates that vary from 0.5 to 1 cm (0.2 to 0.4 inch) per year. Upper Peoria Lake is filling with sediments at a faster rate than any other lake — nearly 2 cm (0.8 inch) per year. The projected half-life of Illinois Valley lakes is quite short — 24-230 years. By the time the half-life is reached, those lakes will be too shallow to provide sufh- cient water for fishing and boating and will provide for only limited waterfowl hunting. Survey, a division of the Illinois Institt »f Natural Resources, operating under the Board of Natural Resources and Conservation collaboration of the Survey staff 220) 2 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF ILLINOIS NAT AL NATURAL RESOURCE HISTOR BUILDING 7 Ff , ARODY CHAMPA n SURVEY LLINOIS INSTITUTE OF ILLINOIS 618 The Illinors NATURAL HISTORY REPORTS New Pine Disease My pine trees are dying. Today this is a common statement made by many I[lli- nois homemakers, foresters, and Christmas tree growers. Dead pine nurserymen, trees are evident along highway plantings, parks, home landscapes, and commercial plantations throughout the Midwest. A given pine tree may appear healthy but six weeks later the entire tree may turn brown and die. The pinewood nematode, Bursaphelenchus xylophilus, and an associ- ated blue stain fungus, Ceratocystis sp., appear to be the causal agents in the pine deaths. Scotch and Austrian pines are the most susceptible in Illinois, but it has been recorded from red, jack, Virginia, and white pine. The pinewood nematode was discovered in Japan in 1913. Currently the nematode is occurring in epidemic proportions in 1.250.000 acres of pines. The first United States dis- Japan, where it has infested covery of the nematode in Scotch pine oc- curred in 1979 in Missouri. There have Monochamus carolinensis, vec- tor of the pinewood nema- tode, feeding on a pine tree (Photo by J. E. Appleby). Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey. Scotch pine tree killed by pinewood nematode-blue stain fungus disease. All needles on this tree were brown. Note needie loss on lower half of the tree (Photo by J. E. Appleby). f 4 Y been confirmed reports of the nematode in 38 Illinois counties. Japanese scientists have reported that the nematode is transferred from tree to tree by several species of longhorned bee- tles. When nematode-carrying beetles feed on healthy pine trees, the nematodes leave the beetles’ bodies and enter the trees through the feeding wounds. Once a tree is infected the nematodes increase in num- bers at an alarming rate. The tree can be infected in early summer and be dead three months later. The longhorned beetle, Monochamus carolinensis, 1s a common pine borer found in Illinois and is a pinewood nematode vector. The adult beetle measures 20-25 . mm in length. Within the breathing pores (spiracles) of a single adult beetle, thou- sands of nematodes have been found. The female beetles deposit their eggs on a dead or dying pine tree that may be in such condition because of the nematode infesta- tion. After the beetle eggs hatch the wood- boring larvae within the pine trees become infected with the nematodes if they are present. The following year when the adult beetles emerge during late spring and summer, they may act as vectors of the nematodes to previously healthy trees. Is it the nematode or the fungus that is the primary cause of pine tree death? Is it a combination of both organisms? ‘To address the problem, a multidisciplinary research team from the Natural History Survey and the University of Illinois has been formed. The members are J. E. Appleby, J. K. Bouseman, T. W. Curtain, E. B. Himelick, J. J. Jokela, R. B. Malek, M. M. Meyer, R. Randell, F. A. Giles, and D. J. Williams. The team will work to solve many of the unknowns about the nematode-fungus-beetle-pine relationships. It is hoped that the research efforts will find a means of preventing the loss of pines within Illinois. Herbert H. Ross to Receive Founders Memorial Award of ESA Dr. Herbert H. Ross has been selected posthumously to receive the Entomological Society of America’s Founders Memorial Award. Dr. Ross, former Assistant Chief, Herbert H. Ross, distinguished entomologist. Principal Scientist and Section Head (Faunistic Surveys and Insect Identifica- tion) of the Illinois Natural History Sur- vey, and Professor of Entomology at the University of Illinois, retired in 1969. The award will be presented at the an- nual meeting of the Entomological Society of America (ESA) in San Diego, Cali- fornia in late November 1981. The award consists of two parts: the Honoree (a for- mer ESA member) and the Lecturer (a current member) Dr. Charles D. Michner, Watkins Professor of Entomology at the University of Kansas and member of the National Academy of Sciences, will re- ceive the Lecturer part of the award. The Founders Memorial Award, established by the Governing Board of the Society, has been awarded annually to honor the memory of a distinguished North American entomologist. Dr. Ross is the only ento- mologist in the history of the ESA to be recipient of both the Lecturer (1970) and Honoree parts of the award. A highly respected scientist, Dr. Ross published 220 scientific works, including 7 books and chapters in 6 other books. The fourth edition of his popular Textbook of Entomology will be published in the very near future. He was active in several sci- entific organizations and served as presi- dent of the Entomological Society of America (1954-55), the Society for the Study of Evolution (1966-67), and the Society of Systematic Zoology (1973-74). Dr. Ross influenced the direction of evo- lutionary biology and systematics. His evo- lutionary emphasis helped to evaluate systematics to its present position as a pro- - gressive, analytical and synthetic science. In order to further honor Dr. Ross and to encourage research in systematic ento- mology, a memorial fund has been es- tablished jointly by the Illinois Natural History Survey and Department of Ento- mology at the University of Illinois. Con- tributions may be made to the Herbert H. Ross Memorial Fund, University of Illinois Foundation, 224 Illini Union, 1401 W. Green St., Urbana, Illinois 61801. Trace Metals in Coffeen Lake The Survey’s trace metal laboratory is participating in a multidisciplinary three- year study of the cooling lake (Coffeen Lake, Montgomery County) associated with Central Illinois Public Service Com- pany’s Coffeen generating station. In addi- tion to serving as a cooling reservoir for thermal effluent from the coal-fired plant, the lake has, in the past, been used for the disposal of local sewage, mine drainage, and runoff from the coal waste storage areas. Recent improvements in the disposal of coal combustion wastes at the plant have eliminated some of the sources of pollution and should contribute to an im- provement in the environmental quality of the lake’s ecosystem. Samples of water, sediment, macro- phytes and three species of fish (black bullheads, gizzard shad and largemouth bass) were collected from four established stations representing various thermal re- gimes and were analyzed for their content of 18 chemical constituents by former Sur- vey analytical chemist Kenneth E. Smith and his associates. During the first two years of the study, the constituents in the collected samples were more concentrated in the first half of the cooling loop of the lake, the area that formerly received dis- charges from the slag and fly ash ponds, than elsewhere in the lake. In addition, the chemical constituents in all samples tended to decrease in concentration from COFFEEN LAKE Map of Coffeen Lake showing sampling stations of trace metals. the first year of study to the second year, the time period when improvements in disposal of coal combustion wastes at the plant were implemented. The mean concentrations of mercury in water exceeded the maximum safe toler- ance level for freshwater aquatic life (0.05 ppb, as determined by the U.S. Environ- mental Protection Agency) in eight of the ten months during the first year of study and in six of the nine months during the second year. However, there was at least a six-fold decrease in average mercury con- tent during the second year. Analysis of water samples collected during the third year of the study is in progress. Preliminary results indicate that the levels of mercury and many of the other chemical constitu- ents continued to decrease during the third year. There has been concern about the re- ported reproductive failure in fish inhab- iting lakes contaminated with selenium. The levels of selenium in gizzard shad and largemouth bass from Coffeen Lake did not change appreciably during the three- year study (averages of 1.27 ppm and 1.72 ppm, respectively). Black bullheads con- tained very low selenium levels (average of 0.35 ppm). Third-year levels in carp, The Illinois NATURAL HISTORY SURVEY ILLINOIS INSTITUTE OF NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 bluegills and channel catfish were 1.17, 1.19 and 0.80 ppm, respectively. These levels are well within the range of concen- trations (0.5-7.0 ppm) reported for fish from other lakes where fish reproduction is normal. Thus the reproductive success of fish in Coffeen Lake should not be affected by selenium at the present. In order to detect any increased concen- tration of particular chemical constituents leaving the plant, a mass balance deter- mination of constituents entering (via coal) and exiting (via slag and fly ash) has been initiated. Core samples taken at six transects of the lake during the third year of study are being analyzed by ana- lytical chemist Susanne G. Wood and tech- nical assistant Teresa A. Schuller to de- termine the concentrations of chemical constituents in the original soil and in the various layers of sediment laid down dur- ing the 14-year lifetime of the lake. Analyses of sediment and macrophyte samples collected during the third year of the study are in progress. Preliminary re- sults indicate a continued decrease in con- _ centrations of the 18 chemical constituents, thus reflecting continued improvement of the environmental quality of Coffeen Lake’s aquatic ecosystem. October 1981. No. 210. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Institute of Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Dr. George L. Godfrey with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, ILLINOIS INSTITUTE OF NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 E. PEABODY, CHAMPAIGN, ILLINOIS 61820. The Illinois NATURAL HISTORY REPORTS Cooling Lake Study Published Reservoirs constructed specifically for the dissipation of waste heat from industry constitute a relatively new aquatic environ- ment that presents both problems and attractive potentials. The most apparent environmental problems are those associ- ated with waste heat from a production process; the most obvious benefits are recre- ational, especially the unique opportunity for open-water fishing in a northern cli- mate during winter. To evaluate the detri- ments and benefits of a cooling-lake eco- system, one must consider the physical attributes of the man-made system before attempting to understand the more com- plex biological relations. Those relation- ships include the entire food chain of the aquatic ecosystem. Lake Sangchris, in central Illinois, provides cooling water for the Kincaid Generating Station, a coal-fired electric generating plant that was developed by Commonwealth Edison Company of Chi- cago in the early 1960's. Under Edison Company, the Illinois Natural His- tory Survey studied this cooling-lake eco- intensively from 1973 through August 1977 to determine the effects of the thermal discharge and com- bustion byproducts on the local environ- ment. detailed studies of water quality, plankton (minute, contract with Commonwealth system August Investigations included Boat equipped with echo-sounding and remote temperature sensing units for determining fish distributions with respect to depth and temperature in Lake Sangchris. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. Researchers collecting fish with an alternating-current electro fishing unit in Lake Sangchris. floating or weakly swimming plants and animals), aquatic macrophytes (plants), clams, benthos (bottom-dwelling organ- isms), fish, fish harvest, waterfowl, trace metals, and pesticides. Some studies (water quality, benthos, clams, and aquatic macro- phytes) were terminated in 1976, and others were initiated to consider the distri- bution of larval fishes in the water-cooling- loop portion of the lake and the effect of the impingement and entrainment of fish in the water-intake system of the power plant. The investigative work was carried out by an interdisciplinary team of specialists. Scientists from the Sections of Aquatic Biology, Faunistic Surveys and Insect Iden- tification, and Wildlife Research partici- pated in the study. The administration and overall coordination of the project were handled at the Illinois Natural His- tory Survey headquarters in Champaign, while field activities were coordinated through a field station at Kincaid, a few miles from the lake. Most of the fishery biologists were based at the field station; other team members were based in Cham- paign, where more extensive laboratory and analytical facilities were available. In general, the scientists found that the power plant and the heated water dis- charged from it created few problems for the animal and plant life of the lake and the surrounding area. On the other hand, the heated water flowing into the lake pro- vided some benefits, such as a longer grow- ing season for largemouth bass and for some forms of plankton. The strength of the Lake Sangchris case history lies in the intensive sampling pro- gram simultaneously carried out over a 4- year period by a team of investigators ap- proaching the problems of ecosystems by looking at all trophic levels. The results of this intensive study have been published in the Illinois Natural History Survey Bulletin as volume 32, article 4, The Lake Sangchris Study: Case History of an Illinois Cooling Lake. Radar Sheds Light on Bird Migration Everyone is familiar with the sight of flocks of birds migrating during the day, either tightly clustered or in a V or echelon formation. Even at night, waterfowl are often heard calling to one another as they make their way across Illinois to the next stopover. However, the vast majority of birds neither fly during the daytime nor call regularly as they migrate — most fly- catchers, thrushes, warblers, and sparrows fly silently or call only occasionally, and they fly at night. Do these smaller birds fly in flocks, or do they make their way alone? Observations with spotlights or observa- tions of birds’ silhouettes as they fly across the face of the moon reveal that there are no tight flocks of small birds at night. Often the birds seem to fly alone; some- _times they appear to cluster in aggregations too loose to be directly seen by these visual techniques. Taking up the question at this point, Ronald Larkin of the Wildlife Research Section has investigated the spatial arrange- ment of small birds at night using a special radar technique that he developed. to record the passage of migrants overhead. The radar, in conjunction with a mini- computer, operates as a bird-counting ma- chine, registering the position in space, time of occurrence, and apparent size of each bird passing through the radar beam. As he reported at a recent International Symposium on Avian Navigation in Pisa, Italy, Larkin obtained good evidence that birds sometimes do, indeed, form loose clus- ters at night. The distance between a bird and its nearest neighbor in one of these clusters was found to be in the region of 50-100 meters. Quantitative comparisons with computer-generated patterns of “bird” positions (random distributions from a so- called Monte Carlo method) showed that chance events could not have generated the observed patterns. The loose clusters of birds pose a pecu- liar problem: If they really represent flocks, how do the birds stay together? It is not likely that the remainder of the ‘‘flock” is easily seen by a bird flying several hundred meters above the ground at night, and few species vocalize enough at night to allow auditory communication among flock members. To shed light on this problem, Larkin hypothesized that small birds do not commonly fly in flocks at night, but rather that some agent in the atmosphere causes the birds to aggregate without actual com- munication. The distinction is often impor- tant in field observations: birds congre- gated around a bird feeder are attracted to a feature of their environment, and the birds may or may not be a social unit. Atmospheric motion was hypothesized to be the agent causing the birds to form clusters as they fly, not the general wind patterns aloft but the smaller details of the These motions (having dimensions of a few hundred meters to a kilometer or two) have been intensively studied by atmospheric sci- entists in the last 10 years or so; they are important in smog dispersal, in turbulence which imperils aircraft, and in generating the forces which drive storms and other large-scale disturbances. alr motion. small-scale Examination of the paths taken by weather balloons released at the radar site, just before or just after the clumping of birds was documented, revealed that when the birds were clumped, wind speeds or directions were different at different alti- tudes. This phenomenon is called wind shear. In one case, no wind shear was found and birds were not clumped. Wind shear almost always generates small-scale waves of the same general kind as those which a breeze generates as it blows across the surface of calm water. Therefore, at least until more definitive data are taken, we can imagine that birds flying at night are acted upon by subtle motions in the atmosphere, resulting in the clumping of birds in loose aggregations. Birds might preferentially fly in certain regions of air to save energy or to obtain navigational infor- mation. Or atmospheric motion may simply bunch the birds like flotsam on the sea. Air-Borne Pollutant Affects Soybeans Sulfur dioxide (SO:) is a gaseous dis- charge from industrial and power plants, and at times, its concentration in the air can be high enough to produce poisonous effects on plants. At a high enough con- centration, SO, causes a_ water-soaking appearance as well as interveinal chlorosis in plant leaves. At the cellular level, SO, affects a number of events, including trans- piration, respiration, and photosynthesis. The exact sequence of events is unclear, but SO, does interfere with the structure and permeability of cellular membranes, and it has been suggested that SO, affects the lipid component of membranes. How- ever, studies to demonstrate the SO. effect on lipid metabolism are few. The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 Research scientists in the Section of Botany and Plant Pathology, in coopera- tion with the Argonne National Labora- tory, have undertaken studies to determine what effects, if any, SO. might have on the various leaf lipids of soybean plants exposed in open-air fumigation systems. In an open-air fumigation system, which con- sists of an array of pipes suspended over the crop, the pollutant is released through small openings at controlled rates, and thus the plants are exposed under environ- mentally realistic conditions. With this system, of course, no comparison is made against plants grown under “clean air.” Sixty-day-old soybean plants exposed to 79 parts per hundred million of SO, for 20 days for an average daily period of 5 hours showed a marked change in fatty acids, both as to quantity and composition. The free fatty acids and polar lipids were greatly vember 198]. No. 21]. Published f the Department of Energy and Natural Resour month ly except in reduced with SO, treatment, while the fatty acid esters increased. A simple overall SO.-induced shift in lipid metabolism is ‘very unlikely, since the quantitative in- crease in fatty acid esters was almost en- tirely due to an increase in linoleic acid, a highly unsaturated fatty acid, while the de- crease in free fatty acids was more general. The degree of unsaturated fatty acids in- fluences membrane viscosity and, hence, membrane-related processes. Survey studies have clearly shown an increase in the unsaturated fatty acids with SO, open-air fumigation, and this change in lipids probably contributes to the in- crease in all permeability and to the water- soaking appearance of leaves. Thus, we have gained another building block of knowledge about how an air-borne pollut- ant affects one of our major agricultural crops. ind Auaqust by the Natural History Survey, a division es, Operating under the Board of Natural Resources and Cc Prepared by Robert M. Zewadski with the collaboration of the Survey staff nd postage paid at Urbar til s. (USPS 258-2 fice of pub t } > Natur q. yurces Buil ) Illinois Persons desiring individual or additional copies of this publication please write to 1: PAUL >. -& ER CH f F ENERGY Ab NATURA RE URCES The Illinors NATURAL Spawning Habits of Darters Darters (Family Percidae) are a diverse group of about 148 species of fishes that are found only in North America. They are second to minnows (Cyprinidae) in num- bers of North American species and are extremely important components of our aquatic ecosystems. ‘['wenty-six species oc- cur or formerly occurred in Illinois. For short-lived species such as darters, which have a maximum life-span of 14 to 1 years, the annual breeding season is a critical period. One or two unsuccessful breeding seasons can eliminate a popula- tion. Ecological conditions necessary for successful reproduction vary from species to species. Information on when, where, and under what environmental constraints dart- ers lay their eggs is requisite for their protection and conservation. Such information 1s available in the sci- entific literature on 50 species of darters. During the spring of 1981, Survey ichthyol- ogists L. M. Page and M. E. Retzer ob- tained data on four more species, the mud, Male, smallscale darter and cluster of eggs on _ over- turned rock (Photo by Les Woodrum, Survey photog- rapher). HISTORY REPORTS bluntnose, coppercheek, and smallscale darters. Darters spawn in three general ways: they bury their eggs in the substrate and abandon them, attach them over a rela- tively large area to objects (usually plants or rocks) above the substrate and aban- dom them, or cluster them on the under- side of an object (rock or log) and guard them until they hatch. Burying eggs is characteristic of primitive species, includ- ing all six species of the genus Percina for which data are available, and of some species of the genus Etheostoma. Attaching and clustering eggs, derived behaviors, are known only in Etheostoma but have arisen independently in several subgenera. The subgenus Nothonotus is the only group of darters in which some species bury their and cluster them. In 1939 in Pennsylvania, eggs of the spotted darters, a species of Nothonotus, were others eges found clustered on the undersides of stones held as territories by males. From 1939 to 1981, no other species of Nothonotus was Material in this publication may be reprinted if credit is given to the IIlinois Natural History Survey. reported to cluster its eggs. In May 1981 the Survey ichthyologists found four clus- ters of eggs of the coppercheek darter in a large rubble riffle in the Buffalo River in Tennessee. Eggs were difficult to find in the swift water, and it was especially diffi- cult to capture a male guarding a cluster of eggs. However, one male was captured beneath a stone with a cluster of eggs attached. ‘To confirm the egg-clustering habit of the coppercheek darter, two males and four females were returned to the Survey and placed in an aquarium out- fitted with a current pump and two stones as potential clustering sites. Within three days, one male had established a territory under a stone and was guarding three small clusters of eggs. Also in May 1981, in a fast riffle in Stones River, Tennessee, a cluster of eggs and an attendant male smallscale darter, another member of the subgenus Nothon- otus, were found. The cluster contained about 346 eggs and was essentially identical to those of the spotted and coppercheek darters. The smallscale darter is a rare species, existing only in a few widely sep- arated rivers. Protection of the species will require maintenance of these rivers as free- flowing, clean streams with suitable sites for clustering eggs. The other two darters studied in 1981 were the mud and bluntnose darters, both common in Illinois. Individuals of each species were transferred at the peak of their spawning periods to aquaria at the Survey and given a variety of substrates on which to lay their eggs. Following elaborate courtship behavior, both species attached their eggs to plant material. Al- though the habitats (sluggish stream pools of both species suggested plant material as the probable site for egg deposition, two close relatives of the mud darter, the rain- bow and orangethroat darters, bury their eggs in gravel riffles. Hangingfly Parasites Mecoptera are medium-sized insects, the _adults of which range from ¥% to 1 inch in length. The two most common families of Mecoptera (Panorpidae and Bittacidae) occur throughout Illinois and generally are found in moist shady woodlands, especially along streams. Adults of the Panorpidae (scorpionflies), represented in Illinois by nine species, generally feed on dead or dying insects. Adults of the Bittacidae (hangingflies) are predaceous and hang by their forelegs from the foliage of low shrubs and herbs where they capture a variety of small prey, including mosquitoes, flies, aphids, and caterpillars. Six species of hangingflies occur in Illinois. Little is known about the biology of most species of Mecoptera, especially their Adult hanging fly Hyalobit- tacus apicalis (Photo by for- mer Survey photographer, W. D. Zehr). Spores of a microsporidium from Hyalobittacus api- calis. Wet mount photographed with Nomirski inter- ference contrast (800X) (Photo by J. V. Maddox, Sur- vey entomologist). natural enemies. Some of these natural enemies are being investigated by Survey entomologists J. V. Maddox and D. W. Webb. They found that entomopathogenic fungi of the order Entomophthorales occa- sionally infect adult Mecoptera but infec- tion rates were less than 5 percent. Neo- gregarine (Phylum Protozoa) infections were also found in adult Mecoptera but again affected less than 5 percent of the total mecopteran population. By far the most common _ pathogens fund in Mecoptera were obligate parasites of the Phylum Microspora (recently moved from the Phylum Protozoa). Adults of the hangingfly, Hyalobittacus apicalis, fre- quently were infected with a yet unde- scribed microsporidium. Infections were widespread throughout the range of H. apicalis in Illinois and have been observed every year since 1971. In one study area, from which H. apicalis adults were col- lected weekly, the infection rate steadily increased from 5 percent in mid-May, when H. apicalis adults first start emerging, to 90 percent in late July, just before H. apicalis populations disappeared. Fat body and midgut tissues of H. apicalis adults were infected by this microsporidium and heavily infected adults soon died from the infection. Microsporidia are normally transmitted from host to host by a resistant spore and in addition they may be _ transmitted through the egg from an infected female to her progeny. At this time, we do not know how the infection increases in H. apicalis throughout the season or whether the disease is transmitted through the egg to larval offspring. The microsporidium from H. apicalis as well as other microsporidia have been found infecting other species of Mecoptera. Some of these microsporidia are being described as new species while studies on their role as mortality factors in mecopteran popula- tions are continuing. James Cedric Carter, 1905-1981 J. CG. Carter, Plant Pathologist and Emeritus Head of the Section of Botany and Plant Pathology at Illinois Natural History Survey and Emeritus Professor of Plant Pathology at the University of Illi- nois, died September 27, 1981, at the age of 75 years. He served as an assistant in plant pathol- ogy at Purdue University from 1931 to 1934 and as a technical research assistant on fungicide studies at the University of Delaware during the summers of 1931 and 1932. On May 14, 1934, he joined the Section of Applied Botany and Plant Pathology of the Illinois Natural History Survey as an Assistant Botanist. He was appointed Head of the Section of Applied Botany and Plant Pathology on January 1, 1955 and received a joint appointment to the faculty of the University of Illinois as Professor of Plant Pathology that same year. After 40 years of outstanding service and devotion as a researcher, educator and ad- ministrator, he retired on June 1, 1974 and moved to Crawfordsville, Indiana, near the place where he was born. He continued part-time teaching at Wabash College in Crawfordsville during his retirement years. 0 ht “aa P James Cedric Carter. The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 Dr. Carter was an authority on shade and ornamental tree diseases. He worked on numerous diseases of trees and shrubs and was a primary influence in the early development of modern urban arboricul- ture in the United States. Some of the major tree diseases on which he worked were Verticillium wilt, wetwood of elm, anthracnose of oak and sycamore, elm phloem necrosis, Dutch elm disease, and several canker diseases of trees and shrubs. For over 25 years he was considered the foremost authority in the Midwest in the diagnosis of infectious and noninfectious diseases of trees and shrubs. His extensive knowledge and experience in observing symptoms of diseases, sectioning of fungal fruiting bodies, and identification of cul- tured organisms from infected plant mate- rial made him a highly valued resource per- son. He was the author or co-author of over 140 scientific publications. His book Dizs- eases of Midwest Trees (first published in an earlier form in 1964 as Illinois Trees: Their Diseases) , remains an important ref- erence on diagnosing tree diseases. In 1970 he published a companion manual on the selection, planting, and care of trees that is widely used by professional horticultur- ists and arboriculturists. Dr. Carter received many awards and honors during his career. Among them were a special award from the National Arborist Association for his research on the wetwood disease of elm; the Outstand- ing Service and Past Presidents awards from the Midwestern Chapter, Interna- tional Society of Arboriculture; and the Author’s Citation, Past Presidents, and Honorary Life Member awards from the International Society of Arboriculture. He was an honorary member of the Indiana Arborist Association and the Illinois Com- mercial Arborist Association. For several years he served as chairman of the Illinois Tree Experts Examining Board. Dr. Carter contributed significantly to the _ professional through his personal research and his many years of association with the International Society of Aboriculture. He was a gracious person who freely shared his knowledge, experiences, and inspired his professional associates. His friendly and kindly disposi- tion were his constant personal traits. Dr. Carter is still with us in the form of the personal inspiration he gave to those who worked with him and the many profes- sional contributions he made for the im- provement of the urban environment through the protection and maintenance of shade trees. Dr. Carter married Margaret Lucile (Rogers) Carter, also originally from In- diana, on August 18, 1934. They always graciously loved and cared for each other throughout their 47 years of marriage. He is survived by his wife, one son, two daughters, 10 grandchildren, and three ereat-grandchildren. Persons desiring individual or additional copies of this publication please write to field of arboriculture - The Illinors NATURAL HISTORY Pheasants Threaten Jasper County Prairie Chickens The introduced ring-necked pheasant has replaced the native prairie chicken over much of the great plains and eastern tall grass prairie region during the last half century or so. Most of the shift in numbers and distribution of the two species resulted from the conversion of native prairies, and later of such substitute prairies as hayfields, pastures, and grass-seed meadows, to the production of corn, soybeans, and small erains. Pheasants are more tolerant of in- tensive agriculture than are prairie chick- ens. According to many wildlife profession- als and laymen, the loss of the native bird and the gain of the exotic was purely a matter of habitat change. This contention is not entirely true according to recent evi- dence gathered by Survey wildlife biol- ogists Ronald L. Westemeier and John E. Buhnerkempe. Once numbering in the millions, prairie chickens in Illinois had been reduced to approximately 300 birds in the spring of 1981. Near Bogota in Jasper County, prairie chickens responded dramatically from 1968 to 1972 to the development of 1,000 acres of nest sanctuaries by increas- ing their numbers from about 80 to 400 birds. Similarly, 640 acres of sanctuaries were established near Kinmundy in Mar- ion County through the combined efforts of the Natural History Survey; the Illinois Department of Conservation; the Prairie Chicken Foundation of Illinois (now dis- banded) ; and the Illinois Chapter, The Nature Conservancy, plus other agencies and private conservationists. Curiously, the Kinmundy flock now exceeds the Bogota flock despite the large difference in sanctuary acreage. A critical factor differ- entiating trends in abundance of prairie REPORTS | chickens on the two areas appears to be the development of a thriving pheasant population over the past 10 years at Bo- gota, whereas the Kinmundy area has al- most no pheasants. The adverse impact of pheasants on prairie chickens at Bogota may be sum- marized as follows: (1) Both the popula- tion of, and nesting effort by, prairie chickens have become increasingly concen- trated on the two central sanctuary units, with the five peripheral sanctuary units largely abandoned or little used. (2) Harassment of courting and mating prairie chickens by pheasants has become rela- tively common. (3) The nesting effort of prairie chickens (number of nests, but espe- ; al A female prairie chicken entering her nest. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. cially hatches per hen) has been substan- dard in several springs (i.e., increasing num- bers of hens have apparently not nested) since pheasants have become abundant at Bogota. (4) For the prairie chickens that do nest, there is an increasing likelihood of parasitism by pheasants, resulting in desertion, predation, or if hatching occurs, a parasitic pheasant brood and the prob- able loss of the prairie chicken brood. Twenty-five prairie chicken nests were found that contained eggs from both species; success in hatching was signifi- cantly lower for these nests than for prairie chicken nests that contained only prairie chicken eggs. In two cases the pheasant eggs were hatched, but the prairie chicken eggs contained dead but nearly full-term embryos. The incubation period — for pheasant eggs is about 2 days shorter than the incubation period for prairie chicken eggs. (5) If parasitism does not occur, the probability of nest abandonment is in- creased, apparently related to the presence of pheasants. (6) If parasitism and deser- tion do not occur, increased embryonic mortality currently results in 1-2 fewer than normal prairie chicken chicks hatched per clutch. This fact suggests altered behavior of nesting hens, such as reduced attentive- ness during incubation due to harassment of pheasants. No species can long withstand such ad- versities as those imposed by pheasants on prairie chickens, when added to more normal problems of predation, weather, and intensive land use. At this point, the survival of prairie chickens in Jasper County must be regarded as uncertain, per- haps doubtful, with pheasants at their present high levels. Should the pheasant become well established on the Marion County prairie chicken sanctuaries —a distinct possibility — the extinction of the prairie chicken in Ilinois seems probable. A sustained program of pheasant control is clearly called for, and is being con- sidered, in programs to preserve the Illinois prairie boomer. Drought and Spruce Canker Blue and Norway spruces are highly prized as landscape trees throughout Ilh- nois. Very blue selections of Colorado spruce, called “shiners,” and the grafted blue cultivar Koster are some of the most expensive landscape plants available. The retail price of a young blue spruce at the nursery may reach $20 per foot of height. Therefore, disease or insect damage on a blue spruce can be of great concern to the grower and even more so to the home- owner. Fortunately, spruces grow well in the Midwest, with few insect or disease prob- lems. However, a stem canker disease caused by the fungus Valsa kunzei appears to be causing increasing damage on both blue and Norway spruces. Although the -disease has been recognized for many years, attempts to cause infection by artificially inoculating vigorous spruce seedlings were unsuccessful. There seemed to be some as- sociation between environmental stress and the severity of infection, but research to confirm this association was lacking until recently. Survey plant pathologist D. F. Schoene- weiss has conducted research on the role of environmental stresses in diseases of woody plants for over a decade. When he inoculated stems of Colorado blue spruce with the canker fungus and subjected the plants to controlled drought stress, typical stem cankers formed, while nonstressed stems remained resistant. The cankers ap- peared as enlarging areas of dead bark surrounding the inoculation points. Al- though the fungus was able to survive and grow to some extent in the wood of both stressed and nonstressed stems, injury was confined to the bark tissues of stressed stems. In contrast, most canker fungi at- tack and kill cells of the water-conducting tissues in the wood, causing wilting and dieback of branches. The level of water or drought stress im- posed on spruces in this study was quite severe, yet stressed plants did not exhibit visible signs of wilting. Needles and twigs of spruce are quite rigid, and it is usually not possible to tell whether a spruce is under water stress by its appearance. Since drought stress may cause spruces to become susceptible to attack by V. kunzei, proper maintenance of landscape spruce trees A Colorado blue spruce from which the lower branches had been removed over a period of several years be- cause of Valsa canker infection. Right: A swollen stem canker with the exuding pitch characteristic of the dis- ease. should include a regular watering schedule, particularly during drought periods. In his research program on stress and plant disease, Schoeneweiss has shown that other environmental stresses, in particular hard freezes following mild weather in the fall, may cause woody plants to become susceptible to attack by stem canker fungi. Studies are now in progress to determine the possible role of freezing stress in the appearance of Valsa canker on spruce. Experimental Ecological Reserves The need for preserving natural areas has long been recognized at both national and international levels. Biosphere Reserves are being established at the international level to conserve genetic diversity and en- courage environmental research and edu- cation. In the United States national wil- derness areas and state nature preserves serve as ecological reference points for The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 base-line monitoring. Research in such pre- serves is necessarily observational so that the area can remain as unaltered by man as possible. The need for other areas where experi- ments can be performed has been recog- nized only recently. In 1974 the Federal Committee on Ecological Research recom- mended Experimental Ecological Reserves “to provide sites for manipulative experi- ments, management testing, and observa- tions of the results of human impact.” The Institute of Ecology, a consortium of pri- vate, state, and national institutions dedi- cated to interinstitutional research and policy analysis in ecology, evaluated po- tential Experimental Ecological Reserves in the United States, Virgin Islands, and Puerto Rico. In 1975-1976, 67 terrestrial sites were selected, and in 1980-1981, 29 aquatic sites, including one submitted jointly by the Natural History Survey and Western Illinois University. The site is unusual because it consists of three loca- tions on two rivers: the Alice Kibbe Life Science Station of Western Illinois Uni- versity on Pools 19 and 20 of the Missis- sipp1 River, the Survey’s River Research Laboratory at Havana located at the mid- point of the Hlinois River, and the Sur- vey’s other river laboratory at Grafton at the confluence of the Mississippi and Illi- nois rivers. These laboratories will provide access to two large alluvial rivers subject to quite different degrees of human impact. The Illinois River has most certainly been the subject of large-scale manipulative experi- ments although the experiments were not designed by biologists. Observations of the results of human impact, such as the di- version of Chicago sewage into the river starting in 1900, have been made for over 100 years. The Mississippi River has been influenced relatively less by man. The joint Natural History Survey-West- ern Illinois University site is the only Ex- perimental Ecological Reserve selected in Illinois and one of only six sites (including terrestrial sites) in the North Central Plains, which includes substantial parts of 12 states. Together with the other 95 sites, the Big River Site should help to achieve the national goal of providing a network of research facilities where the functioning of major ecosystems of the United States can be investigated. Persons desiring individual or additional copies of this publication please write to The Illinors NATURAL i) ia Project Gypsy Moth A bright, sunny June afternoon with millions of caterpillars crawling over patio furniture, sides of homes, and crawling down completely defoliated trees could be a typical scene in an Illinois woodland in the not too distant future. The gypsy moth invasion into Illinois has begun. In 1981 personnel of the Illinois Department of Agriculture captured 2,634 male located Sypsy moths in_ traps throughout the state. The largest number of moths caught were in the Chicago region. The steadily increasing number of captures during the past few years indicates that outbreaks of gypsy moth caterpillars are imminent. The gypsy moth overwinters in the egg stage. Masses of eges containing from 75 to 800 eges are often found along protected areas of the tree trunks, on wooden fence posts, in rocky crevices near the infested trees, on camping trailers and tents, and in a multitude of other places. Eggs hatch in the spring when the tree leaves are un- folding. The newly hatched caterpillars climb to the treetops and often spin down on silken threads before feeding begins. Wind currents during this period can trans- port the caterpillars for miles. If wind- blown caterpillars fall on a suitable host, feeding begins. Gypsy moth larvae feed on many kinds of trees and shrubs but the favorite hosts are oaks. Oak trees which are defoliated for 3 consecutive years often die. The caterpillars feed voraciously on the plant foliage for about 5 weeks. When mature the dark colored caterpillars can be recognized by the 5 pairs of blue and 6 pairs of rust colored dots down the back. With the completion of feeding the larvae wander over tree trunks, the ground, and surrounding structures where they spin cocoons and change into the inactive pupal Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. HISTORY Gypsy moth caterpillar (full grown length ca. 50 mm). (Photo by J. E. Appleby). stage which lasts about 3 weeks. Pupae can be transported great distances if they are attached to automobiles, campers, and rail- road cars. It is during years when high populations occur in the eastern states that pupae are often transported into the Mid- west. Upon emergence from the pupa, the nearly flightless white female moth pro- duces a powerful odor or pheromone It is the synthesized pheromone which is used in The with the which attracts the male moths. traps to capture the male moths. dark brown male moths mate female, and shortly thereafter the female moths deposit the ego clusters. The ego clusters also can be transported great distances by vehicles. High populations of the gypsy moth generally exist for about 3 after which there is a dramatic decline in pop- years, ulation due to diseases, parasites, and predators. Presently, scientists at the Natural His- tory Survey are planning strategies to cope with the anticipated gypsy moth problem. Educational materials to inform the public on how to deal with this problem are being planned. The introduction of parasites, predators and gypsy moth diseases will be studied, and the public will be encouraged to aid in combating the pest. Disaster Species and Blizzards Certain populations of birds are espeé- cially susceptible to winter’s cold and ex- hibit sizeable declines in years with pro- longed periods of freezing temperatures. The problem probably is accentuated by snow cover and shortages of mast and other natural foods. Species that are notably subject to such winter mortality have been dubbed “disaster species,’ and in_ the eastern United States include the Carolina wren, hermit thrush, and eastern bluebird, all of which winter in Illinois. Winter kills of these species are probably particularly severe in the latitudes between 35°-39°N — far enough south to have large popula- tions of the sensitive species and _ far enough north to have the kind of weather which produces kills. But even farther south, populations of more sensitive species such as the house wren and eastern phoebe succumb when the winters are unusually cold. January 1982 was the 5th anniversary of the worst such kill on record in Illinois and surrounding states. The blizzard of January 1977 virtually killed Illinois’ entire popula- tions of the winter wren, Carolina wren, thrush, kinelet, ruby-crowned kinglet, and field sparrow. Other species hermit eolden-crowned (brown thrasher, eastern bluebird, and most of the ground-foraging suffered population losses of 80-90% before the weather ameliorated in sparrows ) February. The occurrence of this high mortality so quickly over such a large area was unprecedented in the experience of Carolina wren, Urbana, Illinois, 15 May 1971. (Photo by J. W. Graber). survey ornithologists Jean and Dick Graber who described the kill in a 1979 paper. Certain general patterns, relating to survival, emerged from the study. There were massive shifts of populations between habitats, as birds searched for food re-. sources. Because of human help in provid- ing food, birds survived better in urban areas than in their natural habitats. Not surprisingly, small species fared worse than large species, and the higher populations were above their average winter level, the more seriously they declined. The 1977 kill was the worst on record, but the sensitive species have endured massive kills before —in (notably) 1941 and 1958-1959. Despite their susceptibility, these populations are healthy as indicated by their ability to recover from such blows. Bluebirds, which were decimated in 1958, were starting to recover by 1962 and were nearly back to normal by 1964. Because of the severity of the 1977 kill and its extent from Iowa and northern Arkansas east to Pennsylvania and West Virginia, there was concern about the chances of recovery. Precisely how the recovery takes place is not understood. Would there be a vast area devoid of, say, Carolina wrens for many years to come as birds filled in slowly from the edges of the areas where they survived? Though we still don’t know the recovery process, the Christmas bird counts provide a measure of how fast it is occurring. The counts made mainly in December of each / SOUTH x / CAROLINA WRENS PER PARTY HOUR Wesel 75 76 77 78 79 80 YEAR Numbers of Carolina wrens seen on Christmas counts in southern, central and northern Illinois before and after the blizzard of January 1977. year did not show the kill of Carolina wrens until about a year later. By that time there was already a tiny population in southern Illinois, but none in the central or northern parts of the state. In spite of two more bad winters, the wren population held on, and by December 1980 (the last Christmas counts available) was starting to climb. Carolina wrens winter especially in the bottomland forests of southern Ih- nois. Censuses by the Grabers in that habitat in late December 1981 revealed population densities of Carolina wrens back to the level they were before the blizzard of °77. We have to admire the resiliency of these little birds. Genetic Studies of Largemouth Bass The largemouth bass, Micropterus sal- moides, is one of the most sought after and highly managed sport fish in the United States. Its original range has been con- siderably expanded through extensive stocking programs. Almost any body of water that could conceivably support a population has been stocked, and in many cases stocked repeatedly with largemouth bass. Unfortunately, little consideration has been given to the genetic consequences of many of these programs. Largemouth bass fingerlings are sometimes transported great distances and stocked into waters with en- vironments quite different native to the fingerlings. Often these finger- lings are stocked into lakes already con- from those taining largemouth bass populations. The possibility exists that such stocking practices may irreversibly alter the genetic structure of these native laregmouth bass popula- tions. It is imperative to determine the magnitude of such changes. Scientists in the Aquatic Biology Section of the Illinois Natural History Survey and the Departments of Animal Science and Genetics and Development at the Univer- sity of Illinois are currently investigating this problem. David P. Philipp, William F. Childers and Gregory S. Whitt have completed a survey funded by the Electric Power Research Institute to determine the genetic variability existing within and among largemouth bass populations throughout the United States. Specifically, the biochemical genetic composition of each of 90 populations of largemouth bass, Micropterus salmoides, was analyzed using vertical starch gel electrophoresis followed by histochemical staining of the gels to detect gene products. The phenotypes at each of 28 enzyme loci were determined for 20 individuals per population to assess the relative number of gene differences among largemouth bass populations. The results of these analyses revealed that significant differences exist among largemouth bass populations from different areas of the country. Most dramatically, the two recognized subspecies of large- mouth bass, the northern subspecies, M. s. salmoides, and the Florida subspecies, M. s. floridanus, are genetically distinct. Each subspecies has unique gene products for certain of its genes. A given population of laregmouth bass, therefore, can be analyzed electrophoretically to determine the per- centage of genes contributed by each sub- species. The results indicated that the ranges of the two subspecies, as well as that of the intergrade zone, are different from those proposed originally. Since certain gene products are correlated with environ- mental parameters, it is highly probable that the genetic composition of individual The Minors NATUR SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 AL HISTORY laregmouth bass is integrally involved in determining the thermal tolerance /prefer- ence limits of this species. This has tre- mendous ramifications for fisheries man- agement practices. Past hatchery procedures have all too often overlooked genetic differences be- tween populations. It is particularly dis- tressine to observe the degree to which ‘Florida largemouths” are being propa- gated and widely dispersed in states other than Florida. The viability and reproduc- tive success of these introduced bass in these foreign environments is unknown. The present demonstration of genetically divergent populations suggests that many states may be wasting valuable resources by attempting to introduce “Florida bass” of questionable genetic composition into their lakes. Once genetic differences between largemouth bass populations are better understood, and once the role that short- term and long-term fitness plays in deter- mining the range and distribution of phenotypes is more fully elucidated, fish- eries biologists will be in a better position to design effective management programs. This study has generated the following recommendations for improving manage- ment procedures for largemouth bass: 1. Each state should be responsible for analyzing samples of largemouth bass from a number of lakes and_ rivers throughout its area to determine the genetic composition of these populations so that baseline data will exist from which sound management plans can be constructed. Each state should determine the genetic composition of samples of all large- mouth bass produced in its hatchery system, as well as of samples of all large- mouth bass obtained from other sources. to insure genetic compatibility with na- tive stocks. Each state should select hatchery brood stock regularly from wild populations highly representative of the area which that hatchery serves. Several batches may be required to produce several — different stocks of largemouth bass, each to be used for different environments or situations. The effectiveness of the stocking pro- eram should be evaluated and long- term effects on the genetic composition of specified laregmouth bass populations should be monitored. All precautions should be taken to in- sure that the genetic integrity of the two subspecies of largemouth bass are pro- tected from uncontrolled promiscuous stocking programs. The Illinois Department of Conservation in conjunction with the Illinois Natural History Survey is currently practicing these recommended procedures in the design and implementation of the largemouth bass management programs within the State of Illinois, procedures which should result in more efficient and effective management of this important game fish. February 1982, No. 214. Published monthly except in July and August by the Natural History Survey, a division »f the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation Prepared by George L. Godfrey with the collaboration of the Survey staff second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Buildina, Champaian, Illinois Persons desiring individual or additional copies of this publication please write to PAUL G. RISSER HIE LLINOIS NATURAL H TORY ry DEPARTMENT OF ENERGY AND NATURAL RESOURCES IURCES BUILDIN 507 £ PEAE yy CHAMPA IS 6182 The Illinows NATURAL HISTORY sU REPORTS | What Are Lichens? Lichens are mysterious and unusual plants, according to Survey mycologist and lichen- ologist J. Leland Crane. Part of the mys- tery lies in their very nature. An individual lichen is a unique organism composed of a microscopic green or blue-green alga and a colorless fungus. The alga and fungus live together in a mutually beneficial asso- ciation termed “symbiosis.” The plant body that is formed has no resemblance to either the algal or the fungal component. The algal partner provides food energy through photosynthesis, and the fungal partner lives on this food, makes up the bulk of the lichen body, protects the alga from dessication, absorbs mineral elements and water, and synthesizes many essential organic compounds. Lichens are widely distributed and are found on a great variety of substrates, such as rocks, trees, woods, and soil. They are found in the Arctic (where they are dominant in the tundra) and the Antarc- tic, from sea level to alpine habitats, in deserts, and in freshwater and marine environments. Some lichen communities last for centuries in the Arctic and Antarc- tic, but if the environment is disturbed. they are eventually replaced by mosses, liverworts, and higher plants. Lichenology, the study of lichens, still lags behind studies of the higher plants and even of mosses and fungi as a de- veloping science, but this lag means that it is an exciting field where many new discoveries can be made. Movements of White-tailed Deer Movements of wild animals have long interested biologists, and a large number Two species of the lichen genus Parmelia attached to rock (left) and to tree branches (right). (Photos by J. Leland Crane) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey of studies have included descriptions of animal movements. Many birds are well known for their long-distance flying ability and seasonal migrations of thousands of miles. The movements of mammals are generally less familiar but can be equally remarkable. The caribou, for example, may travel 500-600 miles between its win- ter and summer ranges. Research has been done throughout North America on the movements of white- tailed deer. Though not as mobile as the caribou, deer travel greater distances than most people realize. In the more southern states, where seasonal changes in weather are slight, deer move only short distances, usually less than 3 miles. In the north, where weather changes are more extreme, deer migrate between summer areas and winter “yards” or concentration areas, which may be as much as 25 miles apart. Deer movements in Illinois have been examined in the past by biologists of the Natural History Survey and Southern Ili- nois University in the more forested south- ern part of the state. They found that marked deer traveled up to 22 miles from the release site, with yearling bucks going the farthest. Until recently, very little was known about the movements of deer in the north- ern, more agricultural areas of the state. Survey biologists C. M. Nixon, Lonnie P. Hansen, and James E. Chelsvig are cur- rently studying the movements of deer at Robert Allerton Park near Monticello in Piatt County. The deer are captured and fitted with radio-transmitter collars or some form of visual identification, such as ear streamers or plastic reflector collars. About 57 percent of the deer marked during the first 2 years of the study are believed to have left the park. Some deer migrate between their winter range in Allerton Park and their summer range somewhere within 15 miles of the park. Other deer that have left the park but have not returned have been observed at Champaign (27 miles), Lake Shelbyville (33 miles), Chesterville (24 miles), Ho- mer (38 miles), Taylorville (48 mules), Sigel (55 miles), and Morris (91 miles). These results indicate that deer in Illinois A doe fawn about 8 months old wearing a reflector collar. (Photographed at Robert James E. Chelsvig) Allerton Park by are not as sedentary as is generally be- lieved. Some questions that remain unan- swered are how many deer move into Allerton Park from other areas, and how far do they come? Answers to these ques- tions will have to come from future trap- ping and tagging efforts in other areas of the state. Dynamics of Insect Adaptation to Soybeans Economic entomologist Marcos Kogan recently prepared a report showing how insect pests adapt to soybeans, what kinds of soybean pests may occur in the future, and the long-term concerns of integrated pest management programs for soybeans. The species composition and structure of arthropods (a phylum that includes crustaceans, insects, and spiders) associ- ated with a crop are the result of a highly dynamic adaptive process. The main com- ponents of this process are the crop with its complement. of production practices, the associated fauna inhabiting or crossing the crop space, and the physical environ- ment in which the crop and the fauna coexist. When a crop plant is introduced into a new region or when the area under cultivation to a crop is expanded, there is a rapid accumulation of arthropod spe- cies capable of using the new food re- sources as they become available. The crop is colonized by numerous arthropod species that may or may not remain asso- ciated with it. Certain of these species may, in time, become predominant ele- ments of the fauna and eventually reach pest status. The development of arthropod com- munities on soybeans in the western hemi- sphere has followed such a process of adaptation. The soybean, a plant native to eastern Asia, was introduced into North America in the early 1800’s. In 80 per- cent of the world soybean acreage this crop has been extensively grown for less than 50 years. As one tries to assess the variation in pest status of arthropod species within regional soybean arthropod communities. four key questions must be addressed. (1) Are all major plant parts, at every growth stage, efficiently exploited by ar- thropod pests? (2) After the introduction of soybeans into a new region, what have been the major sources of colonizers? (3) What are the sources of potential new colonizers after an initial species equilib- rium has been achieved? (4) Can control practices in an integrated pest manage- ment program accelerate or delay the adaptive processes that lead to a fuller exploitation of soybean resources by ar- thropods? Kogan attempted to answer these ques- tions by comparing soybean arthropod communities in North and South America, regions where the crop has been intro- duced rather recently, with arthropod communities in east Asia, the probable center of soybean origin. The answer to the first question (niche occupancy) is that in the Orient there is a rich fauna on soybeans capable of effec- tively exploiting most identifiable resources. The most serious pests in this region are oligophagous (eating only a few, usually related, plants) and are well adapted to soybeans. In America, however, most ma- jor soybean pest species are polyphagous (eating various plants). Furthermore, it seems that several critical niches are un- occupied or incompletely occupied. This is particularly true for pod-boring species in-the United States and to some extent also in major growing areas in Brazil. The second question concerns the sources of colonizers of soybean fields after the plant has been introduced into new areas. When soybeans have been introduced into new regions in North and South America, they usually have replaced other crops or the natural plant cover (meadows or woods). Certain elements of the existing fauna in the region have adjusted to the new crop. These adjustments have been more or less gradual, and in general have included: (1) the expansion of host ranges by polyphagous species to include the soy- bean in their diets, (2) the gradual ad- justment to feeding on the soybean by oligophagous species normally associated with cultivated or wild legumes, and (3) the changing of feeding habits by oli- gophagous species adapted to feeding on other plants so that they have become capable of eating and developing on soy- beans. The answer to the second question is, therefore, that the soybean arthropod com- munity in North and South America is constituted of elements of the fauna that existed in the area before the introduction of the crop. The occupation of soybean niches occurred rather rapidly, generally resulting in a rich fauna associated with the crop. This fauna, however, is not specialized to soybean feeding, and in most instances, plants preferred for feeding and oviposition are other cultivated legumes or plants of the wild flora. In the Orient, however, certain species are highly adapted to soybean feeding. The third question refers to the prob- ability of the replacement of existing spe- cies by others that may have a competitive advantage for occupation of the same niches. These potential colonizers may re- sult from changes in species of the native fauna or from the immigration of exotic species. Natural mechanisms capable of producing changes in the local fauna are (1) legume-associated oligophagous feed- The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 ers becoming better able to exploit soy- bean resources, (2) greater specialization of polyphagous species with regard to the soybean, (3) shifts in the food range of non-legume-associated oligophagous _ spe- cies, and (4) accidental invasion of the area by exotic species. Research shows that such shifts in feed- ing habits have indeed occurred in the past. The fourth and eventually most dan- gerous source of new colonizers is immi- grant species, particularly from countries in which soybeans have been cultivated for a long time. The midwestern states may be particularly vulnerable to this kind of invasion, because species highly adapted to soybeans in the Orient occur in areas of similar latitude and overall ecological conditions. The pod borers are the most serious candidates for movement from the Orient to the Americas, and certain de- foliators may represent a potential threat in the opposite direction. Early detection of possible transcontinental shifts is per- haps the only measure to forestall the im- pact of immigrant species. The final question, then, is whether certain control practices can accelerate or delay the evolutionary processes that lead to a fuller exploitation of available niches in soybeans. Integrated pest man- agement includes, among other tactics, cultural practices (such as the elimination of preferred plant hosts, the associated crops within the agroecosystem, the pres- ence of alternate hosts as sources of colo- nizers, row spacing, various tillage practices, the selection of planting dates, and crop rotation), host plant resistance to pests, and chemical controls. Integrated pest management, as a multifaceted approach to the regulation of pest populations, must consider in each case the long-range effects of every control tactic. Since the ecological balance in agricultural communities is ex- tremely delicate, any changes in these practices may bring about serious shifts in the faunal composition. Some of these have been detected in the past, and others may be predicted for the future. The threat of an evolving, better adapted insect fauna less vulnerable to currently available control tactics must be consid- ered in planning long-term insect pest management systems for soybeans. Moni- toring these faunal shifts should be an integral part of research programs in soy- bean entomology. Person desiring individual or additional copies of this publication please write to The Illinows NATURAL SURYaiae Managing Soybean Insects A very informative publication, ‘‘Soy- bean Insects: Identification and Manage- ment in Illinois,” University of Illinois Ag- ricultural Experiment Station Bulletin 775 recently was published by Marcos Kogan and Donald E. Kuhlman of the Illinois Natural History and the University of Illi- nois. This profusely illustrated 58-page manual contains economic, ecological, and entomological guidelines that are intended to optimize effective, insect pest manage- ment practices for soybean production. Publication of the bulletin was made pos- sible by a grant from the Illinois Soybean Program Operating Board. Soybean in Illinois long has been thought to be somewhat free of major in- sect pests. Actually, insects can attack soy- bean through much of the growing season, and this crop that has become so important HISTORY to Illinois’ total economy should be mon- itored for pest insects. Soybean presently constitutes one-third of the state’s annual cash farm income. This economic signifi- cance has made it important to manage soybean insect pests with greater consider- ation for the overall soybean insect com- plex. “Soybean Insects...” this developing need. For the record, in- sect pest management programs are not developed hastily because of the complex- ity of interrelated issues. Kogan and Kuhl- man synthesized the results of numerous to establish their management guidelines ap- plicable to Illinois. The supporting back- ground can be traced to local, state, na- tional, and international programs in which the Survey and the University of Illinois, plus several other institutions, jointly have participated. is one response to research programs and_ experiences Growth stages of a soybean plant with associated insect complexes (VE-V3 seed- ling; V5 = early vegetative growth; R2 = full bloom; R5 = beginning seed; R8 full maturity). R8 Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. The guidelines established by the au- thors are aimed at a wide audience: grow- ers, extension advisers, pest consultants, pesticide dealers and applicators, pest scouts, and farm managers. The bulletin’s contents cover growth of the soybean, iden- tification and biology of soybean pests, and the procedures for establishing a soybean pest management program. The succinct writing, the informative charts and figures, and the numerous color illustrations lend to a very readable format. Persons desiring to purchase individual or multiple copies of this new publication may address their inquiries to the Univer- sity of Illinois, Office of Agricultural Pub- lications, 123 Mumford Hall, 1301 West Gregory Dr., Urbana, IL 61801 or call © 217-333-2548. Long-Term Ecological Research on Major Rivers A 5-year, 1.3 million dollar grant from the National Science Foundation (NSF) for a Long-Term Ecological Research (LTER) Project has been awarded to II- linois’ Natural History Survey, Geological Survey and Water Survey, all divisions of the Department of Energy and Natural Resources, and to Western Illinois Uni- versity. The project is designed to study the biological processes in large rivers, specifically the Illinois and Mississippi. ‘The study, contingent on the availability of funds and scientific progress, may last as long as 30 years. Richard Sparks of the Natural History Survey is the principal investigator of the overall project. Other Natural History Sur- vey staff members who will be involved in this new study are Ken Lubinski, Michael Wiley, Robert Costanza, Robert Gorden, and Paul Risser, Chief. They will cooper- ate with the co-investigators from the other institutions. The Division of Environmental Biology of NSF began a new emphasis on long- term research in 1980. ‘This was in response to the subtle pressures that human. tech- nology is imposing on many populations, plant and animal communities, ecosystems, and on the earth’s biochemistry. It is an- ticipated that long-term ecological re- search on selected ecosystems will result in understanding them sufficiently to pre- dict their responses to disturbances, and to aid in decision making on policy options, environmental assessment, resources man- agement studies, and instruction of students. The LTER Project awarded to the aforementioned institutions is one of only 11 funded throughout the U.S.A. and is the only one on river systems. The others include temperate forests, grasslands and prairies, a coastal marsh, the Okefenokee Swamp in Georgia, Wisconsin lakes, and the Jornada Desert in New Mexico. Pri- mary considerations of NSF in the accept- ance of the Illinois interinstitutional pro- posal were the willingness of the principal investigators to make long-term commit- ments, the continuity of leadership, in- stitutional cost sharing, physical facilities, site integrity, lack of conflict in site use, and long-term agreement with site owners. Survey scientists will begin their investi- gation of major river ecosystems at 3 se- lected sites: Pool 19 (Keokuk Pool) on the Mississippi; Pool 26 on both the Illi- nois and Mississippi, with research con- centration on the reaches above and below the new dam; and the Peoria Lake portion of Peoria Pool, on the Illinois River. They will start sampling Pool 19 this year, Pool 26 in 1983, and Peoria Pool in 1984. In- tensive sampling will be conducted on each pool every third year, while less intensive monitoring will be continued on all pools every year. Pool 19 was selected because it is the oldest navigation pool on the Upper Mis- sissippi River and is one of the most pro- ductive aquatic areas in the world. Peoria Lake is considered an experimental dis- turbed area on which the Surveys have good statistical data. Pool 26 provides an opportunity to study the ecological effects of a new navigation dam. This will be the first time that ecological data have been systematically gathered before, during, and after construction of a new navigation impoundment on the nation’s largest river. The Survey scientists have developed several predictions regarding effects of disturbances (both natural and man- made) on the plants, animals, and vital processes occurring in river ecosystems. The data gathered during the LTER Project will allow testing of these predic- tions and will form a substantial basis for developing environmental assessment pro- cedures and for promoting management of the Illinois and Mississippi and other large river systems in the nation. Mercury Contamination Problem at Lake Shelbyville Investigators in 1974 found that the muscle tissue of largemouth bass from Lake Shelbyville contained concentrations of mercury in excess of the 0.5-ppm limit set by the U.S. Food and Drug Administra- tion. These fish are near the top of the aquatic food chain, and thus the occur- rence of high mercury concentrations in their tissues was indicative of mercuric contamination at lower trophic levels and quite probably in the lake itself. Because Lake Shelbyville and its watershed are located in a prime agricultural setting with little industrialization, finding excessive mercury concentrations was unusual. A 3- year study to determine the cause, extent, and prognosis of the mercury contamina- tion problem was initiated by former Sur- vey analytical chemist Kenneth E. Smith and his associates and completed by pres- ent Survey chemist Susanne G. Wood and her associates. ae e Qe CHICAGO & EASTERN ILLINOIS R.R. BRIDGE FINDLAY A 7 BRIDGE ——=— BS 53 t REPORTS | in two different forms: plants with three sets of chromosomes and plants with six When first formed. the plants have three sets of chromosomes: sets of chromosomes. these plants produce aborted unviable spores and are therefore sterile. However, through quirks in the meiotic cell division process, viable spores are occasionally pro- duced. These spores may eventually double their chromosome number, a process known as polyploidy, and form plants with six chromosome sets. The new plants, unlike their progenitors, are able to produce nor- mal spores and are fully fertile. Thus, they Herbarium Illinois bladder fern. specimen of the (Photo by Survey Photographer Les Woodrum) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. can reproduce themselves and expand their range independently of their parents. The hybrid and its two parents are found on rock cliffs and tallus slopes. A search of specimens from several Midwest- ern herbaria has revealed a total of seven locations for the Illinois bladder fern. The locations are centered around the Driftless Area where Illinois, Wisconsin, Minnesota, and Iowa meet. T'wo Illinois locations are known for the Illinois bladder fern, one in Lee County and the other in Winnebago County. Moran plans research trips to some of these sites to gain more knowledge concerning the biology of this interesting fern. Alfalfa Weevil Fungal Infection The fungus, Zoophthora phytonomz, has been recognized for many years as the most important natural control agent of the clover leaf weevil, Hypera punctata. In 1973 in eastern Canada researchers found an identical Zoophthora pathogen in larvae of the alfalfa weevil, Hypera pos- tica. This fungus was first discovered in Illinois by Survey entomologists P. L. Wat- son, R. J. Barney, J. V. Maddox, and E. J. Armbrust in Washington County on May 8). IG7Y). They conducted a study to determine whether humidity or photoperiod (the relative lengths of alternating periods of light and dark) was responsible for sporu- lation (the formation of spores) by Z. phytonomi in alfalfa weevil larvae. This study was also designed to determine the method and duration of the infection. Alfalfa weevil larvae were collected from four Illinois counties and one Kentucky county and were held in cartons containing freshly cut alfalfa that was changed daily. Every 2 hours for 24 hours eight dead larvae were randomly selected and were placed in covered petri dishes containing non-nutrient agar, which served to main- tain a high humidity in the petri dishes. Four larvae from each 2-hour period were kept in a 16-hours-light-and-8-hours-dark photoperiod at 78°F, while the other four dead larvae were kept in the reverse photo- period of 8 hours of light and 16 hours of darkness. Every 2 hours the dishes were checked for the typical whitish halo of conidial spores surrounding any of the larvae, indicating that sporulation had oc- curred. After the entomologists had determined the timing of the sporulation, healthy al- falfa weevil larvae were exposed to the in- fectious spores by two methods. Twenty potentially sporulating dead larvae were placed singly on agar disks, and each was inverted over a healthy larva of the second or third instar (a stage in an insect’s life) in a separate petri dish. This method was called the shower technique. In the other treatment, fungus spores were directly ap- plied to the alfalfa weevil larvae, and this was called the contact technique. Ten lar- . vae in the second instar and ten in the third were exposed to spores in each treat- ment. All larvae were exposed to spores for 24 hours, and an alfalfa leaflet was pro- vided to each larva for food during the exposure. Larvae were transferred after 24 hours to separate rearing cages to complete their development at 78°F. The researchers found that the photo- period had no effect on the sporulation of Z. phytonomi in alfalfa weevil larvae. Other scientists had found that peak spor- ulation of the related fungus Z. gammae occurred between 4 and 8 hours after be- ing placed in chambers having high hu- midity. The same was shown to be the case with Z. phytonomi, since the mean time required for dead larvae to produce conidial spore showers was 6.8 hours re- gardless of the photoperiod used. Other researchers had found that peak sporulation of the fungus Z. gammae oc- curred in the early morning hours. Most of the sporulation in this study also occurred between midnight and 4 a.m. The ento- mologists concluded that high humidity was the primary factor initiating sporula- tion by Z. phytonomi in alfalfa weevil larvae. They believe that sporulation by Z. phytonomi under field conditions prob- ably occurs in the early morning hours when the relative humidity is the greatest. High humidity would protect the spores against rapid drying and inactivation and is conducive to further infections, as has been suggested by other scientists. Infected alfalfa weevil larvae died within 7 days regardless of the method of infection. The rate of infection of larvae that were exposed to the spore shower was 95 percent. The contact technique pro- duced infection in 25 percent of the larvae. However, no matter which _ infection method was used, all larvae exposed to spores as second-instar larvae produced in- fectious spores, while those exposed as third-instar larvae produced resting spores. The finding that infectious or resting spores were formed, depending on the larval instar infected, was an unexpected result that may explain the timing of the fungal infection of alfalfa weevil larvae in the field and the quick occurrence and departure of the infection from the field in the spring. Natural History Survey Publications Available to You The mission of the Illinois Natural His- tory Survey is to study and investigate the living natural resources of the state, pre- pare printed reports, and furnish informa- tion on the protection and conservation, development, and use of these resources. Survey scientists recognize that the final step in the research process is the publica- tion of the results of research. Consequently, Survey scientists write many reports each year, most of which are published in scientific and technical jour- nals and some of which are published by the Natural History Survey itself. Most of these publications are available free of charge to residents of Illinois and to sci- entists and research organizations outside of Illinois. In the past year the Survey has published a 459-page monograph on 4 years of interdisciplinary investigations on the ecology of a power plant cooling lake and shorter reports on the life history of a small fish, the Tennessee snubnose darter; effects of ingested lead-iron shot on mallards; and the population, ecology, dis- tribution, and abundance of Illinois pheas- ants. In the preceding year one Survey booklet was titled Observing, Photograph- ing, and Collecting Plants. A 20-page bro- chure about the Natural History Survey has recently been published, and a list of Survey publications is also available. To receive the list of publications, to request a publication, or to have your Illinois Natural research Results of and information on how to apply these results are published as Survey Bulletins, Biological Notes, and Circulars, available free to Illinois residents. (Photo by Survey Photographer Les Woodrum) History Survey name placed on the mailing list for [/linois Natural History Survey Reports, write to Dr. Paul G. Risser, Chief, Illinois Natural History Survey, Natural Resources Build- ing, 607 East Peabody Drive, Champaign, Illinois 61820. Insecticide and PCB Levels in Woodcocks, Robins, and Mourning Doves Levels of heptachlor, heptachlor epox- ide, aldrin, dieldrin, p,p’DDE, and poly- chlorinated biphenyl (PCB) have been de- termined for muscle, liver, heart, brain, and fat samples from 15 woodcocks, 6 robins, and 8 mourning doves from east- central Illinois collected in 1979 and 1980 during an ongoing woodcock population ecology study by wildlife ecologist William R. Edwards and his associates. Although pesticides were recorded at generally low levels, consistently lower than 1 part per million (ppm), all woodcocks were found to contain one or more of the six compounds assayed; the average wood- cock had 2.4 of the six compounds. The same was true for robins, with an average of three compounds per individual, and mourning doves, with an average of 2.4 per individual. Of all 107 samples assayed, 3 (2.8 percent) contained heptachlor, 54 (50.5 percent) contained heptachlor epox- ide, 1 (0.9 percent) contained aldrin, 86 (80.4 percent) contained dieldrin, 22 (20.6 percent) contained DDE, and 9 (8.4 per- cent) contained PCB’s. In general, it appeared that the insecti- cide loads of woodcocks and mourning The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 doves were similar, whereas those of robins showed more individuals with heptachlor and heptachlor epoxide and fewer with di- eldrin. The only incidence of aldrin oc- curred in a robin. Robins may have hada higher incidence of PCB’s; however, sam- ple sizes were small and the results cannot be considered conclusive. On the basis of food habits, the researchers anticipated that the insecticide loads of woodcocks and robins would be similar and that of mourn- ing doves somewhat different, as the former eat large quantities of earthworms and the latter are considered largely seed and grain eaters. At this time the scientists can offer no basic explanation for the ap- parent anomaly in the insecticide loads of May 1982. No. 217 the Illinoi Published monthly ex Conservation Pre pare d by Robert M. Zewadski with the paid at Urbana, Illinois Natural Resources Second-class postage Office of publication: 172 Building ept in July and August by the Department of Energy and Natural Resource collaboration (USPS 2 woodcocks, mourning doves, and robins from east-central Illinois. Chlorinated hydrocarbon _ insecticides have been commonly used to control soil insects in corn since World War II. How- ever, DDT has not been used extensively since the late 1950’s. The use of aldrin de- clined after 1966 and effectively ended in 1976, as did that of heptachlor in 1978. Data from several studies in Illinois and elsewhere suggest that the incidence of DDE, and probably other chlorinated hy- drocarbon residues, is declining in wildlife. This decline is probably not true of PCB’s. Survey wildlife ecologists will continue to monitor pesticide levels in woodcocks and associated bird species. Natural History Survey, a division of operating under the Board of Natural Resources and of the Survey staff 58-220) Champaign, Illinois Person desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER NATURAL RESOURCES CHIEF TLLING RVEY, DEPARTMENT OF ENERGY AND NATURAL >N ILLINOIS 618 S NATURAL HISTORY Sl BUILDING, 607 E. PEABODY, CHAMPAI RESOURCES The Illinovs NATURAL Illinois Agriculture and the Declining Survival Rate of Pheasant Chicks The intensive use of land for agriculture in Illinois generally has caused declines in the abundance of wildlife. However, for many species the actual mechanisms of such declines are unknown. Wildlife ecolo- gist Richard E. Warner is conducting a long-term study of interactions between agriculture and ring-necked pheasant pop- ulations in Illinois. The findings of this may illustrate the effects of declining habitat for a variety of grassland species. For example, information collected for pheasant populations in Illinois suggests that over the past three decades the sur- vival of pheasant chicks has declined. The research Pheasant chick requires insect diet during the first few weeks of life. Without it, there is little chance of survival. (Photo by W. E. Clark) Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. HISTORY REPORTS — average number of eggs hatched per nest has remained relatively constant during this period. Yet the average number of chicks observed per brood along standard- ized routes near Sibley (Ford County) has declined from 6-9 during 1948-1954 to 6-7 during 1955-1959, 5-6 during 1960-1964, approximately 4 during 1965-1969, and 3-4 during the 1970’s. Moreover the Illi- nois Department of Conservation’s brood counts corroborate these trends for most of this state’s pheasant range. The decline in the survival rate of pheasant chicks may be a significant limi- tation for the abundance of pheasants in Illinois. Increased mortality of young pheasants appears to be related to the ex- panded production of corn and soybeans, with associated clean farming practices. Pheasant chicks require a near-total insect diet during the first few weeks of life. Traditionally, broods have foraged for in- sects in oat stubble and forage legume fields; such fields are nearly absent on the landscape in many parts of Illinois today. It is plausible that the reduction in both quality and quantity of forage habitat for pheasant broods is in part related to the decline in pheasant numbers. Because a variety of grassland birds forage for food in similar habitats, the pheasant chick may be representative of a wide-spread decline in the survival of young birds in Illinois. Rare Wasp Found The wasp family Rhopalosomatidae has been found to occur in several states neighboring Illinois, but until now has not been recorded from Illinois. Three speci- Mahomet, mens were collected near Champaign County, by former Survey entomologist Milton W. Sanderson in 1968 and recently were recognized in the Sur- vey’s Insect Collection by Survey entomol- ogist W. E. LaBerge and identified as being Olixon banksu (Brues). This wasp is about % inch long, pale colored, has very short wings and cannot fly, and has extremely long hind legs. The females of Olixon pursue crickets, espe- cially the common small brown or black sround crickets of the genus Nemobius, and lay an egg on the surface of the cricket. The larva which hatches from this egg remains attached to the cricket, feeding as an external parasite and eventually drop- ping to the ground to pupate and emerge as an adult wasp. The cricket begins to die and dies as the wasp larva reaches maturity. It is likely that Olixon occurs throughout the state of Illinois, especially in wooded areas, although it has been collected only this one time. Its small size, inability to fly, and other habits make it easily overlooked by entomologists. The wasps were collected by Sanderson in pan-traps placed with their rims flush with the surface of the soil in a wooded area. About an inch of water with a drop of detergent is placed in the pan and insects that inadvertently drop into the water are unable to escape because of the lowered surface tension. Because of its habits, Olixon banksu must be considered to be a beneficial in- sect, although of such rarity as to be not of great importance. How common or rare it actually is, however, has never been as- sessed. Rare wasp, Olixon banksii (Brues), identified in Sur- vey's Insect Collection. (Photo by David Voegftlin) Water Resources: Assessment of Biotic Integrity The surface waters of the United States absorbed pollutants as well as other im- pacts of a developing society for several centuries before signs of degradation could no longer be ignored. A “dilution-is-the- solution-to-pollution” approach to waste disposal prevailed and typically resulted in grossly polluted water and associated losses of aquatic resources (particularly fishes). By the mid-twentieth century, early legis- lative efforts were initiated to halt and perhaps reverse this ominous trend. Passage of the Water Quality Act Amendments of 1972 stimulated many “efforts to monitor the quality of water re- source systems and to control a host of societal effluents. The primary approach was to restore the chemical quality of water; it was presumed that improvements in biological quality would follow close at hand. In many cases streams were viewed as conduits for the transport of water and. water development schemes rarely in- cluded assessments of biological impacts. As a result habitat quality and thus biotic integrity continued to decline in many areas despite massive expenditures of funds. Ironically, man’s ‘“‘technological solutions” to water resource problems sometimes con- tributed to declines in biotic integrity (e.g., chlorine toxicity in the effluent of sewage treatment plants). Recent legislation such as the Clean Water Act of 1977 clearly called for a more refined approach when pollution was defined as “the man-made or man-induced alteration of the chemical, physical, bio- logical, and _ radiological integrity of water.” Despite this refinement, regulatory agencies have been slow to replace the classical approach (uniform — standards focusing on contaminant levels) with a more sophisticated and environmentally sound approach. The integrity of water resources can best be assessed by evaluating the degree to which waters provide for beneficial uses. Important uses as defined by society may include water supply, recreational, and other uses as well as the preservation of future options for the use of the resource. Since an ability to support a balanced biotic community is one of the best indi- cators of the potential for beneficial use, sophisticated monitoring programs should seek to assess “biotic integrity.” During the past few years, James R. Karr, an affiliate of the Survey’s Aquatic Biology Section and Professor in the De- partment of Ecology, Ethology, and Evolu- tion at the University of Illinois, has con- ducted research supported by the U.S. Environmental Protection Agency that has resulted in the development of a new system for monitoring the quality of a water resource. This system directly eval- uates biotic integrity through the use of a special index, a multi-parameter model similar to the multi-parameter assessments used by economists. The core of the system Fish are collected for evaluation of effects of pollu- tion in Big Creek, Hardin County. (Photo by James R. Karr) IG DITC = oe a =| = 50 BIG CH |Goop ™m = = = === = | mh mM LiisMean uJ LU ieee DIY > in | fT Hoh TT “Srange |raip m HoH a Bl < 40 == oe = See | > a hd til | Wo x aa) T| (QS SS SSS SSS SSS os be uu ra) a POOR Z 30 al H | = & al 1 Pera S66 7 J6e9 STATION Change in Index of Biotic Integrity along a stream gradient (Big Ditch, Champaign County) from head- water (Station 1) to downstream (Station 10). Stations 2 to 4 are low because of sewage input between stations 1 and 2 and stations 7 and 8 are depressed because of the poor quality of habitat conditions. Generally low values (no good or excellent condi- tions) reflect the general agricultural land use in the Big Ditch watershed. involves evaluation of about a dozen attri- butes of fish assemblages in streams. Pa- rameters include species composition and richness as well as several measures of trophic structure (food habits) in the assemblages. Additional parameters in- clude prevalence of disease and hybrid- ization. Fish are a logical group for assessment of biotic integrity because their natural histories are well known, they are relatively easy to identify, the general public can relate to statements about conditions of the fish community, and the results of studies of fishes can be directly related to the fishable waters mandate of the U.S. Coneress. The “Index of Biotic Integrity” can be used to rapidly and inexpensively assess the extent of water resource degradation. Where impaired use is suggested, a more complete monitoring program can be im- plemented to search for the causative agent or agents. With this approach, geograph- ically extensive and expensive monitoring programs can be scaled down at consider- able savings to society. Researchers and planners from through- out the United States and a number of other countries have expressed interest in the Index. Testing and evaluation of the Index continues this year under a grant from USEPA. For more information con- tact James R. Karr, Department of Ecol- ogy, Ethology, and Evolution, 102a Vi- varium, (217) 333-1633. Survey Speakers Available In the spring of 1981, a Survey Speakers’ Bureau was organized and researchers were asked to volunteer their services to the project. Members of the Survey staff volunteered their services, agreeing to speak on a variety of subjects, among which are Water Pollu- tion, River Biology, Integration of Aqua- culture with Agriculture, The Rose Family, Illinois Wildflowers, Natural Areas, Butter- flies in Illinois, Research on Deer, and a general talk on the Illinois Natural History Survey. Anyone wishing to engage a speaker should contact the Speakers’ Bureau at (217) 333-6882. The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 So That We Might Serve You Better In order to update our files and to increase the dissemination of knowledge, the Survey is in the process of revising its mailing list. We ask that you take a minute of your time to fill out this questionnaire and return it as soon as possible. 1. Do you wish to continue receiving the Survey Reports? Yes. _ No___ 2. Have you received a list of our publications within the last year? Yes... _— No__ If not, would you like to receive a copy? Yes No __ 3. Would you like to receive additional information (seminar announcements, publication fliers, etc.) in the area of: Aquatic Biology Yes Botany & Plant Pathology Yes___ Economic Entomology Yesuaae Faunistic Survey Yes___ Wildlife Research Yes__ 4. Why are you interested in our publications? Member of a state agency: — : J : 2 Member of news media: E : Researcher/teacher Business person eaoge Layperson 5. Is your address correct as printed? Yes__._ No__ If not, please correct: ee ee = We appreciate your help. If this questionnaire is not returned, we will have to drop your name from our list due to increased costs of publishing and mailing. Date Signature Do you know of others who would like to receive our publications? June 1982. No. 218. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation Prepared by Shirley McClellan with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING, 607 E. PEABODY, CHAMPAIGN LLINOIS 6182 The Illinors NATURAL Witches’ broom on honeysuckle. Upper photo is ap- pearance in summer (Photo by Les Woodrum) and lower photo is winter David Voegftlin). appearance in (Photo by HISTORY REPORTS - Alien Aphid Finds a Home An aphid thought to be a native of Eurasia has been rapidly making itself at home on many of the species and hybrids of ornamental honeysuckles planted throughout the north-central states. The feeding of this aphid, Hyadaphis tatarica (Aizenberg), causes severe deformation of the vrowinge tips, which are commonly called witches’ brooms. first found in the Montreal, Canada area in 1976. The first record in the north-central states is from Lake County, Illinois in the fall of 1979. The distribution and spread of this aphid was studied in detail during 1981 by David Voegtlin of the Illinois Natural History Survey. The aphid is very efficient at dis- tributing itself and the movement of in- It was fested plants, such as nursery stock, is probably a major factor in its rapid spread. As of the fall of 1981 the aphid was found in Ohio, Indiana, Michigan, Minnesota, Iowa, and Nebraska, as well as Wisconsin, Illinois. The insect probably will continue its spread until it covers the area in which the host honeysuckles have been planted. At present the following species and hybrids of honeysuckle have been found to be attacked by this aphid: Lonicera tatar- ica, L. bella, L. minutiflora, L. muendeni- ensise. Le. None of native to North America and planting any muscavtensis. these is of these is a guarantee of future problems with this aphid. Most nurseries throughout the infested area are no longer stocking these because of the problem with this plant louse. H. tatarica and will not feed on any other plants. The is specific to honeysuckles Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. witches’ brooms can be of two _ types, pendulus or upright clusters. Both are formed by masses of increasingly small leaves which are folded in the middle with the upper side in, forming a pocket in which the aphids are located. To find the aphids one must open these folded leaves. The witches’ brooms are a lighter color than the normal leaves and when the in- festation is very heavy the outer parts of the plant take on a different hue. In late August and early September the witches’ brooms die while the normal leaves re- main green. After the regular leaves drop off in the fall, the damaged areas are highly visible, often retaining the tiny leaves throughout most of the winter. Voegtlin says control can be obtained through the use of systemic insecticides. Local agricultural extension agents can recommend the current acceptable insecti- cides for use against the aphid. Spraying will have to be done often throughout the year as there is so much wild and planted honeysuckle during the summer that a continual supply of winged aphids reinfest the plants. “Gob” Piles To Be Reclaimed If you have ever driven on I-55 south of Joliet or on US-51 north of Blooming- ton-Normal, you may have noticed some large, conical, red and grey waste-rock piles. These “gob” piles are the remnants of the state’s first industrial-scale coal min- ing district, the Longwall District, opened after the Civil War. These mines had access to the booming Chicago industrial market, and in 1882 were producing 34 percent of the coal mined in Illinois. After 1906, however, their production was exceeded by the very large, more mechanized mines in southern Illinois. By 1924, their production dropped to 1 percent of the state’s total. Finally, the Great Depression of the 1930's closed the era of the longwall mine. Over the years, a number of factors have excited interest in the reclamation of these mine sites; the very prominence of the gob piles, the large acreages of many, their proximity to towns, their nuisance and harmful features, and, recently, the creation of the Abandoned Mined Lands Reclamation Council to clean up such problem areas in the state. The Council has granted a contract to the Illinois Natural History Survey to study these longwall waste piles to determine what kinds of reclamation are practical. The mines of the Longwall District generally lie within 20 miles of the Illinois River between Morris and Peoria. Almost all old longwall mines in Illinois are found in this district; it is the only place in the nation where large tonnages of coal were mined by this method. The longwall mining method can be compared to a spoked wheel. A vertical hoisting shaft —like the axle bore — en- _tered the coal from the surface. Radiating from the shaft, like hollow spokes through the shaft pillar and the coal being mined, were permanent tunnels called the “main entries.” The main entries carried coal from the “working face” to the hoisting shaft and were extended as the coal was mined. The working face was the rim of the wheel where the coal was mined. The miners worked crouched in the 3- foot-high seam opening. But along the main entries, they took down about 4 feet of roof rock to make 7-foot high ceilings and gave themselves and their mules head- room. Because all the coal was removed in the mine the rock overhead inevitably settled down into the mine openings. To keep the main entries open, they often had to clear falls and settlements out and haul the rock to the surface. The largest of the gob piles are 180 to 190 feet high and cover 25 to 30 acres. Rains wash and gully their bare sides, carrying away mud and chemicals weath- ered from their pyritic shales. Grasses, weeds, and trees have not been able to take root on the steeper slopes of most of them. It is the purpose of the Natural History Survey to assess the feasibility of revegetat- ing the mined areas. Botanist Diane Szatoni and her associates will be examining the plant species that can survive on the barren gob piles and provide needed wildlife habitat. During June and July 1982, an exten- sive literature review was begun. Special attention was given to plant species selec- tion, soil amendments, and reclamation “Gob" pile in the Longwall District. practices of the high plateau regions, the northern Great Plains, and the eastern bituminous coal fields, where ecological conditions may be similar to those of the north-central Illinois mines. In addition, a preliminary inventory of plant species that occur on the gob piles during the spring, summer, and fall was begun. Aquaculture Workshop Held The importance of the correct selection of fish and other components to suit the aquaculture system was emphasized by Dr. William Lewis, Southern Illinois Univer- sity, at a workshop, Aquaculture-Possibil- ities for Development in Illinois, held recently at Levis Center on the campus of the University of Illinois. Fish which grow rapidly, survive cold winters, have a favorable dressed weight to live weight ratio, feed well on artificial feeds, and have a good market potential are most desirable. New species may have to be selected or developed. Genetic tech- niques are being modified which may en- able scientists to develop and clone fish with desirable traits especially adapted to aquaculture systems, according to David Philipp, Survey fisheries biologist. Although approximately 12,000 miles of streams and rivers, more than 240,000 acres of lakes and impoundments, and over 50,000 acres of reservoirs are located in Illinois, fewer than 2,500 acres are cur- rently used for aquaculture production. Thousands of acres of marginal land in southern Illinois could be converted to aquaculture impoundment systems as well. Marketing potential for fish and fish products is highly competitive with marine and freshwater commercial fisheries and with aquaculture products from _ the southern U.S. Creative production methods using thermal effluents, confinement sys- tems, agricultural waste products as feeds (see Survey Reports, May 1980), and multiple cropping, coupled with shorter transportation routes, may make Illinois aquaculture products more competitive. A study by Dr. Randy Westgren and Professor Margaret Grossman, University of Illinois, has shown that problems in the legal and regulatory environment in Illi- nois aquaculture are due to uncertainty and complexity in state laws brought about by a lack of recognition of aquaculture as a viable form of agriculture. Relatively minor modifications in both statutory and regulatory areas could result in an environ- ment favorable toward aquaculture. It is also clear that the economic infrastructure must become familiar with the potential value of aquaculture before funds for facil- ities and equipment will be available to the producers from lending agencies (see Sur- vey Reports, December 1980). Several producers of catfish and other aquaculture products described problems which range from maintenance of valuable brood stock to oxygen depletion in ponds. In spite of these problems, they have main- tained successful aquaculture operations for several years. The future of aquaculture in Illinois seems dependent upon the wise use of The Illinois NATURAL HISTORY SURVEY = DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 genetically adapted fish to suitable aquatic nition and acceptance by selected agencies; ecosystems; efficient feeding, harvesting, and modification of certain laws and processing and marketing methods; recog- regulations. September 1982. No. 219. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Re- sources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 E. PEABODY, CHAMPAIGN, ILLINOIS 61820. The Illinois NATURAL Black Cutworm Pheromone Trapping The black cutworm, Agrotis ipsilon, can be a serious pest of seedling corn in the US. belt. thought to originate from eggs oviposited corn Damaging larvae are by female moths in fields in early spring before the crop is planted. Many scien- tists believe that the moths that lay these eges immigrate to the corn belt from southern latitudes each spring. Conse- quently, early-season moth detection is im- portant, especially since pest outbreaks tend to be very sporadic. Two Survey researchers, Eli Levine and William G. Ruesink, along with several other researchers from Ohio, Iowa, Indi- ana, and Missouri, recently conducted a study on the trapping of black cutworm (BCW) moths. Once the sex pheromone (a pheromone is a mixture of chemicals released by the female moth to attract a mate) system of this moth was identified, the researchers set out to determine if synthetic-phero- mone (SP)-baited traps would improve early-season moth detection capabilities compared to the previously used black light (BL) trap (light used as a lure). Field studies were conducted in five major corn-producing states (Illinois, Indiana, Iowa, Missouri, and Ohio). In each state, SP traps and BL traps were placed in the proximity of corn or soybean fields and were examined for captured BCW moths at weekly intervals. The results of these studies showed that SP traps were a more sensitive monitoring tool than BL traps during the period when it is most important to monitor moth flight activity; namely, between early April and early June. Through the first week in HISTORY Levine examines two male moths Researcher Eli caught in black cutworm pheromone trap (Photo by Les Woodrum). June in each state, males were caught sig- nificantly sooner (on average, three weeks earlier) and in significantly greater num- bers in SP traps than in BL traps. From a pest management standpoint, it is important to know if female activity is closely related to that of males as mea- sured by SP traps during early season. Evidence suggesting that SP trap catches of males better reflect early female egg- laying activity than do BL catches of fe- males (SP traps catch only male moths, whereas, BL traps catch both males and females) was provided by a concurrent study where the reproductive condition of females from BL traps was examined. In this study, it was found that older mated females were the dominant forms during the early season. On the basis of this find- ing, it was concluded that females had deposited significant numbers of eggs pre- ceding their capture in BL traps, and therefore, the first capture of a male in a SP trap would probably serve as a useful reference point to denote the start of egg Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. laying in the central Corn Belt. A BCW development model (created and refined by Steve Troester, another Survey re- searcher), initiated with this information, could then be used to predict the oc- currence of damaging larvae. This model will provide corn producers with informa- tion on the time (date) when they should actively scout their fields for this pest. Indeed, Illinois, Iowa, and Ohio are al- ready using data from SP traps as a basis for computer prediction models. Winterizing Roses Every year people lose many rose bushes during the winter. Survey botanist Ken Robertson observes that there are several ways to eliminate or minimize this prob- lem: 1) don’t grow roses, 2) plant new roses every spring, or 3) perform some preventive maintenance. These notes have been prepared for those who select al- ternative number 3. Several basic types of roses are com- monly grown in_ Illinois — hybrid teas, erandifloras, floribundas, climbers, tree Beautiful roses are ample reward for the conscien- tious grower (Photo by Ken Robertson). - Stresses roses, and shrub roses. The vast majority of cultivated roses have beautiful but anemic stems that are grafted onto the roots of vigorous wild-type roses. This graft, or bud union, results in a knuckle- like knot of wood at the base of the stem, and the joint is very vulnerable to cold temperatures. When planting rose bushes in most parts of Illinois, the roots should be positioned so that the graft joint is located approximately 1 inch below the surface of the soil. This layer of soil will help protect the most cold-sensitive part of the rose bush from winter temperatures. In addition, most roses will benefit from additional winter protection. Robertson that NONE of the following should be done until AFTER the plants have gone domant and there has been a HARD, killing frost; if this warning is not heeded, more harm than good will be done to the plants. To protect hybrid tea, grandiflora, and floribunda roses, tie the canes together and — cover the lower part of the plant with a mound of soil (or grass clippings) to a height 6”-8”. Do NOT obtain this soil from the immediate vicinity of the rose bush since this will damage the plant’s roots. Then, cover the rest of the lower part of the plant with straw, hay, or styro- foam rose caps or cones. The plant can be dusted or sprayed with rose pesticides before making the mound. Plants may also be pruned back somewhat before covering, but it is important not to prune very heavily because the ends of branches are killed back during the winter, and if the plants have been closely pruned, this can damage major stem branches. The common climbing roses do not need special winterizing, although the base of the plant can be protected with a mound of soil, as outlined above. Some of the fancy varieties are rather tender. To pro- tect these, tie the canes together and bend them over and use stakes to hold the canes parallel to the ground. Then cover the canes with a layer of soil and/or hay. The techniques outlined above for hy- brid teas and climbers can be used for some shrub roses, while other shrub roses require no winter protection at all. Tree roses require rather specialized winter pro- tection, and information on how to do this is available at garden centers and in rose care books. As Robertson says, roses are beautiful plants and have an aura of mystique about them, having been cultivated and revered since Classical times. However, roses are not for everyone’s garden. Rather, like an expensive sports car, they are for people willing to give them considerable attention. These people find their efforts are more than amply rewarded. Study Begun at Jade Acres A study to determine the feasibility of creating a rural center of appropriate energy and agricultural technologies has been initiated by the Illinois Natural His- tory Survey. Offered as a gift to the State of Illinois by Dave and Jane Fletcher, the site for the proposed Illinois Appropriate Technology Research and Education Cen- ter is at Jade Acres near Salem, approxi- mately five miles from I-57 at the Alma exit. The 50-acre rural site is representative of the hilly, sparsely wooded, marginally agricultural land typical of southern Illi- nois. Surrounded by a 7-foot chain link fence with a large brick and iron gateway, the farm offers an impressive and beauti- ful site for research and demonstration. Extensive security measures protect the house and buildings. The 9,000-square-foot English ‘Tudor mansion, constructed in 1976, is well built and well appointed. Many construction changes added to conserve energy have effectively reduced heating and cooling costs. The home will be available for mul- tiple usage, including conference center, library, laboratories, and offices. Additional outbuildings include a storage and loafing barn, milking barn, kennels, smoke house. and summer kitchen. The latter is well equipped for food processing activities. The estate has an in-house computer and tools and equipment for farming, garden- ing and workshop. For the past six years, the Fletchers have developed the farm on organic principles. Pastures, woodlots, gardens, orchards, and pond banks have been planted with a variety of biomass- and food-producing The mansion at Jade Acres will offer facilities for the interdisciplinary research of the Survey (Photo by Mitch Beaver, Dept. of Energy and Natural Resources). perennials. Also on site are a dairy goat herd, chickens, ducks, cows and honey bees. The planned center will be an inte- grated system of energy and agricultural technologies which are efficient and effec- tive for individual homeowners and small farms. Wind, solar and biofuels technol- ogies will be coordinated with alternative agricultural methods, including perma- culture, vegetation biomass, aquaculture and dairy goat production. Research in and modification of existing methods will be an important aspect of the center. A primary goal of the program is to demon- strate soft alternative appropriate tech- nologies which are cost-effective on mar- ginal lands. A site director and advisory group are being sought for the feasibility study. Vol- unteers interested in working on the site in exchange for room, board, and valuable experience should contact: Mr. Dave Fletcher, R. R. #4, Salem, IL 62881, or telephone 618-548-4473. Pheasant Hunting 1982-1983 The ring-necked pheasant is the most popular game species in Illinois. Both the hunting and nonhunting public consider the gaudy ringneck to be a symbolic and highly visible representation of the Prairie State’s rich wildlife heritage. Thus, it is not surprising that recent declines in pheasant numbers have captured the at- tention of the public. Indeed, not all has been well with IIli- nois pheasant populations in recent years. For example, from 1973 through 1978, the The Illinois VTURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 relative abundance of pheasants declined 84% range-wide in Illinois. Declines in numbers of pheasants during the late 1970's and early 1980’s have been largely the re- sult of unusually severe winter weather. The critical long-term factor, however, has been the destruction of habitat. As farms in Illinois have become increasingly corn-soybean enterprises, forage legumes and small grains — prime pheasant habi- tat — have become scarce on the agricul- tural landscape. In spite of the relatively sparse num- bers of pheasants at present, wildlife ecol- ogist Richard E. Warner suggests that there are some factors hunters should con- sider in order to improve their success in bagging a rooster. First, hunters should be aware that the patterns of relative abun- dance and distribution of pheasants have changed substantially in Illinois over the past decade. Hunters who traditionally traveled to east-central counties should now consider arranging trips to Mason County, or northern counties such as Car- roll, De Kalb, Kendall, Lee, Ogle, Stephen- son, Will, Winnebago, or Woodford. Sec- ondly, parties should seek permission to hunt on farms that still produce hay and small grains, and that have unplowed grain stubble and permanent vegetation remaining over winter. Lastly, Warner recommends that hunters be more per- sistent. In recent years, a high percentage of pheasant hunters put their guns away ‘for the season after opening weekend. Often, however, the best pheasant hunting occurs later in the season, after the first snowfall and colder weather. Researchers have concluded that the sport hunting of cock pheasants does not adversely affect reproduction by hen pheasants the following spring. Investiga-_ tions have also shown that releasing pen- raised pheasants generally does not en- hance self-maintaining populations. Illinois pheasants would benefit primarily from habitat improvements. The Illinois De- partment of Conservation offers programs to private land owners that will enhance wildlife populations on their land. Agricultural land use policies will in the future largely contribute to the status of Illinois pheasants. In some regions of Illinois, the production of row crops has resulted in severe soil erosion. Crops that enhance or protect topsoil, such as grasses, legumes, and small grains, are relatively beneficial to pheasants. In general, pheas- ants and pheasant hunters would greatly benefit from agricultural policies and pro- grams that would both mitigate soil loss, and prevent an oversupply of feed grains in the market place. October 1982. No. 220. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Re- sources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G, RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 The Illinovs —— — NATURAL HISTORY Hold That Tiger! In an effort to tmprove the balance be- tween predator and panfish populations, increase the diversity of the angler’s catch, provide a trophy fish, and increase the growth of stunted panfish populations, Survey researchers introduced _ the tiger muskie into some small lakes and ponds of Illinois. The northern pike, muskellunge, and their hybrid offspring, the tiger muskie, are among the predator species that have been used to complement the largemouth bass. have All three of these fishes achieve greater maximum size than largemouth bass and are able theoretically to eat larger bluegill than are normally selected by bass. Because they are cool-water species they exhibit seasonal peaks in food consumption in the spring and autumn; thus, they may com- plement the feeding activity of the large- mouth bass which feeds most heavily in midsummer. The tiger muskie is a hybrid which has proven superior to both parents in many hatchery situations and possesses charac- teristics which also make it useful to the fishery manager. The tiger muskie is be- lieved to be intermediate between parents in angling vulnerability and may therefore contribute to the harvest without being overexploited. Furthermore, there is evi- dence that the tiger muskie has a higher survival and growth rate than either parent and is more tolerant of high summer water temperatures often experienced in Illinois. In 1982 aquatic biologists began a 3-year study to evaluate the impact of tiger muskies on the bass-bluegill combination in small impoundments. The study objec- tives are to determine the survival, growth, REPORTS | hooking mortality, food habits, and _ spill- way escapement of tiger muskies as well as the impact of these large predators on bass- bluegill populations. The value of the tiger muskie as a man- agement tool will not be established until the end of the project, but some useful data have already been obtained. Most of the tiger muskie research is being con- ducted at Ridge Lake, a 15-acre experi- mental fishing lake operated by the Survey in cooperation with the Illinois Depart- ment of Conservation. The lake stocked in the summer and autumn of 1981 with largemouth bass, bluegill, chan- nel catfish and 150 eight-to-ten-inch tiger muskies. was At Ridge Lake, tiger muskies are quite vulnerable to capture by hook and line, but survival of hooked fish is reasonably good. Over 40 percent of the number of stocked tiger muskies were caught during the 1982 fishing season, but only 10 percent of these died as a result of the hooking experience. Good growth, indicated by an approximate doubling in length in one year, suggests that a bass-bluegill population can provide Tiger muskie caught at Clinton measures 35 inches in length and weighs 10 pounds (Photo by Dennis Newman). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. adequate forage for tiger muskies. How- ever, the food selected by the tiger muskies is an important consideration. If large- mouth bass are eaten frequently, the po- tential value of the tiger muskie will be ereatly compromised. The lake was opened to fishing in April of 1982 and remains open each year until October 15. Since all fishermen must pass through a single checkpoint to gain access to Ridge Lake, harvest data relevant to the tiger muskie research are easily ob- tained. Also, since Ridge Lake can be com- pletely drained, it will be possible to collect precise survival and growth information on tiger muskies and associated species at the end of the projects. Two other im- poundments, stocked with tiger muskies in September of 1982, will provide informa- tion on the food habits and bluegill pop- ulation control capabilities of this species. Effects on Economic Injury Levels Of Weed/Defoliation Interactions Current integrated Pest Management systems rely on established economic in- jury levels for control decisions. Economic injury levels have been established for many soybean insect pests, but few are available for the major weeds, diseases, and nematodes; none exist that take into account the concurrent effect of multiple pests. The actual field situation, however, is one where many pests coexist and their effects are likely to be increased as a con- sequence of the multiple-pest interactions. A major difficulty in establishing eco- nomic injury levels for multiple pests re- lates to the complexity of the experimental design necessary to measure the various interactions. For example, economic injury levels for defoliating insects alone are tested using a randomized complete block design with various levels of defoliation effected at various stages of plant growth. As another pest is added, the design changes to a split-plot and each new pest requires a new split. Not only does the de- sign become cumbersome, but in the past, the implementation of the experiment was almost unmanageable. During the past two growing seasons, a method has been developed that permits adequate testing of the combined effects Michael Jeffords Researcher defoliation was completed (Pho'o by Marcos Kogan). spraying a plot after of defoliation and weed competition. The _work of researchers Charles Helm. Michael Jeffords, and Marcos Kogan used a com- mon broadleaf weed — velvetleaf, Abu- tilon theophrasti, and the soybean looper, Pseudophesia includens. The test is estab- lished on a one-acre matrix of conventional soybean of a common commercial variety. They applied a grass herbicide and used hand weeding to eliminate other unwanted broadleaf weeds. Velvetleaf seedlings were grown in the greenhouse and at crop emergence the plots were established with previously se- lected weed concentrations — four weeds per plot in 1981 and four and eight in 1982. Approximately two weeks prior to the date at which defoliation was to be effected, the 6 x 6 feet plots were covered with walk-in saran cages. Defoliation was produced by feeding of soybean looper larvae. The soybean looper is well adapted to soybean but usually does not eat velvetleaf. Each plot’s larval population resulted from eggs oviposited by 100 female moths re- leased inside each cage. The progress of defoliation was carefully monitored until it approached the desired levels (60% in 1981, 30% and 60% in 1982). Random samples of 10 leaflets were taken from each cage and the actual defoliation level was measured with an electronic leaf-area meter. When defoliation reached the de- sired level, the cage was removed, and the larvae killed with a spray of methomyl. In 1981 it was determined the cage had no effect on yield so no control was necessary d« for the variable in 1982. Synchronization of all operations is es- sential. The insect culture in the laboratory must be handled so that ovipositing moths in the correct quantities are available at the proper time. This experimental procedure permits the performance of rather complex testing in a relatively small area and with a lower de- mand for labor. Defoliation is natural and has none of the drawbacks of simulated injury (hand-defoliation). A perimental design is now being considered similar ex- involving superposition of a third class of pest —a leaf disease. Analysis of the 1962 experiment awaits yield data but the Sur- vey scientists are confident, from the ob- servations made so far, that the design is satisfactory and should provide a good first approximation for the establishment of economic injury levels of weed/defoliation interactions. Biology of a Wild Bee Honeybees and bumblebees are among the most familiar and conspicuous insects. The honeybee, well known as a producer of honey and beeswax and as an important pollinator of many crops, represents but a single species of insect, Apis mellifera. It is not native to this country, but was brought from Europe by the early settlers of North America. Bumblebees, large, hairy, usually black and yellow insects, represent a num- ber of species in the genus Bombus, all of which are native to this country. In addition to these, there is a much larger group of bees (in terms of number of species) known collectively as native, solitary, or wild bees. There are perhaps 20,000 species of wild bees in the world Cell of Andrena erythrogaster showing pollen mass with egg laid on top of it (Photo by David J. Voegftlin). and about 350 of them can be found in Illinois. They are a diverse group both in appearance (some being less than a quarter inch long, others as large as bumblebees ) and in behavior. Wild bees are important pollinators of many native shrubs and wild- flowers as well as commercially valuable plants such as fruit trees and alfalfa, a fact that Because of their interesting behavior, wild is often overlooked or little known. bees have been the subject of considerable scientific research and the taxonomy of the superfamily Apoidea group is one of the best known of any group of insects. (taxonomic that includes all bees) Graduate student Eugene Miliczky, un- der the direction of Survey entomologist Wallace E. LaBerge, has been studying various aspects of the biology of several species of native bees belonging to the genus Andrena. Of special interest are three species of Andrena that feed their young almost exclusively with pollen gath- ered from various species of willow trees. These three species, like many other species of wild bees, have an adult stage (the winged, reproductive stage) that is active for only a short time each year. The rest of the year is spent underground, in hollow twigs, and in similar locations (depending on the species) as an immature form or as a “resting” adult. Adults of the three wil- low bees can be found in the Champaign area from late April until the middle of June. At this time the adults have died off and will not be seen again until spring. Their young, however, have been provided for. well Available information indicates all spe- cies of Andrena dig nests in the ground. Andrena erythrogaster, one of the willow bees, is no exception. Nests of this bee, sometimes called the red-bellied bee be- cause of its bright red abdomen, were found in the woods at Lodge Park in Piatt County. Fifteen nests were located and studied during the spring of 1981 and a smaller number in 1982. Each nest was occupied by a single female bee that dug through the well packed dirt using her mandibles (one of her mouthparts) and The resulting burrows descended nearly vertically into the ground for depths of 6-10 inches. Soil from the burrow was legs. The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 pushed to the surface by the bee and made a mound that resembled an ant hill around the entrance. At various points along the main bur- row the bee dug horizontal branches an inch or two in length. At the end of each branch a cavity or cell was made. The cells were oval in shape, about a half an inch long and a quarter inch in diameter. The walls of the cell were made very smooth by the female bee and she then applied a waterproof secretion to them. At this time the bee began to gather pollen and nectar. Several loads of pollen and nectar were brought back to the nest and placed in the cell. They were then mixed together and shaped into a somewhat flattened sphere. An egg was laid on top of the pollen mass and the branch burrow leading to the cell was tightly packed with soil. The female bee had no further contact with the egg or the larva that hatched from it. She had, however, provided enough food for the complete development of a new bee. The larva that hatched from the egg con- sumed the entire pollen mass and then pupated. By early autumn the pupa gave November 1982. No. 22] sion of the sources and Conservation McClellan Prepared by Shirley with the Illinois paid at Urbana (USPS Natural Resources Building Second-class Office postage of publication: 172 Illinois Department of Eneray and Natural Resources £2 990 )O-L£L\ Champaign rise to an adult bee which remained in the cell over the winter. This bee, representing a new generation, dug its way out of the soil the following spring when the willows were once again in bloom. The hard-working female bees probably rear seven or eight offspring each in an average year. By the end of their lives their mouthparts have been worn down by dig- ging, their wings are tattered, and much of their hair has worn off. Exhausted by con- stant work, they die and can be found fre- quently at the bottom of their nests. In contrast to the females, male bees make very poor fathers. Their primary concerns in life are finding and mating with one or more females and locating sources of nectar on which to feed. They take no part in digging the nest or providing for the young. The nesting biology of willow bees is one phase of this research. Others concern the foraging behavior of the different spe- cies of willow bees, phenological relation- ships of the bees and the species of willows they visit, and the role of bees as pollina- tors of willows. Published monthly except in July and August by the Natural History Survey, a divi operating under the Board of Natural Re collaboration of the Survey stoff ) Illinois Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF. ILLINOIS NATURAL NATURAL RESOURCES BUILDING, 607 E. PEABODY, CHAM HISTORY SURVEY DEF ARTMENT OF ENERGY AND NATURAL RESOURCES LLINC The Illinows NATURAL ay Records of North American Big Game The Section of Wildlife Research of the Illinois Natural History Survey was host recently to a training session to certify official measurers for the Boone and Crock- ett Club. The session was jointly sponsored by the Illinois Department of Conservation and the Boone and Crockett Club. Glen Sanderson, head of the Wildlife Research Section at the Survey, has been the only official measurer in Illinois for the past 17 years. Sixteen biologists, veterinarians, and wildlife managers attended the four-day training session. Two were from Illinois; three from Missouri; and one each from Iowa; Indiana; and Alberta, Canada. The Boone and Crockett Club made its first formal recognition of outstanding big- game trophies in North America in the Club’s 1932 records book. This first recog- nition involved only a few specimens and simple measurements such as length and Engaged in measuring are (left to right) Forrest Loomis, Department of Conservation; Al Woolf, Southern Illinois University; Mike Cochran, Depart- ment of Conservation; and W. H. Nesbitt, Boone and Crockett Club. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. HISTORY SI REPORTS spread of horns, antlers, or skulls. The records book of 1932 was followed in 1939 by a records book that included many chapters on a variety of subjects related to big game and hunting. The Club held its first ““competition” for outstanding trophies in 1947. These tro- phies were ranked by a series of measure- ments that were refined in 1950 into the present scoring system for trophies. Since the 1947 “competition,” there have been 17 Awards Programs, as they are now called. In recent years, the Awards Pro- grams are held after the close of a three- year period of entry of trophies. Trophies are measured by official “mea- surers” certified by the Boone and Crockett Club. Because Sanderson has been the only official Illinois, individuals with trophies to be measured often had to make a trip of several hundred miles in order to have a trophy measured. Although a variety of big game animals are measured walrus, elk, moose, caribou, pronghorn, bison, Rocky Moun- - the species most often measured in Illinois is measurer in — hears, cats, deer, tain goat, muskox, and wild sheep the white-tailed deer. Primarily because of increasing interest in “trophy” white-tailed deer in Illinois, for several years Sanderson has been encouraging the training of addi- tional official measurers for Illinois. This interest was shared by Forrest D. Loomis, Forest Wildlife Supervisor, Illinois Depart- ment of Conservation. The was conducted by Harold Nesbitt, Secretary, Records of North Amer- ican Big Game Committee, and his assis- tant Al Manville from the Club office in Alexandria, Virginia. Nesbitt took gradu- ate training in wildlife management at the course Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale. The instructors brought several examples - of the various types of big-game trophies and used them in the training sessions. Many local sportsmen, and other interested individuals, examined these trophies dur- ing the training session. The name “Boone and Crockett” has long been associated with big game tro- phies in North America, and the record keeping program for native big game spe- cies is one of the Club’s better known activities. However, this activity is only one of the many conservation activities of the Boone and Crockett Club. As part of these activities, the club regularly sponsors grad- uate-level wildlife research, primarily on big-game species. Recently the Club spon- sored two workshops on the life history and management of the black bear and the wild sheep in North America. The results of these two workshops have been pub- lished in paperback books. Eight editions of North American Big Game have been published by the Club. These books are valuable handbooks for trophy hunters, wildlife managers, and students of big- game populations. The eighth edition, pub- lished in 1981, lists the trophies added during the 1977-1979 period to those listed previously and brings the total to nearly 7,000 individual trophies in 31 categories. Entries for the 1980-1982 awards must be postmarked no later than December 31, 1982. Individuals who wish information on the Boone and Crockett programs and awards should write to Boone and Crockett Club, 205 South Patrick Street, Alexandria, Virginia 22314. Residents in Illinois inter- ested in having trophies measured should contact Forrest D. Loomis, [linois De- partment of Conservation, 125 North First Street, Monmouth, Illinois 61462. Aquatic Insects and Oligochaetes of North and South Carolina A recent publication, Aquatic Insects and Oligochaetes of North and South Carolina, edited by Allison R. Brigham, Warren U. Brigham, and Arnold Gnilka, is the first comprehensive account of these elements of southeastern fauna. This work should serve not only as an introduction for the beginner, a working manual for the aquatic biologist, and a handy reference for the specialist, but also should provide a stimulus to further investigation into a fascinating area of biology. It treats approximately 2,500 species in 837 pages, and has over 2,000 illustrations plus a systematic index. The book is an outgrowth of the long tradition of aquatic research and faunal studies established at the Illinois Natural History Survey over the last 125 years. The Survey’s scientific collections provided a rich source of speci- mens for the study, and the authors were able to use many of the excellent illustra- tions of insects which have appeared in ‘past Survey publications on the Illinois fauna. In late 1973, Duke Power Company asked Allison R. Brigham and Warren U. Brigham of the Illinois Natural History Survey, and Arnold Gnilka of Duke Power Company, to put together a team of biolo- gists in order to conduct a faunal study - and prepare an identification manual for the freshwater benthic macroinvertebrates in their service area (the piedmont region of North and South Carolina). In addition to A. R. Brigham and W. U. Brigham, M. W. Sanderson, J. D. Unzicker and D. W. Webb of the Survey took part in the proj- ect. Other authors included specialists from the University of Michigan, Univer- sity of California, Eastern Illinois Univer- sity, Clemson University, Kansas State Bio- logical Survey, and the states of North Carolina and South Carolina. Originally the manual was conceived as an in-house document to be used by Duke Company’s staff to provide accuracy of identification of benthic macroinverte- brates in their biotic surveys and long- term monitoring programs in the Carolinas. As the project developed, the scope of the study was expanded to include the fauna of all three physiographic regions (moun- tain, piedmont, and coastal plain) of North and South Carolina. In addition, the authors were asked to review the North American literature on the biology of these organisms, and synthesize it into a single, comprehensive work. Each chapter of the book covers an order of insects plus the aquatic worms or Oligochaeta. Biological Control of the Musk Thistle in Illinois About 120 years ago, the musk thistle was introduced accidently into Pennsyl- vania from Europe. Without its natural enemies to suppress its reproduction, it spread quickly to inhabit roadsides, pas- tures, and waste areas throughout much of the United States. In Illinois, the weed srows well particularly in strip mine areas converted to pastures. In an attempt to control this weed bio- logically, Illinois Department of Agricul- ture personnel, in cooperation with the Illinois Agricultural Experiment Station, released a weevil native to Europe, Rhino- cyllus conicus, at six locations in Illinois during 1979 and at three additional loca- tions during 1980. After the initial estab- lishment of the weevil (see Natural History Survey Reports, September 1980, No. 199), its populations and their effect on musk thistles have been monitored through a joint effort of the Illinois Department of Agriculture and the Illinois Natural History Survey. The weevils overwinter as adults and generally are seen first on thistles in early May. Adult feeding at this time causes small brown spots on the leaves; however, this has little effect on the plant. After feeding and mating, the females lay eggs on the bracts of developing flower heads. The larvae hatch from the eggs and bore into the base of the flower or receptacle. The primary damage to thistles is caused by the larvae. Larval feeding in the receptacle prevents the development of some or all of the seed within the head. To prevent the development of all seeds with- in a head about 20 larvae must inhabit a seed head. At a certain stage of develop- ment the larvae stop feeding and pupate within a hard brown chamber in the recep- tacle. In a few days the final change from pupa to adult takes place. By the end of July, the new adults leave the heads to find overwintering sites, and become dor- mant until the next spring. Larvae of the musk thistle weevil, Rhinocyllus conicus, feeding within the receptacle of a musk thistle seed head (Photo by William Lamp). Weevil populations have been increasing slowly and destroying more seeds each year since the initial releases in Illinois. At a release site in Fulton County this year, Survey Research Associate William Lamp found nearly 90 percent of the terminal seed heads contained weevils and that the weevils had spread to thistles about a half mile away. Last year, 62 percent of the terminal heads contained weevils. A similar pattern of population buildup and dispersal during the first five to seven years is com- mon among release sites in other states, and is usually followed by a rapid increase of weevil populations and a decrease in thistle seed production. The weevil generally attacks the first flower heads developing on a thistle and allows heads developing later to produce their full complement of seeds. At the Fulton County site, up to 17 larvae inhab- ited the terminal heads, but the later- blooming lateral and axillary heads were usually free of weevil attack. The larval stage of another insect species, Homoeo- soma ellectellum, the sunflower moth, was often observed feeding on thistle seeds. The adults of this insect commonly attack the native sunflowers and usually cause little damage to the musk thistle. The weevil is not expected to eradicate the musk thistle, its only host plant in Illinois, but rather to reduce its population If further reduction of thistles becomes necessary, additional bio- to a low level. logical control agents may be released. U.S. Department of Agriculture researchers are currently investigating other insect The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 species that may be released in the USA. As with all biological weed control agents, these insects are tested to make certain they will not become pests on crops and other beneficial plants. The impact of the weevil on musk thistle populations up to this time is diffi- cult to assess. Although original stands in which releases were made have almost dis- on of the Illinois De partment of Eneray and Natu source ind Conservatior Prepared by Shirley McClellan th tk collabora Second-class postag paid af Urbana, Illin Office yt publicati n 172 Natural Resources Buildin 222. Published monthly except in July and August by the Natural History appeared, new stands have developed in nearby areas. This reflects the patchy dis- tribution of the thistle, with the location of stands shifting between generations. Once the weevil severely reduces seed pro- duction, the establishment of new thistle stands and their subsequent population growth are expected to decrease. Survey, a divi sources, operating under the Board of Natural Re ne survey staf paian. Illir Persons desiring individual or additional copies of this publication please write to DR. PAUL G, | SER, CHIEF LLINOIS NATURA H NATURAL RES IRCES BUILDIN \7 FARODY EY { ARTMENT )F ENERGY AND NATURAL RESC N URCES The Illinows NATURAL Injection Wounds and Tree Growth Certain nutritional, entomological maladies of trees can be remedied by implantation or injection of chemicals into the trunks of trees. Ex- amples of two treatments that may be rec- ommended by Survey correction of lime-induced iron chlorosis of pin oaks with implants and treatment of incipient stages of Dutch elm disease in specimen elm trees with injection proce- dures. Trunk wounds are required prior to pathological, or pathologists are treatment and wound size is a major factor in determining the method of treatment. Previous experiments have determined that wound correlated wound width and tree growth. A recently completed study by Dan Neeley, Survey plant pathologist, was designed to deter- mine (1) if intentional wounding over a period of years would result in reduction of closure is with tree growth, and (2) the correlation be- tween tree growth and wound size. Trees of five species at two locations, the Survey arboretum south of Urbana and the HISTORY Morton Arboretum west of Chicago, were treated for four years (1977-1980). Wounds were of two types: circular and pointed elliptical. Four whorls of circular wounds were cut into the trunks at three-inch in- tervals: the whorls were one foot apart. and 11/16 inches in diameter. One whorl of The circular wounds were 3/8, 1/2, elliptical wounds two inches tall and one inch wide was cut into the trunks at three- inch intervals each year. Trunk diameter increases and wound closure were measured annually. The wounded trees grew just as rapidly as the untreated It would appear that wounding of trees for injection or im- trees. plantation of a chemical will not measur- ably slow tree growth if the chemical itself is not toxic to the tree. Although there was a difference among tree species, the 3/8-inch wounds closed in one season with .10 inch, | with .15 inch, and the 11 with .23 inch of radial growth of the tree 2-inch wounds 16-inch wounds trunk. The larger the wound, the lower the Following drilling holes in the trunk, the tree is pressure injected with chemicals that aid in remedy of some vascular diseases (Photo by Eugene Himelick). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. number of wounds that completely closed the first season. In these test plots, essen- tially all of the 3/8-inch wounds closed, 80 percent of the 1/2-inch wounds, and 50 percent of the 11/16-inch wounds closed in one year. This confirms the suggestion that wounds should be as small as practical when using implant or injection tech- niques. Biological Collections Collections of biological materials con- tain enormous amounts of information. This information is contained in the speci- mens themselves as well as in the recorded information taken at the time the speci- mens were collected in the field. The amount of information with the collections increases with the passage of time. This is because the collections record events in history and these data can be used as a comparison between the past and the present. The most obvious use of collections is for the identification of organisms. For example, if an unknown specimen is sent to the Illinois Natural History Survey for identification, the scientist frequently goes to the collection to compare this specimen with previously collected organisms. With- out the collections, it would be more diffi- cult, often impossible, to identify many plants or animals which are collected today. These identifications are frequently of economic importance, perhaps as pest species. Collections also represent a record of the changing distributions of species. By going to the records, it is possible to decide whether man’s activities have had an ad- verse effect on animal and plant popula- tions. For example, a citizens’ group might maintain that a power plant has not de- creased the number of fishes in a given stream. However, by reviewing collection records, it might be possible to show that the stream previously contained much larger fish populations and therefore the power plant could be made to assume the responsibility for the decreased number of fishes. Two other examples indicate ways in which the collections are frequently of great economic value. In 1975, an un- known insect was found infesting soybean fields in southern Illinois. The farmers immediately began spraying because they thought this insect carried a bacterial dis- ease which kills soybeans, the tobacco ring spot. Scientists from the Illinois Natural History Survey collected the unknown in- sect and, using the collections, identified it as a thrips, Sericothrips variabilis. The sci- entists also used the international literature file at the Survey and found an Egyptian paper which indicated that this particular thrips did not carry the bacterial disease. Subsequently, in the laboratory, the sci- entists also confirmed that the thrips did not carry the bacterium. Further, field in- . vestigations showed that fields which had been sprayed actually demonstrated de- creased soybean growth. Within five days, scientists from the Survey were on local television advising the farmers that the thrips did not carry the disease and, furthermore, that spraying should not oc- Gur A second example involved edible plants, i.e., turnips and horseradish. Many of these plants in southwestern Illinois showed deformities during the growing season of 1978. The USDA decided that these Illi- nois crops should be quarantined and not sold. Scientists from the Survey again used the collections and within two weeks had identified the insect causing the damage, the imported crucifer weevil. The investi- gation showed that the quarantine was unnecessary, and eventually a crop pro- tection program was developed. Once again, the collections resulted in an iden- tification which was of considerable eco- nomic value. Adding to the collections is a continuous process. For example, on June 18, 1982, one of the Survey scientists collected a sunflower beetle in East Moline. This was the first recorded occurrence of this insect east of the Mississippi. Unfortunately, this insect is a major pest of commercial sun- flowers in Kansas. Again, the collections provided not only the identity of the organ- isms, but also established a permanent record of its occurrence in Illinois. The Illinois Natural History Survey is the official depository of animal collections within the State of Illinois. There are Researcher Don Webb checks a specimen drawer in the Survey in- sect collection (Photo by Les Wood- rum). almost 5,000,000 specimens in the insect collection. It is the fifth largest in North America, includes the largest collections in the United States of several groups of insects, and contains over 3,000 type speci- mens. Type specimens are the actual speci- mens from which the original species de- scription was written, Also among the Survey collections are 200,000 specimens of soybean arthropods, which represent the International Refer- ence Collection; 75,000 mollusks, the 12th largest collection in North America; 200,- 000 other invertebrates; 400,000 fishes, the 16th largest in North America and the largest collection of Mississippi River fishes in existence; and 11,000 amphibians and reptiles. These collections are maintained in various ways. Insects and arthropods are stored usually as dry specimens on pins in special containers. On the other hand, fishes and some invertebrates are stored in alcohol. Computers Aid in Fight Economic entomologists conducting re- search on insect pests of alfalfa and other forage crops installed a minicomputer and word processor in their laboratory recently. This system allows for storage and retrieval of large amounts of data collected in the field and laboratory, historical type data, and references to published scientific re- search by colleagues throughout the world. Retrieval of information can be easily and quickly accomplished. Because of the sys- tem’s communications capabilities, it is possible for researchers to use all the func- tions of the University’s massive computer system. This, therefore, allows for extensive computer analysis of data. Researchers can also communicate with other researchers throughout the United States. This type of communication is extremely valuable to Survey and Agricultural Ex- periment Station entomologists, W. O. Lamp and E. J. Armbrust, who are in- volved in a multi-state research project to develop comprehensive, unified, econom- ically and management systems for alfalfa. The ob- jective of these systems is to minimize losses to pests while optimizing the produc- tive longevity of alfalfa. Entomologists, weed scientists, and plant pathologists in Illinois, Kentucky, California, Wisconsin, and New York are working together and are being funded in part by the U.S. De- partment these aims. The use of minicomputers and word processors has greatly assisted with the availability of data and its analysis by all researchers in this project. environmentally sound pest of Agriculture to accomplish Lamp and Armbrust have been working extensively with Southern Illinois Univer- scientist, George Kapusta, to potato pests sity weed determine an interaction of the leafhopper insect pest and weed found in alfalfa. Weekly samples of insects, The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 weeds, and crop growth and yield for two years in alfalfa fields has produced large quantities of data that have been stored and analyzed through this minicomputer. The potato leafhopper is a major insect pest in alfalfa and studies have shown that its presence may be reduced by the pres- ence of weeds. The number of leafhoppers averaged 31 percent less in alfalfa where grass weeds were not controlled. Although the weeds do compete with the alfalfa, only the quality of the yield and not the quantity is reduced in this weedy alfalfa. Several explanations for the effect of weeds on insects are presently being pur- sued. For example, the grass weeds are hosts for many other leafhopper and plant- hopper species. ‘These noneconomic insects may compete with potato leafhoppers and reduce their populations. Additional ways that weeds may in- fluence insect pests are by serving as alter- nate hosts, confusing host-locating mecha- nisms, or altering host plant suitability. Once the cause of the observed interaction is known, techniques will be developed to manage the potato leafhopper using infor- mation on weed populations in alfalfa. If economic levels are lowered by such inter- actions, then fewer herbicides will be re- quired for controlling weeds. In addition, fewer insecticides will be required for con- trolling leafhopper populations in weedy alfalfa. In general, the studies of weed- insect interactions have resulted in the integration of control] strategies for pests of different disciplines, thus making the al- falfa production system more efficient. When these control strategies are intro- duced at the grower level, pest population information pertaining to the various pests can be implemented and the proper con- trol strategies can be disseminated through the use of minicomputers. Communication and data storage and analysis at this level of sophistication will make alfalfa pro- duction more efficient with less harm to the environment through the proper use of pesticides. A production system of this type could result in an increase in the longevity of the alfalfa crop. Because alfalfa is a perennial legume with outstanding nitrogen-fixing capabil- ities, it is of major importance in energy and soil conservation. Crop establishment and long-term maintenance costs in terms of energy and erosion can be greatly re- duced through utilization of alfalfa. The development of efficient strategies for pest population regulation and control can further reduce the amount of energy re- quired for production. For example, if the longevity of alfalfa was extended for only one year, the increased production and energy savings would exceed $325,000,000 on a national scale. January 1983. No. 223, Published monthly except in July and August by the Natural History Survey, a divi sion of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Re sources and Conservation. Prepared by Shirley M« Clellan with the collaboration of the Survey staf Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLIN NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING, 607 E. PEABODY, CHAMPAIGN, ILLINOIS 6182 Scientists Unite to Provide Food The problem of providing food and nu- trition for escalating populations in devel- oping countries is enormous, with more than one billion people (about %4 of the world’s population) known to be underfed or malnourished. ‘These numbers and pro- portions may grow even faster than the world population, which is projected to ex- ceed six billion by the year 2000. A major attack on this problem was launched at a recent international confer- ence in Manila attended by Survey Aquatic Biologist D. Homer Buck. He participated in the workshop on Aquaculture and Inte- grated Farming. Buck’s working group numbered 13, including seven from Asia, two from Africa, one each from Sweden and Australia, and Ed Lincoln of the Uni- versity of Florida, who conducts research in the intensive production of microalgae in organically enriched systems. Proceedings and reports emanating from the conference and workshops will be avail- able for reference at the Kinmundy field station. The meeting was called CHEMRAWN Il (Chemical Research Applied to World Needs), with the more formal title of In- ternational Conference on Chemistry and World Food Supplies: The New Frontiers. Principal sponsors were the International Union of Pure and Applied Chemistry and the International Rice Research Institute. The specified objectives of the confer- ence were (1) to identify and put into per- spective those areas of research and devel- opment having the potential to significantly increase food production and improve food 9 storage and processing; (2) to strengthen scientific research in developing nations, REPORTS — particularly in those fields which require professional competence and _ initiative without excessive capital and human re- sources; and (3) to accelerate implemen- tation of research priorities and objectives by fostering cooperation among govern- ments, industries, and universities. The formal scientific papers were pre- sented by a selection of distinguished in- ternational scholars, including five Nobel Laureates. Papers were presented in seven separate sessions: Soil and Crop Manage- ment for Efficient Use of Water and Nu- Integrated Pest Management, The Role of Chemistry and trients, Approaches to Biochemistry in Improving Animal Pro- duction Systems, Contributions of Chemis- try and Biochemistry to Developing New and Improved Food Sources, Chemistry and Biochemistry in the Processing and Storage of Food, Chemistry in the Assess- ment and Control of the Food Supply, and The Forward Edge. As anticipated, the most exciting and imaginative subjects were discussed in the last session, The Forward Edge. Subjects included potentials and addressed here prospects in genetic engineering, wide crosses in plants, new strategies and meth- ods for selection and utilization of germ- plasm, the role of growth regulators and hormones in enhancing food production, the potentials for increasing rates of nitro- gen fixation, and for improving the eff- ciency of photosynthesis. [he second phase of activities, the post- conference workshops, were convened in the impressive facilities of the International Rice Research Institute adjoining the cam- pus of the University of Philippines at Los Banos were Banos. The activities at Los Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey funded by the US Agency for International Development, and were organized by the US National Academy of Sciences, more specifically by the Board on Science and Technology for International Development (BOSTID), which was responsible for se- lecting the participants in four separate workshops: (1) Soil Fertility and Plant Nutrition (2) Plant Growth Regulators and Plant- pest Relationship (3) Food Science and Technology (4) Aquaculture and Integrated Farming Systems. The responsibilities of the workshop par- ticipants were to combine the information presented at the conference with their own knowledge and observations in identifying those research areas having the highest po- tential for improving food supplies in de- veloping countries, and which should re- ceive highest priority for funding. Where possible and appropriate, cooperative stud- ies will be conducted jointly in a devel- oped and a developing country. The Gypsy Moth in Illinois The gypsy moth, a tremendously destruc- tive tree pest, has now reached Illinois from 2640 NUMBERS OF GYPSY MOTHS TRAPPED IN ILLINOIS BY YEAR ] 2635 605 600 435 430 225 NO. MOTHS 220 195 190 the northeastern United States. The moth is often unintentionally transported to Ill- nois by families moving to Illinois from in- fested areas in the east. The Illinois De- partment of Agriculture is responsible for monitoring the spread of this insect by the use of gypsy moth sex pheromone traps for the detection of adult male moths. Jlli- nois Department of Agriculture personnel have traps in all counties of Illinois. The [Illinois Natural History Survey team of scientists and technicians, in coop- eration with the Illinois Department of Agriculture, is using trapping data to as- sess the future probability of outbreaks of the gypsy moth. A high male moth trap catch in a particular area indicates that larvae of the gypsy moth have been feeding in that area for one or more years. Infested areas are scouted extensively for gypsy moth egg masses during the autumn and winter months by Illinois Department of Agriculture’s staff and when egg masses are found they are carefully collected and either destroyed or transported to the Natural History Survey’s quarantine labo- ratory at Champaign. There the eggs are examined for viability, parasites, and dis- ease organisms. Only two percent of the eggs in egg masses collected in March 1982 2639 \ 602 {I Graph shows rapid increase in num- ber of gypsy moths in Illinois; drop in summer of 1982 was caused by severe winter weather of 1981-1982. were viable, and the high egg mortality was attributed to the adverse winter cli- mate of 1981-1982. The first detection of gypsy moths in IIli- nois occurred in 1973 when two moths were captured in Cook County and one each in Rock Island, Sangamon, and Will counties. The records on moth catches in Illinois vary considerably from year to year due to control programs, climatic condi- tions, number of traps used by the State Department of Agriculture and the status of the gypsy moth population in the north- eastern portion of the United States. Se- vere gypsy moth outbreaks in eastern states increase the chances of gypsy moth ege masses and pupae being unintentionally transported into Illinois. Cooperative stud- ies with the Illinois Department of Agri- culture will continue, since their help is vital to our understanding of the gypsy moth problem in the state. Possible Effects of Reduced. Tillage In Corn on a Black Cutworm Parasitoid The black cutworm, Agrotis ipsilon Huf- nagel, is well known to Survey entomolo- gists as a major pest of seedling corn in the Midwest. Adult moths migrate into Illinois in the early spring, and lay their eggs on weeds and crop residues within or border- ing fields before corn is planted. Young larvae feed on these plants till corn seed- lings emerge; they will then start feeding on corn leaves, particularly if planting and cultivation have removed all other vege- tation. Older cutworms cut corn seedlings at the base, and in sufficient numbers can cause serious economic damage. Reduced tillage in corn is currently be- ing encouraged to conserve energy and de- crease soil erosion. These positive effects must be weighed against trade-offs such as increased insect and weed problems. Cer- tain insects, such as the black cutworm, are expected to cause economic damage more frequently in reduced-tillage corn be- cause of increased crop residues and weedi- ness in fields before planting. Survey re- searcher Mike Foster suggests that it is important to determine the effects of re- duced tillage on natural enemies of corn pests as well as the pests themselves. Preda- tors and parasitoids do not control corn pests, but are important because their ac- tivity decreases the frequency and severity of damage. As a graduate student working with Bill Ruesink, Survey entomologist, Foster has been looking at the effects of weeds common in reduced-tillage fields on a major black cutworm parasitoid, Me- teorus leviventris Wesmael. This parasitic braconid wasp attacks cut- worms just old enough to cut corn seed- lings, and the development of its young in- side the host kills cutworms prematurely. Consequently, parasitized cutworms cut fewer corn seedlings. Foster learned from laboratory observations that Meteorus fe- males live longer, attack more cutworm hosts, and produce more offspring if they are provided with an energy source such as honey water. In addition, many species of parasitic wasps and flies are known to benefit from floral nectar both in natural habitats and in various crops. Armed with this information, Foster hypothesized that some of the flowering weeds found in re- duced-tillage corn provide nectar which benefits Meteorus and increases its effec- tiveness as a black cutworm parasitoid. In the fall of 1981, laboratory experi- ments were conducted to determine the ef- fects of five flowering weeds on adult fe- male Meteorus. Three of these weeds, chickweed, mustard, and shepherd’s purse, are common and flowering in reduced-till- age fields before planting. The other two species, wild parsnip and lady’s thumb smartweed, are common and flowering in field borders or nearby uncultivated areas soon after planting. These experiments demonstrated increased longevity, repro- Actual size of Meteorus leviventris female above is 3 millimeters (Photo by Les Woodrum, Survey Pho- tographer). The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 duction, and more hosts attacked by wasps provided with these flowers, in comparison to starved female Meteorus. In the spring of 1982, a field experiment was set up to determine if flowering weeds would result in increased parasitism and decreased cutting damage under seminatu- ral conditions. One-meter-square plots of seedling corn enclosed in field cages were subjected to three treatments: 20 cut- worms, cutworms and 10 female wasps, or cutworms, wasps, and flowering weeds ac- cessible only to the wasps. The results sug- gest increased parasitism and decreased cutting damage in the presence of flower- ing weeds. A greenhouse experiment was conducted in the fall of 1982 to determine how 1n- creased wasp lifespan, an effect on indi- viduals, translates into increased parasitism, an effect operating at the population level. Two variables were manipulated: the presence of flowering chickweed and _ the initial ratio of wasps to cutworms. Foster hypothesized that nectar, by increasing wasp lifespan, would increase the average wasp-to-cutworm ratio over several days and consequently result in greater para- sitism. Flowers did indeed average wasp-to-cutworm ratio over sev- eral days, but this resulted in greater para- sitism only if the initial wasp-to-cutworm ratio was low. These results imply that an adequate nectar supply will have the great- increase the est impact on field rates of parasitism when spring populations of Meteorus are low. The experiments described demonstrate that Meteorus benefits from flowering weeds common in reduced-tillage corn. Two other major parasitoids of the black cutworm are Bonnetia comta, a tachinid fly, and Microplitis (two species) , a braco- nid wasp. Both insects are known to bene- fit from a sugar source and these flowering weeds may also be beneficial to them. Because reduced tillage affects both cut- worms and their natural enemies, its effect on the risk of cutworm damage is likely to be quite complex. For example, if natural enemies are not considered at all, one would predict an increased risk of cutworm damage with moderate levels of weediness before planting. However, if there were sufficiently high levels of Meteorus in the early spring and they were benefited sufh- ciently by a nectar supply, this might offset the increased levels of cutworms. Foster is currently developing a computer model to determine by simulation the effects of weed-Meteorus and weed-cutworm inter- actions on parasitism and cutting damage. This model will allow researchers to dis- tinguish situations in which preplant weed- iness can be tolerated from those in which weediness will increase the risk of cutworm damage. February 1983. No. 224. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation Prepared by Shirley McClellan with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois Office of publication (USPS 258-220) 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G NATURAL RESOURCES BUILDING, 607 E,. PEABODY RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY CHAMPAIGN DEPARTMENT OF ENERGY AND NATURAL RESOURCES ILLINOIS 61820 The Illinois rth + NATURAL HISTORY J REPORTS — (NATURAL HISTORY SURVEY MAR 209 1383 LIBRARY Transmitters Designed for Condor A tiny, solar transmitter designed and made by W. W. Cochran, Jr., associate wildlife specialist at the Survey, has enabled scientists to tag and track a California condor by plane during the past few weeks. Cochran is in California working on an automatic receiver that will eliminate the need for cars and planes in tracking the bird. The first free-flying California condor was captured last fall near Ventura. Dr. Noel Snyder, condor research biologist for the U.S. Fish and Wildlife Service, fired the cannon-net over the condor while it was feeding on a calf carcass. It resisted strenuously, biting the hands of its captors, but displayed no signs of stress during the initial examination. The bird was held at the San Diego Zoo while blood samples were taken and ana- lyzed to determine its sex. It proved to be a 22-pound male. The condor was fitted with two solar-powered transmitters and then released. It has been followed by an air- plane most of the time since the release. Dr. Noel Snyder, U.S. Fish and Wildlife Service, attaches Cochran transmitter to condor as his assis- tants hold bird (Photo by Helen Snyder, U.S. Fish and Wildlife Service). The California Fish and Game Commis- sion authorized the trapping of immature condors late in 1982. However. only two birds can be taken into captivity under the permit for a year. Trapping has now been resumed to capture a female of the species. Begun late in 1979, the purpose of the program is to identify factors causing the continued decline of the wild California condor population, and at the same time, to breed the birds in captivity for eventual release in the wild. The California condor research project is a cooperative effort among the Fish and Wildlife Service, the National Society, the California Fish and Game Audubon Commission, the Forest Service, the Bureau Management, and the Natural History Survey. of Land Illinois For at least 20 years, Cochran has been designing and making various kinds of transmitters and receivers for tracking all kinds of wildlife ducks, geese, rabbits, deer, and even fish. Wildlife that meaningful interpretations of the lives of including small birds. specialists agree more animals will result from finding out what an animal is doing at a particular place at a particular time, and how its pattern of activities fits into its year-round needs for successful survival and reproduction. The Aster Leafhopper: A New Vector of Spiroplasma citri In 1981 University of Illinois plant pa- thologists and Survey entomologists re- ported the discovery that Spiroplasma citri is the causal agent of brittle root disease of horseradish in Illinois. §. citri, well known for its association with a severe disease of citrus in the southwestern United States, is Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. a small, helical, bacterialike organism found in the phloem of diseased plants and trans- mitted by leafhopper vectors. One of these vectors, the beet leafhopper (Czrculifer tenellus), was shown to transmit the spiro- plasma from brittle root-diseased horse- radish to healthy horseradish plants in lab- oratory tests. While the beet leafhopper was collected in horseradish fields during several brittle root epidemics, 1t was not found during the 1975 outbreak despite intensive sampling of horseradish fields. This discrepancy led Survey entomologists Karen O’Hayer, Gerald Schultz, and Catherine Eastman and University plant pathologists Jacque- line Fletcher and Robert Goodman to in- vestigate other leafhopper species as pos- sible vectors of §. citri in Illinois. The aster leafhopper, Macrosteles fascifrons, was of special interest because it is already known as a major vector of several other plant pathogenic organisms and because it 1s collected routinely in Illinois horseradish fields, sometimes in large numbers. An understanding of the type of path- ogen-vector relationship involved was es- sential in determining the best means of testing the aster leafhopper as a potential vector of S§. citri. This spiroplasma is one of several pathogens which are transmitted in a circulative-propagative manner. After being taken up by the insect during feeding, the pathogen must penetrate the gut wall and enter the circulatory system. From there it moves through the insect’s body, Aster plant on left was exposed to infected leaf- hoppers and shows stunting and chlorosis typical of S. citri infection. Aster plant in center was exposed to control leafhoppers, and the aster plant on the right was not exposed to leafhoppers (Photo by Les Wood- rum, Survey photographer). infecting and multiplying in various tissues, including the salivary glands. This whole process may take several days or weeks. The pathogen then can be introduced, along with the saliva, into the phloem of a host plant during feeding. The first step in evaluating the aster leafhopper as a potential vector of S. citri was to determine if this insect could trans- mit the pathogen after being injected with a suspension of cultured spiroplasmas. The microinjection technique involves the in- troduction of a large quantity of the path- ogen directly into the leafhopper’s circu- latory system, thereby increasing the chance of subsequent transmission. Aster leafhop- ‘per adults were injected with a horse- radish isolate of S. citri and were caged on barley plants (a preferred host) for 14 days to allow time for the pathogen to circulate and multiply within the leafhoppers. Then the leafhoppers were confined on aster and horseradish test plants for 7-day feeding periods. In the combined results of two ex-. periments, the leafhoppers transmitted S. citri to 27 of 41 aster (66 percent) and 11 of 46 horseradish plants (24 percent). The success of the microinjection exper- iments indicated that S. citri could multiply in the aster leafhopper and could be intro- duced into plants during feeding. A true test of an insect’s potential as a vector, however, is whether or not it can acquire enough of the pathogen naturally by feed- ing on infected plants to permit subsequent transmission of the organism to healthy plants. Sometimes the digestive tract of an insect species acts as a barrier, preventing passage of a pathogen into the blood. In separate tests aster leafhoppers were con- fined on S. citri-infected plants turnip, or bassicaceous weed yellow rocket for 7-14 days. After another 7-14 days on barley, leafhoppers were caged on. test plants (aster, horseradish, or turnip) for 3-7-day feeding periods. In combined re- sults from four experiments, leafhoppers transmitted §. citri to 9 of 128 aster (7 percent), 1 of 69 horseradish (1 percent), and 3 of 54 turnip (6 percent) plants. Infected aster and turnip plants devel- oped chlorosis and stunting of young leaves and reduced overall plant growth. Infected horseradish plants were stunted and chlor- aster, otic with reduced secondary root growth and phloem discoloration characteristic of brittle root disease. All control plants ex- posed to leafhoppers fed previously only on healthy plants remained free of symptoms. To confirm these results, attempts were made to isolate spiroplasmas from plant tissues; spiroplasmas were present only in plants with the described symptoms. The discovery that the aster leafhopper can transmit §. citri after acquiring it by feeding on diseased plants strongly suggests that this species may be a natural vector of the spiroplasma and, thus, may be involved in the epidemiology of brittle root disease. The transmission frequencies in these tests were low, but this does not lessen the potential importance of the aster leafhop- per as a vector of S. citri. Inefficient trans- mission could be compensated for by the large populations of this insect which often occur in the Midwest. The plant host ranges of both §. citri and the aster leaf- hopper include species in the families Asteraceae, Violaceae, Fabaceae, Brassi- caceae, Rosaceaem, Ranunculaceae, Mal- vaceae, Caryophyllaceae, and Liliaceae. Therefore, the aster leafhopper may be in- volved in the spread of §. citri to other susceptible plants in addition to horse- radish. The potential importance of this insect as a vector of S. citri is enhanced further by the fact that of the four known vectors of spiroplasma, the aster leafhopper has the most extensive geographical range, which includes Mexico, the continental United States, and most of Canada. Aquaculture May Become New Illinois Resource Illinois and nine other states produce about 75 percent of the country’s waste products, Stephen Waite, aquatic biologist at the Survey, believes that this waste may turn out to be one of the state’s most priceless resources. Waite, who hopes to initiate an aqua- culture program in Illinois, even though the state is well known for its land- based agriculture, it has no large scale aquaculture at present. Aquaculture is the cultivation of aquatic plants and ani- mals for human consumption. With pop- ulations increasing and good farmland Because says Swine are confined to cages over water at Kinmundy where aquaculture project was begun in 1975 (Photo by Les Woodrum, Survey photographer). reaching its maximum productivity, more people are exploring ways to use aquacul- ture to meet the rising demand for food. D. Homer Buck, another Survey re- searcher, has been working since 1975 on small-scale aquaculture systems using swine manure to culture fish. Swine, fed com- mercial chow, produce a great deal of manure. The manure is washed into a pond set below the hog pens where it serves as food for those lower in the food chain, specifically plankton and algae. These microscopic organisms in turn serve as food for fish such as carp and fresh- water shrimp. One of the problems sci- entists had to work out was how much manure should be added to the system. Manure releases ammonia which is quickly utilized by algae. The algae bloom, then die. The decomposition process uses large amounts of oxygen, so much so that the fish can suffocate. Waite has spent the last year looking for ways to overcome the problem of excess ammonia in the systems. He found what he was looking for in the Chinese water chest- nut because it is an aquatic plant that re- quires its nitrogen in the form of ammonia. Water chestnuts are a popular food for human consumption and can also provide food for fish. The production of aquatic plants that serve this double function can be extremely valuable with regard to the overall economics of the system. Waite suggests that commercial-sized sys- tems be set up to produce crops year-round for the commercial market. The Survey is The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 planning to design and build several units to demonstrate that aquaculture is eco- nomically feasible from a commercial standpoint in Illinois. Waite says that farmland is so valuable in Illinois that good lands should not be converted to ponds, but lands can be found that are less productive. Because of the relatively short growing season outdoors, indoor systems under covered greenhouses could be used. Solar greenhouses and other specifically designed buildings could be used so that something could be planted and something harvested every month. Indoor systems would have many ad- vantages. It would be easier to eliminate mortality due to predators, to prevent and control disease vectors, and avoid contam- ination from industrial and agricultural toxicants. Land, water, and other resources such as waste heat could be used more efficiently providing greater production per unit space and flexibility for siting near sources of re- cyclable waste. According to Waite, the net benefit of these advantages would be maximum year-— round production on a highly predictable basis — a big point to commercial markets —on a scale that justifies the operation of the systems. New Publications List Is Being Processed A much larger, more comprehensive Publications List is being edited and placed on the word-processor for easier future updating. The new material and method has made the production more time consuming. The new Publications List will be available in early summer. Requests are being held on file and will be filled when the publication becomes available. March 1983. No. 225, Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation Prepared by Shirley McClellan with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER NATURAL RESOURCES BUILDING, 607 E. PEABODY CHIEF, ILLINOIS NATURAL HISTORY SURVEY CHAMPAIGN DEPARTMENT OF ENERGY AND NATURAL RESOURCES ILLINOIS 61820 The Illinovs NATURAL HISTORY U NATURAL asta Qo P QO R T S APR 28 1983 LIBRARY al aa nt: ‘SscusLuva JO NOOSINYH sUve Ww sONnUM) Ho Book on darters was written by Survey researcher L. M. Page (Photo by Les Woodrum, Survey photog- rapher). Handbook of Darters Published About 150 (20 percent) of the 800 species of freshwater fishes in North Amer- ica north of Mexico are darters, small rela- tives of the walleye, sauger, and yellow perch. One species, the snail darter, is well known because of the recent highly publi- cized_ conflict of its habitat in eastern Tennessee and comple- tion of Tellico Dam. Other species are un- known between retention generally to most persons, but are among our most colorful and interesting fishes. David Starr Jordan, a famous ich- thyologist, referred to darters as “the most fascinating, vivacious, and individual of all river fishes.” A just-published book, Handbook of Darters, authored by Survey scientist L. M. Page, is now available from T.F.H. Publi- cations, Inc., Neptune City, NJ 07753. Page discusses the identity, relationships, distribution, and natural history of the 129 named species and comments on most of the recognized but as yet unnamed species. Included in the book are 308 color photos, 89 distribution maps, and summary chap- ters on the ecology, evolution, and zoo- geography of darters. Darters are found in the Mississippi River, Great Lakes, Hudson Bay, Atlantic Slope, and Gulf of Mexico drainages, and one species lives in a Pacific drainage of Mexico. Most Mississippi River system. The largest geo- graphic range is that of the logperch which ranges from Hudson Bay to the Gulf of Mexico and from Saskatchewan to eastern Quebec. The smallest range is that of the Maryland darter, which is confined to one rifle in Maryland. Most darters reach a maximum length of (87) species occupy the less than 100 mm (4 inches). At a maxi- mum recorded length of almost 200 mm (8 inches), the freckled darter, an inhabi- tant of Gulf slope drainages, is the giant among the group. The smallest, at 45 mm 1% the darter, a species occurring in only one spring and its efHuent in southern Texas. inches), is fountain Most species feed on microcrustaceans (copepods, ostracods, and cladocerans) as young and on immature aquatic insects as adults. A few specialize on snails and scuds amphipods ) at for Most spawn in spring, al- latitudes extended periods, and species though southern some may spawn occupying constant-temperature springs Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. may spawn the year round. Maximum life spans vary from 1% to 4% years, with large species living longer than small species. Darters have reached their high level of diversity by occupying a wide variety of habitats. Many species are restricted to major physiographic regions; as examples, the swamp darter is found almost solely on the Coastal Plain, and the longhead darter is restricted to the Appalachian highlands. Other major determinants of distribution are habitat characteristics which may or may not correspond to physiographic boundaries, and competition with closely related species. The stringent requirements of many species make them vulnerable to extirpation, but also make them excellent indicators of the environmental health of streams and lakes. Most species occupy flowing habitats of streams and are unable to live in artificial impoundments. Many populations have been eliminated because of excessive deposition of silt on their former feeding and spawning grounds. Illi- nois historically had 27 species of darters; now it has only 23 species, several of which are rapidly becoming less common. Publication of the Handbook of Darters follows over 150 years of research (the first species was described in 1818). Page has been studying darters since 1967. A sub- stantial portion of recent research, espe- cially life-history and systematic studies has been done at the Survey. Much remains to be studied, and the Handbook serves to elucidate needed areas of research as much as it summarizes existing information. Small Pathogens of Small Animals The Collembola, or springtails, are a group of minute animals that occur im damp soil, leaf litter, under bark, in decay- ine logs, in fungi, and on the surface of some freshwater pools. There are over 2,000 species of Collembola worldwide. They are quite common and often occur in ereat numbers, but because Collembola are so small, usually less than 4 mm long, they usually go unnoticed. This is unfortunate for persons having an interest in biology because Collembola have many fascinating characteristics. Especially interesting is the structure ‘ that gives Collembola the name “spring- a, WS Te Serr Cross section of a spore of a microsporidian species found infecting a Collembola. The actual size is 5 microns long (Photo by Joseph Maddox). tails.’ This is a small forked structure on the ventral side of the fourth abdominal segment. At rest this structure is folded forward under the abdomen and held in place by a clasplike structure on the third abdominal segment. When the clasp re- leases the forked structure, it moves pos- teriorly with force, pushes the Collembola off its perch and propels it forward. A Collembola only 5 mm in length can jump 80-90 Some of Collembola may occasionally cause damage to plants in mm, species gardens, greenhouses, or mushroom cellars, but they are probably most important in the transformation of organic material in upper layers of soil. Until recently microsporidian parasites, common in most groups of insects, had never been reported from Collembola. The microsporidia are a group of tiny animals having infectious spores which are typically between 3-10 microns in length. They are obligate parasites, primarily of inverte- brates. Survey researcher and Collembolan taxonomist, J. A. Mari Mutt several years ago observed that a few Collembola speci- mens in the extensive Natural History Sur- vey collection of Collembola had thousands of small refractive oval bodies in muscle and fat body tissue. In cooperation with insect pathologists, J. V. Maddox and V. Brunjes, Mari Mutt removed the Collem- bola containing these small oval bodies from the glass slides on which they were mounted. They were then processed for transmission electron microscopy, sectioned, and viewed under an electron microscope. This is the first time microsporidia have been mounted specimens. Microsporidian infections were found in five different species of Collembola in the INHS collection. Two specimens were col- lected in Algeria, the other three in France, Portugal, and the Dominican Republic. Before the publication of this study, micro- sporidia were also reported from seven species of Collembola, all collected in the Federal Republic of Germany. The discov- ery of seven species of microsporidia-in- fected Collembola in the Federal Republic of Germany and five infected Collembola in the INHS museum, collected from di- verse locations, suggests a rich source of undescribed microsporidia in the Collem- bola. This is especially interesting to Micro- sporidia and Collembola taxonomists as several of the microsporidia found in Collembola are quite unusual and the Col- lembola, belonging to the sub-class Aptery- gota, comprise a primitive group of animals long isolated phylogenetically from other insects. In fact, many systematists think the Collembola are a separate group between the Insecta and Myriapoda. It will be inter- esting to compare microsporidia from Col- lembola with microsporidia from the Myr- recovered from museum iapod classes according to researchers at the Survey. Kentucky Cave Shrimp With more than 250 species of animals recorded, the Flint-Mammoth Cave System in Kentucky is believed to be the most bio- logically diverse cave in the world. At least 50 of the species are troglobites or troglo- philes. A troglobite is an organism which to survive must spend its entire life in a cave; a troglophile is an organism which may, but is not obligated to, spend its entire life in a cave. The Mammoth Cave region has such a high diversity of life because of the diver- sity of cave types, habitats, food types, and geographic sources of the fauna. In this “ecological theater,” the evolution has in- volved both local species and those that have migrated in from three adjacent cave regions. Three species of cave fishes come from the three regions and co-occur only in the base level stream passages of Mam- moth Cave. ‘The Kentucky Cave Shrimp, in contrast, evolved locally and is unique to the Mammoth Cave System. The shrimp have evolved a life cycle which requires their isolation in pools near annual winter floods recede, the shrimp, which probably lives only one or two years, seeks isolated base-level rivers. As the pools above the low-water level. The or- ganic veneer, deposited by winter floods, provides a propitious habitat for micro- organisms, which are the main food of the shrimp. A favorable food supply as well as protection from predation allow the shrimp to mature during the summer, and allow the newly hatched young to develop sufh- ciently before the annual winter floods begin. The shrimp’s small population size, limited distribution, and specialized re- quirements make it extremely vulnerable to habitat disturbances. They are, therefore, considered to be an indicator species of the health of the entire aquatic ecosystem in the base level rivers of Mammoth Cave. In 1901, William Perry Hay first dis- covered the shrimp in a series of small pools, now known as the Shrimp Pools, in Roaring River of Mammoth Cave. In Kentucky Cave Shrimp is rare and difficult to locate (Photo by Ed Lisowski). The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 1928, during their expedition to caves of North America, the prominent European cave biologists, Candido Bolivar and Rene Jeannel found shrimp in a pool near Echo River and, in 1929, Leonard Giovanolh found shrimp in isolated pools associated with nearby Styx River. Biologists did very little in the cave from 1930 to 1950, but during the 1950’s and until 1967, the Kentucky Cave Shrimp usually could be found in the Shrimp Pools as well as in small pools near the Golden Triangle, a base level stream several miles from Roar- ing River but still part of Mammoth Cave. Since the shrimp were not seen again dur- ing the subsequent 12 years, they were feared extinct. Disturbances of the aquatic habitats in Mammoth Cave may have caused the de- cline in populations of the shrimp from these historic localities. Pollution, both from leaking sewage lagoons within Mammoth Cave National Park and from sources out- side the park have had a negative impact on cave rivers. Dams on the Green River have modified the habitat and altered the flooding cycles of the cave rivers. The pool behind one dam extended into some of the cave rivers, which permanently flooded many of the once seasonally isolated pools, increased siltation, and disrupted nutrient flow into the cave. All three dams altered the flooding cycles by decreasing the in- tensity of winter flooding and increasing April 1983. No. 226 of the and Conservation Prepared by Shirley McClellan with the second-cla postage paid at Urba Illinois Office of publ ition 172 Natur Resources Building Persons desiring individual or additional copies of this publication please write to HIE TURA RESOURCE BU ih 407 EA Y HAMPA Illinois Department of Energy and Natural Resources the frequency of summer flooding. This may have impacted the shrimp by disrupt- ing its reproductive cycle, which is synchro- nized with winter flooding, and by reduc- ing the feeding time in quiet pools for both adults and newly hatched young. Between May 1979 and September 1981, Survey scientist Ed Lisowski searched on a monthly basis for shrimp at their histor- ically known localities. After finding one dead shrimp in the Shrimp Pools in Sep- _ tember 1979, he arranged for cave scuba divers to look for shrimp in the deep pools of Roaring and Echo rivers and in sub- merged cave passages. During four dives between October 1980 and January 1981, they found a total of 17 shrimp, and in January 1981, Lisowski found three shrimp in the Golden Triangle. These data demonstrate that, although not extinct, the Kentucky Cave Shrimp is rare. The U.S. Fish and Wildlife Service has accepted a petition to begin the process of listing the shrimp as a federally en- dangered species, and the National Park Service funded a 2-year study of the shrimp’s biology and distribution so that the Service could develop a management program to conserve the shrimp. Lisowski has volunteered his time to assist with the study. The USFWS has delayed the final determination of the status of the shrimp until the completion of the study in Octo- ber 1983. Published monthly except in July and August by the Natural History Survey, a division operating under the Board of Natural Resources rollaboration of the Survey staff (USPS 258-220 Champaian, Illir MENT OF ENERGY AND NATURAL RE NATURAL HISTORY SURVEY Vj AY Z D LIBRARY The Declining Grassland Birds Until at least 1959, populations of grass- land species of birds in Illinois were re- markably preserved, considering that the original prairie was all but gone and had been for many decades. It was true that the sharp-tailed grouse had been extirpated, that the greater prairie chicken was greatly reduced, and that the Eskimo curlew —a once abundant transient of the Illinois prairie — was near extinction, but song birds of the prairie were surviving. They had adapted well to the mixed agricultural practices of the day. 1957 and north, middle, and south of Illinois by Drs. Censuses in 1958 across the Jean and Richard Graber of the Survey’s Wildlife that breeding populations of the prairie species Research Section showed of song birds were nearly as numerous (or even more numerous in some cases) as in 1906-1909 first transect censuses were made for the Illinois Natural History Survey by Alfred O. Gross and Howard Ray. For example, there were about 4,000,000 birds of the two meadow- lark species in Illinois in 1906-1909 and 3,800,000 in 1957-1958, about 1,200,000 bobolinks in 1906-1909 and 1,900,000 in 1957-1958: and about 1,700,000 dickcissels in 1906-1909, and 3,400,000 in 1957-1958. Hayfields and pasturelands were providing when the cross-country adequate habitat for these and other grass- land species in Illinois. After 1960, farming practices changed rapidly with increasing specialization and emphasis on the production of corn and soybeans. The managed grasslands that had prairie birds supported populations of dropped precipitously in acreage — as much REPORTS | Male bobolink (left) and female bobolink in grassland nesting habitat (Photos by Richard and Jean Graber). as 50 percent per decade, and it was clear that grassland species of birds were declin- ing. Populations of birds cannot increase their densities in a dwindling area of hab- itat, but if such an ability existed, Illinois provided a supreme test case in the 1960’s and 1970’s. Censuses were needed to see precisely what was happening. When the 70th anniversary of the first series of cen- suses arrived, the Grabers were completing a study of heron populations in the state, but in 1978 and 1979 they censused as much grassland habitat during the nesting season as they could cover in the time avail- able. It was difficult to find enough erass- land to census, but ultimately about 450 acres were censused in northern and central Illinois. The results were surprising, for population densities of almost every grass- land species had fallen 80-90 percent below those of 1957-1958. Combining density loss habitat total among grassland species of birds has been and loss, population — loss catastrophic. Total losses for representative orassland species are shown in the table. of the range of some prairie species, the data refer Because southern Illinois is south to northern and central Illinois only. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey Population Loss Since Species 1957-1958 (%) Upland Sandpiper =92 Bobolink or Meadowlarks (2 species) — 84 Dickcissel —=—96 Grasshopper Sparrow =~ 96 Savannah Sparrow —98 Henslow's Sparrow = 94 When we consider that such great changes occurred in about 20 years — only a brief moment in the history of a wild population — the figures are alarming. A large decline was expected because of habitat loss, but why did the densities de- cline? Have qualitative changes occurred in the habitats? Or do the problems of the grassland birds lie along the migration routes, or on the winter ranges of the various species? The group includes species which winter south of the equator in South America (Bartramian sandpiper and bobo- link), in Central America (dickcissel), and along the Gulf coast of the United States and Mexico (grasshopper and sa- vannah sparrows). Are there problems for the species in all these places and in Illinois too? The answers require intensive field work not yet begun, but, obviously, no popula- tion can endure such losses for long. Pesticide Biodegradation: Too Much of a Good Thing? Over the last 25 years soil insecticides have become an important tool in the con- trol of soil insect pests. Almost 50 percent of the corn acreage in Illinois (about 6 million acres) is treated at planting time with an insecticide. In general, these tools have been very effective in reducing root damage caused by heavy infestations of corn rootworms in fields planted to corn in consecutive growing seasons. However, dur- ing this period a few of the insecticides have performed poorly or inconsistently. It would be a simple matter to switch to more effective chemicals, but the rate of intro- duction of new insecticides has slowed considerably. The arsenal of soil insecticides is becoming more limited, especially when one considers that the currently used prod- ucts generally lack chemical diversity. Within the last 15 years a gradual change has occurred in the kinds of soil insecticides used. In the 1950’s and 1960's the chlorinated cyclodienes (i.e., aldrin, heptachlor, and chlordane) were com- monly used for soil insect control through- out the Midwest. The use of these chem- icals was eventually discouraged and then suspended because they persisted in the environment for excessively long times and tended to accumulate in biological tissue. The organophosphate and carbamate in- secticides slowly replaced the cyclodienes. These chemicals degraded quickly in the environment and were shown to have a low tendency for bioconcentration. On the other ‘hand, the organophosphates and carba- mates are generally less active against insects in soil than the chlorinated cyclo- dienes. Thus, changing chemical usage pat- terns have demanded extensive study of the principles affecting the environmental and toxicological behavior of soil insecticides. One research area gaining more attention. centers on performance problems of soil pesticides. Survey entomologist and insecticide toxi- cologist, Allan Felsot, has been investigat- ing the cause of soil insecticide perfor- mance problems. Entomologists are quick to suspect the development of insecticide resistance when an insecticide performs poorly. Corn rootworm beetles developed resistance to the chlorinated cyclodienes in the 1960’s, but monitoring of different rootworm beetle populations in Illinois during the last three summers failed to show any relationship between insect sus- ceptibility to carbofuran and control effi- cacy. Research from other states also indi- cated that the susceptibility of the corn rootworm to various insecticides had not changed significantly over the last decade. These results led to a second explanation for insecticide performance problems based on the potential of the currently used prod- ucts to degrade rapidly in soil. An effective soil insecticide must be present at a toxic concentration from 1 to 2 months following application because the corn rootworm does not hatch and start feeding in Illinois until early June. In several soils that were collected from northwest Illinois, carbo- furan insecticide completely degraded with- in 30 days. These soils were collected from fields where the chemical had been used for several consecutive years before a con- trol failure was noted. Further studies in- dicated that the insecticide was being de- eraded by microorganisms which had proliferated in this soil. Apparently, some eroups of soil microorganisms use added pesticides as nutrient or energy sources and thereby greatly expand their populations. When a soil containing these conditioned microbial populations is retreated, the pesticide is degraded at a very rapid rate and its concentration falls below the level necessary to kill the insects. At present, it is not known which soil types contain microorganisms capable of adapting to the pesticide, nor exactly which pesticides are susceptible to this rapid biodegradation. Further studies are being conducted to characterize this phenomenon and its im- plications for the chemical control of the corn rootworm in the Corn Belt. Transplanting New Trees Transplanting is a major operation from which most plants recover slowly, even when growing conditions are ideal. Nor- mally, a tree maintains a certain balance between its top and root system. Water and nutrients are taken in through the roots to supply the plant with elements necessary for food production in the leaves. The transplanting operation, regardless of how carefully it is performed, is destructive to a large portion of the absorbing root area. Once the roots are severed during the dig- ging operation, the tree is in varying de- grees of water stress until new roots are regenerated and able to absorb the neces- sary water and nutrients from the soil. In studies conducted in the Survey’s ex- perimental tree nursery, up to 98 percent of the root system of trees 3-6 inches in diameter is removed in the transplanting operation when the soil balls are as much as 4 feet in diameter. Smaller soil balls will contain even fewer original roots. The study also showed that the density of fine roots was greatest in the top 4 inches of soil and that the large main structural roots were predominantly located at the soil depth of 5-13 inches, with limited develop- ment in the top 4 inches and decreasing development at depths below 13 inches. In general, most tree species tending to be more deeply rooted are not as tolerant to heavy clay soils having seasonal high water tables, a condition which often exists in many urban soils. These field studies gave substantial evidence of the shallowness and importance of the development of the fine absorbing root system of transplanted trees. ev at va a nd Uy: on St “nk Careful preparation is made for transplanting a tree (Photo by Eugene Himelick). se In lawn areas, it has been shown that competition from grass is an important factor limiting the development of the shallow tree roots. This evidence supports previous work in which mulching the soil around trees increases the fine root devel- opment by reducing or eliminating grass competition and by helping maintain ade- quate soil moisture and aeration in the upper soil layer. A guide to the ease of moving various tree species and the best season to trans- plant them was recently prepared and is available upon request. Those tree species difficult to transplant should receive the utmost care during transplanting and con- tinued maintenance after transplanting. Spring planting of most tree species has the advantage of ample soil moisture and avoids the possibility that sufficient roots may not become established before freez- ing weather. If trees cannot be planted be- fore they start leafing out, it is essential for most tree species to wait until after the early rapid spring growth has slowed before moving trees in leaf. Watering of recently transplanted trees was found to be the most important main- The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 tenance practice, and under normal urban soil conditions, overwatering frequently caused more root damage than if the trees had not been watered at all. Watering should be done at the time of planting to assure adequate soil moisture in the soil ball and the soil filled around the soil ball. Following the first watering, additional water should be provided only when there has not been sufficient rain to keep the soil moist. The critical months for watering are May through September and for 2-3 years after transplating to assure that the root systems are well established. For slow-grow- ing trees, a period of prolonged drought even during the second or third year can cause severe water stress and make them very susceptible to attack by bark borers and development of trunk cankers caused by various fungi. A newly planted tree is most easily watered if a mound of soil + inches high is prepared around the edge of the original planting hole. The mound of soil serves as a reservoir that should be May 1983. No filled with 6-8 gallons of water at 7- to 10- day intervals during the dry periods of the growing season. Urban soils are frequently thigh in clay subsoil and tend to drain poorly. Under these conditions, allowing the water hose to run for prolonged periods of time in the reservoir can result in over- watering and cause the roots to drown from lack of adequate soil aeration. Extensive field surveys of recently trans- planted trees have shown that the home- owners are largely responsible for the death - and general poor vigor of their trees. Poor tree selection, poor planting stock, and im- proper planting were frequent causes for early decline and death of trees. Improper watering, lawnmower damage, and injury from weed killers used on the lawn were found to be common causes of decline after the trees were transplanted. Researchers in the Section of Botany and Plant Pathology of the Illinois Natural History Survey are willing to offer advice on various tree problems if you wish to write or call. 227. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR. PAUL G NATURAL RESOURCES BUILDING, 607 E. PEABODY RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY CHAMPAIGN DEPARTMENT OF ENERGY AND NATURAL RESOURCES ILLINOIS 61820 The Illinois NATURAL HISTORY ' REPORTS Natural History Survey To Observe Anniversary On June 30, 1858, the Natural History Society of Illinois was organized at Blooming- ton in the office of the Illinois State Normal University. The same organization has be- come, after several transformations through the years, the Illinois Natural History Survey, located in the Natural Resources Building in Champaign. This year marks the 125th anniversary of this organization. Because of circumstances preventing the attendance of many friends of the Survey in June, the celebration dates have been moved to the end of September. Plans are being made for a symposium to be held on Saturday, September 24. There will be a luncheon at the Illint Union and a mor informal meal in the evening. On Sunday, September 25, there will be an Open House and the Survey and its annex facilities, and many of the scientific research projects, will be shown and explained to visitors. On Friday, September 23, preceding the Saturday symposium, a chartered bus tour will take members of the staff and the public to visit three field stations; Kinmundy, where the aquaculture project is in progress; Bogota, the home of the prairie chicken research; and Sullivan, where aquatic biologists conduct their work on Lake Shelbyville. Partict- pants will take a sack lunch and pay their own bus fares, the amount of which has not yet been determined. Inquiries about the anniversary celebration may be directed to Shirley McClellan, 999 009 general chairman and coordinator of anniversary events, at 217-333-6882. Corn Damaged by Stalk Borers The stalk borer, Papaipema nebris, has not been a serious pest of seedling corn in the midwestern United States 1930’s, but recent increases in conservation since the tillage have led to a greater incidence of stalk borer problems. Female moths lay eges primarily on grasses in fence rows, contour strips, grass waterways, or in weedy fields during the late summer and early fall. The eggs do not hatch until the following spring. At that time, larvae first begin feed- ing on grasses but move to larger plants as they outgrow their original hosts. In conventionally tilled fields, damage by the stalk borer is generally confined to the first four to eight rows of corn that are adjacent to field margins, contour strips, and grass waterways. In Illinois, larvae have been found moving into fields of corn and attacking seedlings any time from crop emergence through the end of July. In corn fields where minimum tillage, partic- ularly no-till, is practiced, serious infesta- tions can occur throughout entire fields. When infested fields are planted using a no-till system, herbicides used to kill the existing weeds force the young larvae to move to the only remaining food source — the corn seedlings. Corn plants attacked by the stalk borer may become misshapen or stunted, severely damaged plants usually die. Even if plants survive, they generally produce less grain than uninjured plants. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. Stalk borer larva (top) feeding in giant foxtail stem. When the larva outgrows its original host plant or its host plant is killed with a herbicide, the insect may move to corn. Stalk borer quackgrass (bottom) (Photo by Eli Levine). eggs on Eli Levine, a Survey entomologist, con- ducted laboratory studies to determine temperature thresholds and thermal re- quirements (degree-days) for stalk borer development. He found that 50 percent of the eggs hatched when 329 heat units ac- cumulated above a threshold temperature of 47°F and that total development from ege to adult moth was completed by 50 percent of the individuals when 3,504 heat units accumulated above an overall devel- opmental threshold temperature of 41°F. Levine also showed that female moths be- gan laying eggs three days after emergence from pupae. These laboratory data were validated with data on egg hatch im an outdoor screenhouse and on moth catches in a light trap. The results showed that the dates of one-half the egg hatch under screenhouse conditions and one-half the moth capture by light trap were within one and seven days, respectively, of predicted dates based on laboratory data. Knowing when common stalk borers hatch and when adults lay eggs will be a help in the control of this pest. Destroying weeds in noncrop areas prior to egg hatch can not be recommended because the cover is needed for beneficial insects and it helps combat soil erosion. However, erowers may wish to mow these noncrop areas just prior to stalk borer egg laying and thus make the areas less attractive to moths. These areas, however, should not be mowed between planting and early July since this practice just drives the larvae into the corn and makes problems even worse. In no-till fields, herbicides used to kill existing vegetation in spring force the young larvae over to the emerging com. To reduce the potential of this occurring in a subsequent season, good weed contro] with- in a field is essential prior to the egg-laying period of the moths (usually from mid- August through mid-October in northern Illinois). Levine is currently working on other cultural and chemical control strat- egies to combat this pest. ante Effects of Air Pollutants Gardening, like most things, is largely what you make of it —a hobby, a serious pursuit, a game, an art, a science, or a tedious chore. It can be an infinite pleasure or a vital concern. Whether your interest is for ornamental vegetables, successful gardening requires some knowledge of plant care basics — soil texture, moisture and drainage, pH, nutri- tion, sunlight, weed and pest control, tem- perature requirement — and availability of species and varieties to the home gardener. However, many gardeners overlook air pollution which interacts strongly with gardening. Since most people live in or near urban areas, much gardening is concentrated where pollution levels tend to be high as a result of transportation systems, space heat- ing, industrial activity, and other human- oriented activities. Gardening also creates its own pollution problems from the need for frequent and sometimes heavy use of pesticides and fertilizers. The role of gardening in providing at- tractive, safe, and nutritious fruit and vegetable foods or an aesthetically pleasing landscape is beset with pollution problems. Air pollutants, such as ozone, sulfur dioxide, fluoride, nitrogen oxides, and other forms of pollution may visibly injure plants, re- duce growth rates and yield, and impair homeowner or consumer acceptance. According to Natural History Survey Botanist Anton G. Endress, when any air pollutant impinges on plants, many factors shrubs, cut flowers, or. A a come into play to determine what effect the pollutant will have on the vegetation. A wide range of effects is possible, depend- ing on the interaction of the biological characteristics of the plant species, the nature of the pollutant, and the environ- “mental conditions. The tolerance or sensitivity of vegetation to pollutants depends on (1) genetic make- up, (2) age, health, vigor, and state of metabolic conditions, and (3) rate of pol- lutant uptake and accumulation. The vary- ing sensitivities of individual plants to pollutant injury may be due to differences in genetic constitution which controls the biochemical and physiological tolerance for the pollutant. Leaves at different stages of development also may show different de- grees of sensitivity to the same pollutant. The nature of a pollutant is defined by its chemical characteristics and its persis- tence. The response of vegetation to air pollution depends on the pollutant concen- tration and length of exposure time. High concentrations of pollutants often produce an immediate and acute impact with some easily recognized symptoms. Low concen- trations, however, produce more subtle or chronic effects that develop gradually and are not readily identifiable. If plants are exposed to a pollutant mixture, the total effect may be synergistic, additive, or antagonistic. Plant response to air pollutants is par- tially controlled by a number of environ- mental factors such as temperature, light, relative humidity, soil moisture, nutrient status, and time of year. Generally, the environmental conditions that are most favorable to plant growth also produce the maximum air pollution response. Other factors such as wind direction and speed, and temperature inversions, are also impor- tant because they determine the dispersal and dilution of the pollutants. Vegetation weakened by stresses such as adverse climatic conditions, a nutrient de- ficiency, or disease and insect disorders re- sponds to air pollution much more readily and severely than healthy vegetation. Plants under stress before even mild air pollution episodes may not possess an adequate defense mechanism to protect themselves against pollutant injury. Similarly, plants data from a_ nine- Botanist Anton Endress checks chamber pollution exposure system with various monitors, greenhouses, and controlled growth chambers (Photo by Les Woodrum, Survey Photographer). suffering air pollutant stress may be pre- disposed to attack by insect or fungal pests. The significant characteristics of the symptoms caused by ozone and_ sulfur dioxide are outlined below. Ozone Leaf markings are divided into three categories by plant type: (1) broadleaf plants — pigmented (red-brown) spots or bleached tan to white areas on upper sur- faces of leaves; small irregular areas of dead tissue on both leaf surfaces that may coalesce to form large blotches; chlorosis and premature aging may occur, (2) grasses — scattered necrotic areas on both leaf surfaces; sometimes larger lesions or necrotic streaking may occur, and (3) con- itfers — brown-tan necrotic needle tips without separation between dead and healthy tissue. A. Sensitive garden species or cultivars Beans (especially white flower varieties, such as Pinto, Tempo, Sanilac, Bush Blue Lake 274) , corn (especially Golden Midget, Golden Jubilee), cucumber, eggplant (wide range of sensitivity be- tween cultivars), lettuce (especially Dark Green Boston, Grand Rapids Forcing, Buttercrunch), muskmelon, onion, potato (especially Chippewa, Cobbler, Plymouth), radish (especially Cherry Belle, Crimson Giant, Comet, Champion), spinach, tomato, grape (wide range of sensitivity), alder, crab- apple, bridalwreath, honey locust, lilac, eastern white pine, privet, snowberry, The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 E. PEABODY CHAMPAIGN, ILLINOIS 61820 sycamore, begonia (especially white flower varieties, such as White Comet, Cinderella White), carnation, chrysan- themum (especially Tranquility, Mt. White, Mango, King’s Ransom, Touch- down, Corsage Cushion, Gay Blade), petunia (especially white flower vari- eties, such as Snowstorm and White Cascade). B. Similar Markings Red spider mite and certain insects may cause an upper leaf surface fleck of bleached tan to white areas. Some leafspot fungi may give similar patterns. Pathogen-induced tip burn in conifers may resemble ozone injury. Sulfur Dioxide Leaf markings are divided into three categories by plant type: (1) broadleaf — irregular bifacial (both sides), marginal, and interveinal necrotic areas bleached white to tan to brown; chlorosis may be associated with necrotic areas or a general chlorosis of older leaves may develop; diffuse to stippled colors ranging from white to reddish-brown have been ob- served, (2) grasses — irregular, bifacial, necrotic streaking between larger veins that is bleached tan to white; chlorosis not usually pronounced, and (3) conifers — brown necrotic tips of needles often with a ‘banded appearance; generally chlorosis of adjacent tissue; needles of the same age are uniformly affected. A. Sensitive garden species or cultivars Bean (table), beet, broccoli, Brussels sprout, carrot (very few cultivars have been tested) , endive, lettuce, okra, pea, pepper, pumpkin, radish, rhubarb, - spinach (wide range of sensitivity among. cultivars), squash, Swiss chard, turnip, apple (especially Golden Deli- cious), currant, birch, larch, mulberry, pear, eastern white pine, Lombardy poplar, aster, bachelor’s button, begonia (especially White Comet) , cosmos, four- o’clock, morning glory, sweet pea, tulip (especially American Flag, Grand Hotel, Gold Medal, Red Shine, Queen of Night) , verbena, violet, zinnia. B. Similar markings Leafhopper injury, rose chafer injury, various mosaic viruses, cherry leafspot. and other fungal disease producing blotchy markings; winter, drought, and red spider mite injury in conifers. June 1983. No. 228. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservatior Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR PAUL G. RISSER, CHIEF ILLINO|I NATURAL RESOURCES BUILDING, 607 £ PEABODY NATURAL HISTORY SUR VEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES CHAMPAIGN 182 LLINOIS The Illinows NATURAL HISTORY PRUPOR LS. —_ siligeeles HR» Me a a The Natural History Survey Celebrates 125 Years of Biological Research One hundred twenty-five years of bio- logical research have been completed by the Illinois Natural History Survey, which will celebrate this anniversary September 23 through September 25. A 125th Anniversary Symposium will be held on Saturday, September 24, in the Medical Sciences Building on the Univer- sity of Illinois campus and will be open to the public. Featured speaker at the lun- cheon in the Illini Union will be Dr. Lorin I. Nevling, Director of the Field Museum of Natural History, Chicago. Several “Friends of the Illinois Natural History Survey” will be honored at this time. A limited number of luncheon tickets are available at $8.00 each. On Sunday, September 25, an open house will be held from 1 p.m. to 5 p.m. at both the Natural Resources Building and the Natural Resources Studies Annex located on the south campus of the Uni- versity of Illinois. The insect, plant, fish, and other collections will be open to visi- tors in the Natural Resources Building. Special projects in progress will be on dis- play and will be explained by researchers in the Annex. To open the three-day anniversary cele- bration, on Friday there will be a bus tour to three field stations, Bogota, where prairie chicken research is being conducted; Kin- mundy, where aquaculture projects are in progress; and Lake Shelbyville at Sullivan, where aquaculture biologists are conduct- ing various studies. The bus will leave at 8 a.m. from the Natural Resources Build- ing in Champaign and will return there about 5:30 p.m. Lunch will be provided at Kinmundy (hot dogs, potato chips, and Two researchers of ‘‘the olden days,'' Charles A. Kofoid (front) and Miles Newberry, traveled the Illinois River bottoms at high water in the early 1900's. beverage) or participants may bring thei own “brown bags.” The bus fare will be $12.00 payable to the Survey when a reservation is made. Inquiries about the 125th Anniversary Celebration should be directed to Shirley McClellan, nator, 172 Natural Resources Building, 607 East Peabody Drive, Champaign, IIli- nois 61820, or call (217) 333-6882. Anniversary Events Coordi- Bulletin to Publish Symposium Papers Distinguished scientists of the Natural History Survey and from universities and other research organizations will present papers at the symposium, and these papers will be published in a special 125th Anni- versary Symposium Proceedings issue of the Illinois Natural History Survey Bulletin. Among the speakers at the symposium will be Dr. D. H. Janzen, Department of Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. Biology, University of Pennsylvania, whose topic will be “The Other Reasons Why a Plant Is a Good/Bad Host: The Plant as a Habitat.” Dr. C. R. Goldman, Division of Environmental Studies, University of Cali- fornia, Davis, will speak on “Lake Tahoe, a Microcosm for the Study of Change as the Basin Is Developed.” Speakers from the Illinois Natural His- tory Survey in the morning session include Dr. R. L. Metcalf, speaking on “Plant Karimones and Insect Pest Control’; Dr. A. S. Felsot, who will have as his topic “The Evolution of Environmental Aware- ness Through Pesticide Chemistry and Toxicology Research”; and Drs. R. D. Neely, D. F. Schoeneweiss, and E. B. Hime- lick on “Biotic and Abiotic Stresses as Primary or Predisposing Factors Affecting Illinois Trees.” In the afternoon session, Survey speakers will be Dr. D. P. Philipp, whose topic will be “Application of Genetic Techniques to Fisheries Management”; Dr. L. M. Page, speaking on “The Evolution of Reproduc- tive Behaviors in Percid Fishes”; and Mr. W. E. Cochran presenting “Wind Drift and Migration of Passerines.” The Illinois Natural History Survey Bul- letin containing the Proceedings of the 125th Anniversary Symposium will be pub- lished in the spring of 1984. Early History of the Survey The beginnings of the Illinois Natural History Survey go back to December 1857, when Cyrus Thomas of Carbondale pro- posed to the State Teachers’ Association that a Natural History Society of Illinois be established. On June 30, 1858, the Society was organized at the Illinois State Normal University. The constitution provided that specimens should be collected and depos- ited in the museum of the State Normal University. The state charter awarded to the Nat- ural History Society in 1861 authorized the Society to establish its own museum at the State Normal University. In 1871, as a condition for receiving financial assistance, the Society relinquished ownership of the museum to the state. The Illinois legisla- ture in 1867 established the State Entomol- ogist’s Office, and 10 years later authorized Dr. Stephen A. Forbes changing the Illinois Museum of Natural History at Normal to the State Laboratory of Natural History. Stephen Alfred Forbes, who later be- came the first Chief of the Survey, was both Director of the State Laboratory of Natural History and State Entomologist in 1885 when he moved from Normal to Urbana to accept an appointment as pro- fessor of zoology and entomology at what was then the Illinois Industrial University. Later in the same year the legislature approved the transfer of the Laboratory from Illinois State Normal University to the University of Illinois. Thus, both the State Laboratory of Natural History and the State Entomologist’s Office became located in Urbana. There they continued as separate until 1917, when the General Assembly combined them as the Illinois Natural History Survey to carry on the intensive program of biological re- search begun 60 years earlier. There are those who speculate about the name, Illinois Natural History Survey. Chief Forbes believed that “survey” meant more than mere plant and animal censuses. He felt that any study should show the relationships between living organisms and their environments...an ecological sur- units Dr. Frison vey. This theory prevailed in all his work and firmly underlined the research done at the Illinois Natural History Survey. Stephen A. Forbes Led the Way Dr. Harlow Mills wrote of Forbes in the 100th Anniversary Bulletin: “No one has molded the character of the Illinois Natural History Survey so much as Dr. Stephen A. Forbes, a man of irrepres- sible intellect and insatiable curiosity, and the fourth and last Illinois State Entomol- ogist... “After the resignation of Cyrus Thomas as State Entomologist in 1882, Governor Shelby M. Cullom appointed Forbes to that position. In 1884 Indiana University awarded Forbes the Ph.D. degree by ‘thesis and examination.’ He did not have a bachelor’s degree. In 1885 he moved to the University of Illinois, where he was Pro- fessor of Zoology and Entomology, Director of the State Laboratory of Natural History, and State Entomologist... “He was especially interested in the in- teractions of organisms and has been called ‘the father of ecology.’ His interest covered all of biology. He investigated or directed investigations of the food of fishes and birds, the fishes of the state, and the biol- ogy of the Illinois River, and he directed forest surveys of Illinois... “He was a member of many learned societies and the recipient of many honors. Beyond this, he was active in his church, helped organize the first golf club at the University, was a member of a hiking club, and late in life delighted in driving an Dr. Mills Dr. Sprugel automobile. On his eightieth birthday he was arrested for speeding, an incident which gave him some pleasure . . . “When the State Laboratory of Natural History and the State Entomologist’s Office were united in 1917 to form the Illinois Natural History Survey, Forbes became the first Chief of the new organization. He held this position until his death, March 13, 1930, when almost 86 years of age.” Survey Chiefs Through the Years The Natural History Survey has been very fortunate in having a series of out- standing men who served as Chiefs. Each in his own way has contributed to the Dr. Paul G. Risser The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 growth of the Survey, economically, sci- entifically, and philosophically. Theodore H. Frison (1931-1945) grew up in Champaign-Urbana, and as a per- sonal friend of Dr. Forbes, he knew the needs of the Survey long before he be- came its Chief. Along with Dr. M. M. Leighton, Chief of the Geological Survey, he concluded that the two Surveys had outgrown the space allotted to them in the Natural History Building on Green Street. The two men were able to obtain the land and funds for the Natural Resources Build- ing, which the Surveys moved into in 1940. This was the Natural History Survey’s first permanent home. Frison, whose specialty was bees, had many interests. As soon as he became Chief, he began the development of wildlife re- search as a separate discipline. He was in- strumental in organizing the Midwest Wild- life Conference, the initial meeting of which was held in Urbana in 1935. He was also a charter member of the Wildlife Society. In intellect and aggressive enthusiasm, he was a worthy successor of Forbes. A coworker cited Dr. Harlow B. Mills’ (1947-1966) greatest achievement as that of “welding together the Survey into a marvelous cohesive scientific structure.” The staff had more than doubled, the re- search budget had increased by more than 225 percent, and areas of living natural resources were being explored in depth. Dr. Mills’ success in developing the Survey was partly due to his knowledge of both entomology and wildlife combined with his remarkable ability to get people to cooperate. George Sprugel, Jr. (1966-1980) came to the Survey from the National Park Ser- vice in Washington, D.C., where he was -Chief for the Division of Natural Sciences. His outstanding contributions to the growth of the Survey included the building and instrumentation of the Natural Re- sources Studies Annex south of St. Mary’s Road in Champaign, the development of an extensive grant and contract program, and the expansion of eight field stations around the state. During a very trying time in the state’s economy, Dr. Sprugel was able to keep the staff intact and maintain the quality of scientific research at a high level. Relatively new to the Illinois Natural History Survey is Dr. Paul G. Risser, who came here in June 1981 from Norman, Oklahoma, where he was chairman of the department of botany and microbiology at the University of Oklahoma. A dynamic and energetic man, he has implemented a number of his ideas for making the Survey a smoother operating, more productive organization. To date, he has installed a sophisticated word-processing and computer system, in- creased the grants and contracts program, and is continually working to strengthen Survey relationships with other state agencies. On seeing him in operation, one knows that he has only just begun... .. September 1983. No. 229. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, ILLINOIS 61820. The Illinovs NATURAL SURVasae “Friends of the Survey” Honored Six ‘Friends of the Illinois Natural His- tory Survey” — Gaylord Donnelley, Leon- ard Durham, Murray O. Glenn, Marion Hall, Sam A. Parr, and Robert Webb - were honored at the Survey’s 125th Anni- versary Symposium Luncheon held on September 24 in the Illini Union Building. Framed certificates designed by Survey L- lustrator Lloyd Le Mere were presented to the honorees. Gaylord Donnelley has demonstrated his friendship and concern for conserva- tion, research, and the arts on an interna- tional, national, and _ state financial support and by serving on many boards and commissions on all three levels. Leonard Durham, Director of the Divi- sion of Life Sciences at Eastern Illinois University, has sent more than 200 student interns to work at the Survey. Murray O. Glenn, whose certificate was accepted by members of his family, died in 1981 at the age of 87. He spent 46 years studying the Lepidoptera (butterflies and moths) in his free time. His collections of 30,000 specimens presented to the Survey have contributed significantly to the classi- fication and study of ecology of moths in the Midwest. Marion Hall, Director of the Morton Ar- boretum at Lisle, provided an insectory; he even provided housing for members of the Survey staff while they were working there. Hall has also assisted in getting funds for Survey research. Sam A. Parr started as a game warden, but as he advanced in the Department of Conservation, he provided close coopera- tion, support, and friendly help for wild- life and fisheries studies at the Survey. scale by his Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. ‘ As) HISTORY The sixth honoree is Robert Webb, for- mer Director of the Dixon Springs Agri- cultural Station at Simpson. He _ hosted and in many ways encouraged research on the Experiment Station lands, ponds, and forests. Domestic Cats in Rural Illinois The few available facts pertaining to domestic cats in the United States suggest that these feline pets may have increased by as much as 65 percent over the past decade. The pet food industry estimates that there are about 42 million cats in this country. However, these estimates have been derived primarily from human-cat ratios for metropolitan areas. What are typical densities of these felines for rural areas? Do they significantly affect wild animal populations? In a preliminary 5- year study of a rural cat population in IIli- nois, wildlife ecologist Richard Warner addressed these questions. The primary study site was a 20-square- mile area located between Sibley and Mel- vin in Ford County. With the cooperation of rural residents of the area, the demog- raphy of their cats was studied, 1976- 1981, with emphasis directed toward the late summer population. To compare num- bers of cats in this area with those living in other parts of rural Illinois, early morn- ing roadside transect counts were con- ducted on this area and townships in central Illinois, 1977-1981. Further, the Illinois Department of Con- servation provided cat census data from four other spring roadside counts of mammals along approximately 40 different routes through- out rural Illinois, 1981-1983. In conjunc- tion with census work on the primary study area, 11 cats were fitted with small, lightweight radio transmitters and were _ radio monitored during summer and early autumn. Over the 5-year period, there was an average of 5.6 cats per residence in the Ford County area in late summer. Breed- ing females averaged 1.5 per residence with little annual variation, because residents tended to limit numbers of actively breed- ing females. Late summer cat densities ranged from 10.4 to 22.4 per square mile and averaged 16.3 cats per square mile from 1976 to 1981. Farmsteads with live- stock typically had three times as many cats as residences without large animals had. Warner found no evidence of feral cats — felines reproducing in the wild and avoiding or rejecting domestication and domestic food sources. Only 5-10 percent of the cats survived to 3 years of age, with less than 1 percent surviving to 7 years. From deaths documented by cat owners in the Ford County area, 1979-1981, road kills accounted for 26 percent of the mor- tality, and dispersal or disappearance and disease each accounted for 17 percent of the deaths. Humans, dogs, cats, and winter weather were also common feline killers. ————==F BGP = Bluegrass Pasture Qa———A : 07 C = Corn On= = = = == O = 08 HH = Harvested Hay Be ome = 09 HP = Hay Pasture O = Farmstead 0 = Oats = Field Border SB = = Road Right-of-Way Woe Wheat = Waterway i Primary Residence of 07,08,09 Soybeans Ranges of four domestic cats radio tracked in Ford County during July and August 1978. Male 06 tended to be vagrant during the period of study, having no permanent residence and avoiding farmsteads except for feeding. Females 08 and 09 were pregnant during the radio-tracking period. Radio tracking of seven females indi- cated a typical summer range of 278 acres, with females commonly roaming within a radius of about 0.9 mile from their resi- dences. Male cats evidenced greater move- ments, with four radio-monitored males averaging 563 acres of range; they were commonly found within a radius of 1.3 miles from their residences. Ranges of ma- ture males tended to be separate from those of other sexually active male cats. A group of females and juvenile males at a given farmstead generally had overlapping ranges within the territory of one mature male (see map). Excluding farmsteads, 73 per- cent of the radio-location points for the ‘11 monitored cats were in some form of linear habitat or edge (ecotones that were highly attractive to wildlife) such as field edge, waterways, or roadsides. All cats in the Ford County area fed regularly at residences, but they also hunted, at least to some extent. In fact, all radio-monitored cats hunted, primarily . between 6 p.m. and 6 a.m. when tempera- tures were relatively cool and dew was present. During 1978 and 1979, residents noted prey brought to farmsteads by their cats; 77 percent of the residences reported rodents; 12 percent, other small mammals; 13 percent, cottontail rabbits; 9 percent, pheasants; and 43 percent passerines or other small birds. The evidence suggests that well-fed cats hunt regularly, compete with other predators of small animals, and destroy desirable forms of wildlife. The data from this preliminary. study indicate that there are probably 10-15 mil- lion cats in Illinois, 75 percent of which may be free ranging in rural areas. These numbers imply that currently accepted estimates of numbers of feline pets in this country may grossly underestimate the rural population. Perhaps the sketchy un- derstanding of cat numbers in the United States, and how free-roaming cats affect natural ecosystems, in part explains the fact that only 1 out of every 10 county-level governments in this country attempts to control numbers of feline pets and their ownership. Stresses Affect Illinois Trees Before 1800, over 40 percent of Illinois was covered by forest. Today only about 11 percent of its total acreage is forested, less than that of any state east of the Mis- sissippi River. The conversion of wooded acreage to farmland, highways, and urban and industrial development has steadily reduced the forest resource base in Illinois to less than 3.5 million acres, compared with nearly 22 million acres of corn and soybeans. Even farm windbreak and hedgerow trees have disappeared in many areas, resulting in increased wind and water erosion of fertile topsoil. Because of their relative scarcity, the protection and preservation of trees in Illinois are vital is- sues for the state. Many of the trees remaining in Illinois are suffering from stresses caused by biotic and abiotic factors, particularly urban trees along streets, parkways, and on pri- vate property. Biotic stresses are caused by insects and disease organisms, while abiotic stresses result from such things as drought, flooding, soil compaction, toxic herbicides and pollutants, and mechanical injuries. In many cases, trees are damaged by the combined effects of abiotic and_ biotic stresses. When trees are weakened by stress, they often become predisposed to attack by disease pathogens; consequently, out- breaks of tree diseases are common follow- ing a hard winter or after an extended drought. The severe drought of 1983 has had an obvious effect on corn and soybean yields, but it may be several years before the resulting damage to Illinois trees can be estimated. Many abiotic and biotic stresses affect dozens of species and varieties of trees in Illinois. Although epidemic diseases, such as chestnut blight, oak wilt, and Dutch elm disease, have killed thousands of trees and are familiar to the public, many less well-known diseases cause significant dam- age each year. Keeping up to date on tree diseases requires a constantly changing and evolving program of basic and applied re- search. Plant pathologists in the Survey’s Section of Botany and Plant Pathology have researched the biology and control of biotic and abiotic tree diseases for over 50 years. Currently, three pathologists, Drs. E. B. Examples of biotic stresses affecting Illinois trees. A. Verticillium wilt on green ash. B. Nectria canker on thornless honey locust. C. Sporulating cedar-apple rust galls on red cedar. D. Anthracnose lesions on black walnut. Himelick, Dan Neely, and D. F. Schoene- weiss, each with 25 or more years of ex- perience, are conducting research projects on tree diseases. These projects include studies on the biology of specific fungal pathogens, the evaluation of fungicides for disease control, root loss and root regenera- tion during and after transplanting, wound healing, the damaging effects of lawn herbicides on trees, the cause and preven- tion of tree declines, and basic research on the histology and biochemistry of tree re- sistance to disease and the breakdown of resistance under predisposing stress. There is increasing demand in Illinois for trees, not only for shade and orna- mental value, but as noise and pollution filters, for reforestation of marginal lands, and for energy-yielding biomass. At the same time, trees are becoming increasingly subjected to stresses because of high costs for care and maintenance and the use of labor-saving transplanting equipment, which removes most of the root system when trees are moved. A continuing re- search effort will be required for the fore- The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 seeable future to meet the issues raised by these changes. New List of Publications Available A long-awaited book, Publications of the Illinois Natural History Survey, 1876- 1983, has recently been published and is now available. This list of Survey publica- tions is far more extensive than earlier lists, and it appears in a completely different, more useable format. This new book lists all publications of the Illinois Natural History Survey in the Bulletin, Biological Notes, and Circular series as well as in other Survey series no longer published. It also lists contributions of Survey staff members to serials and vol- umes published by other organizations and reprints of articles written by Survey staff and published in various journals after MNT. The book is divided into five main sec- tions, corresponding to the five scientific research sections of the Natural History Survey: Aquatic Biology, Botany and Plant Pathology, Economic Entomology, Faunistic Surveys and Insect Identification, and Wildlife Research. Within each sec- tion, publications are listed by author name in alphabetical order, and a standard bibliographic style is used in each listing. Accompanying each listing is a symbol indicating whether the publication is avail- able through the Natural History Survey. available only through the author, or out ‘of print or not available from the Survey. Out-of-print Survey publications may be examined in the Illinois Natural History Survey Library. Complete instructions for ordering publi- cations are included. Single copies of Ilh- nois Natural History Survey publications are furnished free to persons requesting - them. Orders for more than one copy from educational institutions and similar or- ganizations in Illinois and from others are filled whenever possible. However, because of publishing costs and limited supplies, the Survey attempts to limit distribution of its publications to persons and institutions that will make the best use of them. To order a copy of Publications of the Illinois Natural History Survey, 1876-1983, send your request, including your name and complete address, to the Chief, Illinois Natural History Survey, 172 Natural Re- sources Building, 607 East Peabody Drive, Champaign, Illinois 61820. October 1983. No. 230. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, ILLINOIS 61820 The Illinovs NATURAL SURV Ea LUMP Issues First Land Report With the publication of Illinois Land Report: Rice Lake Conservation Area, the Illinois Lands Unsuitable for Mining Pro- gram (LUMP) has become a reality. As a result of recent state and federal legisla- tion, this program establishes a process whereby Illinois citizens may petition the state to designate certain areas of land unsuitable for coal mining. Petitioned areas may be declared “unsuitable” if reclama- tion is not feasible, or if mining would con- flict with existing land use plans, damage fragile or historic lands, reduce produc- tivity of renewable resources, or increase natural hazards. The Illinois Department of Mines and Minerals (DMM) has the responsibility to determine whether the petitioners’ allegations are justified and sufficient to prohibit or limit mining of the area in question. The Illinois Department of Energy and Natural Resources (DENR) has two roles in this process: first, to maintain a natural resource information system and data base which will be available to the public to HISTORY The osprey, an American hawk and an Illinois endangered _ species, carries fish as it flies over Rice Lake. The photograph was taken Septem- ber 21, 1983 by Survey researcher Christopher Burnett. assist petitioners; and second, to prepare a land report on each petition area to pro- vide DMM with the information needed to make its determination. These tasks will be greatly facilitated by a computerized “geographic information system” that is currently being installed at the Illinois Natural History Survey (INHS) to man- age the vast amounts of data available on Illinois’ natural and cultural resources. In addition to INHS, four other DENR divi- sions — the Geological and Water Surveys, the State the Energy and Environmental Affairs Museum, and Division of -con- tribute to the preparation of the Land Re- ports. The INHS is specifically responsible for evaluating biological and soil resources. Land Reports must address whether min- ing would have any of the undesirable effects, as well as contain a detailed state- ment on the potential resources of the area, the demand for coal, and the impact of designating an area unsuitable on the environment, the economy, and the supply of coal. Land Reports must state available infor- Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. mation objectively, but will not recom- mend whether the petition should be granted or denied. Following publication ~ of the report, public comments are ac- cepted and a public hearing is held to pro- vide citizens with opportunities to present evidence or testimony regarding the peti- tion. The Rice Lake Conservation Area, sub- ject of the first Land Report, is located in Fulton County in west-central Illinois. The area covered in the Land Report en- compasses 2,694 acres managed by the Illinois Department of Conservation pri- marily as migratory waterfowl habitat. The petition to prohibit mining was filed in December 1982 by the Save Rice Lake Area Association, Inc., a not-for-profit citi- zens’ group. In terms of biological resources, the Rice Lake Land Report predicts that mining and subsequent reclamation would most likely have positive impacts on water- fowl and sport fishing but negative impacts on undisturbed plant communities, endan- gered species, nonconsumptive recreation, commercial fishing, and various ecosystem functions. For soil resources, compaction would likely be the major problem in re- storing productivity should mining occur. Reclamation of wildlife habitat would be possible but would take several decades. These predictions regarding biological and soil resources will be weighed along with numerous other factors in the decision- making process. DMM is required to rule on the petition by 28 December 1983. Amphibian and Reptile Bulletin Updated In 1961, the Illinois Natural History Survey published a Bulletin entitled The Amphibians and Reptiles of Illinois. This extremely popular state report, written by Survey zoologist Philip W. Smith, has been reprinted without revision several times and has frequently served as a model for authors of books on the amphibian and reptile faunas of other states. The appearance of the volume pre- cipitated publication of more than 300 articles and books citing Illinois specimens or Illinois populations of amphibians and reptiles in the ensuing 20 years. Because of the immense amount of literature, biolo- gists involved in preparing environmental 4: ste i eas Dr. Philip W. Smith, author of The Amphibians and Reptiles of Illinois, and also one of the authors of the new publication, An Annotated Bibliography of the Illinois Herpetological Literature, 1960-1980, and An Updated Checklist of Species of the State. impact reports have needed a summary of publications that have appeared in print since 1961. Prompted by the environmentalists’ need for recent data, Michael A. Morris (South- ern Illinois University-Carbondale) , Rich- ard S. Funk (Ohio State University), and Philip W. Smith (Illinois Natural History Survey, retired) produced a new Bulletin entitled An Annotated Bibliography of the Illinois Herpetological Literature, 1960- 1980, and An Updated Checklist of Species of the State. Publications listed in the Annotated Bibliography are arranged alphabetically and numbered consecutively. Species listed in the Updated Checklist of Species are arranged phylogenetically and also num- bered consecutively. The List of Titles and the Checklist are cross-referenced. Thus, a researcher can quickly ascertain which species are discussed in each of the publi- cations listed and, after consulting the Checklist, he can determine which publi- cations are pertinent for each of the IIli- nois species of amphibians and reptiles. The new Bulletin is thus a great time-saver for environmental biologists and provides them with a means for determining the a ee eT Nn eee Four poisonous snakes of the state found chiefly in southern Illinois. They are (upper left) massasauga or swamp rattlesnake taken in Piatt County (Photo by former Survey photographer, W. E. Clark); (upper right) timber rattlesnake; and (lower left) cotton mouth or water moccasin, both taken in Jackson County, near Murphysboro (Photos by former Survey photographer, R. Hesselschwerdt); and (lower right) copperhead, taken in Randolph County, near Chester (Photo by former Survey photographer, Ray Hamm). present environmental status for all Illinois species. Single copies of the new publication are available upon request to: Chief, Illinois Natural History Survey, 607 East Peabody Drive, Champaign, Illinois 61820. No Pesticides Found in Well Water Samples Since almost half the population of the United States uses ground water from wells or springs as a source of drinking water, great concern has been expressed recently about the potential contamination of ground water by agricultural and in- dustrial chemicals. Ground water is also important in irrigated crop production, and more importantly, it is an integral part of the hydrologic cycle of earth. When ground water sources, or aquifers, become contaminated by pathogenic microorgan- isms or toxic chemicals, there are only three courses of remedial action: forbid use of the aquifer and obtain alternate water supplies; attempt to rehabilitate it; or con- tinue to use the water but treat it to re- move the contaminants. Contamination of ground water by agri- cultural chemicals has been noted in 13 states. When Wisconsin reported contami- nation of wells in the Central Sands region by pesticides that are registered for use in Illinois, Illinois Natural History Survey scientists decided to survey ground water quality for potential pesticide residues. Insecticide toxicologist Allan Felsot, in the Section of Economic Entomology, organized an interagency committee consisting of representatives from the State Water Sur- vey, the Illinois Environmental Protection Agency, the Illinois Cooperative Extension Service, and the Illinois Departments of Public Health and Agriculture to study the problem. The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 Owing to limited funds for nonroutine monitoring of pesticide contamination, the first action was to identify areas in Illinois where there was a high risk of ground water contamination. Since it is known that contamination is highly correlated with the downward leaching of chemicals in sandy soils, four such regions in Illinois were designated high risk. Areas of this nature that were sampled included Kankakee County, Mason County, Whiteside County, and Gallatin County. Stephenson County was included as a fifth region because of the occurrence of bedrock outcroppings that are also considered susceptible to ground water contamination. Illinois Department of Agriculture work- ers collected five well water samples in each region during the month of June. Both deep and shallow wells were included in the sampling protocol. ‘The samples were divided and sent to analytical laboratories at the Department of Public Health and INHS. Waters were analyzed for a wide variety of insecticides, herbicides, and fun- gicides with a detection limit of one part per billion (ppb = 1 microgram of pesti- cide per liter of water). No pesticides were detected at the five locations sampled in Illinois. Although the United States EPA has not set any no-observed-effect levels for pesticide residues in ground water, the detection limits in this study were equal to or less than the levels set for public water supplies. Several chemical and field factors are known to facilitate the movement of pesti- cides into ground water supplies. Chemical factors include the pesticide characteristics of high water solubility and relatively little adsorption to soil surfaces. Field factors in- clude well-drained or sandy soils with low organic matter content, high rainfall, and shallow, unconfined aquifers. Although ~ these factors were applicable to several of the pesticides and wells tested, all waters were free of contamination. Since remedial action for cleaning con- taminated wells is very expensive and may not be feasible, the best method of ensur- . ing clean ground water is prevention of contamination. This survey for potential pesticide contamination in Illinois ground water illustrates the cooperative interest among the various state agencies in main- taining good ground water quality in rural Illinois, and it is hoped the data generated will serve as a background for future mon- itoring studies. November 1983. No. 231. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, ILLINOIS 61820. Illinovs NATURAL HISTORY beeee we ee - JAN 11 1984 Chicago Area Deer Research SRAM A 3-year study of deer and deer-related problems in urban areas of Cook, Du Page, Kane, and Lake counties is being con- ducted by the Illinois Natural History Survey. It was initiated | July 1983. The investigation is being funded cooperatively by the U.S. Fish and Wildlife Service and the [llinois Department (DOC). An extensive deer population has devel- oped in the urban area of northeastern Illinois on local forest preserves, parks, and other suitable habitats. Deer herds sometimes reach a point where their num- bers seemingly explode—a_ population bomb. The evidence indicates that deer numbers in the suburban Chicago area have reached critical proportions. Deer- motor vehicle accidents have increased alarmingly, with numerous injuries and damage to vehicles. Deer browsing on trees and shrubs have caused extensive damage in parks and forest preserves. Numerous complaints have been received from area residents about deer eating valuable orna- mental plants and damaging gardens and crops. Deer have also become a problem on runways at O’Hare International Air- port and have been removed from the air- port on occasion. Urban deer problems are not unique to Illinois; they exist in the urban areas of Minneapolis, Milwaukee, Cleveland, De- troit, and along the east coast. Experience in these localities has shown that deer management and control strategies must be tailored to local conditions and atti- tudes. In rural areas, deer numbers are held Conservation within reasonable bounds by the annual mo oREPOR TS: Deer herd gathers in the kind of natural habitat they seek, but are sometimes unable to find (Photo by W. N. Wandell). removal of excess deer by hunters accord- ing to seasons and regulations carefully prescribed by the DOC staff. However, hunting is prohibited in many urban situa- tions and alternative strategies must be sought. The urban deer problem is seen as being the sum of a series of local problems involving a number of different parks and forest preserves 1n the Chicago area. A basis of current, factual data is es- sential to solving wildlife-related problems. It is the responsibility of the Conservation Department to work with various local governmental agencies and with the owners of private property in trying to solve deer- related problems. The objective of the Survey in the deer study is to collect, ana- lyze, and make such information available both to the DOC and to local units of government. The urban deer research study project team is being supervised locally by Dr. Jim Witham, who is headquartered on land owned by the Cook County Forest Preserve District. He is being assisted by Jim Chels- vig, who has been transferred to the area Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. from Champaign. Dr. Glen C. Sanderson, head of the Survey’s Section of Wildlife _ Research, is the principal investigator for the project. For several years, scientists of the Section of Wildlife Research have been studying management strategies for deer in the rural areas of Illinois. The primary objectives of this urban deer study are to determine how many deer are in the four-county urban area, where they are, how fast their numbers are increasing, what their behavior and _ habi- tats are, whether they are healthy, how much damage they are causing, how many need to be removed for effective control, and relative costs of several possible meth- ods of control. 3 Along with what the biologists refer to as the “population study,” a management study will be initiated. The management study will evaluate methods of capturing deer on metropolitan parks and forest pre- serves and subsequently releasing them elsewhere in the state. In the past, Depart- ment of Conservation and Survey biologists have captured and transplanted relatively small numbers of deer, primarily for re- search and restocking purposes. However, capture and removal may not prove to be effective at a scale demanded by deer in the four-county urban region. Information from DOC biologists and Survey studies indicates that the problem of deer in urban areas may relate, in part, to deer immigrating considerable distances from rural townships, as deer are highly mobile. Thus, Survey researchers have been asked to census deer throughout Cook, Kane, Lake, and Du Page counties to determine deer abundance, any damage problems, and the attitudes of landholders and. homeowners toward possible control methods for deer in these four counties. There is general agreement that a real problem exists and that it warrants im- mediate attention. It may be necessary to remove several hundred deer from the four-county area. A new crop of fawns comes each spring, and the surplus will probably need to be removed each year if effective population control is to be maintained. Mexican Bean Beetle Population Is Monitored in Illinois In Illinois, the Mexican bean beetle (Epilachna varivestis, Coleoptera: Coc- cinellidae) has historically been considered only as a pest of garden beans, and seldom, if ever, has it been found attacking soy- beans. However, this beetle is a well-known pest of soybeans in several eastern coastal plain states, and recently it has become established as a serious soybean pest in areas of Ohio, Kentucky, Tennessee, and throughout most of Indiana. Yearly changes in the composition of the arthropod fauna on Illinois soybeans have been closely monitored by researchers in conjunction with the Illinois Cooperative Extension Service. Monitoring the incidence and trends in soybean-feeding arthropods is considered an important component of the state’s Insect Pest Management (IPM) program. Any crop grown over such ex- tensive areas as soybean in Illinois is highly vulnerable to exploitation by “new” pests- resulting in serious economic impact. Thus, the Mexican bean beetle has been the focus of attention in this respect for some years, due to the apparent expan- sion of its range westward in states neigh- boring Illinois. Although as early as 1971 the beetle was observed feeding on soy- beans in a single field in east-central IIli- nois, there has never been an infestation of economic consequence. However, in 1981, Survey researchers Marcos Kogan and Charles Helm observed moderate popula- tions of this insect in two counties border- ing Indiana, and in 1982, the first instance of economically damaging populations of this beetle occurred in these same counties. Outbreaks were reported late in the season in both conventionally planted and late- planted or double-cropped beans as beetles massed in the few remaining green fields. Although nearly every field sampled con- tained a few adult beetles in the early spring of 1983, there have been no reports or observations of beetles on subsequent visits. However, perhaps most alarming was the report of a heavy population in a field nearly 50 miles due west of these original outbreaks. Mexican bean beetle is shown on damaged soybean leaf (Photo by T. E. Benner). Outbreaks such as this necessarily raise the question of changes in adaptation of the beetle to soybeans and/or changes in the susceptibility of Illinois soybean plants to the pest. Both hypotheses are currently being tested in the laboratory. Presently there appears to be little evidence that these apparent changes in feeding prefer- ence of Illinois beetles are due to genetic changes in the beetles themselves. There is some evidence that these changes are re- lated to the quality of the plant; however, both of these hypotheses require consider- able additional testing. Continuous monitoring of not only beetle populations, but also agricultural practices and ecological conditions, in ad- dition to laboratory studies, will provide a much better understanding of the mech- anisms involved in the expansion of this beetle’s range and host preference. Urban Pesticide Usage by Arborists Seventy-four percent of the population in the United States lives in urban areas surrounded by 200 million trees and 800 million shrubs. The use of pesticides to keep these plants free of insect pests and diseases is increasing. Advancement in pest control procedures is years behind the cur- rent developments in agricultural fields and urban Integrated Pest Management (1PM) is in its infancy. One of the major users of pesticides in urban areas is the arborist. Commercial arboriculture is a | billion dollar per-year industry involving pruning (37 percent), spraying (18 per- cent), and tree removal (16 percent). No data assessing the use of pesticides by arborists are available. The research objectives by Dan Neely and Eugene Himelick, plant pathologists, were to determine |) the pests to be con- trolled, 2) the pesticides used to control them, 3) the host plants being treated, 4 the quantity and cost of pesticides applied, 5) the time of application, and 6) the equipment being used. The relative eco- nomic importance of pesticide application to the total value of services offered by commercial arborists was also sought. The objectives were fulfilled through questionnaires and _ personal interviews. Separate questionnaires were prepared for the commercial and the municipal arbor- ists to present their differing interests, methods, and goals. Questionnaires were mailed to 529 tree experts with licenses to practice commercial arboriculture in Illi- nois. Of the 529 questionnaires mailed to licensed arborists, 156 were returned. Of the 40 questionnaires mailed to arborists that are employed by municipalities, 20 were returned. These, plus the 16 licensed arborists employed by municipalities, com- posed the data sample for municipal arbor- ists. The results can be summarized as fol- lows. Most of the arboriculture firms per- form tree maintenance services other than tree pest control. In 29 percent of the firms, the pest control income is less than $7,000 annually. In 63 percent of the firms, this income is substantial, from $8,000 to $150,000. The remaining 8 percent is over $150,000. Most of the pest control services are performed for homeowners on private grounds. The training of employees who operate sprayers for arborists is pri- marily on the job. Applying the pesticide at the proper time seems to be the most difficult of the problems related to tree and shrub pest control. The insecticide usage by Illinois arborists is substantially greater than the fungicide The Illinois VATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 usage: thirteen times as many applications of insecticides alone as fungicides alone, and two times as many insecticides alone as combinations of insecticides and fungicides. The disease most important to commercial arborists is scab, followed by rust and anthracnose. The most important insect problem is scale, followed by aphids and bagworms. The 20 arborists who responded on the municipal arborist survey form con- firmed the Neely and Himelick opinion that Dutch elm disease has been the major problem for Illinois cities. The size of the municipal budgets to be used at the discretion of the muncipal arborists for pest control activities is small. Three arborists state they have no funds specifically to be used for tree-pest activi- ties; another three of 12 responding to this question had over $20,000 in the 1982 budget. The average for the 12 cities was $15,000 for protection of city trees. Appli- cation of sprays at the proper time is rated the most difficult problem for municipal arborists; diagnosis of the problem is rated the second most difficult. The apparent need to apply substantially more insecti- cides than fungicides was similar in both groups. An effort was made to personally inter- view arborists with a range in interests and size of operation. An effort was also made to select arborists distributed geograph- ically throughout Illinois. The tree hosts with eight or more insect-pest problems in- clude crabapple, elm, honeylocust, maple, - oak, and fruit trees. The tree hosts with three or more disease problems are crab- apple, hawthorn, oak, and fruit trees. June was the month of greatest activity for insecticide application with almost 1 mil- lion treatments to trees. April and May were the only months with extensive treat- ments with fungicides. The dollar value of pesticides purchased by licensed commer- cial arborists in Illinois in 1982 was sub- stantial, averaging $8,500. Of this, 15 per- cent was for fungicides and 85 percent was for insecticides. According to the calcula- tions of Himelick and Neely, over 2 million dollars were spent by licensed arborists in Illinois for pesticides in 1982. Persons desiring individual or additional copies of this publication please write to NATURAL HISTORY | FEB uprati”* The genus Torula was established by Persoon in 1795 for fungi with dark, bead- like, one-celled, asexual spores (conidia). Because of this vague generic concept, a large number of unrelated organisms have been grouped in this genus which presently contains nearly 600 species. Included among these fungi are pathogens of man and animals which cause localized swollen lesions on the hands and feet (Torula jeanselmei) as a result of subcutaneous in- fections or which cause pulmonary nodules or systemic infections of the lungs (7 orula neoformans). The identifications of many medically important fungal pathogens are difficult because of incomplete descriptions Monographic Study of Torula 5 tT. ff | = with poor or no illustrations. This, in turn, affects diagnosis and treatment. Torula fungi are commonly encountered in soil, water, air, and on decaying and living substrates. They represent an important segment of any mycological flora, and studies that will define the generic and species concept in Torula are necessary for a better understanding of the species and their accurate identification by mycologists and persons in allied professions. Presently, Lee Crane, Survey mycologist, is attempting to establish the range of variability in Torula herbarum, the species which delimits the group (genus). In this study, the classification of the genus will be based on developmental and morpho- Photomicrograph of Torula herbarum illustrating the heavily melanized, coronate, conidiogenous cells and chains of conidia. X 2,000 (Photomicrograph by Lee Crane). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. logical characters. In T. herbarum and other bonified species, the cell that pro- duces the asexual spores (conidia) appears to be the diagnostic character. It is crown- like and heavily colored at the base. The conidia are ornamented with warts, and the spore size and number of cells per conidium are constant within a range for each species. All recognized species of Torula appear to fall within two basic groups: those with the conidia borne singly and those with conidia in chains. The bio- logical constancy of these characters will be studied. A key and detailed descriptions with illustrations will be provided for the accepted Torula species and any new spe- cies. Information for each species on typifi- cation, synonomy, geographical distribu- tion, and host or substrate range will be provided. The monograph will include an index of all names published in Torula along with the source of publication, his- tory, and present disposition. This study will provide basic biological information on a genus about which there has been much confusion since its estab- lishment and will serve as a reference manual to the early mycological and medi- cal literature where species named as Torula are cited. Effect of Stalk Borer Injury on Corn Yield Female moths of the stalk borer, Papai- pema nebris, oviposit primarily on grasses in fence rows, contour strips, grass water- ways, or in weedy fields during the late summer and early fall. After the eggs hatch the following spring, the larvae begin feeding on grasses but move to larger plants as they outgrow their original hosts. Corn may serve as this larger plant if planted in or near infested grasses. Stalk borer larvae injure corn plants in two ways: by burrowing into the base of the plant and tunneling up through the center of the stalk or by entering the plant through the whorl and tunneling down. Both types of attack may result in mis- shapen or stunted plants and_ severely damaged plants may die. The recent increased use of conservation tillage practices by field corn producers in the central corn belt has led to a greater incidence of stalk borer problems. In par- ticular, serious infestations can occur throughout entire fields where no-till is practiced if these fields harbor stalk borer eggs and larvae before spring planting. After herbicides are applied to kill exist- ing weeds, the stalk borer larvae are forced to attack the corn seedlings, the only remaining food source. For convention- ally tilled (fall-plowed, spring-disked ) corn fields, stalk borer damage is usually re- stricted to the first four to eight rows of corn that are adjacent to field margins, contour strips, or grass waterways contain- ‘ing stalk borer infested grasses. Eli Levine, a Survey entomologist, as- sessed the impact of natural populations of stalk borer larvae on the ability of corn plants to recover after injury was inflicted at different plant growth stages (leaf stages two through eight). The study was con- ducted in three no-till fields and three con- - ventionally tilled or reduced tilled (fall chisel-plowed) fields over the course of 3 years (1980 to 1982). He found that yield losses resulting from injury by larvae were due to both the reduction in the number of plants producing ears and the reduction in grain weight per ear. In general, seedlings injured earlier in devel- opment produced fewer harvestable ears (plants producing ears that contained a kernel weight of 30 or more grams at 15.5 percent moisture were considered harvest- able) and less grain than plants imjured later in development. Injured plants also tended to sucker (grow additional shoots more than uninjured plants. He also found that of the injured plants that did not set harvestable ears, over 58 percent survived to harvest time. These nonproductive plants probably competed with the un- injured plants for sunlight, moisture, and soil nutrients until harvest. Levine did not find new damage in plants beyond the eight-leaf stage. He also found that dam- age to corn in plots adjacent to field mar- gins containing stalk borer-infested grasses varied by row with the row immediately bordering the field margin generally sus- Inflated caterpillar of Dasychira Caterpillar of vagans (Barnes & McDunnough), collected in 1898 and first illus- trated in a 1913 publication on tussock moths (Photo by G. L. Godfrey). Carroll taining the most damage. The results of this study should be useful in the develop- ment of damage thresholds for this pest. When this information is generated, corn producers will have a better idea when chemical control is economically justified. Dasychira vagans: Octogenarian Visitor A well-traveled, 86-year-old tussock moth caterpillar specimen (first picture) , Dasychira vagans (Barnes and McDun- nough), that formerly resided in Illinois visited the Survey briefly in 1983. The caterpillar was collected in the summer of 1898 near Meach Lake, Quebec, Canada, was inflated for preservation, and spent the next 30 years in the collection of the late Dr. Williams Barnes of Decatur. In the early 1930's, it, along with the rest of the large Barnes Collection, was sold to the US Department of Agriculture which transferred its custody to the United States National Museum of Natural History (Smithsonian Institution), Washington, D.C. Its temporary return to Illinois was arranged by Associate Insect Taxonomist George L. Godfrey, who spotted it in the National Museum and recognized it as the specimen that had been illustrated in a 1913 publication on the Lymantriidae Dasychira basi- flava (Packard) on white oak, Mississippi Palisades State Park, E. County, 1983 (Photo by G. L. Godfrey). White-marked tussock moth cat- erpillar, Orgyia leucostigma (J. Smith), normally feeds on deciduous trees and_= shrubs, rarely found on soybeans (Photo by G. L. Godfrey). Illinois, June (tussock moths). The clue was a mis- placed, black seta (hair) on the right side of the body about one-third of the way from the head. Godfrey normally does not check cater- pillars to see if their hairs (setae) are in place before photographing them, but in this case was involved in a study of the North American tussock moth caterpillars and was searching for museum specimens to complement those that he had reared (middle picture) in order to complete the project. The lymantriid study that was recently completed is Godfrey’s third contribution on caterpillars to a national project about immature North American insects that F. W. Stehr, Michigan State University, is coordinating. The lymantriids include several major and minor pests of trees and shrubs. Examples from Illinois include the notorious gypsy moth caterpillar, Ly- mantria dispar (Linnaeus), and the lesser known, white-marked tussock moth cater- pillar, Orgyia leucostigma (J. E. Smith) (third picture). Presented in the study are photographs of representative caterpillars of all the North American lymantriid genera, a synthesis of the known _ host plants, phenological and distributional in- formation, and the basic diagnostic char- acters for identifying the caterpillars. The Illinors NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 Rural Cats — A Look into the Future A recent article in the Natural History Survey Reports described a free-ranging rural cat population in central Illinois. What are likely trends for future numbers of cats in this state? Wildlife Ecologist Richard E. Warner estimates that cur- rently there are approximately 5.5 million cats in Illinois; further, if national trends continue for a growing percentage of households with cats and more cats per household, there could be up to 10-15 million cats in this state by the year 2000. Because free-ranging cats prey upon wild animals, a potential change in densi- ties of felines in rural areas is an important consideration. There are two shifts occur- ring in the human population that suggest a high probability of greater numbers of rural cats in the future. First, there have been about 850 new hobby farms (less than 50 acres) established each year in Illinois since the late 1960’s. Secondly, rural com- munities are expected to sustain a growth in numbers of households. For example, 75 percent of the small towns in the 34 - southernmost counties of Illinois are pres- ently growing. Hence, as people show a growing preference for rural living, there is little doubt that feline pets will appear in growing numbers on the rural land- scape. January 1984. No. 233. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES, CHAMPAIGN, ILLINOIS 61820 The Illinows NATURAL SURVEY Endangered and Threatened Species in Illinois In his fervor to improve his lifestyle and conquer all natural barriers, Man has ex- ploited and changed most of the native habitats of the earth. As one result, the natural process of extinction has been drastically altered and_ significantly in- creased. Since the early 1600's, over 500 species of native plants and animals have become extinct. Many others have been brought to or near the edge of extinction and are considered, respectively, endan- gered or threatened. The official list of endangered threatened plants for Illinois contains 363 and Xanthocephalus xanthocephalus, yellow-headed black- bird, in Typha, cattail marsh (Drawing by Ms. Patti Katusic). Material in this publication may be reprinted if credit is given to the Illinois HISTORY species. The official list of such vertebrates for Illinois includes 13 fish, 11 amphibians and reptiles, 40 birds, and eight mammals. Of these, one fish, four birds, and two mammals also are listed as federally en- dangered. While no official state list of endangered or threatened clams presently exists, four of the 23 federally endangered clam species are known to occur in Illinois. In Illinois, endangered species are de- fined as those naturally reproducing native species likely to be extirpated from this state in the near future. Threatened species are those likely to become endangered in the near future. Most of the native species of plants and animals existing in Illinois today are surviving in marginal or de- tached habitats. Of principal concern is the protection of critical habitat necessary for the successful reproduction of endangered and threatened species within the state. The Illinois Department of Transporta- tion (IDOT), Bureau of Location and En- vironment, is required by the Endangered Species Act of 1973, as amended, to con- duct biological inventories for the purpose of identifying federally listed endangered and threatened species likely to be affected by its highway construction projects. Plant and animal species listed as endangered or threatened in Illinois by the Illinois En- dangered Species Protection Board are considered in a similar fashion. The Illi- nois Natural History Survey (INHS) in cooperation with IDOT, has conducted such inventories since 1981. Survey staff members in the Sections of Faunistic Sur- veys and Insect Identification and Botany and Plant Pathology primarily have been responsible for these inventories. Scien- tific staff members include Project Coordi- Natural History Survey. nator W. U. Brigham; Project Manager, M. J. Wetzel; Botanists, K. R. Robertson, R. GC. Moran, and W. McKnight; and Zoologists, L. M. Page, L. Suloway, R. Grosser, M. E. Retzer, J. Kasprowicz, M. Morris, and S. L. Sandberg. The objectives of these studies are (1) to locate all existing populations of the endangered and threatened plants and animals in the study area; (2) to establish from literature, field observation, and con- sultation with experts, the boundaries and abundance of each population; (3) to document the known life history and the ecology and environmental requirements of the species; and (4) to assess the poten- tial impact of the proposed project on these populations within their specific habitats. The collective efforts of the Natural Land Institute, Illinois Natural Areas In- ventory, Illinois Department of Conserva- tion, Illinois Endangered Species Protection Board, the Audubon Society, the US Fish and Wildlife Service, Morton Arboretum, The Nature Conservancy, and many other public and private groups have provided the information needed to assess the status of native species in our state. While the principal objective of these inventories 1s to protect critical habitat used by Illinois endangered and threatened species from reduction or elimination from highway construction, the information assembled also can be used to address the special problems of these species. Preservation of land, reintroduction of native species, man- agement of natural and artificial habitat, breeding programs, and life history studies are all options available for managing en- dangered and threatened species once critical habitat has been identified. Their current status as “endangered” and “threatened” species is the result of the ex- pansion of the human species. Thus, it is appropriate that we make the effort to assure their survival. Present and future land ethic in Illinois must give priority to its natural resources. Fungal Pathogens of Insects in Alfalfa Alfalfa is the world’s cultivated forage crop. In most valuable the United States, it is surpassed in total acreage only by corn, soybeans, and wheat. This forage crop is recognized as providing the best food value for all classes of livestock as it produces about two times as much digest- ible protein as clover and four times as much as timothy-clover hay or corn silage. In addition, alfalfa adds nitrogen to the soil, improves water filtration, and im- proves soil structure. Alfalfa is grown as a perennial and as such is a unique agroecosystem. It is rela- tively long lasting (3-5 years) but is harvested every 4-6 weeks which creates short-term cycles. Because of its relatively low per-acre economic value, alfalfa can ‘tolerate a level of insect pest presence which might not be allowable in another crop. Therefore, alfalfa is ideal for the application of integrated pest management techniques. Of the many insects which live in alfalfa, the alfalfa weevil (Hypera postica) and the potato leafhopper (Empoasca fabae are considered the primary pests. Alfalfa weevil larvae occur in the spring causing serious economic damage by defoliating the plant. The adult alfalfa weevils dis- perse to wooded areas near the alfalfa field to remain dormant through the hot sum- mer months. In the fall, the adults migrate back to the field and begin laying eggs. The potato leafhopper, on the other hand, does not overwinter in Illinois. This small green insect migrates from the gulf coast states each spring and becomes a pest dur- ing the second and third alfalfa growth periods in midsummer. It causes damage by sucking plant sap and blocking con- ductive tissues. This feeding causes leaf tips to yellow and die which leads to a re- duction in total protein produced. Both of these insects have fungal path- ogens which attack them. The alfalfa weevil is attacked by Erynia phytonomti. This pathogen was initially discovered in 1974 in Ontario, Canada, and since then has spread rapidly throughout the United States. At times, disease incidence may range as high as 100 percent in certain populations of weevils given ideal micro- climatic conditions. When this disease occurs early enough in the weevil’s life cycle, economic damage is averted, thus reducing the need for an insecticide appli- cation. Presently, Survey entomologists are working to determine what factors are important in the initiation and spread of naturally occurring epizootics and how this disease affects other biological agents (e.g., parasites and predators) of the alfalfa weevil. Erynia radicans is a fungal pathogen which infects the potato leafhopper. In 1982, Survey entomologists received a leaf- hopper with this disease from researchers in Wisconsin. This generated an interest in the potential use of this pathogen as a biological control agent. A literature sur- vey indicated that very little research has been done with this pathogen, but several reports indicated that at times potato leafhopper populations had been severely affected by E. radicans. A survey of Illinois in 1983 failed to locate any leafhopper populations which were affected by any pathogens. However, a trip to Wisconsin yielded several leafhoppers infected with E. radicans. Presently, researchers are working with these isolates to determine: (1) basic transmission and epidemiological parameters involved with this pathogen- host system; (2) host range of E. radicans; (3) mode of overwintering; and (4) why this pathogen was not found in Illinois in 1983. Once the basic biology of these two pathogens is understood, integrated pest management tactics may be developed control Typical abandoned mine site in northern Illinois, near Standard, showing severe erosion and lack of vegetative cover. which would facilitate their use as bio- logical control agents. Abandoned Mines in Northern Illinois Illinois has an abundance of coal with approximately 65 percent of the state overlying coal-bearing strata. Ever since the first mine opened in 1810, Illinois has been an important provider of this re- source. However, until 1962 little was done to protect the environment. During that year, the first surface mine law became effective in Illinois, and in 1972 the Pollution Control Board issued regulations concerning water quality from deep- and surface-mining operations. Con- sequently, a large number of sites, aban- doned prior to the 1960’s, were never re- claimed and many still pose environmental hazards. During 1982, Claus Grunwald and Diane Szafoni of the Illinois Natural History Survey were granted a contract from the Abandoned Mined Lands Recla- mation Council to study revegetation pos- sibilities of the abandoned mines of the Longwall District in northern Illinois. Louis Iverson, also a Survey staff member, has since joined the research group. Deep mines in the Longwall District were in operation from 1875 to 1930, and the area presently contains over 100 refuse piles, generally lying within 20 miles of the Illinois River between Morris (Grundy County) and Peoria (Peoria County), Illinois. reclamation The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 Revegetation of most of these mine sites by natural processes, even after 50 or more years, has been negligible and thus causes a number of environmental problems, 1n- cluding sedimentation and decreased water quality of streams. The natural establish- ment of vegetation has not occurred be- cause of generally very steep topography, lack of moisture, relatively high soil acidity, and the exposure to poor soil texture and fertility conditions. The mine waste represented material removed from directly above and below the No. 2 coal seam during the Longwall mining process. A complete inventory of plants growing on the poorly revegetated pile was conducted during the summer and fall of 1982 and the early summer of 1983. A total of 40 species of vascular plants was found, with most of the vegetation con- fined to the lower slopes. Even though the mine has been closed for many years, most species represent early successional stages. Measurements of water potentials and temperatures of the gob material re- vealed excessively harsh growing condi- tions, especially on southern slopes. The combination of steep slope and poor mois- ture retention of the gob material makes water availability an important limiting factor restricting plant growth. Chemical analyses of the mine gob mate- rials have revealed additional potential problems. Although the pH ranges between 3.2 and 4.0, lime requirements to correct this problem were reasonably low. Nitro- found to be extremely deficient, and fertil- izer would be required for proper plant growth. The gob material was also fairly high in aluminum and iron which could present a toxicity problem at low pH: however, adjustment of pH through liming should correct any toxic effect. To further explain some of the nutrient problems, a greenhouse experiment has been devised which eliminated water as a limiting factor. The soil modifications that were tested were lime, fertilizer, lime plus fertilizer, and sewage sludge. The total biomass accumulation plus the shoot: root - ratios were monitored for three grasses (tall fescue var. ‘Kentucky 31’, little blue- stem, and side-oats grama) and two le- gumes (black locust and crewnvetch). With all species, except black locust, the addi- tion of sewage sludge produced the great- est production of plant biomass. Black locust responded best to fertilizing. In gen- eral, the fertilizer treatment ranked sec- ond and the lime plus fertilizer third, fol- lowed by the lime treatment and the sand treatment. The poor responses to sand or lime treatments underscore the nutrient deficiency problems; gob texture or pH problems are secondary in importance. It would appear from these results that the use of sewage sludge, both for its water- retention and nutritive qualities, should be pursued further for the revegetation of northern Illinois mine gob piles when economically and environmentally accept- able. gen, phosphorus, and potassium were February 1984. No. 234. Published monthly except in July and Auqust by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation Prepared by Shirley McClellan with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publications: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR, PAUL RISSEF NATURAL RESOURCE HIEF BUILDING, 607 EAST PEABODY DRIVE ILLINOIS NATURAL HISTORY SURVEY. DEPARTMENT OF ENERGY AND NATURAL RESOURCES, CHAMPAIGN 182 ILLING The Illinors NATURAL ) NATURAL HISTORY tiPORTS MAR 2 3 1984 Newly Discovered Plant Hosts of Spiroplasma citri Brittle root has been the most destruc- tive disease of Illinois horseradish since it was first reported in 1936. In 1981, plant pathologists and entomologists at the Uni- versity of Illinois and the Illinois Natural History Survey, in cooperation with re- searchers at the University of California at Davis, provided a key to understanding brittle root with their reports that the causal agent of this disease is the helical bacteria-like organism Spiroplasma citrt. The Illinois team further demonstrated that the beet leafhopper (Circulifer ten- ellus) can transmit §. citri to and from horseradish, and that the aster leafhopper (Macrosteles fascifrons) is also an experi- mental vector of this pathogen. Many questions remain concerning the epidemiology of brittle root in Illinois. The disease is present in horseradish at a very low level almost every year and has oc- curred at irregular intervals in epidemic proportions with heavy crop losses. Do leaf- hopper vectors bring S. citri into the state from the western United States, where S. citrt causes a major disease of citrus? Or are there plant hosts, especially weeds, serving as reservoirs of §. citri in Illinois or elsewhere in the Midwest from which leaf- hoppers could transmit this pathogen to horseradish ? Recently, Entomologists Karen O’Hayer, Gerald Schultz, and Catherine Eastman, and Plant Pathologist Jacqueline Fletcher conducted a study to explore the feasibility of the local weed reservoir hypothesis. S. citrt has a wide experimental host range which includes several wild brassicaceous plants, and field-collected weed species LIBRARY Chlorosis and stunting resulting from S. citri infection in (A) shepherd's purse, (B) yellow rocket, and (C) wild mustard. In A-C, the plants on the left were ex- posed to infected C. tenellus and the plants on the right to control leafhoppers. have been found to harbor spiroplasmas in California and Arizona. No work had been done, however, to determine the suscepti- bility of wild plant species to midwestern citrt. O’Hayer and her col- leagues set out to determine if three brassi- isolates of JS. caceous weeds common in the Midwest — yellow rocket (Barbarea vulgaris), wild mustard (Brassica kaber), and shepherd’s Capsella serve as sources for transmission of an IIli- purse bursa-pastoris) — could nois isolate of S. citri to horseradish. First, beet leafhoppers injected with sus- pensions of cultured S. citri were used to inoculate yellow rocket, wild mustard, and shepherd’s purse test plants to determine their susceptibility to S. cztri infections. In- jected leafhoppers and non-injected con- trols were held on sugar beet plants for 22 days to allow time for spiroplasma multi- plication within the injected insects and infection of their salivary glands. Then they were caged in groups of 10 on five Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey seed-grown test plants of each weed species. After 7 days, surviving insects were trans- ferred to fresh test plants of the same species for another 7 days. Chlorosis and stunting of young leaves characteristic of S. citri infection developed in 4 of 10 yel- low rocket and shepherd’s purse test plants and in six of nine wild mustard. Enzyme- linked immunosorbent assay (ELISA), a diagnostic test which uses serum contain- ing antibodies generated in response to a specific pathogen, confirmed the S. citrz in- fections. All test plants caged with control leafhoppers remained free of symptoms and were negative by ELISA. To determine if beet leafhoppers could acquire and subsequently transmit S. cztri from these infected weeds, leafhopper nymphs were confined in separate cages with four source plants or four healthy plants of each weed species for 7 days and were held on sugar beet plants for another 26 days. Insects fed on source plant species were then caged in groups of 10 on five test plants of the same species and on five horseradish test plants. After 7 days, sur- viving insects were transferred to fresh plants of the same species for another 7 days. Leafhoppers previously confined with either infected yellow rocket or shepherd’s purse plants transmitted S. citri to all 10 yellow rocket or shepherd’s purse test plants, respectively, and to all 10 horse- radish test plants. Leafhoppers confined with infected wild mustard transmitted the spiroplasma to all 10 wild mustard and to 9 of 10 horseradish test plants. Plants were diagnosed as infected by symptom- atology and confirmed by ELISA. All test plants caged with leafhoppers fed pre- viously on healthy weeds remained free of symptoms and were negative by ELISA. Preliminary searches for spiroplasma-in- fected weeds near horseradish fields in Illinois have been unsuccessful, but inten- sive studies have yet to be conducted. The report that yellow rocket, wild mustard, and shepherd’s purse can be infected by S. citri expands the host range of this spiro- plasma and is the first study to use a mid- western isolate. ‘The demonstration that these weed species can serve as sources for transmission of S. citri to horseradish is an encouraging first step in long-term research to determine the possible involvement of local or regional wild plant populations in the epidemiology of brittle root disease. Prairie Chicken Management — Cycles, Densities, and Thresholds Illinois’ long-term data base on prairie chickens is matched by few other states within the range of the species. Yet, ade- quate answers to some basic questions are still needed. For example, is there a mini- mum population size below which demo- graphic factors, environmental variations, natural catastrophes, or genetic factors - such as inbreeding, may depress a popula- tion to extinction? Grouse such as prairie chickens sometimes show cyclic fluctuations in their numbers at intervals of about 10 years. Are prairie chickens in [Illinois cyclic? If so, how much variation in popu- lation densities can be expected between cyclic lows and highs? Grassland habitat suitable for successful nesting has long been recognized as the critical factor limit- ing the abundance of prairie chickens in Illinois. But how much grassy nest cover is re- quired for the long-term preservation of the species? Should nest cover be a single, large block? Or, if a scatter pattern of sanc- tuaries is best, there are questions of num- ber, size, shape, and dispersion to answer. These topics were addressed by Illinois Natural History Survey Wildlife Ecologist Ron Westemeier at a recent meeting of the National Prairie Grouse Technical Council in Emporia, Kansas. Some geneticists believe that, in general, a population must not fall below 50 indi- viduals, yet others indicate that for those species like the prairie chicken that per- form their courtship and mating activities on special display grounds or areas, the minimum population size may be more like 150-200 individuals. The prairie chicken flock near Bogota in Jasper County ap- proached the supposed threshold of 50 birds in the mid-1960’s, but recovered dramatically to some 400 birds in 1972- 1973. Currently, the Bogota flock is down to 100-120 birds, probably due principally Prairie chickens on booming ground of their natural habitat. Cocks are larger and more ornate birds than the hens. to competition by pheasants. The prairie chicken flock near Kinmundy in Marion County was down to about 50 birds in 1971, but by 1982 this flock probably ex- ceeded 200 individuals. These responses provide some basis for speculating that a minimum population size for prairie chickens may be somewhat below 50 birds. A basic phenomenon to be considered in studies of the dynamics of grouse popula- tions is the tendency for their numbers to cycle at intervals of about 10 years. The prairie chicken population in Jasper County showed (1) probable highs in 1962-1963, (2) definite highs in 1972-1973, and (3) if pheasant counts are added, a high was also evident for 1982. Pheasants were added to the prairie chicken counts be- cause of their overlap in ecological re- quirements. Both species are concentrated on the sanctuaries. In Marion County, although relative stability was maintained from 1963 through 1979, a definite high in 1982 was in synchrony with the combined prairie chicken-pheasant population at Bogota and population highs in Wisconsin and Minnesota. Thus, cycles may indeed be natural phenomena to be considered. Over a decade, abundance can be ex- pected for several years —typically in MARION COUNTY - KINMUNDY AREA PRAIRIE CHICKEN COCKS 166 is) 8 63 62-67 69 71 73 75 77 79 81 83 YEAR JASPER COUNTY - BOGOTA AREA 266 i568 PHEASANT COCKS \ 188 36 PRAIRIE CHICKEN COCKS 8 63 65 6f 69 71 73 73 7¢ 79 BI S32 Two graphs show the fluctuations in the counts of prairie chicken and pheasant cocks only on two separate sanctuaries. Counts for cocks and hens are usually about 50-50. The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 years ending in 1, 2, or 3 —but relative scarcity must also be expected about half the time — typically in years ending with GS), 7, Cie Be Currently, two scatter-patterns of sanc- tuaries totaling 1,920 acres (14 separate tracts) in Jasper and Marion counties are managed cooperatively by the Survey, the Illinois Department of Conservation, and The Nature Conservancy. Although sanc- tuary acquisition began in 1962, a good test of the density of prairie chickens that can be maintained through so-called cyclic lows did not occur until the 1976-1978 period. By that time, a stabilized program of sanctuary management was underway in both counties. The two populations did not show simultaneously clear troughs in 1976-1978, but their numbers were rela- tively low. The prairie chicken densities then were essentially identical in both counties — 70 cocks per square mile of nest cover (on sanctuaries). On average, densities of 100 prairie chicken cocks per square mile of nest cover appear realistic for Illinois (perhaps the highest in the range of the species). During cyclic highs, the density may be 2 or 3 times that of the density at cyclic lows. The data on cycles, densities, and pos- sible thresholds suggest an acreage goal of March 1984. No. 235. Published monthly except in Jul of the Illinois Department of Energy and Natural Resou: and Conservation Prepared by Shirley McClellan with th : ynd-class Office of publications: 172 Natural Re collaboration o (USPS Building postage paid at Urban Illinois 1,500 acres in each of two areas of Illinois, of which about 75 percent might realisti- cally provide quality nest cover on an annual basis. Such an acreage could be ex- pected to support 200 prairie chickens dur- ing cyclic lows, an average of 300 birds, and up to 600 grouse at cyclic highs. These population sizes would range from 4 to 12 times the supposed extinction threshold of 50 birds and provide a measure of safety against such factors as pheasant competi- tion, oil development activity, heavy pre- dation of nests on the sanctuaries, and in- creasingly intensive land use around the ~ sanctuaries. Thus, an additional 1,000 acres of sanc- tuaries should be added to the present systems. Because of the success of Illinois’ scatter patterns and the historically poor “track record” of single, large refuges in Illinois and in other states, new sanctuaries should also be scattered. Sanctuaries may range from 80 to 160 acres or more in size, and not be more than about | mile apart. Better management of existing sanctuaries is also a critical need. Hopefully, Illinois’ new nongame wildlife check-off program will provide funding to help meet manage- ment needs of the prairie boomer and other components of our prairie eco- system. f the Survey staff Cn npaian, titinors Persons desiring individual or additional copies of this publication please write to EPARTMENT NATURAL H - APR 2 6 1984 LIBRARY In winter few people expect to see in- sects crawling about on the snow, but Sur- vey biologists, John Unzicker and Allison Brigham, are studying the biology of a wingless fly that does just that. A member of the forest litter community in Illinois, this small (3-4 mm long) insect, Chionea stoneana, is active on the snow at tempera- tures as low as 10°F (—12°C). Since invertebrate animals are cold- blooded (poikilotherms), keeping active during winter is important to the sur- vival of insects like Chionea. This dark- colored fly can be seen walking on snow in woodlands from mid-November through early February. Chionea belongs to an ar- thropod community active in the forest litter layer under winter’s snowy blanket that includes other animals such as beetles, spiders, mites, gall-making wasps, scorpion- flies, centipedes, millipedes, and springtails. The genus Chionea in North America occurs in relatively dry oak-hickory forests, northern beech-maple associations, and the mixed deciduous and evergreen forests of eastern Canada. In the western mountains, Chionea may be found from the lower dry forests of ponderosa pine up through the It’s a Snow Fly! The small (3-4 mm long) insect, Chionea stoneana, as drawn by Mary Beth Kidd. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. zone of lodgepole pine, and into the high alpine forests of spruce and fir. Adult Chionea appear during the cold months of the year, mate, disperse, with females laying eggs in the forest litter or on the soil surface beneath the litter. The eggs apparently take 1 or more months to hatch. The wingless condition of these flies is utilized in an interesting way. Gravid females hold eggs in the thorax as well as in the abdomen. Since these insects lack wings, the thorax is not packed with large flight muscles. Therefore, the space in the thorax can be storage used as additional The Chionea stoneana grow throughout the warm months of the year, with pupation occurring at the end of the summer or in space for eggs. larvae of early autumn. Adult emergence begins in mid-November, completing the cycle. Little else is known about the activities of this fly in the litter-soil surface layer be- cause it blends in with the drab colors of the twigs, leaves, and bark that constitute most of the plant biomass of this layer. The snow layer on the soil protects the ani- mals living in the litter layer and on the soil surface. A 6-inch layer of snow will keep the soil surface up to 15°F warmer than the air above the snow. As the snow melts exposing the bases of trees and other woody vegetation during “warm spells,” openings or channels occur in the snow through which animals can escape to disperse throughout the wood- land. Chionea have been seen to walk in a straight line as far as 100 feet on the sur- face of the snow. The activity of this winter insect on the snow is limited by light intensity, tempera- ture, and blowing snow. They are most active during calm, sunny days when air temperatures reach 40°F (4.4°C) or more. Chionea avoid the lethal effects of freezing temperatures during cold weather by a process called supercooling or lowering the freezing point of their body fluids. Unzicker 3righam these insects three winters woodland sites in east-central Illinois to determine their distribution and population densities and to understand other aspects of their life cycle. Climatological data were recorded, including air temperatures (above ground, at ground level above the litter layer, and at the soil surface under the litter layer), precipita- tion, and sky conditions. Additional studies planned for recent winters to characterize Chionea genetically have been hampered by unusually warm weather that restricts the activity of these winter-hardy insects! studied at two and have over maximum-minimum Arbor Day — A Holiday of the Future In many countries, it has long been the tradition to hold a tree or forest festival annually. ‘The origin of such celebrations must date back to antiquity, according to E. B. Himelick, plant pathologist at the Survey. But the idea of calling a special day Arbor Day, as it is commonly known today throughout the world, evolved from the idea of one man living in the Great Plains of the United States. The idea spread widely to other countries where today it is variously celebrated as the ‘Festival of Trees,” “Greening Week” in Japan, “The New Year’s Day of the Trees” in Israel, the “Tree-Loving Week” in Korea, the “Af- forestation Week” in Yugoslavia, the “Stu- dents Afforestation Day” in Iceland, and the “National Festival of Tree Planting” in India. Arbor Day, in its various forms, is now recognized in more than 50 countries. The first Arbor Day was observed in the state of Nebraska on April 10, 1872. More than 1 million trees were planted in Ne- braska on that day. During the 1870s, other states passed legislation to observe Arbor Day. Several United States presi- dents have proclaimed a national Arbor Day, but many states, because of different climatic zones, continue to celebrate the —_— - a The tulip tree pictured is a good tree for Arbor Day © planting. It is decorative in early spring and gives good shade in the summer. Disease resistant, it is a sturdy, durable tree, and it grows quickly. holiday at different times of the year. Most states observe the holiday on the last Friday of April, as we do in Illinois. Some do their actual tree planting on the state’s own Ar- bor Day, which varies from January to February in the southern United States to May in the northernmost states. The idea of Arbor Day was conceived by J. Sterling Morton, then a member of the Nebraska State Board of Agriculture. He was a journalist and became editor of Nebraska’s first newspaper. Through his articles, he provided information on the use of trees and his suggested planting day, to be called Arbor Day. J. Sterling Morton was tirelessly enthusi- astic about planting trees. He realized that although the Great Plains were essentially treeless, they had the climate and the soils favorable for tree growth. His articles were about trees which were best suited to the area, and he encouraged the settlers to plant trees around their homesteads. Mor- ton also advocated tree planting by schools, civic organizations, and groups of every kind. The earliest recorded celebration of Ar- bor Day involving school children occurred on April 27, 1882. On that day, 21 trees were planted in Eden Park in Cincinnati, Ohio; one for each United States presi- dent up to that time. The first tree planted was a white oak, in memory of George Washington. Approximately 30,000 per- sons attended the tree planting. Schools let out, businesses closed, and many promi- nent persons attended. Eden Park now has an area called Presidents’ Grove. J. Sterling Morton, upon learning of the Arbor Day celebration in Cincinnati, was delighted to learn of the involvement of school children in planting trees on that day. Morton considered the adoption of Arbor Day by schools the most important aspect of the holiday’s development. Mr. Morton died in 1902. One of his favorite sayings adorns a memorial marker to him in Nebraska City, Nebraska: “Other holi- days repose upon the past; Arbor Day pro- poses for the future.” Celebrated by chil- dren, Arbor Day is becoming a holiday of the future, for when a child plants a tree, net only is work done for which the com- munity might benefit, but also for which he or she, in later years, might benefit. Probably one’s first unconscious reaction to a community is caused by the absence or abundance of trees. It is frequently said that no single item distinguishes one city or town from another more than its green areas and streets lined with trees. Trends in Mallard Numbers in Illinois Each fall, thousands of waterfowl pass through Illinois enroute from their summer breeding grounds in Canada and _ the northern United States to their wintering grounds in Arkansas, Louisiana, Missis- sippi, and the Gulf Coast. Because Illinois lies between the breeding and wintering grounds for waterfowl in the Mississippi Flyway, it provides critical migration habi- tat for several species. Each day spent in Illinois during the fall migration provides waterfowl with an opportunity to rest and feed, and thereby to maintain their physi- ological condition at a level that will allow further migration. Days spent in Illinois also reduce the duration of stay on the wintering areas and, therefore, the amount of food that the wintering areas must pro- vide. Stephen P. Havera and Frank C. Bell- rose, along with the staff of the Havana Field Station, are currently investigating the abundance and distribution of water- fowl throughout Illinois during the fall migration. Bellrose initiated the aerial in- ventories of the Illinois and Mississippi river valleys in 1948, thereby providing us with 36 years of continuous information on the waterfowl use of the rivers. Survey researchers believe that these inventories are the longest continuous series of water- fowl censuses in the United States. In 1971, Robert Crompton assumed the responsibili- ties of aerial censuses which have been ex- panded recently to include wetlands and rivers in northeastern, northwestern, cen- tral, and southern Illinois. Thus, although every duck that passes through Illinois each fall is not counted, there is a yearly index available of the numbers of approximately 20 species of waterfowl to use for compari- son of trends in abundance, distribution, and chronology of migration. The number of ducks that arrive at fall migration areas and the duration of their stay is determined by several factors. These factors include the size of the breeding population in the spring, the habitat and weather conditions on the breeding grounds, the conduciveness of weather conditions to migration along the flyway in the fall, and the amount of food and the presence of refuges on the migration areas. With this information, the long-term FALL PEAK NUMBERS OF MALLARDS IN ILLINOIS, 1948-1983 2868 _ 1758 o 4 ILLINOIS VALLEY 1580 4 CO MISSISSIPPI VALLEY ” u8 1258 iN Oo = o S; 1808 z A <8 3 << 758 aw < = 1950 1955 1960 1965 1970 1975 1980 YEAR Peak numbers of mallards censused each fall in Illi- nois and Mississippi River valleys, 1948-1983. The Illinovs NATURAL HISTORY SURVEY’ DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 trends of waterfowl use for these major migration sites can be examined. In recent years, mallards have consti- tuted approximately 50 percent of the nearly 400,000 ducks harvested annually in Illinois. In addition, mallards have repre- sented about 86 percent and 47 percent of waterfowl use of the Illinois and Mississippi rivers, respectively, since 1960. The highest number, or peak number, of mallards counted at any one time during the fall migration each year from 1948 to 1983 for the Illinois and Mississippi river valleys is shown in the accompanying figure. The Illinois River has always accommo- dated more mallards than the Mississippi River, but the difference in numbers is be- coming smaller. The 10-year averages of the peak numbers of mallards counted for 1950-1959, 1960-1969, and 1970-1979 are 1,126,200; 652,800; and 767,400; respec- tively, for the Illinois River as compared to 440,300; 490,700; and 562,100 for the Mississippi River during the same periods. For the 1980-1983 period, however, the average of the peak number of mallards for both rivers has been substantially lower, averaging 374,500 for the Illinois and 277,800 for the Mississippi. The reduced numbers of mallards counted since 1980 are a reflection of the low level of the mal- lard breeding population and drought conditions on the breeding grounds. The peak number of 307,600 mallards in 1983 for the Illinois River was the lowest num- ber ever counted since the inventories be- gan in 1948. Similarly, the 1983 mallard peak of 212,200 for the Mississippi River was the lowest counted since 1950. A comparison of the downward trend of mallard numbers using the Illinois River and the stable-to-slightly-upward trend of mallards inventoried on the Mississippi River can be explained by the waterfowl habitat associated with each river. In the - Illinois River valley, wetlands have been degraded by sedimentation which has greatly reduced the variety and abundance of aquatic plants and other natural foods available to mallards. In addition, the popularity of plowing harvested corn fields in central Illinois dur- ing the fall has sharply decreased the waste grain resource for mallards. By contrast, the aquatic plant life of the Mississippi River thus far has been less affected by sedimentation. Moreover, several public areas and refuges have been established during recent years in key locations along the Mississippi and these sites are being effectively managed for waterfowl. April 1984, No. 236. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE ILLINOIS NATURAL HISTORY SURVEY CHAMPAIGN DEPARTMENT OF ENERGY AND NATURAL RESOURCES, ILLINOIS 61820 The Illinovs NATURAL HISTORY URVEY Society for the Illinois Scientific Surveys The Natural History Survey, the Geo- logical Survey, and the Water Survey have just initiated a not-for-profit corporation entitled the Society for the Illinois Sci- entific Surveys (SISS). Chief Paul Risser from the Natural History Survey is the first executive secretary, and a full board of directors is presently being appointed. As the society develops during the coming year, membership opportunities will be- come available, a publication will be pro- duced, and several interesting field trips and educational activities will be presented. The purpose of the society is to offer a means for more Illinois citizens to recoeg- nize, understand, and appreciate the state’s natural resources by (a) providing infor- mation that is technically sound but com- prehensible by the layperson, (b) orga- nizing activities through which natural resources can be observed and discussed, (c) making programs of the three sci- entific Surveys widely known, and (d) nurturing various processes that permit the citizens of the state to supply data, infor- mation, and materials to the scientific Surveys. In a broad sense, the purpose of the society is to enhance the wise use and management of the natural resources of Illinois through support of the activities and three Surveys. Plans for the publication are not yet complete, but possible articles include the following: programs of the scientific (1) feature stories on topics of specific interest ; (2) feature series on topics of general interest, e.g., urban deer problems, contamination of aquifers, earth hazards (landslides, earthquakes, mine subsidence, etc.) : (3) monthly short information items such as pictures and descriptions of birds or spiders most likely to be seen, or the supply/demand outlook for Illinois’ mineral resources: (4) in-depth discussions, with data, about topics treated more superfi- cially in the newspapers, e.g., erosion Michigan utilization of Illinois coal: of Lake shores. better (5) commentaries about natural re- sources issues by well-known indi- viduals in the state, e.g., governor, legislators, members of advisory boards ; (6) letters to the editor; ) a column where readers can ask questions to be answered by the Surveys’ staffs; and 3) a directory where specific services or information may be obtained. Periodically, individuals and businesses wish to make contributions to the Surveys in the form of money, equipment, or prop- erty. Since the society will have a tax- exempt status, such gifts can now be re- ceived in a manner which benefits these donors. The activities of the society will not re- place the Surveys’ responsibilities to the state. Rather, the society will assist the Sur- veys in dispersing information to the citizens of Illinois and elsewhere, and in providing a greater educational role for all three Surveys. Winter Diving on the Mississippi River What do river fish do in the winter time? How susceptible are these fish and Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. their habitats to disturbances from dredg- ing activities or winter barge traffic? Until recently, river biologists have only specu- lated on the answers to these questions. In January, however, Survey biologists from the Grafton field station cooperated with other state and federal agencies and com- mercial divers to make first-hand observa- tions under the ice cover of the Mississippi River, a first vital step to answering the above questions. Visual observations of the bottom of the river are possible only during the winter, when water clarity extends beyond 2 or 3 feet. Ken Lubinski led the research team that compiled 20 hours of “down time” at five sites on Navigation Pool 13, Mississippi River, between Belleview, Iowa, and Savanna, Illinois. Most of the dives were made by Robert Anderson, Great Lakes Consultants, Inc., out of Traverse City, Michigan. Dives averaged about an hour in length. The divers used specially designed dry- suits for thermal protection. Air was sup- plied by large-volume tanks on the surface of the ice connected to the diver’s helmet by an umbilical cord. At each site, ground- lines were deployed to guide the diver and provide reference points for his observa- tions, which were communicated by micro- phone wires to the surface where they were recorded in a dive log. Still photo- graphs and video tapes were also made. Of the five main channel sites explored, two had been used previously as experi- mental thalweg (the deepest part of the channel) disposal sites by the U.S. Corps of Engineers. At these sites, dredged material, mostly sand, was removed from areas where it might impede navigation and deposited in the thalweg. Several unexpected observations were made by the dive team. Rather than being uniformly barren sand flats and dunes, as was previously thought, three of the five sites (including one disposal site) turned out to have mixed substrates of gravel and cobbles and supported large numbers of mussels. Large concentrations of dormant flathead catfish, ranging from 2 to 35 pounds, were observed seeking shelter in ‘and around log piles at two sites. Other fish species included channel catfish, log- perch, silver chub, gizzard shad, silver lamprey, and shovelnose sturgeon. At the edge of one disposal site, deposited sand graded immediately into large numbers of mussels on firm substrate, indicating that some mussels, as well as periphyton and. aquatic insects, had probably been buried during disposal. The observations suggested that catfish and shovelnose sturgeon, because of their dormant behavior, would be the most susceptible species to winter disturbances. The variety of habitats, substrates, and organisms observed resulted in a recom- mendation to survey or sample future sites before disposal to eliminate any chance of burying aquatic populations or valuable habitats under sand. Robert Anderson, principal diver, prepares to descend to the bottom of the Mississippi River. Assisting him are Tim Adamsky and Greg Busch. Birds and Woodlots Reduction of total forest area and the fragmentation of native forest into isolated patches have affected populations of many bird species adversely, especially those songbirds that winter in the tropics. Be- cause forest habitat is also disappearing at an alarming rate in Latin America where these birds winter, there is an urgent need to determine the area requirements of those species that depend on forest interior habitat. In a study funded by the U.S. Fish and Wildlife Service, researchers at the Uni- versity of Illinois, Department of Ecology, Ethology, and Evolution, studied birds in 15 woodlots in east-central Illinois. ‘Their goals were to determine how many species disappear as the area of woodlots decreases and what species are least able to maintain populations in small woodlots. After censusing bird populations, John Blake and James Karr (who has an affili- ate appointment at the Natural History Survey) showed a strong correlation be- tween area of woodlot and number of breeding species. A 1,500-acre woodlot supports about 40 species of breeding birds. At 100 acres, only 30 species remain and Small s Sade Fs aah 5-acre woodlots support only 10 to 15 species. Species that winter in Central and South America seem especially susceptible to local extinction in the face of habitat fragmen- tation. In contrast, numbers of permanent and, short-distance migrants, were not strongly correlated with residents especially forest area. Short-distance migrants gen- erally do not require forest interior habitat for breeding, and they are not as likely to suffer population reductions following forest fragmentation. These findings are similar to those reported from the Middle Atlantic states in 1979. Many warblers, vireos, thrushes, gnat- catchers, tanagers, and among the neotropical migrants most de- pendent on large tracts of forest for nest- ing. Examples of the smallest tract on which birds were found during the breeding season in east-central Illinois are 1,500 acres for the hooded warbler; 290 acres for the American redstart; 160 acres for the Cerulean warbler; 70 acres for the Acadian flycatcher, the blue-gray gnatcatcher, the northern parula, and the ovenbird; and 40 acres for the scarlet tanager. Although these species defend territories of only 2 to 5 acres during the breeding flycatchers are woodlots such as this one in southern Piatt County, Illinois, are essential to the preservation of vanishing species of birds. The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 season, a block of forest many times that large is needed to attract even small pop- ulations of these area-sensitive species. ‘This concept must be taken into account in planning the acquisition and management of natural areas. : Much controversy over optimal size of natural areas has centered on the impor- tance of small reserves and, in particular, whether two or more reserves equal in total area to a single large reserve will sup- port more or fewer species. Despite in- herent differences in species’ biologies, few analyses of species occurrence in large or small forests have adequately addressed species composition (as opposed to species number) in relation to forest area. Con- sequently, many arguments over reserve size have not addressed a central purpose of many parks and reserves; that is, the preservation of species that are most at risk of extirpation or extinction. Blake and Karr used data from east-central Illinois to examine the relative benefit of multiple and small reserves versus single and large reserves. Although two small forests may, in some cases, hold more total species than a larger one, a single large reserve will pre- May 1984, No. 237 serve more of those species that are most dependent on forest interior habitat; that is, those species that are most at risk. Man- agement strategies, to be most effective, must focus on species most in need of con- servation efforts. The conservation value of woodlots in highly disturbed landscapes such as east- central Illinois extends beyond the breed- ing season. During migration, many species pass through Illinois on their way to northern breeding grounds or southern winter grounds. Because migration is an energetically expensive activity, birds must be able to periodically replenish energy supplies. Because agricultural land _pro- vides little adequate habitat for most mi- grants, the presence of natural patches of habitat, such as woodlots, can be of great benefit. In many cases, species that breed only in very large woodlots use even small patches of forest during migration for foraging and resting. Large woodlots sup- port greater numbers of species and indi- viduals, but during spring and fall migra- tory periods, woodlots of almost any size provide valuable habitat for many species. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation Prepared by Shirley McClellan with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES. NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 The Illinows NATURAL SURVEY Special Publication On Landscape Ecology In recent years a new field of science, called regional ecology or landscape ecol- ogy, has been emerging. Current ideas about landscape ecology are influenced by the theories, methods, and points of view of a number of scientific disciplines, and “these influences appear to have stalled the crystallization and communication of the current understanding of landscape ecology, especially as the concept might facilitate basic and applied research on natural resources.” So wrote the authors of a recently published report titled, Land- scape Ecology: Directions and Approaches, LANDSCAPE ECOLOGY Directions and Approaches publication on Cover of ecoolgy (Photo by R. A. Evers). new special landscape HISTORY Illinois Natural History Survey Special Publication Number 2. One method of speeding the integration of a landscape ecology approach was to gather together experienced individuals with different viewpoints but with a strong desire to examine landscapes through the ideas of ecology and related disciplines. With funding from the National Science Foundation, Dr. Paul G. Risser, Chief of the Illinois Natural History Survey, called together 24 other scientists for a workshop meeting on landscape ecology, to evaluate the potential of such a discipline, and to describe its application to basic and applied natural-resource issues. Dr. Risser and two of the other project directors, Dr. James R. Karr of the De- partment of Ecology, Ethology, and Evolu- tion, University of Illinois, and Dr. Richard T. T. Forman, Department of Biological Sciences Botany) , University, took the materials of these meetings and Rutgers fashioned them into a coherent series of statements about the scientific research ap- proaches being used and the directions which research might take in the new field of landscape ecology. Early in the report the authors point out that disciplines of ecology, such as population, community, 1 “Landscape ecology differs from sub- and ecosystem ecology, in matters of primary emphasis. Landscape ecology focuses explicitly upon spatial pat- tern. Specifically, landscape ecology con- siders the development and dynamics of spatial heterogeneity, spatial and temporal interactions and exchanges across hetero- geneous landscapes, influences of spatial heterogeneity on biotic and abiotic pro- cesses, and management of spatial hetero- Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. geneity.” They go on to say, “Principles of landscape ecology help to provide theoret- ical and empirical underpinnings for a variety of applied sciences, e.g., regional planning, landscape architecture, and nat- ural-resource management.” Copies of this report may be obtained from the Illinois Natural History Survey, Natural Resources Building, 607 East Pea- body Drive, Champaign, Illinois 61820. Information System Being Developed A computer-based natural resource in- formation system is being developed at the Natural History Survey. The system con- tains data on the biological, geological, and hydrological resources of Illinois as well as cultural resources (anthropology and his- torical sites) and social and economic data. The system is a cooperative effort between five divisions of the Department of Energy and Natural Resources: Energy and Environmental Affairs, the Natural History Survey, the Geological Survey, the Water Survey, and the State Museum. A large amount of funding for the system has come through the Lands Unsuitable for Mining Program sponsored by the federal office of surface mining. The natural resource information system is an important new research tool and a significant advancement in the manage- ment of natural resource data. It will stimulate new directions in research by allowing scientists to synthesize, analyze, and display large amounts of data within a geographic context. For example, re- searchers will be able to model the poten- tial for insect infestations, habitat loss, mine land reclamation and other threats to natural resources. ‘The relationships be- tween factors such as vegetation and soil may be studied on a regional as well as a local scale. The system will also be used to maintain detailed inventories of the state’s natural areas, streams, wetlands, and forests. Comprehensive data files are being compiled on the distribution and chacter- istics of Illinois’ fish, wildlife, and plants. Computer access to the data will allow responses to the public’s need for natural resource data to be more timely and com- plete than what is now possible using manual methods. As a central repository, ~the system will improve archival storage and sharing of natural resource data. The system is being developed on a Prime 750 minicomputer located in the Natural Resources Building in Champaign. Communication lines give all five Energy and Natural Resources divisions direct access to the system. Each division is equipped also with a graphics work sta- tion to be used for data entry and analysis. A graphics work station consists of a digitizer and a graphics terminal. A digi- tizer is a special device resembling a light table and is used for encoding map infor- mation. The graphics terminal is a TV-like device used to display the data once it has been entered into the computer. The sys- tem has three pen blotters which can pro- duce maps and other graphics in four colors at speeds up to 18 inches per second. A colorgraphic recorder is available to produce color slides or 8x 10 prints. The system has been under development for - almost 2 years. Computer operations began in September 1983. Recent efforts have been concentrated on training staff and installing data on the system. It’s Boring Survey entomologists studying corn in- sects were baffled for several years by a “mystery” borer that sporadically was de- tected in the stems of young field corn in the northern one-third of Illinois. The caterpillar was first noticed in Kane County during July 1978 and as far west as Carroll County in subsequent years; and Wisconsin researchers recently have seen it in Mani- towoc County of that state. Efforts to identify the caterpillars were unsuccessful until a single specimen was reared to the moth stage in 1983 by entomologists George L. Godfrey and Eli Levine. The moth proved to be Amphipoea americana Speyer, a moderately common species but whose caterpillar has not been described. The caterpillar of A. americana is very similar to the hop vine borer, Hydraecia immanis Guenée, which was discussed in Survey Reports No. 196 (April 1980) and described along with the potato stem borer, H. micacea (Speyer), in Illinois Natural History Survey Biological Notes No, 114 (February 1981). Similarities include phys- ical appearance and the same geographical distribution (in Illinois). Another species with which it may be confused, at least in the earlier larval stages, is the stalk borer, Papaipema nebris Guenée (see Survey Re- port No. 228 (June 1983). Levine hypothesizes that acreages of corn planted using reduced tillage practices may result in increased populations of A. americana. Published information on this species is very meager, and it is impossible to ascertain the species’s potential eco- nomic significance until the basics of its life history and host plant preferences are understood. Therefore, Levine is planning to study its ecology feeding damage on corn in 1984 to clarify the situation. Godfrey will be supporting the work by assessing mor- phological characters that may be used by other researchers to help distinguish A. americana caterpillars from other corn boring caterpillars. Persons suspecting that they may have this species are encouraged to contact either Godfrey or Levine at the Survey (see the address on page 4 of this issue ) . Mature caterpillar of Amphipoea americana 25 mm in length (Photo by G. L. Godfrey). Mature caterpillar of the hop vine borer, Hydraecia immanis, 30-35 mm in length (Photo by G. L. Godfrey). The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 Recent Publications Neely, Dan. 1984. Dutch elm disease control in I]linois municipalities. Plant Disease 68 (4) 302-303. O’Hayer, K. W., G. A. Schultz, G>E. Eastman, and J. Fletcher. 1984. Newly discovered plant hosts of Spiroplasma citri. Plant Disease 68(4) 336-338. Risser, Paul G., James R. Karr, and Richard T. T. Forman. 1984. Landscape ecology: directions and approaches. Illinois Natural History Survey Special Publication Number 2. 18 p. Ruesink, W. G., and M. E. Irwin. 1984. A model for the impact of mosaic virus in soy- _ bean. 10th International Congress of Plant Protection 1983 im Proceedings of a conference held at Brighton, England 20-25 November 1983. Sparks, Richard E., and Michael J. Sandusky. 1983. Identification of the water quality factors which prevent fingernail clams from recolonizing the Illinois River, phase III. Research report 179 — Bureau of Reclamation, U.S. Department of the Interior, Washington, D.C. 55 p. Voegtlin, David. 1983. A new aphid species, Cinara radicivora (Homoptera: Aphi- didae), living on white fir. Pan-Pacific Entomologist 58(3) : 196-201. Warner, Richard, Stanley Etter, J. Blair Joselyn, and Jack A. Ellis. 1984. Declining sur- vival of ring-necked pheasant chicks in Illinois agricultural ecosystems. Journal of Wildlife Management 48(1) : 82-88. Wiley, M. J., R. W. Gorden, S. W. Waite, and T. Powless. 1984. The relationship be- tween aquatic macrophytes and sport fish production in Illinois ponds: a simple model. North American Journal of Fisheries Management 4: 111-119. ynd-class postag paid it Urban Illine (USPS 258 Office of publication: 172 Natur Resources Building, Champ 1. Hlinois Persons desiring individual or additional copies of this publication please write to The Illinows NATURAL BELA. SURVEY © WILLIAM LUCKMANN COMPLETES 35 YEARS OF PUBLIC SERVICE Dr. William H. Luckmann retired from the Illinois Natural History August 31 after and Head of the Section of Economic En- tomology since 1965. Dr. Luckmann began his long career at INHS as a assistant in the Section of Economic Ento- mology in 1949. Survey on as Entomologist serving research Dr. Luckmann’s chief research interests have been in corn entomology and the en- vironmental impact of pesticides. In the field of corn entomology, he has been particularly concerned with the European and the overwhelming corn borer, the corn rootworms, black cutworm, consequence to producers of corn in Illi- nois. His work on the pact of insecticides has manifested itself in residues in insects of environmental im- the monitoring of pesticide crops, soil, and wildlife. He has been par- ticularly concerned that Illinois tural producers not find their products unmarketable because of residues. agricul- Dr. Luckmann’s research endeavors have led to the effective management programs that serve to maxi- mize crop protection vironmental disruption. formation of pest- with minimal en- Through the medium of the widely ac- cepted book Introduction to Insect Pest Management that he co-edited with Dr. Robert L. Metcalf, bers of students and crop protection spe- cialists here and abroad with his philos- ophy of modern pest management. he reached large num- In his administrative role, Dr. Luck- mann structured his staff effective teams of researchers that have enjoyed con- into siderable success in combating the pests of Ltigiti Dr. William H. Luckmann (Photo by Les Woodrum) corn, alfalfa, fruit orna- mental plants, and vegetable crops. He has become in- soybeans, crops, also encouraged his staff to volved in international programs in agri- culture in the knowledge that a broader base of experience would help certain solving the problems confronted by Illinois agriculture, and he himself studied and consulted in India, Iran, and Puerto Rico. Dr. Luckmann’s leadership in research, administration, and education has gained recogni- North Entomological national and international tion. He served as President of the Central Society of him 3ranch of the America in 1978 and 1979. From Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. Dr. Luckmann using hand sprayer on corn earworm in 1952 (photo by W. E. Clark). A young Bill Luckmann working on corn borer research with Dr. George Decker. It was part of Luckmann’s thesis in March 1950 (photo by C. L. Scott). Sitting on commercial sprayer, he is again spraying for corn earworm near Rochelle, Illinois in 1952 (photo by W. E. Clark). In 1964 he was releasing Tiphia wasps, parasites of the Japanese beetle. Sorghum plant heads are examined for insects. Picture was taken in 1957 (photo by W. E. Clark). Section Heads meet with Dr. George Sprugel in 1967. Dr. Luckmann is on the far left. Left to right are Dr. Herbert Ross, Faunistic Surveys and Insect Identification; Dr. George Bennett, Aquatic Biology; Dr. Cedric Carter, Botany and Plant Pathology; and Dr. Glen Sanderson, Wildlife Research (photo by W. D. Zehr). The Illinovs NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 Clarence White and Luckmann release ladybugs in corn and alfalfa fields in 1975 (photo by Larry Farlow). 1977 to 1979, he was Chairman of the Pesticides Subcommittee of the Task Force on Agricultural Nonpoint Sources of Pollu- tion. He is listed in American Men and Women of Science and Who’s Who in America. A native of Cape Girardeau, Missouri, he began his long career at INHS as a re- search assistant in the Section of Economic Entomology in 1949. He received an ap- pointment as Assistant Entomologist at INHS in 1951, the year that he received his M.S. degree in entomology from the University of Illinois. In 1954 he was pro- moted to Associate Entomologist, and 2 years later he received his Ph.D. degree in entomology from the University of Illinois. He was promoted to Entomologist at INHS mm 11959) In addition to his appointments at INHS, from 1965 until his retirement he served as Head of the Office of Agricul- tural Entomology in the College of Agricul- ture at the University of Illinois and as Professor of Entomology in the Department of Entomology of the School of Life Sci- ences at the University of Illinois. September 1984. No. 239. Published monthly except in July and August by the Natural History Survey, a divi- sion of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G, RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, ILLINOIS 61820. NOV 12 1984 LIBRARY Trees must receive regular maintenance for rapid growth and good health, accord- ing to E. B. Himelick, Survey plant pa- thologist. Such maintenance includes water- ing, fertilizing, pruning, pesticides, bracing and cabling, preventing grade changes, and protecting against chemical injury. Pruning Shade Trees spraying with surgery, and_ lightning Proper pruning is often neglected for too long and trees become hazardous and quire extensive corrective measures. Magnificent trees of almost every species erown on the home grounds are deformed by “local talent” tree trimmers. Himelick says these trimmers, through ignorance or the need for an extra dollar, tend to cut entire tree tops or sides of the crown, leav- aaa BE; P O R ah hae oh Se eres Se co ing only the trunk and large stubs. Such trees are either killed outright or, if they survive, produce vigorous sucker growth form. The stubs left by this practice will even- with short-lived crowns and ugly tually decay and produce only a shell to support future growth of large branches. Pruning should be done by an expe- rienced arborist with on- the-job training, proper equipment, and one who is familiar with the techniques and hazards of work- The use of climbing ing on large trees. spurs or irons is not recommended and should not be used on living trees. Crown reduction should be done on a continual basis to avoid extensive pruning any one year. The growth habit of a par- ticular species dictates how the tree should be pruned. Excessive pruning by severely cutting back all major branches frequently results in dying back of the in- jured branches (photo by Ray Hamm). Material in this publication may be reprinted if credit is given to the Extensive pruning of large branches or leaders usually results in the production of thick masses or clumps of slender, weak branches (photo by Ray Hamm). Illinois Natural History Survey There are four types of pruning: fine, medium, coarse, and drop-crotch. Fine pruning is the most extensive and includes the removal of dead, dying, diseased, and interfering branches and selective thinning to decrease wind resistance. Medium prun- ing is similar but generally is a less severe type of pruning. Coarse pruning consists only of removing dead and weakened branches 2 inches in diameter and larger. Drop-crotch pruning consists of top and side reduction through the selective re- moval of vertical and lateral branches. All pruning cuts should be made close to the trunk or parent limb, without cutting into the branch collar or leaving a protruding stub, so that bark-callus closure can de- velop. When done properly, this type of pruning involves cutting branches back to lower lateral branches having at least one- third the diameter of the branches removed. Drop-crotch pruning is used when branches interfere with utility lines, when major branches or root systems are severely damaged, or when unusual and rapid branch growth in the tops or sides of tree crowns occurs. This type of pruning may be re- quired periodically on fast-growing trees such as silver maple, Siberian elm, and willow. Drop-crotch pruning is basic to any pruning operation and is used to reduce the height and spread of the crown while retaining its natural shape. Tree crowns are sometimes pruned or thinned to increase the vigor of remaining branches. Opening the crown permits more light penetration and _ stimulates lateral bud growth. Selected removal of excessive succulent growth will encourage the devel- opment of strong branching laterals and increase the general vigor of crown devel- opment. Judicious pruning of trees with weakened branches or damaged root systems will lessen wind resistance and weight of the crown. Thinning and drop-crotch pruning requires both skill and time and if done correctly, it will benefit both the tree and its aesthetic appearance. The best compli- ment an arborist can receive after major pruning is having the average person fail to notice a tree has been pruned. Pruning standards published by the National Ar- borist Association offers general guidelines followed by most arborists. Homeowners should be aware of the re- sponsibilities they have in the preservation of their trees. Old trees that decline and have weak and dead branches can often be kept healthy for many years through proper pruning. Wood-chip mulch, fertilization, proper watering, and disease and pest con- trol practices will also be beneficial in pro- longing the life of a valuable tree. Much thought should be given to proper tree selection and planting location to avoid the expense of extensive corrective pruning years later. Food, Fiber, and Fugitive Insects Among the many specimens submitted to systematists of the Illinois Natural History Survey for identification during 1983 were two species of insects and one of an insect- ally, a tick, which represents first detections for the state. The newcomers included two species of long-horned beetles which breed in dead and dying pine trees. These beetles are potential carriers of the pinewood nema- tode, a causative agent of pine wilt which has been very destructive to pines in Illi- nois in recent years. The newly detected tick is of veterinary importance and, in addition, is believed to be a cause of tick paralysis in man. Two of the migrants undoubtedly moved into Illinois from ad- jacent states, and one was seemingly intro- duced from overseas. The phenomenon of the active dispersal and passive transportation of pest species of insects into Illinois from neighboring continental areas and from elsewhere is well-known and _ obviously continuing. Readers of Illinois Natural History Survey Reports will be aware of such examples as the alfalfa weevil, the imported crucifer weevil, the western corn rootworm, and the gypsy moth. A recent estimate of the Entomological Society of America numbers the major and minor pest species that have been introduced into the borders of the United States to be more than 800. Ac- cording to that study, among the imported species are a number of serious pests which collectively are responsible for over 50 per- cent of all insect losses in the United States. The migration of pest species from out- side the state is not a recent development in Illinois. Benjamin Walsh, a pioneering entomologist who became the first State - Entomologist of Illinois in 1867, wrote an article on the subject of imported and migrating insects as early as 1866. Writing from Rock Island, he stated that fully one- half of the worst pest species known in Years of first detection in Illinois of some insects and insect allies of economic importance. 1938 JAPANESE BEETLE, Popillia japonica Newman (on ornamentals) 1939 EUROPEAN CORN BORER, Ostrinia nubilalis (Hubner) 1940 IMPORTED LONGHORNED WEEVIL, Calomycterus setarius Roelofs 1953 JAPANESE BEETLE (on field crops) 1957 MIMOSA WEBWORM, Homadaula anis- ocentra Meyrick 1959 FACE FLY, Musca autumnalis De Geer 1959 BROWN RECLUSE SPIDER, Loxosceles reclusa Gertsch & Mulaik 1963 SOUTHWESTERN CORN BORER, Dia- traea grandiosella (Dyar) 1964 ALFALFA WEEVIL, Aypera postica (Gyllenhall) 1964 WESTERN CORN ROOTWORM, Dia- brotica vergifera vergifera LeConte 1965 AZALEA LEAF MINER, Caloptilia azal- eella (Brants) 1965 CEREAL LEAF BEETLE, Oulema mel- anopus (Linnaeus) 1966 LONE STAR TICK, Amblyomma amer- icanum (Linnaeus) 1967 ASIATIC OAK WEEVIL, Cyrtepistomus castaneus (Roelofs) 1973 GYPSY MOTH, Lymantria dispar (Lin- naeus ) 1974 SOUTHERN GREEN STINKBUG, WNe- zara viridula (Linnaeus) 1976 TWOBANDED JAPANESE WEEVIL, Callirhopalus bifasciatus (Roelofs) 1977 IMPORTED CRUCIFER WEEVIL, Baris lepidii Germar 1979 HONEYSUCKLE APHID, Hyadaphis tartaricae (Aizenberg) 1983 GULF COAST TICK, Amblyomma mac- ulatum Koch 1983 A Longhorned beetle, Neoclytus muri- catulus (Kirby) 1983 A longhorned beetle, Xylotrechus sagitattus (Germar) 1984 WHITESPOTTED SAWYER, chamus scutellatus (Say) Mono- America at that time were known to have been imported from Europe. Walsh was also familiar with range adjustments in native insects. In documenting the arrival of the Colorado potato beetle in Illinois in 1864, he noted that it was the first record of a pest species spreading from the western United States to the east. All previous importations and migrations had been from the east. An interesting example of an insect that arrived in Illinois from the south is provided by the boll weevil. Although the boll weevil was detected in Illinois several decades ago, the fact is little known even among entomologists because of the minor extent of cotton production in Illinois. Because of the continuing arrivals of new pest species in the state, crop protec- tion specialists in Illinois face a difficult task. As resident pests are studied and brought under scientific management, new pests arrive on an almost yearly basis. The systematists of the Illinois Natural History Survey work to insure that these invaders will be promptly and correctly identified upon their first detection in the state. Two Recent Survey Publications Recreational Fishing in the Kankakee River, Illinois by Robert J. Graham, R. Weldon Larimore, and William F. Di- mond is a recent publication in the Illinois Natural History Survey Biological Notes series. This 13-page booklet reports the findings of a 2-year study of the fishermen, fishing effort expended, and fish harvest in the lower Kankakee River and related in- formation. The researchers found that fishing effort averaged 3,823 man-hours per kilometer per year. Although most of this effort was not expended in pursuit of any particular fish species, the three species caught in greatest numbers were the carp, channel catfish, and shorthead redhorse. The mean annual catch rate for all fish species was 0.13 fish and 56.7 grams of fish per man- hour of fishing effort. The estimated total harvest was 469 fish weighing 217 kilo- grams per kilometer per year. A profile of the people fishing the river, The Illinovs NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 the methods they used, their reasons for fishing in the Kankakee, and similar infor- mation of interest to fishermen, fisheries managers, conservationists, and others is presented in this booklet. Another recent publication in the Bio- logical Notes series is Bibliography of Illi- nois Vegetation by Paul G. Risser, Chief of the Illinois Natural History Survey. Dr. Risser has gathered together a list of 1,277 publications about the plant life of Illinois and has presented them in bibliographic style to assist researchers, naturalists, and others interested in the vegetation of our state. He has classified also the literature in five indexes. As Dr. Risser points out in his intro- duction, “The vegetation of Illinois has been studied for more than 100 years. These studies have produced a rich literature de- scribing the plant communities. . . . 1984, N 240 ion of the Illinois Department of Ene 1y and October Persons desiring individual or additional copies HIEF sources, operating t uly ina August by “Collectively, this literature constitutes the basis for a number of thoughts and themes about plant ecology — ideas that originated from the work of ecologists who worked in plant communities in Illinois. ... The literature on the vegetation of Illinois is impressive in its volume and quality and, as such, represents a sound base upon which to build further studies on the plant communities of the state. At the same time, this bibliography, and the individual indices, indicate that biologists still have enormous opportunities for re- warding investigations on the vegetation of Illinois.” To obtain these or other Survey publi- cations, write to the Illinois Natural His- tory Survey, 172 Natural Resources Build- ing, 607 East Peabody Drive, Champaign, Illinois 61820. the Natt iral History Surve a div ider the Bo | xs =< of this publication please write to EY \ 4 F El HAA The Illinows NATURAL HISTORY REPORTS Air Pollution and Illinois Soybean Production The variety, quantity, and pervasiveness of materials added to the environment con- cern many persons. These materials include gases, agricultural chemicals, and particu- lates to the atmosphere, sewage and chemi- cals to water systems, and solid wastes to the land. Whether they act alone or to- gether, pollutants affect man’s food supply, health, and well-being, or air pollu- environmental sometimes adversely. “Smog,” tion, is usually identified with large cities, such as Chicago, St. Louis, Los Angeles, or New York. However, scientists are aware of and often disturbed by the apparent in- crease of air pollutants in non-metropoli- tan and rural areas whose economic base is frequently agricultural. Indeed, clean ait is not the normal environment for plant and animal growth in many locations. Environmental quality has been a majo1 interest of Illinois Natural History Survey scientists for a long time. The Survey’s par- ticipation in environmental studies includes investigations of plant-air pollution inter- actions. Anton G. Endress of the Botany and Plant Section has Pathology con- Comparisons of soybean yield of plants exposed to ozone alone, sulfur dioxide alone, or mixtures of ozone and sulfur dioxide in greenhouse studies. Cylinder 1 (extreme left) shows the yield from the control plants that received greenhouse air during their development. The addition of ozone alone to greenhouse air reduced soybean yield (compare cylinders 2 and 3 to control), but the addition of sulfur dioxide alone to greenhouse air had no effect on yield (compare cylinders 4 and 7 to control). Mixtures of ozone and sulfur dioxide also reduced soybean yield (compare cylinders 5, 6, 8, and 9 to the control) as much as or more than when ozone only was supplied (Photo by Anton Endress). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey structed a chamber system to examine the effects of exposure to air pollutants on the development, growth, yield, and quality of plants. Endress and a colleague, Claus Grun- wald, have recently completed a study of soybean growth and development as it is affected by mixtures of ozone and sulfur dioxide, the two most common gaseous air pollutants in Illinois. Soybeans were ex- amined because Illinois is a leader in soy- bean production in the United States and several studies have shown that soybeans are sensitive to air quality. Soybeans (cultivar “Corsoy”’) were raised in the greenhouse for an entire season. During their growth, the soybeans were ex- posed to ozone alone at three concentra- tions for a total of 260 hours, to sulfur dioxide alone at three concentrations for a total of 42 hours, or to mixtures of both ozone and sulfur dioxide. Throughout the study, plants were periodically removed, cut apart, and weights of the various organs determined. At the end of the experiment, the remaining plants were harvested for seed yield. The periodic plant harvests allowed Endress and Grunwald to evaluate the dy- namic response of the soybeans to air pol- lutant stress. They determined that the air pollution treatments reduced total plant biomass and leaf area. The harvested seeds also showed a response to the presence of air pollutants. Ozone by itself caused re- ductions of seed weight per plant and weight per seed, while sulfur dioxide alone had no demonstrable effect. However, the mixtures of ozone and sulfur dioxide pro- duced the greatest yield reductions (as much as 38 percent) with fewer pods and seeds per plant and smaller seeds. Although the results are incomplete, there is apparently no effect of either ozone or sulfur dioxide on the protein content of the seeds. Growth and yield reductions in soybeans caused by air pollutants have been known for some time and have occurred when leaves showed visible markings. The unique findings of these Survey studies are that growth and yield were reduced even though the plants demonstrated no observable symptoms. Furthermore, the scientists were _ able to isolate the effects of sulfur dioxide and ozone when the plants were exposed to a mixture of these two pollutants. Stalk Borer Oviposition The stalk borer, Papaipema nebris, can be a serious pest of seedling corn, particu- larly of corn planted using conservation or reduced tillage practices. Female moths are thought to deposit their eggs on vegeta- tion or plant debris in fence rows, contour strips, grass waterways, or in weedy fields during late summer and early fall. After the eggs hatch the following spring, the larvae begin feeding on grasses but move ‘to larger plants as they outgrow their origi- nal hosts. Corn may serve as this larger plant if planted in or near infested fields. To learn which fields might serve as pre- ferred egg-laying sites for the stalk borer, Survey entomologist Eli Levine recently determined the ovipositional preference of female moths in cage tests among a variety _ of weeds and plant debris representative of that found in or immediately adjacent to corn fields damaged by this pest. In addi- tional cage tests, the ovipositional prefer- ence of female moths among various cover crops typical of those planted under the United States Department of Agriculture’s payment-in-kind (PIK) crop diversion program was examined. In the first cage experiment, Levine found that quackgrass and giant foxtail were highly preferred by ovipositing moths, Stalk borer eggs deposited on quackgrass. Notice how most of the eggs are laid between curled sec- tions of leaf (Photo by Eli Levine). while dead foxtail stems, corn stalk debris, and giant ragweed were less preferred. In the second cage experiment using PIK cover crops, orchardgrass and dead winter wheat were among the most highly pre- ferred cover crops tested, while red clover and alfalfa were among the least attractive. The results of Levine’s study suggest that female moths prefer to lay their eggs on plants in the grass family, particularly species with numerous leaf sheaths and/or folded or rolled leaves. Wild females probably behave in a simi- lar manner and oviposit on grasses in fence rows, grass waterways, or contour strips. Oviposition may occur in crop fields if grasses are present during the period moths are laying their eggs (late summer and early fall). Fields containing these preferred plant species should be closely monitored the fol- lowing spring for stalk borer infestations if these fields are planted to corn using re- duced tillage methods. Good grass control within a field is essential in preventing re- curring outbreaks of this pest. Corn pro- ducers wishing to participate in a study to evaluate the effectiveness of this technique should contact Levine at the Survey. WILLIAM F. CHILDERS 1922-1984 In January 1953, while still an under- graduate student, William F. Childers was employed by the Illinois Natural History Survey to help in the trapping and tagging of ducks at the Havana Laboratory. Al- though it was so cold those first few months that Bill frequently had to chop duck traps out of the ice, he slept in the unheated Anax, the Survey’s river research boat that had been pulled up in dry dock. From the very beginning of his professional career, Bill Childers had a tough intimacy with natural systems. In June of that year, Bill began working with Weldon Larimore on streams, beginning a close professional and personal association that lasted throughout Bill’s career. During the following 3 years while working with stream fishes, Bill also studied the behavior of black and white warmwater DR. WILLIAM F. CHILDERS crappies with Professor Hurst Shoemaker, which led to the master’s degree in 1956. His first professional honor came when a paper that he and Larimore published on intermittent streams was recognized as the best technical paper published in Volume 88 of the Transactions of the American Fisheries Society. In June 1956, Bill left the stream investi- gations to work with George Bennett on fish populations of ponds and lakes. With Bennett’s consistent encouragement, Bill be- gan his study of hybrid sunfishes that led to his Ph.D. degree in 1965 and to a paper that was judged by the Wildlife Society to be the best fisheries paper published in North America in 1967. Studies of genetics occupied his interest for the rest of his career. With his protege, David Philipp, and with Professor Greg Whitt of the Univer- sity of Illinois, Bill developed a strong pro- fish gressive program in fish genetics, which earned both national and international rec- ognition. Bill was twice invited to the USSR to lecture and to attend symposia, and just weeks before his death a paper which he published with Philipp and Whitt received recognition as the best paper of The Illinots NATURAI SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 HISTORY Volume 112 of the Transactions of the American Fisheries Society. Probably no other American fishery biologist has re- ceived such honors for three separate scien- tific investigations Bill was a craftsman with great skill and imagination. As his work demanded, he designed and constructed various traps and. weirs and showed exceptional creativity in solving technical problems in both the field and laboratory. He was always generous in sharing these abilities with his colleagues. His deep interest in fish and game be- havior and habitat, supported by many special skills with rod, gun, and dog, made Bill an enthusiastic and successful sports- man. He made each cast with the concen- trated intention of catching a fish, and with each shot he intended to brmg down game. His enthusiasm for fishing and hunt- ing and his high standards for courtesy among sportsmen made Bill a pleasant companion in the field. Bill was a superb storyteller, with fan- tastic recall of incidents and details of spe- cial episodes. He used storytelling not only in communication but also as an art form — an art form in which he excelled. Bill died September 20, 1984. To that day, he retained his keen scientific interest in finding the right answers and in draw- ing the proper conclusion; but his some- times severe scientific discipline was always tempered by a kind and generous nature, a delightful sense of humor, a great love of people, and a joyful enthusiasm for what- ever he was doing. Recent Publications Duffield, R. M., W. E. LaBerge, and J. W. Wheeler. 1984. Exocrine secretions of bees —VI. Aliphatic esters in Dufour’s gland secretion of Svastra obliqua obliqua (Hy- menoptera: Anthophoridae). Comparative Biochemistry and Physiology 78B(1) : 47-50. Graham, R. J., R. Weldon Larimore, and William F. Dimond. 198+. Recreational fish- ing in the Kankakee River, Illinois. Illinois Natural History Survey Biological Notes No. 120. 14 p. Page, L. M., and D. L. Swofford. 1984. Morphological correlates of ecological special- ization in darters. Environmental Biology of Fishes 11: 139-159. Page, L. M., and K. S. Cummings. 1984. A portable camera box for photographing small fishes. Environmental Biology of Fishes 11: 160. Perry, L. G., and John A. Tranquilli. 1984. Age and growth of largemouth bass in a thermally altered reservior, as determined from otoliths. Journal of Fisheries Man- agement 4:321-330. November 1984, No. 241. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, ILLINOIS 61820 The Illinows NATURAL HISTORY REPORTS Bird Communities of Amazonian Forests Western Amazonia contains the richest, but least understood, bird communities in the world, according to Scott Robinson, Survey ornithologist. Several lowland sites have nearly 550 species in areas of less than 19.5 square miles. These small areas con- tain far more species than have been re- corded in the entire state of Illinois. One of these sites, the Cocha Cashu Biological Sta- tion in southeastern Peru, has been the site of a long-term study of bird community dynamics since 1973. This site is located in Manu Na- tional Park, an area that still contains un- the huge (3.7-million acre) contacted tribes of natives. It takes 5 or 6 days to get to the biological station from Cuzco, the nearest city, 2 days by truck and 3 or 4 days by dugout canoe from the end of the road. The sheer inaccessibility of the site has protected it from logging and sys- tematic hunting. For this reason, the Manu Park has a full complement of species, in- cluding many large predators at natural population levels. Large cats, including jaguar, puma, and ocelot, walk the forest The tree pictured is a Sloanea, one of a large genus of tropical timber trees (family Elaeaocarpaceae) having alternate leaves, small petal-less flowers with numerous stamens, and usually very hard wood (Photo by William O. Robinson). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. at night. Many large birds that have been hunted to extinction elsewhere are still common and easily found inside the park boundaries. Thirteen species of monkeys, nearly all of which are remarkably tame, abound in the area around the station. In short, the Manu Park provides an excellent opportunity to study pristine communities of birds and mammals. Results of these studies can be used to gain perspectives on the far more disturbed forests of North America, including those in Ilinois. In September and October, Robinson took a leave of absence from the Survey to continue an intensive study of the Manu bird community in collaboration with John Terborgh of Princeton University. This project, funded by the National Science Foundation, involves a large-scale census of the birds found in each of the major habitats of the Manu Park and an investi- gation of the factors that determine which species occur in each habitat. Mature forest, which is exceedingly complex in structure, contains the greatest number of species (240 species per 250 acres), whereas the structurally simple successional vegetation along river edges contains the fewest species (85 species per 250 acres). However, both habitats contain 5 to 10 times more species than do habitats of comparable vegetation structure in IIli- nois. Tropical birds, however, are rarer on the average than birds of temperate forests. Roughly 190 of the 240 species found in mature forest have population densities of fewer than 5 pairs per 250 acres. Many small insectivorous birds have territories of 12-49 acres, which is 5 to 10 times larger than those of comparably sized birds in temperate forests. Apparently, the tremen- dous increase in species richness of tropical forests comes at the expense of decreased population densities of each species. Neotropical migrants, many of which breed in or pass through Illinois, are largely restricted to river edge and _ successional habitats on their winter grounds in south- eastern Peru. Shorebirds, including 13 species that migrate through the Midwest, occur on the beaches that are exposed when the river level drops during the dry season (June to November). Such familiar Illinois species as Eastern Pewee, Eastern Kingbird, and Swainson’s Thrush are most abundant in floodplain forests dominated by mahogany, figs, and trees of the laurel family. Unfortunately, these river-edge forests are the first to be logged and con- verted to agriculture following human settlement. Very few North American species winter in mature upland forest, which covers most of the Amazon basin. Robinson and Terborgh have found evi- dence that interspecific aggression also may play a key role in determining which species occur in each habitat. A common pattern is for closely related species to occupy different habitats. In the Manu area, often one species occupies early successional vegetation and another from the same genus occupies mature forest. In these pairs of species, one is usually dom- inant over the other. The dominant species attacks when it hears the song of the sub- ordinate. The subordinate species, in turn, usually retreats when it hears the song of - the dominant. Apparently the dominant species, generally the larger of the two, occupies the preferred habitat and forces the smaller one into marginal habitat. To date, this relationship has been found in 12 of 14 genera tested. These results suggest that interspecific competition may be wide- spread and important in determining hab- itat selection in Amazonian birds. Nest predation also plays a key role in determining habitat selection in many Amazonian birds. Many arboreal mam- mals (including most monkeys), snakes, hawks, and even toucans are inveterate predators of the eggs and young of birds. Though few species have been studied in detail, predation rates for some species probably approach 90 percent of all nests. To escape predation, birds must either hide their nests in tree holes or dense vine tangles or nest in areas where monkeys cannot reach them. Isolated trees, such as those on islands, are often covered with nests of many species, some of which are colonial. The availability of such safe nest sites may play an important role in limiting the populations of many tropical species. Such studies of tropical bird commu- nities can provide valuable insights into what factors might also be structuring temperate communities. Competitive inter- actions, which appear to be important in a great many tropical genera may also be important in the temperate zone, where many closely related species occupy differ- ent habitats. Similarly, nest predation may be far more important in temperate bird communities than is generally recognized. Perhaps the major advantage of working in the temperate zone is that many species are common and therefore relatively easy to study. Therefore, tropical forests provide the opportunity to study ecological inter- actions between many species, while tem- perate habitats provide an opportunity to study fewer species in much greater detail. Snug As a Bug ina..... Pearly wood nymph caterpillars (Eudryas unio) begin abandoning the leaves of their host plants, evening primrose (Oenothera) , willow herb (Epilobium), and grape (Vitis), in late September and early Octo- ber in search of suitable pupating and over- wintering sites. Many of Eudryas unio’s 3,000 moth relatives in North America un- obtrusively construct pupation chambers in the duff, or below the soil surface. In contrast, EL. unio prefer to pupate in soft wood or the stems of large, erect herbs and excavate their chambers with remarkable persistence. One Madison County resident near Edwardsville observed this activity in September 1983, reporting to the Survey that “thousands” of caterpillars (identified as , unio by Survey entomologist G. L. Godfrey) were “eating” recently purchased lumber that had been stacked near his home. Caterpillars and pupae of FE. unio were found in dead stems of the soldier rose- mallow (Hibiscus militaris) in Cleveland, Ohio, in 1868, according to the late C. V. Riley, internationally known entomologist. On October 13, 1983, Godfrey and his Survey colleague, D. J. Voegtlin, observed a similar situation in clumps of soldier rose- mallow in Fayette County near Carlyle Lake, although living stems also were in- volved. By splitting the stems, they found eight pupal chambers, each within 25 cm of the stem base. Two chambers held E. unio which had not yet pupated, and the caterpillars which had been exposed began to construct new chambers on intact stem segments. One caterpillar spent 11 hours and the other 12 in completing their new chambers, including the addition of “window dress- ing.” Excavation commences with the cater- pillar, head downward on the stem, biting a hole 4-5 mm wide (just large enough for passage of the caterpillar’s head) in the stem and discarding the removed pieces of stem tissue onto the ground. This sounds sumple. However, bear in mind that the caterpillar keeps biting, imwardly and obliquely downward for nearly its full body length, while intermittently ejecting stem material packed between its mandibles from the chamber without retreating from Eudryas unio pupal chamber (left to right): a larva cutting the entrance hole (1 hour), wood chips being attached to the clear silk plug (10 hours later), a camouflaged plug (separate specimen), a split stem with the pupa in the chamber (the top chamber contains the puparia of a parasitic tachinid fly) (Photos by G. L. Godfrey). The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 it. The head and part of the body fill the chamber during the biting process, but the caterpillar, with its flexible exoskeleton, has enough agility to loop itself sideways, bring its mandibles to the chamber’s entrance, and shove out the scrapings with its hypo- pharynx (‘tongue’). After approximately 9 hours of excavat- ing, the caterpillar turns end for end. With its head now directed toward the entrance, the caterpillar spins a silk plug over the hole. The strands of silk coalesce and by themselves would form a transparent win- dow, but during the 2- to 3-hour spinning process, small particles of stem are taken from the top of the chamber and attached to the inner surface of the plug to effec- tively conceal the entrance. Under natural conditions the caterpillar pupates within a week, and the resultant pupa is quite protected by its chamber through autumn, winter, and spring. The moth of E. unio escapes from the pupal case and breaks through the silk plug to emerge the follow- ing summer. Recent Publications Risser, P. G. 1984. Bibliography of Illinois Vegetation. Illinois Natural History Survey Biological Notes No. 121. 51 p. Voegtlin, D. 1984. Notes on Hyadapis foeniculi and redescription of Hyadaphis tataricae (Homoptera: Aphididae). Great Lakes Entomologist 17 (2) :55-67. Webb, D. W. 1984. A revision of the Nearctic species of the family Solvidae (Insecta: Diptera). American Entomological Society Transactions 110:245-293. Dex nber 1984, No. 242. Published n Departn nt of Eneray mnthly exce pt of the Illinoi and Conservation Prepared by Shirley McClellan with the collaboration of Illinois paid at Urbana Natural Resources second-class postage Office of publication: 172 ind Natural Res (USPS 2 Building, Champaign, Illinois Persons desiring individual or additional copies of this publication please write to DR. PAI G. RISSER HIEF ILLIt NATURAL HISTORY NATURAL RES RCE f | N¢ . FAST PEA SURVEY. DEPARTMENT OF ENERGY AND NATURAL RESOURCES HAMPA NATURAL HISTORY The Biogeochemistry of North American Ungulates In a study published in 1976, Harold C. Hanson of the Illinois Natural History Survey and Robert L. Jones, a soil mineral- ogist at the University of Illinois Depart- ment of Agronomy, reported on the rela- tionships between minerals and soils and their absorption by plants, their consump- tion and absorption by geese, and the mineral levels found Keratin essentially functions as a metabolic wastebasket for excess minerals. Insights into the progression of minerals through this segment of the ecosystem enabled these investigators to determine the birthplaces of wild geese. These findings have been shown to have immense practical applica- tion to the management of migratory birds, particularly waterfowl. in feather keratin. A spin-off of this study and of an evalu- ation of the role of sulfur in ecosystems was the realization that, despite many decades of study by big game specialists, the bio- geochemical aspects of mineral licks of big game (ungulates) were poorly understood. Yet the dependence of ungulates, world- wide, on mineral licks for survival has probably been known since the time of early man. The failure in recent decades to arrive at a common denominator, or de- nominators, involved in mineral lick use was that each study had been confined to a small area. It became apparent that the phenomena would be subject to decipher- ing only if the use of mineral licks was studied comparatively against the whole spectrum of geologies on which the animals live. To remedy this gap in the knowledge of ecosystems, Jones and Hanson solicited a TRE. 4 % oF 7 o ‘ # ae vue b> Oh Tar ee, we 2%, : g »_ mineral lick somewhere in Alaska Dall sheep at (Photo by Wayne Heimer). continent-wide collection of earth materials from mineral licks to learn the chemical basis of the dependence of animals on earth supplements in their diets. The result of this endeavor is a book just published by Iowa State University Press — Mineral Licks, Geophagy, and Biogeochemistry of North American Ungulates. The authors found that the primary reason that ungulates visit mineral licks is to avoid grass tetany —a convulsive con- dition that can lead to death resulting from the consumption of spring forages inordi- nately high in potassium and low in mag- nesium. As the plant matures or growth latent absorption of magnesium by the plant. This proceeds, there is a delayed or sequence of events has been shown to be Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. exhibited in the hair of moose. These rela- tionships have overriding significance, as both magnesium and calcium are required for the normal transmission of nerve im- pulses and muscular responses. Licks high in sodium or magnesium and/ or calcium solve the seasonal mineral im- balance for plant consumers — sodium by its reciprocal effect in reducing potassium levels and magnesium by compensating for losses of this latter mineral caused by an increase of the hormone aldosterone from the adrenal cortex. Concomitantly, in- creased sodium intake probably aids in more efficient absorption of magnesium — thus having a dual effect in correcting min- eral imbalances resulting from high potas- sium intake. : The results of mineral lick analyses and the line of reasoning developed in this study have been applied to the understand- ing of two age-old riddles— the 4-year cycles in rodents, particularly the micro- tines (meadow mice and lemmings), and the 10- to 11-year cycle of abundance in snowshoe hares. The die-off of lemmings has been associated in spring with con- vulsive conditions — both in Norway and Alaska. In snowshoe hares, the die-off at population peaks has been called a re- sponse to “shock disease” or hypoglycemia — basically a low blood sugar condition. But magnesium is a required co-factor for 8 of the 13 enzymatic steps in the glycolysis, or the metabolism, of blood sugars. Readily drawn upon magnesium reserves in animals have very narrow limits. Thus, this factor, coupled with possible cyclic lows of mag- nesium in woody plant foods and in geo- logic substrates and soils low in magnesium, sets the stage for die-offs precipitated by mineral imbalances. Insect Resistance in Soybean Pest Management An insect-resistant variety of a crop plant is one that possesses some biochemical or morphological trait which allows it to avoid, tolerate, or recover from insect injury. If possession of these traits prevents a partic- ular insect species from reaching damaging population levels, the use of such varieties becomes a very powerful pest management es = be SOON FAA oo SS Erect hairs along stems and leaves of most commercial soybean varieties interfere with potato leafhopper feeding (Photo by Y. I. Lee). tool. For example, the erect hairs along the stems and leaves of most soybean varieties have virtually eliminated the potato leafhopper (a tiny sucking insect) as a potentially serious pest of this crop. This simple morphological trait of most commercially grown soybean varieties pre- sents an effective barrier to feeding and egg laying by this highly mobile, abundant insect pest. Since 1970, entomologists, plant physiol- ogists, and biochemists at the Illinois Natural History Survey and plant breeders and geneticists at the United States De- partment of Agriculture Soybean Labora- tory on the University of Illinois campus have teamed their efforts to better under- stand the insect host-selection process and the physiology of resistance within the soybean crop. This program in host-plant resistance has two main components: (1) breeding soybean plants for improved re- sistance to defoliators and (2) studying the mechanisms of resistance. Within the breeding portion of the pro- gram, Survey entomologists routinely screen as many plant introductions, breeding lines, and varieties from the germ plasm collec- tion as possible. During 1984 alone, over 370 breeding lines were evaluated in the field and in laboratory choice tests for resistance to insect feeding. Through the course of this research, thousands of soy- bean lines have been screened, and num- erous varieties have shown measurable levels of resistance to one or more insect pests. A primary goal of the Illinois breed- ing program has been to transfer desirable resistance factors into agronomically ac- ceptable varieties. Using plant introduc- tions numbered 171451 and 229358 as sources of resistance (previously identified in South Carolina as highly resistant to the Mexican bean beetle), five promising soybean lines have been developed and released for public use in additional breed- ing programs. Efforts to better understand the exact mechanisms of the resistance phenomenon in the soybean crop must deal not only with the morphological and biochemical differences between resistant and suscep- tible varieties, but also with the way in which the insect perceives them. In-depth plant-chemical profiles of resistant and susceptible lines are being compiled in an attempt to detect subtle differences which may explain the insect response to a given food plant. Additionally, detailed morph- ological and electrophysiological studies of insect sensory structures are under way, and these may help to explain exactly where and how an insect makes the deci- sion to accept or reject a soybean line as a suitable host. Unlike the example of leaf hairiness and the potato leafhopper, the causes of most insect resistance in crop plants are likely to be complex and very seldom due to a single trait or chemical. Progress toward the development of agronomically accept- able, insect-resistant soybean cultivars has been painstakingly slow. However, given the complexity of the host-plant selection process and the difficult genetic manipula- tions required in the breeding program, this time frame for the development and release of insect-resistant soybean varieties is not abnormal. Nevertheless, host-plant resistance has tremendous potential for future use in successful integrated pest management programs. Resistant varieties are highly compatible with existing management strategies, should lower production costs, and should reduce or even eliminate the need for insecticide applications, thereby improving the quality of our environment. Continued emphasis on the development and understanding of insect resistance in soybeans by this multidisciplinary team should result in becoming a major component of pest man- agement systems for Illinois soybean pro- ducers. insect-resistant varieties Survival Rates in Squirrels Gray and fox squirrels are among the most popular small game animals in IIli- nois, with annual harvests exceeding 1 million. Unfortunately, information from unexploited fox squirrel populations, which could be used to aid in the understanding of fox squirrel population fluctuations and the establishment of harvest regulations, has not been available. Wildlife ecologists Charles Nixon, Lonnie Hansen, and Stephen Havera studied an unhunted fox squirrel population for 7 years to answer questions about the de- mography of squirrels. These answers will be pertinent to management practices. One of the most important questions investigated involved survival rates and factors affect- ing survival rates in natural populations of fox squirrels. Longevity of male and female squirrels Young fox squirrels nesting in wood duck box (Photo by W. E. Clark). The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 was found to be similar but squirrels 1 year and older when first captured lived on the study area much longer than those less than 1 year old when first captured. ‘These differences likely reflected not only higher mortality rates of young squirrels, but also a greater tendency of young to scatter from the study area. Surprisingly, fox squirrel survival was not correlated with production of tree seeds, as has been found by researchers studying gray squirrels. ‘This lack of correlation may be attributed to the abundance of tree seeds during the 7-year study, the varied diet of the fox squirrel compared with that of the gray squirrel, and the tendency of fox squirrels to use agricultural crops. Severity of winter weather, as indicated by snowfall and temperature deviations from normal, also did not appear to affect recapture rates. Recapture rates of subadult and adult immigrant squirrels were negatively cor- related with densities of adult females. Survival of resident squirrels was not affected by adult densities. These results suggest that social conditions initiated by the adult female may limit the number of new squirrels recruited into the population. Maximum densities of fox squirrels within a forest, therefore, could be limited in this way. These results have important manage- ment implications because they suggest that attempts to increase squirrel densities arti- ficially, for example, by releases, would likely fail if a resident squirrel population were present. Detailed experimental studies of fox squirrels are currently being per- formed to substantiate the role of adults in density regulation and to evaluate the effects of exploitation on fox squirrel demography. Persons desiring individual or additional copies of this publication please write to LIBRARY Scientists Seek Biological Control of Gypsy Moth As part of a cooperative agreement with the U.S. Forest Service, Survey entomol- ogists Joseph Maddox and Michael Jef- fords will travel to Europe this spring to collect microscopic, single-celled organisms called microsporidia from gypsy moth pop- ulations. These pathogens, disease-produc- ing organisms, will be tested, both in the laboratory and in a greenhouse model for- est ecosystem, for their potential as bio- logical control agents of the gypsy moth and for their environmental safety. Mad- dox and Jeffords hope to find one or more promising species to introduce into North American gypsy moth populations as per- manent mortality factors. If these efforts prove successful, it will be the first time that a classical biological control program involving a pathogen will have been con- ducted against the gypsy moth. Many insects that have attained pest status in the United States, including the gypsy moth and European corn borer, are not native species but were introduced from other countries. When an imported insect encounters a new environment with suitable weather conditions and abundant food, it often undergoes an explosive pop- ulation increase because it has been intro- duced without natural ganisms that the resource. Natural enemies, including preda- its enemies — or- use insect as a food tors, parasites, and pathogens, are ex- tremely important in keeping insect popu- lations in check. Biological control is the planned reloca- tion of natural enemies from one place to another. The objective of classical bio- logical control is to find the most effective Material in this publication may be reprinted if credit is gi ven Microsporidian pathogens collected in Europe will be studied for their potential as biological control agents of the gypsy moth in North America. Top: Spores of a microsporidium in the genus Nosema — actual length 5 microns (Photo by J. V. Maddox). Bottom: Mature larva of the gypsy moth, Lymantria dispar — actual lengih about 2 inches (Photo by J. E. Appleby). to the nois Natural History Survey natural enemy species and to colonize them in the new environment of the pest insect. The first successful biological control in the United States took place in 1888 when the predaceous vedalia beetle was imported from Australia to control the devastating cottony cushion scale. The fledgling citrus industry in southern California was saved, which generated a great deal of enthusiasm for this control strategy. Many successful introductions of natural enemies followed. The United States Department of Agri- culture first became involved in the bio- logical control of pest insects in 1905 by importing natural enemies of the gypsy moth. The gypsy moth was brought from Europe to Massachusetts in 1869 by Leo- pold ‘Trouvelot, who had planned to breed’ it with the silkworm to produce a better silk-making caterpillar. Several gypsy moths escaped during the course of his experi- ments, and within a few years populations were high enough to cause noticeable de- foliation of trees in the area. Since its in- ception, the U.S.D.A. gypsy moth natural enemy introduction program has resulted in the establishment of one predator species and ten species of parasites imported from Europe and Asia. Although the combined mortality inflicted by these imported spe- cies can be significant, the gypsy moth con- tinues to reach outbreak levels, especially in newly invaded parts of its range. In 1981, one of the worst gypsy moth out- breaks to date occurred: 13 million acres of trees were defoliated and damage was $764 million nationwide. Researchers are beginning to find that pathogens are often the most important mortality factors affecting forest insect populations. While most classical biological control work has involved introductions of parasites and predators, success has been achieved in Canada by using imported viruses to control forest insect pests. In the United States only one pathogen, a nu- cleopolyhedrosis virus (NPV), causes sig- nificant gypsy moth mortality. Gypsy moths in Europe, however, are infected by a number of other pathogens in addition to the NPV, including microsporidia. High levels of microsporidian infection have been implicated in the collapse of gypsy moth populations, and if Maddox and Jeffords find the right ones, control of the gypsy moth may improve greatly. Supplement to Aquatic Oligochaeta of the World is Published Oligochaete! Thou taxonomic pain! My mouth and mind and memory affirm, °Twould be much less a stress upon the brain To designate you merely as a worm. But then again, perhaps it is untrue To brand you as too simple for your name. For possibly, the tests we put you through "Just don’t quite fit your undulating frame. Psychologists are on the highest ground When studying the ways of mice and men. But with invertebrates theyre often found Quite ignorant of how they should begin. The object of my study is to try To help both man and worm see eye to eye. —D.N. Howell (1974) Earthworms are familiar enough to any- one who has worked with soil or gone fish- ing. More than 80 percent are close rela- tives of the common garden earthworm. Several families of worms are entirely aquatic, while other families which are primarily terrestrial have one or more genera inhabiting aquatic or semiaquatic habitats. In December 1984, Dr. Ralph O. Brinkhurst of the Institute of Ocean Sci- ences in Sidney, British Columbia, and Mark J. Wetzel of the Section of Faunistic Surveys and Insect Identification, pub- lished a paper entitled Aquatic Oligochaeta of the World: Supplement. A Catalogue of New Freshwater Species, Descriptions, and Revisions. This contribution provides an annotated list of freshwater oligochaete genera and species described or revised since the global review of the literature on this subject by the senior author and B. G. M. Jamieson in 1971. The intent of the authors was not to provide a formal taxonomic revision based on the examination of old and new material, but rather to organize and pre- sent recent published information so that such revisions by subsequent authors might be completed more efficiently. This com- pilation should be particularly useful to authors wishing to publish species descrip- tions, revise copies of regional keys, or recognize synonyms employed in the wider, nontaxonomic literature. Discussions of major diagnostic characters of new taxa, possible synonyms suggested by the litera- ture, and transfers of species between genera which result in several new com- binations are presented. The most significant change in oligo- chaeta systematics since 1971 has been the recognition of intraspecific variation and environmental modification of setae, or hairs, resulting in the synonymization of some species. The authors report on several research programs which question the prior heavy reliance on setal form for generic decisions, even in the presence of other dis- tinguishing characteristics. Increasingly re- fined research being conducted on oligo- chaete systematics has suggested that the issue is really one of intraspecific variation in any character. Other research programs have demonstrated that some setal forms reflect a degree of development rather than the presence or absence of certain char- acters, as described in most species defini- tions. The authors suggest that such fine differences between species within certain families of worms, established by the typo- logical method, may have little practical value for ecologists; the resolution of this issue depends on an increase in the amounts of field work on these families, which has just begun. Lead Poisoning in Illinois Waterfowl Ducks, geese, and other birds become exposed to lead poisoning when they in- gest lead shotgun pellets that have been deposited in waterfowl habitat as a result of sport hunting. The pellets are retained in the gizzard, where the lead is gradually dissolved and then absorbed by blood and subsequently by other body tissues. In ad- Dr. Frank Bellrose, nationally known wildlife specialist who recently retired from the Survey's Havana field station, retrieving dead ducks that ingested lead shot at Rice Lake, near Banner, Illinois. dition to contaminating the bird’s blood, liver, and kidneys, lead also enters the brain. Such contaminated birds often die. In fact, in his definitive study of lead poisoning, Survey researcher Frank C. Bell- rose estimated in 1959 that 2-3 percent of the entire North American waterfowl pop- ulation succumb to this disease annually. With today’s populations, this means a loss of 1.6-2.4 million birds each year. Illinois Department of Conservation bi- ologist William L. Anderson and Survey researcher Stephen P. Havera recently in- vestigated the extent and severity of lead poisoning among waterfowl] in Illinois. In a sample of 13,246 gizzards from mallards harvested on 55 areas from 1979 through 1983, 5.9 percent contained one or more ingested pellets. Ingested pellets were found in gizzards from virtually all areas, reveal- ing that lead poisoning occurs throughout the state. Incidences of ingested pellets in mallard gizzards exceeding 10 percent oc- curred in several areas in some years, and the astounding rate of 20 percent, or one out of every five gizzards, was evident on occasion. For lesser scaup, more popularly called “bluebills,” the incidence of ingested pellets in 753 gizzards was 3.2 percent. In a sample of 526 Canada geese, the inci- dence was 4.2 percent. When it is recognized that these inges- tion rates represent merely “‘still images” of a dynamic process in which lead pellets are continuously being ingested and dis- The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 solved (in about 3 weeks), it is evident that 20-30 percent of Illinois’ waterfowl popula- tion is contaminated with lead each year. Incorporate into this calculation the fact that several million ducks and geese mi- erate through or winter in Illinois annu- ally, and the number of individual water- fowl that contract lead poisoning in our state becomes excessive. Anderson and Havera extended their investigations of lead poisoning by collect- ing blood samples of 2,265 waterfowl cap- tured on seven areas during the fall and winter periods of 1980-1981 through 1982- 1983. These blood samples were analyzed for concentrations of lead and protopor- phyrin. Protoporphyrin is a precursor to hemoglobin, and it increases as a response to lead poisoning in ducks and geese. The rates of lead poisoning indicated by ele- vated protoporphyrin in blood were equal to or greater than those suggested by in- gested pellets in gizzards. Moreover, lead poisoning as revealed by elevated lead in blood was about twice as great as the rates indicated by elevated protoporphyrin levels and ingested pellets. It was evident that lead in blood was the most sensitive tech- nique for detecting lead poisoning in waterfowl, protoporphyrin in blood was intermediate, and ingested pellets in giz- zards was the least sensitive. Anderson and Havera concluded that the incidence of ingested pellets in gizzards provided con- servative estimates of the severity of lead poisoning in Illinois’ wild waterfowl popu- lations. Thus, lead poisoning of waterfow] in Illinois is probably more serious than originally predicted. Research has shown that the ingestion of a single lead pellet by a duck always re- sults in lead contaminating the blood, liver, kidneys, and brain. The very least conse- quence of waterfowl ingesting lead is the inhibition of enzyme activity in these vital body tissues, and, at least in the brain, cellular damage occurs. The brain damage is irreversible, and without question places the bird at a disadvantage in attempting to survive, migrate, and reproduce in the wild. The other possibility is death as the result of acute lead poisoning. The loss of thousands of waterfowl throughout the United States to lead poisoning each year can be eliminated by the conversion to non- toxic steel shot for use in the sport hunting of ducks and geese. February 1985, No. 244. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY. DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, ILLINOIS 61820 The Illinots NATURAL HISTORY | SURVEY a5 Frank Bellrose Receives Aldo Leopold Medal FRANK BELLROSE Frank Bellrose, former wildlife specialist at the Survey, was presented the Aldo Leopold Memorial Medal for his dis- tinguished service to wildlife conservation at the 50th Anniversary meeting of The Wildlife Society in Washington, D.C. re- cently. The award is the ultimate recogni- tion of a wildlife professional and Bellrose is the first Illinoisan to receive it. The dedication and deep convictions of this scientist have led to a better under- standing of wetland resources. He has long been concerned with the and problems along the Illinois and Mis- wildlife trends Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. » sissippi flyways. The first scientist to report the poisoning of countless waterfowl by lead shot, he is closely associated with ex- cellence in waterfowl research and man- agement and is widely regarded as “Mr. Waterfowl.” Over 90 publications are credited to his work and consist of a wide variety of topics ranging from waterfowl food plants, to muskrats, to waterfowl migration corridors. One of his most notable contributions is associated with the rewriting and revision of the Ducks, Geese, and Swans of North America. This book has been recognized as one of the most complete waterfowl refer- ences in print. He has received numerous honors and awards, including The Wildlife Society Publication Award, the Oak Leaf Award from the Nature Conservancy, American Motors Conservation Award, and the Na- Wildlife Award. He is a Fellow of the American tional Federation Conservation Ornithologists’ Union, an honorary life member of The Wildlife Society, and re- cipient of an Honorary Doctor of Science degree from Western Illinois University. The 1985 honoree was born in Ottawa in 1916, and completed his academic train- ing in Zoology at the University of Illinois. His wildlife career began with the Illinois 290 Natural History Survey in 1938 as an As- sistant Game Technician. He progressed to Assistant Specialist in 1945; to Wildlife Specialist in 1955; and to Princi- pal Scientist with the Survey in 1981. Since Game 1963, he has been an Adjunct Professor and Research Associate at Western Illinois University. Bellrose retired from the Survey in 1983, but he continues to work almost daily at the Havana Laboratory or in the field. Sapsuckers Damage Trees Sapsucker damage is caused by a bird known as the yellow-bellied sapsucker, a member of the woodpecker family. The damage caused by the sapsucker is pri- marily done in early spring when the bird migrates back from its winter environment. Small, closely spaced holes formed in regu- lar rows around the trunk and branches can be found on pine, birch, maple, linden, and other tree species that “bleed”’ freely from bark wounds. The “drilled” holes made by the sapsucker extend into the wood and usually completely encircle the stem and branches, and are the result of the natural feeding habit of the bird. The bird is one of the smaller woodpeckers, having black and white plumage, a wide white stripe on the wings, a red patch on the forehead, and a yellowish breast. Unlike most members of the wood- pecker family, sapsuckers rarely drill into the bark to search for insects, but do drill holes in the bark of healthy trees to obtain tree sap on which they feed as it seeps from these bark wounds. It is believed that half of the food material sapsuckers con- sume, at least in early spring, is composed of sap and of the insects that are attracted to tree sap. Some of their other foods are small fruits and insects they catch on the bark. Hummingbirds also visit rows of sap- sucker holes to feed on the sap and insects. Because several rings of holes are fre- quently made, and because trees may be injured several years in a row, the bark can be riddled with wounds that cause severe reduction of the normal transport of sugars down to the root system. Also, the outer wood is damaged and water and nutrient transport to the crown is greatly reduced. When several bands of holes ex- tend around the branch or trunk, the top of the tree may die. Sometimes on smaller trees a bulge will develop above the ring of holes indicating a backup of sugar transport through the inner bark. In areas of high sapsucker migration, many Scotch pine and sugar maple trees will exhibit injury made over a period of several years. Towns in agricultural areas, such as east central Illinois, tend to attract many sapsuckers because there are so few The branch sections pictured were cut from Scotch pines that were fed on heavily by sapsuckers. After one to two years, sapsucker wounds will develop as square or rectangular holes in the bark as a result of further tree growth. trees in the region. In addition, many of the trees that have been planted as orna- mental shade trees are among the favorites of the sapsucker. Frequently, one tree will be singled out for heavy feeding. Because the birds are shy creatures, they are easily disturbed by humans, are observed infre- quently, and are seldom seen or heard when they drill holes in the trees on which they feed. Sticky, bird-repellent materials applied to the trunk have not been successful in repelling sapsuckers, and they are imprac- tical to apply to large areas of a tree trunk. Strips of shiny aluminum foil that will flutter in the wind and are attached by string to a few branches may help to frighten the birds away. No other pro- cedures are known that have been success- ful repellents. Injured trees will be helped in recovering from sapsucker injury if they are fertilized in the spring or early sum- mer, and watered during the dry periods of the summer. Survey Investigates Fruit Crop Pest The plum curculio, Conotrachelus nenu- phar (Herbst), feeds on many fruit crops east of the Rocky Mountains, including apple, apricot, blueberry, cherry, nectarine, peach, and plum. Adults feed on green fruit in the spring, and sometimes on ripening fruit in the fall. Females make crescent-shaped incisions on the fruit, lay- ing a single egg in each incision. ‘The de- veloping larva feeds inside the fruit, and may cause premature fruit drop. Less is known about the plum curculio than any other key pest of stone or pome fruit. Scientists have been unable to pre- dict exactly when plum curculio will first appear on fruit crops in the spring. As a result, growers are forced to apply several insecticide treatments to ensure that at least one application will be on time to prevent plum curculio damage. Milt McGiffen, an Assistant Supportive Scientist in Economic Entomology, found that insecticide usage could be greatly re- duced if sprays were precisely timed. While working with John Meyer at North Caro- lina State University, McGiffen examined the effect of overwintering behavior and spring migra- environmental factors on tion in plum curculio, hoping to find a key to the accurate prediction of the spring appearance of C. nenuphar on fruit crops. He concluded that the return of plum curculio to their host plants is the result of two events in the insect’s life cycle, dia- pause termination and postdiapause migra- tion. Diapause is a state of suppressed devel- opment similar to hibernation. Respiration rate, characteristically low during dia- pause, may be used as an assay for the physiological changes associated with over- wintering. With the aid of a gas chromato- graphic technique developed by a fellow graduate student, Jack Boyne, McGiffen used the respiration rate to determine when diapause ends in plum curculio. He (Upper left) Plum curculio rests on the fuzzy surface of a peach. (Lower right) Adult curculio make crescent- shaped incisions on fruit. The developing larvae feed inside the fruit and may cause premature fruit drop. The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 found that diapause termination (the physiological processes involved in com- pleting diapause) is completed before winter ends, and thus does not determine when spring migration is initiated. Low temperatures act to suppress activity and conserve energy during the transition from diapause to reproduction, a life stage called postdiapause development. Plum curculio is vulnerable to starvation if sustained periods of warm temperatures occur during postdiapause development. However, most overwintering plum cur- culio do not initiate migration to food plants until the temperature reaches 60°F (to warm flight muscles) and _ relative humidity exceeds 50 percent (plum cur- culio are sensitive to desiccation or drying out). Further, deaths due to the insect dis- ease, Beuvaria bassiana (Balsamo) Vuille- min, increase rapidly as temperature rises. The impact of these factors on plum curculio populations may be severe during certain situations. If spring weather is warm and dry or fruiting of host plants is not synchronized with migration, plum curculio populations may suffer high mor- tality rates. From an evolutionary stand- point, the plum curculio’s dependence on temperature and humidity as signals to initiate migration are understandable: spring is usually humid, and host fruit availability is dependent upon tempera- ture. Because of these findings, it was con- cluded that the timing of plum curculio migration from overwintering sites to host plants is critical in predicting when the pest first appears on fruit crops. A simple model of the relationship between plum curculio flight initiation and ambient tem- perature and humidity was developed. Re- searchers hope the model’s predictions will allow more precise timing of insecticide applications, and thus lead to better con- trol practices for this serious pest. March 1985, No. 245. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by Shirley McClellan with the collaboration of the Survey staff Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, DEPARTMENT OF ENERGY AND NATURAL RESOURCES ILLINOIS 61820. The Illinows = 2 eid JF; ORR ve SS oa Endangered Illinois Fishes A large number of fishes have disap- peared from Illinois within historical time, and several more are on the verge of ex- tinction. Already gone from Illinois are the Ohio lamprey, blackfin cisco, longjaw cisco, rosefin shiner, greater redhorse, gilt darter, stargazing darter, crystal darter, and native populations of the muskellunge. On the verge of extinction are several other fishes, the more critical of which are the lake sturgeon, alligator gar, cypress minnow, bigeye chub, bluehead shiner, pugnose shiner, blacknose shiner, northern madtom, and harlequin darter. For some species nearing extinction in Illinois, the problem seems to be an inabil- ity to adjust to pervasive aspects of en- vironmental degradation (e.g., stream silta- tion) over a large area of the state, and it may not be possible to prevent the loss of these species. An example is the bigeye chub, which once ranged over much of eastern and southern Illinois but now is found in only a few small streams. For other species, the protection of critical hab- itat could save the Illinois populations. Among the most endangered fishes in IIli- nois are six species which appear to fall into the latter category: the cypress minnow, pugnose shiner, bluehead shiner, northern madtom, bluebreast darter, and harlequin darter. Each is confined to a small area of Illinois and appears to be endangered be- cause its population is small and vulnerable even to minor modifications of its habitat. A study designed to locate the largest Illinois populations of three endangered fishes, the pugnose shiner, bluehead shiner, and harlequin darter, and to identify char- acteristics of the habitat most critical to Material in this publication may be reprinted if credit is given HISTORY EPORTS | their survival, was initiated by Survey sci- entists L. M. Page and K. S. Cummings. These three fishes were selected bec ause they are considered extremely endangered in Illinois, and protective measures must be taken quickly if Illinois populations are to survive. Fortunately, all occur in areas and habitats amenable to protection. With partial funding by the Illinois Department of Conservation, field work began in July 1984 and should be completed by the fall of 1985. The pugnose shiner has been referred to the North America, and one which is undergoing an as one of rarest minnows in alarming decline throughout its range. Its decline seems to be related to increased turbidity and the concomitant loss of aqua- tic vegetation. It has disappeared from the state of Ohio, is considered threatened with extinction in Wisconsin, and is extremely rare in Minnesota, New York. In Illinois. the pugnose shiner is one of Indiana, and the rarest fishes. Originally described in 1885 from Fox River in McHenry County, —7 * Pa NN SS ) eas =~ a WAY YY . 1} LYV Pr. Pugnose Shiner (Drawing by Craig Ronto). Illinois, the species was found in Fourth Lake in Lake County in 1892 and in a floodplain lake of the Illinois River in Ma- son County in 1909. Additional observa- tions of the pugnose shiner (all in Lake County) were made in Channel Lake in to the Illinois Natural History Survey 1965, and Loon Lake and Grass Lake in 1968. No observations of the pugnose shiner in Illinois were made between 1968 and 1984 and it was believed that it might already have disappeared from the state. Nearly all of the natural lakes in north- eastern Illinois, where most of the pugnose shiners have been found, now are sur- rounded by human dwellings and receive ever-increasing amounts of pollution. Many have had deliberate introductions of sport fishes, all of which are highly predatory and are known to alter the natural balance in predator-prey relationships. However, some lakes appear to remain in a sufh- ciently natural condition to support the pugnose shiner. The bluehead shiner has a highly dis= junct range, with the Illinois population being the only one found east of the Mis- sissippi River and is far to the northeast of any other known population. In Illinois, it has been found only in Wolf Lake and in the contiguous LaRue Swamp, in Union County. It was first discovered in Wolf Lake in the mid-1950’s and last observed there in 1974. Several recent attempts to document its continued presence have been unsuccessful, but Wolf Lake is an ex- tremely difficult place to sample, and the species may still be present. LaRue Swamp Bluehead Shiner has been sampled many times in recent years, but the bluehead shiner has not been found, and its earlier presence there is as- sumed to have represented stragglers from Wolf Lake. Wolf Lake is an old, deep, mud-bot- tomed oxbow of the Big Muddy River, margined with emergent and submerged vegetation. Elsewhere the species occupies similar lakes and backwaters of sluggish small- to medium-sized streams. Usually the habitat is heavily vegetated and has a bottom of mud or sand. Other populations “of the bluehead shiner are known in Ar- kansas, Louisiana, and Texas. The harlequin darter also has a highly disjunct range. The Illinois population, now apparently confined to the Embarras River (and possibly the Wabash River), is a relict of a more widespread population. No harlequin darters have been found in Indiana since 1890, and a similarly dis- junct population in the Patoka River in Indiana now may be extinct. The harlequin darter was discovered in the Embarras River in 1964, and a few specimens were found at several sites in Vayu 4 inna? Ve gan one? Harlequin Darter Cumberland and Jasper counties between 1964 and 1968. It was not seen again in Illinois until 1983 when one was found in the Embarras River below the Charleston Dam in Coles County. Harlequin darters live in rocky riffles and accumulations of leaves and debris over sand or gravel in runs of small- to medium- sized rivers and large creeks. The species is found sporadically from the Wabash River system in Illinois and perhaps Indiana, south in tributaries of the lower Mississippi River to Louisiana, and in Gulf Coast drainages from the Escambia River in Flor- ida to the Neches River in Texas. The spe- cies seldom is common anywhere. Although the Embarras River has been dammed at Charleston, channelized in its lower reaches, and suffers from siltation, the stretch of the river from Charleston to Newton retains an excellent variety of habitats and supports large populations of many fishes. The 1983 observation of a harlequin darter in the river attests to the possibility of protecting the Illinois popu- lation by protecting the river. All localities in Illinois at which these three species are known to have occurred will be revisited in 1984-1985. Additional localities in Illinois which are within the geographic domain of the species and ap- pear to have suitable habitat will be sam- pled also. Included in the results of the study will be an assessment of the status (i.e., distribution and abundance) of each of the three species in Illinois, a description (based on observations and published in- formation) of the ecological requirements important for survival of the species, an as- sessment of the causes for the decline of the species in Illinois, and identification of habitats in Illinois critical to the continued survival of the species. Field work to date has located a popula- tion of the pugnose shiner in East Loon Lake in Lake County, and confirmed the continued existence of the harlequin darter in the Embarras River below Charleston Dam in Coles County. Researchers have been unable to locate bluehead shiners in Illinois; however, a search for this species in Horseshoe Lake in Alexander County, a lake similar in many respects to Wolf Lake, produced a cypress minnow, a spe- cies not seen in Illinois since 1940 and thought to have been extirpated from the state. [Fish drawings were taken from Fishes of Illinois by Philip W. Smith.] Caddisfly Systematics The caddisflies comprise the insect order Trichoptera, containing nearly 10,000 spe- cies worldwide grouped in several hundred genera and approximately 35 families. Caddisflies are aquatic insects which live in lakes and streams. Survey entomologist J. D. Unzicker has been studying the sys- tematics of the family Hydropsychidae, which occurs throughout the world. Hydropsychid caddisflies are known as net-spinners because the immature stage or larva constructs a silken net or retreat to filter microscopic articles of food from moving water. Caddisflies are an integral and important part of the aquatic food chain in Illinois’ streams and lakes. Until recently hydropsychid genera have been diagnosed to a large extent on the basis of structures of the adult stage. Un- zicker and a Canadian colleague have ana- lyzed the 20 North American species of the genus Symphitopsyche using both adult and larval structures. Closely related spe- cies were clustered first on larval and then adult characters, and then the two sets of species groupings were compared. There was almost complete overlap of the clusters based on characters of two different life stages. This method provides a high degree of confidence in the characters selected as diagnostic for a genus in the Hydro- psychidae. Unzicker has already published a new alignment of eight North American genera in the subfamily Hydropsychinae, but an important problem remains to be solved. How do these eight genera fit with the 22 other genera occurring on other continents? He is now examining these 22 genera in the subfamily in order to find structures Adult net-spinning caddisfly of the genus Hydropsyche (Drawing from Caddisflies of Illinois by Herbert Ross). The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 in both the adult and larval stages which will be diagnostic for each genus. The combination of adult and larval characters provides valuable evidence for inferring psylogeny (i.e., history of the lines of evolu- tion) and, if this is known, their diverse distributions should make possible the in- ference of past dispersal routes which have led to present day distributions of these genera. Unraveling the relationships of the many genera in the family Hydropsychidae is the goal of Unzicker’s research. The INHS/IDOT Program The Natural History Survey has assisted the Illinois Department of Transportation (IDOT) for several years by conducting faunal and floral inventories and surveys of endangered and threatened species and natural areas likely to be affected by high- way and bridge construction, replacement, or repair activities. A typical year has re- quired 25 to 30 detailed studies, each need- ing from several days to months of investi- gation and research. The Survey’s program with IDOT was expanded in scope and number of studies to be conducted for fiscal year ’85 to in- clude two additional areas of responsibility. In the first, Survey scientists are mapping and evaluating soils, and determining the presence, characteristics, and extent of No Illinois 246. Published De partment of Ene ray and Natural R monthly e April 1985, of the xcept in ion and Conservation Prepare i by Shirl : nd-class postage paid y McClellan with the it Urbana, Illinois. (USPS ollaboration Office of publication: 172 Natural Resources Buildir Ju }, Cha ly SOL of the Surve st ral prime farmland and wetlands for each of 400 to 500 new highway projects per year. Scientists are also providing a preliminary screening of the biological resources to assess the need for additional study. Recommendations for additional research are one source of detailed studies such as those performed in the original pro- gram. Also, projects occasionally require extensive investigation by a diverse re- search team (such as the detailed botani- cal, zoological, water quality, and_ soils research performed at the Morton Arbore- tum). Such “special projects” are covered in the second new area of the INHS/ IDOT program, established to coordinate these extended studies. Ten new Survey positions were created for this expanded program and are funded by contract from IDOT. These include: biology assistants (2), botanists (2), soil scientist (1), soil mappers (2), biologist/ coordinator (2), and an administrative as- sistant (1). Warren U. Brigham serves as Director of the INHS/IDOT program. Project coordinators are Allison R. Brig- ham, screening studies; Gene Ardner, de- tailed studies; and Mark J. Wetzel, ex- tended studies. Most of the staff and workload for this expanded program is in the Section of Faunistic Surveys and Insect Identification, with support from the Sec- tion of Botany and Plant Pathology. the pe rating under and Auaust by Natural History Survey, a the Boar aivi rces a of Natural Resources ff paian, tilinois Persons desiring individual or additional copies of this publication please write to PAU ; E§ HIEF | IN NAT L H ARTMENT OF ENERGY AN NATURA ESOURCES The Illinois An Epizootic in the Alfalfa? Epizootiology, or the study of disease dy- namics in insect populations, is a relatively new area of research. Three major factors are important in the development of epi- zootics, or epidemics: (1) a pathogen, or infectious agent; (2) a group of susceptible ) 3) an effective method insect hosts; and (3) of disease transmission among hosts. The ecology of epizootics, and the environ- mental factors that affect their develop- ment, are important areas of research. Economic Entomology staff members Marilyn Morris and Michael McGuire are currently studying fungal pathogens of the alfalfa weevil and the potato leafhopper, two major pests of alfalfa in Illinois. Cer- tain factors limit the effectiveness of each pathogen in controlling pest populations, and neither pathogen is part of an existing Illinois pest management program for al- falfa. In the case of the alfalfa weevil patho- gen, Erynia phytonomi, disease epizootics have been observed routinely since the late 1970’s. The epizootics, however, often oc- cur too late in the season to keep the weevil population below a crop-damaging level, so that chemical sprays are needed. This late occurrence is characteristic of many fungal pathogens and can limit their pest- controlling capabilities. One management strategy that could increase the effective- the dis- ness of this pathogen is to cause ease to begin earlier in the growing sea- son. Disease activity typically begins when over-wintering resting spores germinate in the spring and begin the infection cycle in the host population. Genetic selection for earlier resting spore germination could in- crease the effectiveness of epizootics. Un- Material in this publication may be reprinted if credit is giver NATURAL HISTORY REPORTS. fortunately, the field conditions that pro- mote resting spore germination are poorly known. Survey researchers are examining the possible influences of temperature and photoperiod on germination. Another method of inducing early dis- ease onset is to “seed” fields with cultures of the actively growing fungus early in the season. Conidiospores, released by the cul- tures and responsible for the spread of in- fection among insects, would infect suscep- tible hosts, allowing the disease to become established in the insect population earlier than usual. This method could also be used to establish the pathogen in an area where it does not exist. Using this method, an at- tempt was made to establish the potato leafhopper fungus, Erynia radicans, in Illi- nois. While this fungus is present in Wis- consin, it has never been found in Illinois. Sporulating cultures of E. radicans were introduced into potato fields where unin- fected potato leafhoppers were present. Al- though cultures produced many spores, subsequent sampling yielded only a few “ 4 4 " Me - ae! ‘ rn ts 2 ee oat Co + Fy i oe ’ oy Z a’ ‘% » . >! ° . 2 », » * a ° 4 \ i * = ~ ee ~ Healthy alfalfa weevil larvae and larvae infected with the pathogenic fungus, Erynia phytonomi (Photo by Marilyn Morris). infected leafhoppers and the infection soon disappeared from the field. The failure of FE. radicans to become established may be due to adverse environ- mental conditions. Environmental factors play a very important role in the develop- ment of epizootics and can limit or en- hance the growth and spread of pathogens. For fungal diseases, high humidity is con- sidered to be among the most important requirements for spore formation and ger- mination. If humidity is adequate, temper- ature may be a limiting factor. Growth studies have shown that E. radicans grows poorly, or not at all, at the high tempera- tures common during the midsummer in Illinois alfalfa fields, when potato leafhop- pers are abundant. The inability to develop at high temperatures may explain why the introduction of the pathogen into Illinois fields was unsuccessful. The selection and subsequent introduction of fungal strains that can grow and infect leafhoppers at higher temperatures may facilitate the use of this fungus for biological control. FE. phytonomi, the alfalfa weevil fungus, also grows poorly at high temperatures. How- ever, the susceptible stage of the weevil is present in Illinois in late spring, and the typically cool temperatures at that time al- low for fungal growth and the observed epizootics. In addition to initial infections and fa- vorable environmental conditions, a thresh- old population of susceptible hosts and an efficient means of disease transmission are also needed for an epizootic to develop. For the alfalfa weevil and its associated fungus, E. phytonomi, approximately two weevils per alfalfa stem must be present before an epizootic will develop. This pop- ulation level is very close to the weevil density above which insecticidal spray treatments are applied. In order to avoid the use of chemical sprays and maximize the role of the pathogen for insect control, certain agricultural cropping methods that increase the transmission efficiency of the fungus can be employed. An early first har- vest of alfalfa, timed to coincide with the first incidence of diseased larvae could con- centrate weevil larvae on the stubble and, by removing the alfalfa foliage, allow the airborne spores to spread more readily to the remaining weevil population. Before either of these two insect patho- gens can be used effectively in Illinois ag- riculture, additional laboratory and field studies are needed. Both enhancement of the naturally occurring alfalfa weevil fun- gus, or introduction of a more suitable strain of the potato leafhopper fungus, will require a thorough understanding of the factors that influence the growth and spread of disease in populations of these alfalfa pests. Analysis of Fish Communities in Illinois Impoundments Fishing is one of the most popular pas- times in the state. Annual license revenues from Illincis residents have exceeded 4.5 million dollars since 1980. Angling pres- sure has increased at a faster rate than the construction of new impoundments, and has affected fish populations significantly compared with natural causes. Typical Illinois impoundments are very productive, so management is not neces- sarily the stocking of new fish, but influ- encing the natural productive processes to provide the size and species of fish desired by the angling public. Stocking of fish is usually expensive, but can sometimes be justified in particular cases, such as (1) when an impoundment has to be reno- vated, (2) for desired species outside their natural range when they cannot survive throughout the year (e.g., trout), or (3) for species which cannot reproduce or re- cruit successfully in the artificial environ- ment of an impoundment (e.g., channel catfish) . There are two extreme approaches to management. The first is to act on a hunch or some unquantified previous experience. The second is to follow a prediction based on a model of the system which is in turn based on quantified previous experience. In practice, recreational fisheries management operates somewhere between these tremes, but typically close to the first. Once the experience has been gained, a good manager can succeed in this manner, but the experience cannot easily benefit a new manager, or other managers working with e€x- similar fish communities in other im- poundments, or policy makers who need to allocate resources statewide. Also, since the previous information often was not quantified or recorded, the ability to detect and correct an adverse change in the fish populations and evaluate the results of management was impaired. To approach the second more scientific extreme requires an investment in (1) or- ganizing a system of standardized sampling to facilitate comparisons, (2) calibrating the sampling methods under various con- ditions to provide unbiased measures of the fish populations, and (3) data man- agement systems to assist managers and permit assembly of statewide data for pre- dictive model construction and provide data for statewide resource allocation. The benefits will be both in short-term manage- ment strategies at the local and state levels, and in our scientific understanding of fish communities in impoundments, which through predictive models can assist in long-term management and future short- term decisions. In summary, we need to increase benefits in terms of angler satisfaction by making the management process closer to biological and fiscal reality. Human resources are required which have recreational, research, and direct field sampling perspectives. Such resources are available at the Illinois De- partment of Conservation (DOC) and the Illinois Natural History Survey. A project was designed and initiated by Peter Bayley in January 1984 to: (1) make the individual data sets comparable with- out losing the unique characteristics of each water body; (2) calibrate the stan- dardized sampling techniques so that we can produce estimates of abundance, bio- mass, and biological production of fish, which are prerequisites for realistic predic- tive models; (3) ultimately be able to re- late all the data sets for across the State with other influencing factors, such as fish- ing pressure, natural effects, and antici- pated demands on the resource; and (4) develop a system to periodically summarize the findings so that optimal management decisions can be made. Existing fish sampling facilities and per- sonnel at both the DOC and the Survey and existing computers at the Survey will be utilized. Additional microcomputers are being purchased for permanent installation with DOC District Biologists who manage impoundments, and software development is underway. The project is supported by the federally administrated Dingel- Johnson fund which depends on a tax based on fishing tackle purchases. Although the project is funded for 3 years, the system of data acquisition, storage and analysis will be permanent, and the benefits will accrue over many years. Bacterial Populations in Two Pools of the Mississippi River Bacterial populations associated with aquatic plants in Pools 19 (Keokuk) and 26 (Grafton) of the Mississippi River rep- resent a significant portion of the total amount of bacteria available to consumers in the pools. Bacteria contribute to the food web by transforming dissolved organic car- bon released from living plants into bac- terial biomass and by aiding in the decom- position of dead plant parts. As a part of the Long-Term Ecological Research (LTER) Large Rivers study, Michael S. Henebry and Robert W. Gor- den are using direct microscopic counts to estimate the amount of bacteria in the water column, in sediments, and on the surface of plants in different habitat types in Pools 19 and 26. Water, sediment, and plant samples were collected from 37 sites along eight across-the-river transects in Pool 19 in August and October 1984. Lo- cation, water depth, sediment type, and presence or absence of rooted aquatic vege- tation were used to classify sites as either Typical vegetation bed being studied is American lotus, Nelumbo lutrea (Photo by Mike Henebry). The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 main channel, main channel border, vege- tated main channel border, or side channel habitats. Bacterial cell sizes and numbers in Pool 19 water samples were similar to those found in other freshwater systems. Bacterial populations at vegetated main channel bor- der sites were significantly higher than those at main channel sites. ‘The numbers of bacteria on aquatic plants such as ar- rowhead (Sagittaria) and eelgrass (Vallis- neria) were higher than numbers in the water column and sediments. To compare the total bacterial biomass in vegetated areas of the pool to that in areas without plants, values from the water column, sediments, and on macrophytes were converted to number of grams of car- bon per square meter and then multiplied by the habitat area to yield total biomass as kilograms of bacterial carbon. Although at low flow only 7 percent of the total water ; area in Pool 19 is in the vegetated main channel border habitat, that habitat sup- ported 16 percent of the bacterial biomass. Data suggest that organic matter, pro- duced in the plant beds and processed by bacteria is transported into vegetationless areas via current and wave action. Al- though the vegetated area of Pool 19 is relatively small, the decomposing plant ma- terial and associated bacteria are important sources of carbon and energy (nutrition) for consumers, such as the abundant popu- lations of mayflies (Hexagenia) and finger- nail clams (Musculium) in adjacent main channel border areas without vegetation. Determination of the source of nutrition for the large populations of mayflies and fingernail clams is an important step in explaining the high productivity of pooled reaches of the Mississippi River. This re- search will continue in the summers of 1985 and 1986. Persons desiring individual or additional copies of this publication please write to The Illinois NATURAL Aquatic Plant Research and Management Infestations of aquatic plants in ponds, lakes, and reservoirs in Illinois have in- creased dramatically during the past 30 years, due largely to increased nutrient in- fluxes and the establishment of exotic spe- cies. Concurrently, there has been an in- creased demand for recreational and _ in- dustrial uses of our water resources; these uses may be severely restricted by dense stands of aquatic plants. Therefore, safe, effective, and affordable aquatic plant con- trol technologies are needed. As part of the Aquatic Macrophyte Re- search Program at the Illinois Natural His- tory Survey, Pamela P. ‘Tazik, Michael J. Wiley, and their associates are formulating an effective, ecologically safe, and compre- hensive aquatic plant management pro- eram for Illinois; to do so, the basic biology and ecology of aquatic plants must be un- derstood. As a first step, they have identi- fied the nuisance aquatic plants in Illinois and evaluated the effectiveness of current control methods. Although plants that may reach nuisance propor- Illinois has many aquatic tions, generally a few species cause most of the problems. American elodea (Elodea water milfoil (Myriophyllum Ceratophyllum sum), naiads (Najas spp.) , and pondweeds canadensis ) , spp-), coontail demer- (Potamogeton spp.) are the primary prob- lem plants in Illinois, infesting waters throughout the state. Of the three basic aquatic plant control strategies (chemical, mechanical, and _ bi- ological), the most commonly used in IIli- nois is chemical control. Seasonal control of | ' pondweeds and naiads can usually be ob tained through herbicide application, but Material HISTORY one of the commoner nuisance Potamogeton pondweeds found in Illinois waters (Photo by Wilmer Zehr). SPP., coontail, American elodea, and water mil- foil often are not controlled effectively by herbicide application. Herbicides are ex- pensive and require annual (or sometimes semi-annual) application; they may also be toxic to non-target aquatic organisms with improper application. Mechanical control, such as harvesting, shading chemicals, fertilization, and ben- thic barriers, are used to a limited extent [his appropriate for ponds and small areas of in Illinois. type of control may be lakes and reservoirs, but it is often pro- hibitively expensive if used in a large-scale herbicides. application. Like aquatic me- chanical control methods provide short- term or seasonal control. Biclogical control is not widely used in Illinois, but it holds considerable promise for future application. With biological con- trol. il organisn is ntroduced in this publication may be reprinted if credit is given t inhibit or control the growth of aquatic plants. Herbivorous fish, mammals, inverte- brates, and microorganisms are all possible bio-control agents. Unlike the other avail- able methods, biological control may be ef- fective over many years. The herbivorous grass carp (Ctenopharyngodon idella) 1s the most widely used and studied bio-con- trol agent for aquatic plants. These fish have a tremendous feeding and growth capacity, making them a potent control agent. However, those traits also make them a serious potential pest, especially if they become established in the large rivers where they could reproduce. Consequently, grass carp are illegal currently in Illinois. Two genetic derivatives of the grass carp have been produced since the late 1970’s, the hybrid carp (female grass carp x male bighead carp) and the triploid grass carp (two grass carp parents). Shortly after pro- duction of these fish began, the Illinois Natural History Survey initiated a study to determine: (1) their effectiveness in con- trolling aquatic plants, (2) their reproduc- tive potential, and (3) the environmental impacts associated with their use. That study indicated that neither the hybrid nor the triploid grass carp could reproduce, but only the triploid grass carp retained the plant-eating capabilities of the grass carp. The development of these sterile herbivo- rous carp, particularly the triploid, has made bio-control feasible and acceptable for use in Illinois. Wiley, Tazik, and associ- ates have recommended the legalization of the sterile, triploid grass carp and have de- veloped a computer-implemented model to aid in stocking recommendations. When these fish are legalized, Ilinois citizens will be able to stock the triploid grass carp as an ecologically sage aquatic plant man- agement mechanism. “People” Diseases of Trees Some of the most destructive diseases of trees are caused by humans. In spite of the amount of money and effort used to plant and maintain their trees and shrubs, some persons are unknowingly responsible for the injury and death of their trees. Common person-caused injuries to trees are often related to construction and the building of additions to homes. Construc- tion damage includes (1) actual mechani- cal damage from heavy equipment scarring the trunk and branches and cutting off the roots, (2) causing grade changes by either removing soil or placing soil over the roots, (3) changes in the water table by ditching and draining in developing subdivisions or in homesite developments, and (4) trench- ing and ditching close to established trees that sever large areas of the trees’ root systems. Soil compaction from running heavy equipment over the soil, especially during wet periods of the year, is destructive to both the soil structure and to the roots of the trees. The compacted soil will remain deficient in essential oxygen for proper root respiration, and water will not penetrate a hard soil surface for several months. Grass will do poorly in compacted soil, and trees and shrubs will often die. When the soil is compacted around established trees, a 3- to 4-inch layer of woodchip mulch placed over the root area will help the soil to restructure and become less compacted over a shorter period of time than if reseeded to bluegrass. Any type of cultivation to loosen the compacted soil around established trees will be de- structive to roots that normally develop in the upper 4 to 6 inches of the soil. The more shallow roots are essential to the proper uptake of nutrients and water by most urban tree species. Excessive pruning out of large branches of trees having roots injured during con- struction is not recommended. A profes- sional arborist should be consulted before construction begins, and should be retained to help maintain the trees after construc- tion is completed. Trees can be saved and maintained in a vigorous condition with proper and timely professional advice and care. New Publication on Shorthead Redhorse A multidisciplinary aquatic monitoring program has been conducted in the Kan- kakee River near Wilmington, in an effort to characterize the segment of river near Commonwealth Edison’s intake and dis- charge structures for the Braidwood Sta- tion. The study area includes a variety of habitats including Horse Creek, a small tributary. Different assemblages of fishes populated the various habitat types. The Shorthead redhorse, Moxostoma macrolepidotum, is one of the important and least known river fishes and its biology is detailed in the recently published Bio- logical Notes No. 123, “The Life History of the Shorthead Redhorse, Moxostoma macrolepidotum in the Kankakee River Drainage, Illinois.” The species was studied intensively dur- ing May, August, and November of 1977, 1978, and 1979 and in August of 1981 and 1982. Supplementary collections were made during other ice-free months. The short- head redhorse was a dominant fish in elec- trofishing collections. Large numbers of fish collected in August 1981 were the re- sult of two strong year classes and high water levels that increased the susceptibility of the fish to shoreline electrofishing. Pre- ferred habitats were cobble areas in waters 1-2 m deep with velocities of 23-63 cm/sec. Shorthead redhorse began to gather in a tributary, Horse Creek in early March and spawned in late April and early May. On April 30, 1979, 81 reproducing males and 27 females were collected in Horse Creek. Approximately 3,000 shorthead redhorse were present in a single raceway-riffle area of Horse Creek at that time. Each female produced an average of 18,000 eggs. A low recovery rate of tagged individuals indi- cated extensive movement and dispersion of this species from the monitoring area. The foods eaten, types of Chironomidae (midge larvae) consumed, and a lack of burrowing mayflies in the diet suggested that shorthead redhorse fed in riffles and riffle margins. Copies of this publication may be ob- tained by writing to the Chief of the Illinois Natural History Survey. Hybrid Crappie Study The black and white crappies are two of our most colorful and attractive fishes, and two of the most sought after by anglers. In their classic treatment of Illinois Fishes, Forbes and Richardson (1908) noted that both crappies ranged over all of Illinois, Black and white crappie (Photo by George Bennett). and over much of the eastern U.S. and southern Canada. The white crappie was found abundantly in “lakes, ponds, and bayous,” but were plentiful also in the smaller rivers and creeks. Black crappie shared many of the same waters, but were less abundant generally than the white, showing an affinity for cooler, less turbid waters. Present distributional patterns are similar: the white is common in impound- ments, both large and small; while the black has an irregular distribution in the larger reservoirs and is less common in smaller impoundments. Both may maintain relatively stable populations in large im- poundments, but tend to overpopulate when stocked in small impoundments and farm ponds. Overpopulation leads to stunting and severe competition with bass and bluegill. Many management strategies have been employed, including introduction of forage species to increase the crappie food supply, reduction of crappie numbers by various chemical or mechanical means, and use of large predators such as largemouth bass and northern pike. However, failure to de- velop dependable strategies for small im- poundments has led managers in most of our states to forego the crappies for more manageable species. In Illinois, manage- ment recommendations now exclude crap- pies from farm ponds, and most biologists favor their elimination in all poundments smaller than 250 acres. It is now im- The Illinots NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 recognized, however, that crappies are highly favored by anglers, and that a solu- tion to the problem could increase sportfish harvests in thousands of small impound- ments where crappies are now a problem, or have been excluded. The late W. F. Childers, long-time Sur-_ vey biologist, was probably the first to sug- gest that hybrid crappies might at least minimize the “crappie problem,” and was the first to produce hybrid crappies in the laboratory and to stock them experimen- tally. Childers believed that natural hy- brids occurred widely in Illinois, and that several 4- to 5-pound crappies examined by him were all hybrids. He believed also that hybrid crappies grow faster than either parent, and might be less inclined to over- populate, but he never completed his in- vestigations. Current studies by Survey biologists Ho- mer Buck and Mike Hooe are the first in- volving hybrid crappies since the pioneer work by Childers. The principal studies are being conducted in the laboratory and in earthen ponds at the Sam A. Parr Fisher- ies Research Center near Kinmundy. Ge- netic identities of experimental fish are determined by starch-gel electrophoresis in the Survey fish genetics laboratory super- vised by David Philipp. The basic purpose of the investigation is to evaluate hybrid TORS yoo, No. 248 Illinois Departme June Published monthly ¢« sion of the nt of Eneray and and Conservation Pre p i1red by Se Shirley McClellan with the cond-class postage paid t Irbana. Illinois (USPS of publication: 172 Natural Re urce Building, C Persons desiring individual or xcept in July Natural Res collaboration of the h crappies as sportfish. Half-sibling hybrid and pure stock crappie fry were produced in the laboratory by stripping eggs from a female and fertilizing half with milt from a black crappie, and half with milt from a white crappie. Natural hybrids were pro- duced also in ponds by isolating males of one species with females of the other. Both interspecific F, hybrids have made signifi- cantly faster first-year growths than either parent when sharing the same environ- ments in all populations studied, and pre- liminary analyses indicate that second-year growths by F, hybrids may also be superior to that of either parent. The reciprocal F, hybrids were found to be indistinguishable, and to more closely resemble the black parent than the white. Morphological dif- ferences between the F, hybrids survived in significantly greater numbers than whites when stocked as fry, and F, hybrids and black crappies survived seining, netting, and handling much better than whites. All F, populations examined had 50:50 sex ratios, and a male F, hybrid backcrossed with a white female crappie. Future studies will evaluate later generations of hybrids in terms of growth, fecundity, catchability, and their ability to sustain desirable, fish- able populations in small impoundments also containing desirable populations of largemouth bass and bluegills. ind August by the Natural Histor urces, ope y Survey aq aiyv p rR r the Board of Natural Resources Survey staf npaiar additional copies of this publication please write to NE Y AND NA A £ The Illinois NATURAL SUR ia Fall Food Habits of Mallards in Illinois, 1979-1982 Illinois is a major migration area for waterfowl in the Mississippi Flyway. The last comprehensive study of the food habits of waterfowl during fall migration in IIli- nois was conducted in 1938-1940. Since then, the wetlands and croplands of the Midwest have undergone dramatic changes. During the hunting seasons of 1979- 1982, Survey researchers Stephen P. Hav- era and G. Alan Perkins collected 9,300 mallard gizzards by weekly periods from 48 sites throughout Illinois. Emphasis was placed on the mallard because it comprises approximately 86 percent and 47 percent of waterfowl use in the fall in the Illinois and Mississippi river valleys, respectively, and makes up about 50 percent of the Illi- nois duck harvest. The mallard gizzards were examined to determine (1) the prin- cipal foods used, (2) changes in food habits since 1940, (3) variation of major food items within the state, and (4) varia- tion of food habits within and among years. The researchers identified a variety of food items in the gizzard contents, includ- ing 300 plant species, 65 invertebrate taxa, and one vertebrate group. Examination of food habits indicated that the Illinois River region and Mississippi River region border- ing central Illinois received similar use by mallards of corn (48 percent and 49 per- cent by aggregate volume, respectively). Corn is generally available to mallards as waste grain in agricultural fields or on areas managed for waterfowl. The volumes of moist-soil plant seeds were also similar in gizzards collected from the Illinois River (25 percent) and the Mississippi River (20 HISTORY percent). Moist-soil plants are naturally occurring annual plants that become estab- lished on exposed mud flats during the summer months. were some. striking differences, however, in diets of There mallards using the Mississippi and Illinois river valleys. Man- aged or cultivated agricultural foods, such as buckwheat, Japanese millet, and milo represented 10.5 percent of the diet on the Illinois River as compared with only 1.3 percent for the Mississippi. In contrast, submergent and emergent aquatic plants such as coontail and pondweeds were more prevalent in mallard gizzards from the Mississippi River (10.1 percent) than in those collected the (trace). These differences can be explained by the virtual elimination of aquatic plants from the Illinois River as a result of sedi- from Illinois valley Mallard ducks are pictured migrating through Havana looking for food, usually the gleanings of a corn field (Photo by W. E. Clark). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. mentation and its devastating effects on aquatic communities during the past three decades. The degradation of the aquatic habitat via sedimentation has not been as severe in the Mississippi River. Conse- quently, aquatic plants are still common among mallard diets in the Mississippi River valley, but they have been replaced in the diets of mallards frequenting the II- linois River by cultivated agricultural foods provided on private and public-managed waterfowl] areas. Similar results appeared when the mal- lard food habits from the Illinois River val- ley were compared between 1938-1939 and 1979-1982. During both periods, corn was the leading food item (48 percent during both periods) followed by moist-soil plants (24 percent versus 25 percent, respec- tively). However, the managed agricultural foods of Japanese millet, buckwheat, and milo did not occur in the mallard diets of 1938-1940, whereas aquatic plants repre- sented 15 percent of the diet. In 1979-1982, managed agricultural foods represented 10.5 percent of the diet of mallards, but aquatic plants were essentially non-existent. Migrant mallard populations using the Ilh- nois valley are now heavily dependent upon waste grain and managed foods while in- creasing their body reserves before resum- ing their southward trek toward wintering areas. Analyses of mallard diets also uncovered another interesting finding. Generally the amount of corn in the diet increased dur- ing the fall in most regions of Illinois. For example, the percentage of corn in the diet increased from an average of about 35 percent in late October in the Illinois val- ley to about 65 percent by early December. Corn contains a high percentage of carbo- hydrates and, therefore, is relatively high in energy content, but many natural foods provide similar caloric values. However, a large amount of corn can usually be eaten quickly and satisfy mallards’ energy re- quirements in a short period of time. The late season switch to corn did not occur in the diet of mallards using the confluence region of the Illinois and Mississippi rivers. In the confluence region, seeds of moist- soil plants made up approximately 50 per- cent of the diet throughout the fall, whereas corn consisted of only about 10 percent. Apparently natural vegetation was so abundant in this region that mallards did not utilize corn to the same degree as in other areas of Illinois. This finding might provide some insight into the diet of mallards in mid-latitude migration areas before corn was cultivated in presettlement times. Perhaps corn is replacing acorns and other mast that is no longer available to mallards as it once was in the vast expanse of timber that graced the bottomlands. Tenth Bird Publication Available _“TIlinois Birds: Vireos,” Biological Notes No. 124 published in August, is the most recent publication of the Illinois Natural History Survey. This paper is the tenth in a series on Illinois birds written by Jean W. Graber, Richard R. Graber, and Ethelyn L. Kirk. In some other reports in the series, Richard R. Graber was the senior author. According to the authors, seven species of the Vireo family occur in Illinois, one —the Philadelphia — only as a transient in spring and fall. Another species — the solitary vireo—has been found nesting only at Sand Ridge State Forest and occurs _ ILLINOIS BIRDS: VIREOS Jean W. Graber, Richard R. Graber, and Ethelyn L. Kirk i Winois Natural History Survey Champaign, linois - August 1985 State of tiners Department of Energy and Natural Resources Natural History Survey Division Serological Notes No 12 Tenth bird publication in a series by the Grabers and Ethelyn L. Kirk. in the state primarily as a transient. The other five species nest regularly in Illinois and occur also as migrants. They are the white-eyed vireo, Bell’s vireo, yellow- throated vireo, the warbling vireo, and the red-eyed vireo. As in the earlier bird Biological Notes, the emphasis is on population dynamics and habitat relationships, not their taxo- nomy. Where no authority is cited for a record, the record is the Grabers’. Sexual dimorphism in plumage is essentiallly lack- ing in vireos, and reference to sex in the field observations are based on behavior, especially singing. The paper discusses not only the distri- bution of the various species in I]linois, but also maps their general distribution in the United States. Other data include informa- tion about egg laying and migration sea- sons, nesting habits, food preferences, and phonetic interpretations of the birds’ song. The excellent photography was done chiefly by the authors and shows close-ups of most of the birds on their nests. Books included in the series are Biologi- cal Notes No. 68, 1970, “Illinois Birds: Mimidae”; Biological Notes No. 75, 1971, “Tllinois Birds: Turidae”’; Biological Notes No. 80, 1972, “Illinois Birds: Hirundini- dae”; Biological Notes No. 83, 1973, “Il- linois Birds: Laniidae”; Biological Notes No. 86, 1974, “Illinois Birds: Tyrannidae” ; Biological Notes No. 102, 1977, “Illinois Birds: Picidae’’; Biological Notes No. 109, 1978, “Illinois Birds: Ciconiiformes”; Bio- logical Notes No. 110, 1979, “Illinois Birds: Syviidae”; and Biological Notes No. 118, 1983, “Illinois Birds: Wood Warblers.” These publications are available upon request to Chief Paul Risser, Illinois Natu- ral History Survey, 607 East Drive, Champaign, Illinois 61820. Peabc dy Forest Caterpillars Notodontid caterpillars feed almost ex- clusively on the foliage of broad-leafed shrubs and trees in natural and maintained settings. Several species, including the vari- able oakleaf caterpillar (Lochmaeus man- teo), redhumped oak worm (Symmerista albifrons), walnut caterpillar (Datana in- Last larval stage of Ellida caniplaga following moult (left) and 32 hours later (right) (Photos by G. L. Godfrey). The Illinovs NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 tegerrima), and saddled prominent cater- pillar (Heterocampa guttivitta) are not- able defoliators. As leaf eaters, notodontids are well adapted to an arboreal habitat and have some very interesting ways of avoid- ing would-be predators and parasitoids. These include chemical (some species are- capable of spraying formic acid), physical (synchronized head and tail jerking by gregarious species), and cryptic (resem- blance of whole, partly eaten, twisted, or tattered leaves) defenses. During the course of larval development, i.e., the growing and moulting process, some notodontids exhibit remarkable changes in body shape and/or coloration. wo exam- ples of this are illustrated by Heterocampa obliqua which feeds on various species of oak, especially white oak and burr oak, and Ellida caniplaga which occurs on basswood. The first larval stage of Heterocampa obliqua is adorned with branched, antler- like tubercles and is nearly solidly colored. The “antlers” disappear after the first moult, and the subsequent larval stages are evenly contoured and distinctly patterned. There virtually are no clues to indicate that the latter larval stages represent the same species as does the first stage. Ellida caniplaga maintains the same basic body shape during successive larval stages but undergoes a distinct intensification of col- oration during the first 24-32 hours after moulting into the last stage. There is a basic change in the feeding behavior associated with larval develop- ment. Entomologists have long known that an early stage notodontid caterpillar skele- tonizes the leaf on which it feeds (it eats into the flat surface of the leaf blade, re- moving soft tissues and leaving the veinlets and veins), but that an older caterpillar moves to the leaf’s edge where it removes strips of tissue. Survey entomologist, George L. Godfrey, is showing that this switch is correlated with a change in the adaptive design of the mandible. The mandibles of the more advanced stages are smooth and are used for clipping. The loss of teeth is not attributable to wear. The basic purpose of Godfrey’s study of the developmental morphology and_ the feeding behavior of notodontid caterpillars is an attempt to understand more clearly the phylogenetic relationships among the notodontid species and between them and the related noctuids (armyworms, cut- worms, and green fruitworms). This work is being done in collaboration with fellow Survey entomologist, James E. Appleby, to enhance the recognition of all larval stages for selected notodontid species during the development of management programs for Illinois forest insect pests. Persons desiring individual or additional copies of this publication please write to The Illinois NATURAL Des Plaines River Microorganisms Since the passage and enforcement of laws regulating point sources of pollution (e.g., power plant effluents and discharges from sewage treatment plants), contami- nation of many rivers and streams in IIli- nois has been reduced. However, because of numerous nonpoint sources of pollution (e.g., topsoil runoff from agriculture and road construction) , habitats for plants and animals have not been restored and the variety of native species found in our water- ways has decreased. The Des Plaines River and its natural floodplain in the Lake County Forest Preserve in northern Illinois provide good examples of relatively “clean” habitats that are degraded stream channelization and excessive silta- tion. In spring 1985, the Des Plaines River Wetlands Demonstration Project was initi- ated by Dr. Donald Hey of Wetlands Re- search, Inc., to determine if the diversity of plants and animals could be enhanced by re-creating a wet prairie habitat along the because of Two researchers gather samples from the Des Plaines River (Photo by Virginia Henebry). REPORTS. HISTORY river, reducing the river’s silt load, and increasing the diversity of aquatic and ter- The Des River will be diverted through a series of restored restrial habitats. Plaines marshy wetlands, which should remove much of the silt load. The clarified water from the experimental wetlands will then flow through two quarry lakes to increase their nutrient supply, and ultimately in- crease fish production. As part of a multi-disciplinary team, Michael Robert Aquatic Biology Section, collected baseline Henebry and Gordon, data on the microbial populations (algae, bacteria, and Protozoa) in the Des Plaines River, the quarry lakes, to help determine if the site its associated wetlands, and is now receiving sewage or other forms of organic pollution. Bacterial types, numbers, and biomass in water column samples were comparable to those found in silt-laden, but otherwise un- polluted, sites. The variety and total num- bers of Protozoa, which feed on bacteria, were also low. The number of algal species and the population abundance of algae in the river and quarry lakes were well within the range expected for heavily silted rivers or unproductive lakes. Algal populations at the river sites were probably limited by light penetration through high levels of suspended solids. In quarry lakes, where water turbidity was low, algal abundance was significantly higher but was still limited by low nutrient levels. The production of algae in both the river and quarry lakes was too low to provide an adequate base higher organisms, such as for abundant fish. Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. In summary, there was no microbiolog- ical evidence of significant amounts of sew- age pollution or organic enrichment at the project site. On the basis of indicator bac- teria and total microbial populations, both the Des Plaines River and the quarry lakes were relatively unpolluted and unproduc- tive. The abundance and variety of bacteria, algae, and Protozoa is expected to increase in the proposed experimental wetland areas because of increased retention of nutrients and improved water clarity. The wetland plants will also act as attachment sites for microorganisms; this additional periphyton colonization and primary production should result in the production of important fish species. Catalogs, Life Histories, and Bibliographies In a dedicated effort to enable the citi- zens of Illinois to make the best possible use of its natural resources, the Illinois Natural History Survey conducts a wide variety of research projects related to the biological populations and ecosystems of the state. Much of this research is of a rather specialized nature and deals with sophisticated laboratory equipment, exotic field measuring devices, or complex theo- retical and analytical techniques. Examples might include the tracking of migrating insects with radar or computer simulation models connecting fish behavior with telem- etry data on dissolved oxygen levels in streams. However, one of the unique features of the Survey is its long-term run of biological and ecological processes. ‘This has resulted in many publications which are definitive benchmarks on the plants and animals of the state and future evaluations of the natural resources will be based on these fundamental life-history studies. Since the early years of its 127-year exis- tence, the Survey has made extensive stud- ies of the Illinois flora and fauna which are probably better known than in any other state. Much of the resulting knowl- edge has been offered in life-history studies, catalogs, and bibliographies which con- veniently organize information about spe- cies and habitats. CATALOGS AND LIFE HISTORY STUDIES — VERTEBRATES Amphibians and reptiles (Smith 1961) Birds (Ridgeway 1881, 1889, 1895) Ciconiiformes (Graber, Graber, and Kirk 1978) Ducks, geese, and swans (Bellrose 1976) Geese (Hanson and Jones 1976) Hirundinidae (Graber, Graber, and Kirk 1972) Lanidae (Graber, Graber, and Kirk 1973) Mimidae (Graber, Graber, and Kirk 1970) Mourning dove (Hanson and Kossack 1963) Picidae (Graber, Graber, and Kirk 1977) Pheasants (Labisky 1975), (Warner 1981) Prairie-chicken (Yeatter 1943), (Weste- meier 1980) Prothonotary warbler (Loucks 1894) Sylviidae (Graber, Graber, and Kirk ISS) Tyrannidae (Graber, Graber, and Kirk 1974) Turdidae (Graber, Graber, and Kirk ISNA) Vireos (Graber, Graber, and Kirk 1985) Wood warbler (Graber, Graber, and Kirk 1983) Cottontail rabbit (Lord 1963) Fish Bantam sunfish (Burr 1977) Blackside darter (Thomas 1970) Cavefish (Smith and Welch 1978) Cypress darter (Burr and Page 1978) Darters (Page 1983) Dusky darter (Page and Smith 1970) Fishes (Jordan 1878), (Forbes and Richardson 1920) , (O’Donnell 1935), and (Smith 1979) Knothead carp (Thompson 1928) Least darter (Burr and Page 1979) Logsperch (Thomas 1970) Mud darter (Cummings, Grady, and Burr 1984) River darter (Thomas 1970) Shorthead redhorse (Sule and Skelly 1984) Slabrock darter (Page and Burr 1976) 7 -_=ewia en Se oo ee EE Some publications of Survey scientists (Photo by Les Woodrum). Slenderhead darter (Thomas 1970), (Page and Smith 1971) Slough darter (Braasch and Smith 1967) Spottail darter (Page 1974) Stripetail darter (Page 1975) Warmouth (Larimore 1957) White crappie (Hansen 1951) Fox and gray squirrels (Brown and Yeager 1945) Mammals (Hoffmeister and Mohr 1957) Reptiles and amphibians (Garman 1892) White-tailed deer (Pietsch 1954) CATALOGS AND LIFE HISTORY STUDIES — INVERTEBRATES Agromzidae (Mulloch 1921) Ants (Ross, Rotramel, and LaBerge 1971) Bees (Schrader and LaBerge 1978) Butterflies (Irwin and Downey 1973) Caddisflies (Ross 1944) Crayfishes and shrimps (Page 1985) Damsel flies (Garman 1917) Dermoptera and Orthoptera (Hebard 1934) Dragonflies (Needham and Hart 1901) Hirudinea (Moore 1901) Jassidae (Woodworth 1887 ) Land snail (Baker 1939) Leafhoppers (DeLong 1948) Mosquitos (Ross 1947) Mayflies (Burks 1953) Molluscs (Baker 1906) Oribatoidea (Ewing 1909) Orthoptera (Thomas 1876 Pentatomoidea (Hart 1919) Plant bugs (Knight 1941) Plant lice (Hottes and Frison 1931 ) Pseudoscorpions (Hoff 1949) Scorpionflies (Webb, Penny, and Marlin 1975) Soybean insects (Kogan and Kuhlman 1982) Soybean spiders (LeSar and Unzicker 1978) Stoneflies (Frison 1935) True flies (Pechuman, Webb, and Tesky 1983) Treehoppers (Goding 1894) Terevidae (Irwin and Lyneborg 1980) Thrips (Stannard 1968) LIFE HISTORY STUDIES — PLANTS AND VEGETATION Plants Drug plants (Tehon 1951) Filmy fern (Evers 1961) Fungi (Burrill 1876, 1885) Mosses, liverworts, and lichens (Wolf and Hall 1878) Native and naturalized trees (Miller and Tehon 1929) Native shrubs (Tehon 1942) Plankton (Kofoid 1897, 1898, 1899, 1903, and 1908) Trees (Carter 1955, 1966) Wildflowers (Survey 1936) Vegetation Forest survey (Miller 1923), (Chapman and Miller 1924), (Telford 1926) Hill prairies (Evers 1955) Prairie (Sampson 1921) Sand areas (Hart and Gleason 1907) BIBLIOGRAPHIES — INVERTEBRATES Alfalfa weevil (Wood, Armbrust, Bartell, and Irwin 1978) Bean leaf beetles (Nichols, Kogan, and Waldbauer 1974) Bollworm, earworm, and fruitworm and budworm (Kogan, Sell, Stinner, Bradley and Kogan 1978) Crucifer weevil (Bouseman, Irwin, and Eastman 1978) The Illinots {TURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 Egyptian alfalfa weevil (Wood, Armbrust, Bartell, and Irwin 1978) Green stink bug (DeWitt and Godfrey 1972) Mexican bean beetles (Nichols and Kogan 1972) Northern and western corn rootworm (Irwin 1977) Northern and western corn rootworm (Luckmann, Chiang, Ortman, and Nichols 1974) Pea aphid (Harper, Miska, Manelitz, Irwin, and Armbrust 1978) Pinewood nematode (Kogan, Appleby, and Bouseman 1982) Pod borers (Qu and Kogan 1984) Potato leafhopper (Gyrisco, Landman, York, Irwin, and Armbrust 1978) Spotted alfalfa weevil (Davis, Nichols, and Armbrust 1974) Velvetbean caterpillar (Ford, Strayer, Reid, and Godfrey 1975) Weevil species (Morrison, Pass, Nichols, and Armbrust 1974) BIBLIOGRAPHIES — VERTEBRATES Fur animals (Yeager 1941) Herpetological literature (Morris, Funk, and Smith 1983) BIBLIOGRAPHIES — PLANTS AND VEGETATION Bryophytes (McKnight 1986) Vegetation (Risser 1984) Recent Survey Publications Godfrey, George, Chairman; John Bouseman, William Edwards, Kenneth Robertson, and Robert Zewadski, Eds. 125 years of biological research 1858-1983: A sym- posium. Proceedings of the 125th Anniversary Symposium of the Illinois Natural History Survey. Bulletin 33, Article 3, August 1985. p. 139-334. Graber, Richard R., Jean W. Graber, and Ethelyn L. Kirk. 1985. Illinois birds: Vireos. Illinois Natural History Survey Biological Notes No. 124. 38 p. Page, Lawrence M. 1985. The crayfishes and shrimps (Decapoda) of Illinois. Illinois Natural History Survey Bulletin, Vol. 33, Art. 4. p. 335-448. Persons desiring individual or additional copies of this publication please write to The Illinows NATURAL SURVEY Smelt Fishing in Lake Michigan Rainbow smelt (Osmerus mordax) sup- port a lively, if brief, sport fishery along the Illinois shoreline each spring. On almost any Saturday evening in April, over 1,000 smelt fishermen may crowd Montrose Har- bor and the immediate vicinity, while another 5,000 may use other sites along the shoreline of Lake and Cook counties. Most fishermen use gill nets — curtains of netting designed to entangle the gill covers of the small silvery fish as they swim along the shore seeking places to spawn. Smelt are anadromous. The ocean-dwelling populations spawning into freshwater tributaries along northern coastlines of North America, Eu- rope, and Asia. In Lake Michigan, smelt are vulnerable to shore fishermen in spring adults of migrate for as they swim into the tributary streams or shallow areas to spawn. In Illinois, where tributary nonexistent and sheltered shallows are rare, the fate of eggs is unknown. In other states bordering streams are largely AKAs Me heeded Ss feeedegize 4a, HISTORY. NOVEMBER Lake Michigan, mature smelt go upstream at night, deposit their eggs, and retreat downstream the following morning. Fertile eggs hatch in 10-30 days and the fry drift downstream into the lake. During the spawning catch hundreds of ing over 50 smelt per net per hour. One party of five fishermen this spring landed peak, anglers may f fish each night, averag- over 1,000 smelt in approximately 2 hours on a Sunday night. However, the catch is unpredictable; the following Saturday, the catch rate fish per net per hour for all fishermen interviewed. was less than one During the spawning run of 1985, Wil- liam H. the Aquatic Biology Section, with support from the Illinois Department of Conservation, conducted a creel of the smelt fishery. Fish- ing activity was assessed on 10 nights and Horns and his assistants in 749 smelt fishermen were interviewed to determine the economic importance of the fishery. Each fisherman was asked how much he or she spent on food, gear, and > aS \ WiWlalee se sai) ay ee ZF THT 44 Wee ——* RARE _ The rainbow smelt is usually a green-gray color with a silvery bottom (Original drawing by Craig Ronto). Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. transportation for the present trip. The average reported expenditure was $6.00. It was estimated from the nightly head counts that Illinois residents made 70,000 trips to Lake Michigan to fish for smelt, for an estimated total seasonal expenditure of $420,000. Smelt were introduced inadvertently into Lake Michigan sometime between 1912 and 1923 and the population has fluctu- ated widely since then. The seed stock for Lake Michigan smelt probably was derived from the freshwater population native to Green Lake, Maine. The smelt that colon- ized Lake Michigan migrated from Crystal Lake, Michigan, where smelt were stocked in 1912 as forage for the introduced Atlan- tic salmon. The first smelt found in Lake ~ Michigan was captured in 1923. By 1936, smelt could be found throughout the lake. The commercial harvest of smelt has varied widely in Lake Michigan, reaching a peak of 9.1 million pounds in 1958. In Illinois today the harvest of smelt by com- mercial fishermen is negligible. Smelt have often been blamed for the decline of lake herring in Lake Michigan. Although smelt will eat lake herring fry and the life histories and spatial distribu- tions of the two species would permit pre- dation, the evidence against smelt is only Scanning electron microscope photo of hyphae of a canker fungus in xylem vessels of healthy white birch, showing a hole in the cell wall of a burst hyphal tip (Photo by J. M. McPartland). circumstantial and may be confused by other factors, such as human exploitation and rapid expansion of alewife populations several years ago. Dramatic fluctuations of other Lake Michigan fish populations in- cluding sea lampreys, lake trout, yellow perch, and emerald shiners, have also oc- curred in this century. Smelt may be assuming a position of greater importance in the diet of salmonids in southern Lake Michigan. For many years, alewives have comprised the bulk of the diets of chinook salmon, coho salmon, and lake trout. However, with the recent declines in alewife populations, smelt are being consumed at higher rates and may become an important food for salmon and trout populations in Lake Michigan. Enzymes Versus Fungi? Fungi that cause plant diseases com- monly enter resistant and susceptible host plants with equal frequency, but are un- able to attack and damage resistant hosts. However, even resistant plants may be- come susceptible to fungal attack if they are weakened by environmental stresses. Many of the stem cankers and root rots of trees and shrubs appear following drought periods or after plants are subjected to freezing stresses during the winter. The mechanisms involved in disaster re- sistance have been studied intensively over many years, yet we understand little about how these mechanisms operate. In most cases, resistance is an active metabolic re- sponse of the plant to infection. Some plants produce compounds called phyto- alexins, which inhibit fungal growth, while others produce enzymes or toxic com- pounds that kill fungi. Nearly all of our knowledge on disease resistance mech- anisms comes from research on crop plants. How trees and shrubs resist attack by pathogens has not received much attention by researchers. In a recent study on the influence of en- vironmental stresses on stem canker dis- eases of woody plants, Survey plant pathol- ogists D. F. Schoeneweiss and J. M. Mc- Partland used a scanning electron micro- scope (SEM) to examine the morphology of canker fungi in healthy and drought- stressed stems of white birch. At this ex- Orconectes stannardi, one of the two species of cray- fish endemic to Illinois, occurs only in the Little Wabash River system (Photo by Lawrence Page). tremely high magnification, the SEM re- vealed interesting surface structures of fun- gal hyphae. A high percentage of the hy- phal tips, which are the growing points of fungal hyphae, were swollen and burst in healthy stem tissue, while those in stressed stems appeared normal. A closer examina- tion revealed distinct holes in the cell wails of burst hyphal tips, indicating possible enzyme degradation of the cell walls. Enzymes that lyse or degrade cell walls of fungi are known to be present in for- est trees and it has been hypothesized that these enzymes serve a disease-resistant mechanism against fungal attack. Results of research at the Survey support this hy- pothesis. When and how these enzymes are produced and the effect of environmental stresses on these processes are questions that will require additional research to answer. The Crayfishes and Shrimps (Decapoda) of Illinois The first article in the first volume of the Bulletin of the Illinois Museum of Nat- ural History (which later became the Illi- nois Natural History Survey) was an an- notated list of the Crustacea of Illinois. It was written by Stephen A. Forbes, the first Chief of the Survey, and noted the pres- ence in Illinois of nine species of decapods (crayfishes and shrimps). Little research on the systematics and distribution of these organisms was published subsequently to that early report, although two unpub- lished theses on the ecology and distribu- tion of crayfishes were completed at the University of Illinois (in 1912 and 1955). The recently published “The Crayfishes and Shrimps (Decapods) of Illinois” (Illi- nois Natural History Survey Bulletin 33 (4) :335-448) was based on collections made at 1,294 localities in Illinois between 1972 and 1982, and raises to 23 the num- ber of decapod species known in the state. Although Illinois decapods constitute a group of only 23 species, they often are present in large populations, are among our largest aquatic invertebrates, and exert an important influence on the ecology of Illinois streams and lakes. The greatest diversity of crayfishes and shrimps in Illinois occurs in the extreme southern part of the state. Seventeen of the 23 species in Illinois can be found in the Shawnee Hills and on the Coastal Plain; 10 species are restricted to this area. Two crayfishes, Orconectes illinoiensis and O. stannardi, occur only in IIlinois. Two species known historically in Illi- nois appear now to be extirpated. One of them, the crayfish Cambacus robustus, may have disappeared naturally rather than be- cause of man-induced changes in the en- vironment. Our earliest records indicate that C. robustuswar is relict in Illinois, pre- sumably having been reduced from a more widespread distribution to small areas near Quincy (found in 1885) and Decatur (1912). Elsewhere in the U.S. and Can- ada, it inhabits cool to cold streams. It apparently was reduced in warm postgla- cial Illinois to small populations that sub- sequently were unable to perpetuate them- selves. The other species, the shrimp Mac- robrachium ohione, probably disappeared because of the extensive modification and degradation of Illinois’ largest rivers. Four other species appear now to be in grave The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 danger of extirpation and have been rec- ommended for inclusion on Illinois’ List of Endangered and Threatened Species. The most recent addition to the Illinois fauna is a crayfish (Orconectes rusticus) native to southern Ohio and northern Ken- tucky but now distributed widely outside its native range through its extensive use as fish bait. It has become established in several streams in northeastern Illinois and near Peoria. Once introduced, this species usually displaces native species and ex- pands its range, apparently because it is a large and aggressive species able to survive in disturbed habitats. Because it displaces native species and is a vigorous consumer ~ of aquatic vegetation, its continued use as bait in Illinois should be discouraged. “The Crayfishes and Shrimps (Deca- poda) of Illinois,’ by Survey zoologist L. M. Page, describes the appearance of each species, discusses its distribution, both within and outside Illinois, describes char- acteristics of its habitat, its diet and its re- productive cycle. This publication, which may be obtained by writing to the Chief, INHS, is the latest in the Survey’s series of reports on the biota of Illinois. November 1985, No. 251. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conservation. Prepared by members of the Survey staff and edited by Shirley McClellan. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, ILLINOIS 61820. The Illinovs NATURAL URVEY A Directory of Systematists and Ecologists in Ilinois A data base of systematists and ecologists that live and/or work in Illinois has been compiled by scientists of the [lnois Natu- ral History Survey. A Directory of Illinois Systematists and Ecologists will be pub- lished early in 1986 with partial financial support from the Illinois Department of Transportation, Bureau of Location and Environment. The ongoing project is under the direction of Kenneth R. Robertson, with Philip J. Burton and Bill N. Mc- Knight (all of the Survey’s Section of Botany and Plant Pathology) doing the data computerization and summarization. Illinois is fortunate in having a large number of biological systematists and ecol- ogists affiliated with colleges, universities, museums, botanical and zoological gar- dens, private companies, and governmental agencies. While a number of professional societies have membership lists, there has been no single source that gives addresses, telephone numbers, and areas of expertise for this group of scientists in Illinois. Systematists study the classification and evolutionary relationships of organisms, while ecologists study the interactions of organisms with their biotic and abiotic en- vironments. Systematists and ecologists generally share common interests in the evolutionary history and dynamics of or- ganisms and in the conservation of thei both groups of scientists include field biologists existing populations. In addition, well versed in the taxonomic identification of organisms and the estimation of pop- ulation and _ habitat Because of increased environmental aware- S1ZeS requirements. HISTORY ness, the practical skills of this group of re- searchers are in high demand for use in en- vironmental impact statements, natural area inventory and management, agricul- tural and forestry management, and for public education. Information for the directory was ob- tained from a questionnaire that was mailed to more than 800 persons in January 1984. All responses (435) received by December 198: files. The directory includes a summary of have been entered into computer responses to all questions and is organized alphabetically by name. Separate indices have been prepared for broad groups of organisms studied, systematic techniques used, and ecological interests, as well as for specific geographical place-names and key words denoting areas of taxonomic and eco- logical expertise. The indexing system allows complete cross tabulation of chosen response categories and/or key words. Both the data base and the published directory will be updated periodically to keep them current. Working scientists should find the directory handy as an address book of colleagues, and others are expected to use it as a re- source book to locate systematists and ecol- ogists with specific areas of expertise. Many interesting features of this segment of the biological research community be- came apparent while summarizing the in- formation supplied by respondents. For ex- ample, almost all respondents (96.5% within the 111 re- (79 respondents listed Illinois as their address: state, Urbana-Champaign (with spondents) and Chicago have the largest number of respondents. Half of the respondents (49.1% ated with colleges and universities. are affili- while Material in this publication may be reprinted if credit is given to the Illinois Natural History Survey. 100 90 Activity Key 80 60 of Time 50 40 20 Eas ZZ tov 30 Bas 10 Academia Natural History Survey L, YY, Y; | | Aki : Other Museums Others Overa Government and Average Agencies Gardens Institutional Category A Directory of Illinois Systematists and Ecologists includes summaries of the time commitments (shown he:e by affiliation) and research interests of this group of scientists in Illinois (graph drawn by Phil Burton and Bill McKnight). the remainder are approximately evenly distributed among the Illinois Natural His- tory Survey (14.2%), other state, federal (14.0%), mu- seums, arboreta, parks, gardens, and zoos (11.6%), and others (11.1%). Differences in time-allocation among re- and municipal agencies spondents were some of the most interesting results summarized from the biographical data presented here in a graph by two of the authors (see above). A total of 386 respondents (89.8%) re- ported having a bachelor’s degree, 323 (75.1%) have or are working on a master’s degree, and 290 respondents (67.4%) have or are working on a doctoral degree. These figures are indicative of the long period of training and post-graduate work generally required to be a practicing systematist or ecologist. Of the 1,013 college degrees re- ported by respondents, a total of 345 (34.1%) were awarded by Lllinois colleges The bachelor’s degree was 1965, 1969 for a mas- or universities. average year for a ter’s degree, and 1971 for a doctorate. On the average, respondents have been with their organizations since 1973, indicating resident an experienced contingent of oe 5 D1 |i FISTS. All individuals included in the directory will receive a copy, while other interested persons may obtain single copies of this Special Publication 3 free of charge from the Office of the Chief, Illinois Natural History Survey (address at the end of this publication). Sediment Contamination in Waukegan Harbor Waukegan, situated in northeastern IIli- nois 36 miles north of Chicago and 8 miles south of the Wisconsin border, is one of the state’s primary Lake Michigan ports. Wau- kegan Harbor handles commercial ship- ping, serves as a base for chartered fishing boat excursions, and is a major center for pleasure craft. Since 1975 the harbor has been identified as a site of serious con- tamination by polychlorinated biphenyls (PG@B's). PCB’s are a family of synthetic organic compounds with high heat capacity, low electrical conductivity, and strong resistance to oxidation and vaporization. They were used as insulating material for electrical transformers and capacitors, and as a heat- absorbing medium in the cooling phase of metal casting processes. PCB’s are very stable molecules, tending to persist for many years if released into the environ- ment. While not very soluble in water, they are highly soluble in lipids and oils, per- mitting them to accumulate in fatty tissues. Tissue concentrations of PCB’s are magni- fied as they move up the food chain, and laboratory studies have linked them to liver cancer in rats, infertility in rhesus monkeys, and stomach nodules in dogs. In 1979 the United States Environ- mental Protection Agency (USEPA) ex- pressed concern about human health risks from consuming fish caught near Wauke- gan. Preliminary studies showed high PCB concentration in sediments at many loca- tions in Waukegan Harbor and in 1981 a clean-up program was proposed. Since that time a lengthy series of litigations between USEPA and Outboard Marine Corpora- tion (OMC) has forestalled any remedial action. The situation is complicated by the fact that accumulating sediments have re- duced water depths in some locations to the point where navigation is limited. The ex- tensive dredging operations required to cor- rect this would create further environmen- tal problems. A team of State Survey scientists has been formed recently to answer some ques- Harbor Henebry tions concerning the Waukegan PCB Michael Philippe Ross, both in the Aquatic Biology Section of the Natural History Survey, and J. Bruno Risatti, in the Geochemistry Sec- problem. and tion of the State Geological Survey, have re- ceived a grant from the State Department of Energy and Natural Resources (DENR), through the Hazardous Waste Research (HWRIC), for the “Assessment of Ecotoxicological Hazard of Waukegan Harbor Sediments.” and Information Center One of their objectives is a thorough sampling and mapping of the area to de- termine the extent of the contamination problem. PCB concentrations in sediments. benthic organisms, and fish will be mea- sured. These results will be especially use- ful because many data files from prelimi- nary studies have been legally sequestered pending the outcome of the judicial process. Using a process known as elutriation, the research team will simulate the effect of dredging operations on the release of PCB’s and other contaminants from the sediments into the water column. A series of toxi- cological tests will help estimate risks to An aerial view of the Waukegan harbor. Lake Michigan is to the east (photo courtesy D. Caplice, USEPA). The Illinois NATURAL HISTORY SURVEY DEPARTMENT OF ENERGY AND NATURAL RESOURCES NATURAL RESOURCES BUILDING 607 EAST PEABODY DRIVE CHAMPAIGN, ILLINOIS 61820 aquatic life. These tests will measure mor- tality and growth rates for zooplankton and nematodes, sublethal effects on meta- bolic processes of bacteria and algae, and mutagenesis in bacteria. Another series of tests will look at the effects of exposure to Waukegan Harbor water on aquatic protozoan communities. Artificial substrates made of polyurethane foam blocks will be used to collect proto- zoans at a relatively “clean” site in Lake Michigan. Some of these colonized sub- strates will then be transferred to sites in the harbor, and the number of different species and their population densities will be measured over different time intervals and compared with substrates remaining at the clean site. Recent work on PCB’s in sediments sug- gests that anaerobic bacteria may declori- nate PCB’s and utilize these compounds as a source of materials for growth. This pro- cess, which could help alleviate the con- tamination problem in Waukegan Harbor, is being studied in two ways. First, intact sediment cores are taken back to the labora- tory where PCB breakdown rates from specific sites are determined by analyzing PCB concentrations in sediments that have been incubated at different temperatures for various periods of time. Overall bac- terial activity in the sediments containing PCB’s will be correlated with methane pro- duction. In this way the possibilities for natural breakdown can be estimated. Sec- ond, the feasibility of introducing other bacterial species to accelerate the break- down process will be assessed. If sediments in Waukegan Harbor and other contami- nated sites could be “seeded” with PCB- degrading organisms (which would then die off when no more PCB’s remained), this would be an exciting development in environmental waste management. December 1985, No. 252. Published monthly except in July and August by the Natural History Survey, a division of the Illinois Department of Energy and Natural Resources, operating under the Board of Natural Resources and Conseryation. Prepared by members of the Survey staff and edited by Shirley McClellan. Second-class postage paid at Urbana, Illinois. (USPS 258-220) Office of publication: 172 Natural Resources Building, Champaign, Illinois. Persons desiring individual or additional copies of this publication please write to DR. PAUL G. RISSER, CHIEF, ILLINOIS NATURAL HISTORY SURVEY, DEPARTMENT OF ENERGY AND NATURAL RESOURCES, NATURAL RESOURCES BUILDING, 607 EAST PEABODY DRIVE, CHAMPAIGN, ILLINOIS 61820. . iva Th pee Leth y ~WIGe Hi? ra x Pad MN eee Te ; We 4 Pi CEA, } s , ; : =) ES a ee / a f ’ wT) “* 7 Na i " ore .. WwW; pa jy ae se @ ‘ > ae LS : 7 a Lis 0 Me i } yo vA : . -, - 1 ie pacer . i 7 — Depa pm aap! | 24 " « 2 oa 7 = a » he lhe oy wn EY an ig tog, Si wey : te - eptblivs:’. oe — 7 ay - ; 7 7 : Sp a oe SSSAEEN