Aiba HNL th ee : a i ete v4 nh Phas i ey pats athe ul Hatt cs wy Hatchet fe aria Nines oe hl added peas tare Mot u i ti ae ce f abit ae iota TM oe Bauer rie Hy eat tt 4 bi tae rN a its hy aries eT ALT ia WE a eteh dt ilook sta) " rH MUTT Nba itd + ist le’ ~~ aia i] Hata setae a } “4 Hi Het ’ SURVEY Digitized by the Internet Archive in 2010 with funding from University of Illinois Urbana-Champaign http://www.archive.org/details/controlofroundhe40chan S.C CHANDLER _ P. FLINT ILLINOIS NATURAL HISTORY SURVEY SAE SVN ID, OMe Ue NCO} MSS Dwight H. Green, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Frank G. Thompson, Director Control of Reundheaded Apple Tree Borer Sy (Gh iS delve ID sl oat Winks Erne Printed by Authority of the State of Illinois NATURAL HISTORY SURVEY DIVISION Theodore H. Frison, Chief Circular 40 THE LUybanap= +; April 1942 NADp 1 “NALD OF oe OU it STATE-OF PLLINOTS Dwicut H. Green, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Frank G. Tuompson, Director BOARD OF NATURAL RESOURCES AND CONSERVATION Frank G. THompson, Chairman WiviiaM TRELEASE, D.Sc., LL.D., Biology Artuur Cutts WILLARD, D.Eng., LL.D., Ezra J. Kraus, Ph.D., D.Sc., Forestry President of the University of Illinois L. R. Howson, B.S.C.E., C.E., Engineering. | Epson S. Bastin, Ph.D., Geology Rocer Apams, Ph.D., D.Sc., Chemistry NATURAL HISTORY SURVEY DIVISION Urbana, Illinois SCIENTIFIC AND TECHNICAL STAFF Tueopore H. Frison, Ph.D., Chief Section of Economic Entomology Section of Aquatic Biology W. P. Fuint, B.S., Chief Entomologist C. C. Compton, Ph.D., Associate Ento- mologist M. D. Farrar, Ph.D., Research Ento- mologist J. H. Biccer, B.S., Associate Entomolo- 15st. 5.°C. CHANDLER, B.S., Southern Field Entomologist L. H. SuHropsuire, M.S., Northern Field Entomologist B. G. Bercer, M.A., Assistant Ento- mologist H. B. Petry, Jr., B.A., Assistant, Ento- mology Extension J. E. Porter, B.A., Entomological Assist- ant C. J. Weinman, Ph.D., Research Fellow in Entomology Georce F. Lupvik, B.A., Research Fellow in Entomology J. M. Macner, B.A., Funior Entomolo- gist (U.S.B.E.P.2. and Commodity Credit Corporation, cooperating) Section of Insect Survey H. H. Ross, Ph.D., Systematic Entomolo- gist Cart O. Monr, Ph.D., Associate Ento- mologist, Artist B. D. Burks, Ph.D., Assistant Entomolo- gist G. T. Riecet, M.S., Entomological Assist- ant Katuryn M. SomMErMAN, M.S., Artist, Entomological Assistant Section of Forestry James E. Davis, M.F., Extension Forester Lee E. Yeacer, Ph.D., Forester Davin H. Tuompson, Ph.D., Zoologist Georce W. Bennett, Ph.D., Limnolo- gist D. F. Hansen, Ph.D., Assistant Zoologist Bruno Limsacu, B.S., Zoological Assist- ant Section of Game Research and Manage- ment R. E. YeaTTeER, Ph.D., Game Specialist Section of Wildlife Experimental Areas Artuur S. Hawkins, M.S., Game Tech- nician (On leave) F. C. BE Lirose, Jr., B.S., Assistant Game Technician J. B. Low, Ph.D., Assistant Game Tech- nician W. H. Exper, Ph.D., Assistant Game Technician Cooperative Wildlife Restoration Pro- gram (State Department of Conservation and U. 8. Fish and Wildlife Service) Harry G. Anperson, M.A., Funior Bi- ologist L. G. Brown, B.S., Funior Biologist R. E. HesserscHwerpt, B.A., Funior Biologist C. S. Spooner, Jr., M.F., Funior Biolo- gist Section of Applied Botany and Plant Pathology L. R. Tenon, Ph.D., Botanist D. B. CrREAGER, Ph.D., Research Patholo- gist J. C. Carter, Ph.D., Assistant Botanist G. H. Borewe, M.S., Field Botanist Section of Publications James S. Ayars, B.S., Technical Editor Consuttant: Herpetology, Howarp K. Gioyp, Ph.D., Director of the Museum, Chicago Academy of Sciences This paper is a contribution from the Section of Economic Entomology. (19423—3 M—3-42) <> PRCONTROL of Roundheaded Apple Jree Borer S. C. Chandler and W. P. Flint Thee grower who sets an apple orchard of several acres, and then fertilizes, sprays and cultivates it for 5 to 10 years, has made a large investment. If, during this period, roundheaded apple tree borers kill 25 per cent of the trees, a serious loss has resulted. Such losses occur rather frequently in central and northern Illinois. Any grower who has an apple orchard, large or small, in these sections of the state should be on the lookout for borers. The roundheaded apple tree borer, Saperda candida Fabrici- us, figs. 1 and 2, tends to be more localized than some other major apple pests. It may be very serious in one orchard and not found at all in an adjacent one. Growers have observed that it is fre- quently confined to some one part of the orchard, especially if that part is near woods in which are growing service berry or shadbush, haw and other wild host plants related to apple. In such situations many trees are greatly weakened or are killed. Fig. 2.—Adult beetle of the round- headed apple tree borer. Its body, covered by a dense mat of flattened hairs, appears silvery white in color Fig. 1.—Larvae of the roundhead- ed apple tree borer. The damage is done by this borer in the larval stage. The larva is usually 1% inches or less in length and is white except for a dark brown head. except for three longitudinal brown stripes on the back. Pte 2 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 406 The young borers hatch from eggs laid near the base of the tree in slits cut in the bark by the female beetle. These borers enter chiefly at the base of the tree, near the ground line, as indicated in figs. 3, 4 and 5, tunneling up or down a few inches from the point of entrance. Presence of borers is indicated by whitish or brown frass at the point of entrance. The young borers work near the surface of the bark, but the older ones are found as much as one-half inch beneath the bark, in the heart- wood and sapwood. Injury is produced by the cutting off of the flow of sap and the girdling or partial girdling of the tree. The adult beetle, fig. 2, which lays the eggs from which the borer hatches, is about three-fourths inch long. Its body is entirely covered by a dense mat of flattened hairs; this hairy covering is silvery white, except for three longitudinal brown stripes on the back. These conspicuous beetles are active, mating and laying eggs during June and July in Illinois. The borers, usually 114 inches or less in length, fig. 1, are white, except for a dark brown head. In Illinois, they require 2 years to complete their development. The borer is usually more troublesome in neglected orchards than in those regularly sprayed; the beetles, feeding to some extent on foliage and tender twigs, are poisoned by the insecti- cides. The roundheaded apple tree borer should not be confused with the flatheaded apple tree borer, which usually works higher on the trunk of the tree and which confines its attacks mostly to the south and west sides of the tree. In the past, no very satisfactory control was evolved for the roundheaded apple tree borer. The grower had to rely on the old jackknife and wire method used to remove borers. This method is slow and laborious, not very efficient, and requires a certain amount of skill. We have attempted to work out a chemical treatment somewhat like that used for the borers in peach, and have developed one that is more rapid than the old system, less expensive and more effective. Early Tests With PDB in Oil Following the success of PDB (paradichlorobenzene) in Dendrol (a miscible oil) for the lesser peach borer,* we applied this mixture in October, 1935, to affected areas of apple trees in an abandoned nursery near Godfrey. Using PDB in Dendrol at *Described by S. C. Chandler in The Peach Tree Borers of Illinois. Tllinois Natural History Survey Circular 31. Feb., 1939. CHANDLER & FLINT: ROUNDHEADED APPLE TREE BORER 3 the rate of 2 pounds of PDB to 1 gallon of the miscible oil, we made up two dilutions: one in which we added enough water to make a total of 2 gallons and the other in which we added enough water to make 4 gallons. One dilution now contained 2 ounces and the other 1 ounce of PDB to each pint of liquid. Enough of the soil was removed from the base of the tree to enable the operator to locate the injured areas indicating the presence of the borers, the spots were painted with the diluted material and the soil was scraped back; the trees were not mounded. The results of this test are given in table 1. Table 1.—Results of tests for control of roundheaded apple tree borer: ele in Dendrol and water painted on affected areas of trees, Godfrey, Octo- er, 1935. V TorTaL Drab Per Cent INJURY Marertat Usep BoRERS Borers Drab TO TREES PDB in Dendrol and water Zounces)to i pint. ....>.... 21 13 61.9 None iwounce tomlpints.. 2. .....- 11 3 20.3 None Check, no treatment.......... 13 1 7.7 None Tests With Ethylene Dichloride Because ethylene dichloride emulsion had proved to be very effective in killing peach borer larvae, we tested it for round- headed apple tree borer control, using it in the abandoned nursery Table 2.—Results of tests for control of roundheaded apple tree borer: ethylene dichloride emulsion, Godfrey, 1938, 1939. Il Or SERENE, NUMBER Rowan || wap PER NUMBER OF TREES Treatment | ETHYLENE OF Bonus Boas CENT INJURED AND DIcHLORIDE| TREES Drab EXtTENntv oF INJURY Spring, 1938. 50% 7 6 6 100.0 |3 dead, 4 badly injured Spring, 1938. 25% 10 7 7 100.0 |All badly injured Spring, 1938. Check 5 5 ) 0.0 | None injured Fall, 1938... 15% 9 9 100.0 |7 severely injured, 1 slightly injured, 1 | uninjured Fall, 1938... 10% 9 7 7 100.0 |4 severely injured, 2 slightly injured, 3 uninjured Fall, 1938... Check 5 2 0 0.0 |None injured Fall, 1938. . . 5% 10 0 — — 1 slightly injured, 9 uninjured Fall, 1988... 244% 10 0 | — — |None injured Fall, 1939... 5% 10 8 2 25.0 | None injured Fall, 1939... Check 5 4 0 0.0 | None injured 4 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 40 near Godfrey in 1938 and 1939, starting with strengths thought necessary to kill the larvae and continuing down through lower dilutions as injury to the tree developed. Table 2 summarizes the data obtained. From these tests we concluded that although ethylene dichloride is very effective in killing borers in apple when used at strengths of 10 to 50 per cent, any strength sufficient to give a good kill of borers will injure the apple trees. Later Tests During the years 1939, 1940 and 1941, we tested three treat- ments in three orchards, as follows: Treatment 1: 20 per cent strength of carbon bisulfide, in a fish oil soap emulsion, one-half pint applied per tree, tree mounded. Treatment 2: PDB in Dendrol, one-half pint applied, fig. 5, per tree (2 pounds PDB in 1 gallon Dendrol, made up to 2 gallons with water), tree mounded, fig. 6. Treatment 3: Carbon bisulfide (unemulsified), injected into insect burrows from oil can, fig. 3, tree not mounded but trowel full of earth placed over each treated spot. Treatment 4: Check, no treatment. = 78 “ we r oe Fig. 3—Oil-can method of injecting carbon bisulfide into burrow of the roundheaded apple tree borer. The location of the burrow near the base of the tree is indicated by whitish or brown frass. CHANDLER & FLINT: ROUNDHEADED APPLE TREE BORER 5 The data from these tests are summarized in table 3. In table 3 the data on circumference show that the dosages in treatments 1 and 2 were effective on trees averaging 6 to 22 inches in circumference. No correlation was found between Table 3.—Results of tests for control of roundheaded apple tree borer: PDB in Dendrol, and carbon bisulfide. “ - AVERAGE TREAT- ATE UMBER PER TREE mew | Yecamens | Mop Pon | foret| Bese. | Gow | Cincom No. TREATMENT | TREES Drab FERENCE, INCHES 1 |Washington./Oct. 18, 1939) 10 20 16 80.0 16.5 Schuyler... ./Oct. 19, 1939} 10 21 16 76.2 6.0 Washington.|Sept. 21,1940) 10 19 il?/ 89.5 Cer Washington./Oct. 7, 1940 5 16 10 62.5 aioe Washington.|Sept. 26, 1941 10 28 26 92.9 21.9 Summary,| Treatment 1.. 45 104 85 81.7 2 |Washington.|/Oct. 18, 1939) 10 36 33 91.7 21.6 Schuyler..../Oct. 19, 1939} 10 36 34 94.4 8.5 Washington.|Sept. 21,1940) 10 17 15 88 .2 eae Washington./Oct. 7, 1940 5 29 21 72.4 ciate: Washington.|Sept. 26, 1941 10 41 40 97.6 21.2 Summary,| Treatment 2.. 46 159 143 89.9 3 |Schuyler....j/Oct. 19, 1939) 10 25 9 36.0 6.5 Madison..../Oct. 3, 1939) 10 8 8 100.0 10.0 Washington./Oct. 18, 1939) 10 20 9 45.0 21.9 Washington./Sept. 21,1940) 10 17 9 52.9 = Washington./Oct. 7, 1940 5 u 3 42.9 Washington.|Sept. 26, 1941 10 21 14 66.7 19.8 Summary,| Treatment 3.. 55 98 52 53.1 4 (|Madison..../Oct. 3, 1939 5 4 0.0 0.0 Schuyler... .|Oct. 19, 1939) 10 23 0.0 0.0 Washington.|Oct. 18, 1939 5 14 0.0 0.0 Washington.|Sept. 21, Oct. 7, 1940 5 21 0.0 0.0 Washington./Sept. 26, 1941 10 27 0.0 0.0 ae Treatment 4.. 35 89 0.0 0.0 failure to kill and size of tree. Evidently one-half pint of the materials used was sufficient for all trees in this range of size. The results obtained from each treatment were fairly uni- form for the 3 years and for the different localities. Probably the reason for not obtaining a complete kill in treatments 1 and 2 was frequently due to the height to which the larvae had tunneled above the ground line, as shown in fig. 4. Three possible explanations help to account for failure to obtain a better kill in treatment 3: some borer holes were missed 6 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 40 in the oil can injection; much less material was used than in treatments 1 and 2, and so the amount of gas generated was insufficient to kill the borers; lack of mound resulted in too rapid an escape of the gas. In addition to securing data on kill of larvae, we made exam- inations for immediate injury to trees and kept the orchards Fig. 4.—The knife blade indicates the height, about 6 inches above the base of the tree, at which a borer larva was found in tunnel. Laryae move up or down the trunk from the point of entrance near the base of tree. under observation for any permanent injury affecting growth. In all these treatments, we found a browned area on some of the trees. Contrary to expectations, this browning was more serious and appeared on a larger percentage of the trees in the two car- bon bisulfide treatments than in the treatment with PDB in oil. The percentage of trees showing any degree of browning in the 3 years of tests was as follows: Treatment 1, Carbon bisulfide emulsion.........-... 31 per cent Treatment 2, PDB in Dendrol and water............ 11 per cent Treatment 3, Carbon bisulfide injection......... ..24 per cent Later examinations showed that even trees with a consider- able degree of browning were not permanently injured. Recommended Treatments Inasmuch as the injury in the trees treated with PDB in Dendrol and water was less both in percentage of trees injured and in area affected in each tree, and the kill of borers was highest, we feel safe in recommending this treatment. Do not use PDB in crystal form as in that form it will cause serious injury to apple trees. CHANDLER & FLINT: ROUNDHEADED APPLE TREE BORER 17 It may be seen in table 3 that the percentage of kill with PDB in Dendrol and water was nearly 90 for a 3-year average. To prepare this recommended material, stir 2 pounds of PDB crystals in 1 gallon of Dendrol until the crystals are dissolved. Heating the oil a little, not over 100 degrees F., will hasten this process. Increase the dilution to 2 gallons by the addition of water. This means the addition of somewhat less than a gallon, because the PDB occupies some space. The material is then ready for use. Apply one-half pint of the emulsion per tree, pouring it around the base of the infested tree, touching the bark as shown in fig. 5. Mound with four or five spades full of soil as indicated in fig. 6. The mound of earth will tend to confine the gas given off by the PDB and aid in killing the borers. We consider carbon bisulfide emulsion as the next choice. Emulsify the carbon bisulfide cold, pumping together 50 per cent of carbon bisulfide and 25 per cent of fish oil soap dissolved in 25 per cent of water. Before using, dilute this 50 per cent stock to 20 per cent by mixing 4 parts of the stock in 6 parts of water. Apply one-half pint of the diluted emulsion per tree, as described for PDB in Dendrol. We have made no extensive investigation concerning the best time of year for applying the mixture of PDB and Dendrol, re ee 4 >. 2 wes 3 “ae J re ir Gs ©) ig .u8 ae > = Fig. 5.—Method of applying one-half pint emulsion of PDB, Dendrol and water to borer entrance at base of tree. 8 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 40 but our experience shows that late September or early October is favorable for Illinois. Experiments have shown that a soil temperature of 55 degrees F., at 1 inch below the surface, is about the lowest at Fig. 6.—Tree mounded after application to base of tree of one-half pint of PDB in Dendrol and water. which PDB in Dendrol and water is effective against peach borers. We do not recommend treating for the roundheaded apple tree borer when the soil temperature is lower than this. Although we have had little experience with any but fall treatments for the apple tree borer, we see no reason why spring treatments should not be effective if the soil temperature at the time is above 55 degrees F. Other Publications of Interest to Fruit Growers Some Causes of Cat-Facing in Peaches. By B. A. Porter, S. C. Chandler ae F. Sazama. Ill. Nat. Hist. Surv. Bul. 17(6):261-75. 10 figs. March, 1928. Peach Yellows in Illinois. By L. R. Tehon and G. L. Stout. Ill. Nat. Ist. Circ. 2). 23 pp., 9 figs. Nov., 1929. Epidemic Diseases of Fruit Trees in Illinois, 1922-1928. By L. R. Tehon see Culbert L. Stout. Ill. Nat. Hist. Surv. Bul. 18(3) :415-502. 31 figs. Aug., 1930. Practical Sanitation for Apple Orchards. By M. D. Farrar, S. C. Chandler, H. W. Anderson and W. V. Kelley. Ill. Ag. Exp. Sta. and Ext. Serv. Cire. 448. 23 pp., 9 figs. Jan., 19386. The Peach Tree Borers of Illinois. By S. C. Chandler. Ill. Nat. Hist. Surv. Cire. 31. 36 pp., 22 figs. Feb., 1939. Controlling Peach Insects in Illinois. By S. C. Chandler and W. P. Flint. Ill. Nat. Hist. Surv. Cire. 33. 40 pp., 32 figs. Aug., 1939. Bramble Fruits: Raspberries, Blackberries and Dewberries. By A. S. Colby, H. W. Anderson and W. P. Flint. Ill. Ag. Exp. Sta. and Ext. Serv. Cire. 508. 72 pp., 34 figs. June, 1940. Directions for Spraying Fruits in Illinois, 1942. By W. P. Flint and a W. Anderson. Ill. Ag. Exp. Sta. and Ext. Serv. Cire. 492. 32 pp., illus. an., 1942. Available Numbers in the Biological Notes Series Illinois Natural History Survey 10.—Progress in the Control of Elm Diseases in Nurseries. By J. C. Carter. 19 pp., 5 figs. (Mimeographed.) June, 1939. 11.—Lake Management Reports 3. Lincoln Lakes Near Lincoln, Illinois. By David H. Thompson and George W. Bennett. 24 pp., 8 figs., 2 maps. Aug., 1939. 12.—_The Waterfowl Research Program in Illinois. By Arthur S. Hawkins, Frank C. Bellrose, Jr., and Harry G. Anderson. 16 pp. (Mimeo- graphed.) Oct., 1939. 13.— Quail and Pheasant Studies in an Orchard County. By Frank C. Bell- rose, Jr. 11 pp. (Mimeographed.) May, 1940. 14.—Lake Management Reports 4. A Second Year of Fisheries Investiga- tions at Fork Lake, 1939. By George W. Bennett, David H. Thompson and Sam A. Parr. 24 pp., 10 figs., 4 pls. Aug., 1940. 15.—Preliminary Report on Availability and Use of Waterfowl Food Plants in the Illinois River Valley. By Frank C. Bellrose, Jr., and Harry G. Anderson. 14 pp. (Mimeographed.) Dec., 1940. 16.—A Contribution Toward a Bibliography on North American Fur Animals. By Lee E. Yeager. 209 pp. (Mimeographed.) Dec., 1941. Any of the publications listed above may be ordered from the Illinois Natural History Survey, Natural Resources Building, Urbana, Illinois. / Recent Publications — A.—ILLINOIS NATURAL HISTORY SURVEY BULLETIN. Volume 21, Article 3.—Studies of Nearctic Aquatic Insects. By H. H. Ross and T. H Frison. September, 1937. 52 pp., frontis. + 86 figs., bibliog. 50 cents. ) Volume 21, Article 4.—Descriptions of Nearctic Caddis Flies (Trichoptera), with special reference to the Illinois species. By Herbert H. Ross. March, 1938. 84 pp. frontis. + 123 figs., foreword, index. $1.00. Volume 21, Article 5.—Preliminary Studies on Parasites of Upland Game: Birds ane Fur -Bearing Mammals in Illinois. By W. Henry Leigh. August, 1940. 10 pp.) frontis. -+- 2 maps. : Volume 21, Article 6—Preliminary Investigation of Oak Diseases in Illinois. EB Ve rae ee June, 1941. 36 pp., frontis. + 51 figs., bibliog. (Bound with} Article. 7. Volume 21, Article 7—A Needle Blight of Austrian Pine. By Robert L. Hulbary. June, 1941. 6 pp., frontis. + 3 figs., bibliog. (Bound with Article 6.) Volume 21, Article 8—Duck Food Plants of the Illinois River Valley. By Frank Bellrose, Jr. August, 1941. 44 pp., frontis. + 35 figs., bibliog., appendix. Volume 22, Article 1—The Plant Bugs, or Miridae, of Illinois. By Harry H. Knight September, 1941. 234 pp., frontis. + 181 figs., bibliog., index: B.—ILLINOIS NATURAL HISTORY SURVEY CIRCULAR. 32.—Pleasure with Plants. By L. R. Tehon. April, 1939. 32 pp., frontis. + 9 figs. Contents: What is botanizing? Ways*to botanize; Where to botanize; When to botanize: How to botanize; Studying plants; Equipment for studying plants; The herbarium; Usefa books; Maps; Conclusion. | 33.—Controlling Peach Insects in Illinois. By S. C. Chandler and W. P. Flint. August 1939. 40 pp., frontis. + 32 figs. Contents: Part I. Insects attacking bark and trunk of the peach tree; Part II. Insects atta ing twigs, foliage and fruit of the peach tree. 34.—Rout the Weeds! Why, When and How. By L. R. Tehon. January, 1940. (Second ” printing.) 47 pp., color frontis. + 13 figs. _| Contents: The importance of weeds; Weeds as economic factors; Weeds as harborers insects; Weeds as harborers of plant diseases; Relation of weeds to public health; Contre | methods ; Thirteen noxious and pernicious weeds of Illinois. : 35.—Diseases of.Small Grain Crops in Illinois. By G. H. Boewe. September, 1939. 13 pp., frontis. ++ 47 figs. ~ | Contents : Nature of cereal diseases; Wheat diseases; Oats disease Barley diseases ; diseases ; Cereal disease control. | 36. —Planting and Care of Shade Trees. By J. E. Davis. March, 1941. 23 pp., frontis + 16 figs. Contents: Introduction; Planning for shade: Planting shade trees; Care of newly planted trees; Care of older trees; Some common trees used for shade. 37.—Outwitting Termites in Illinois. By W. E. McCauley and W. P. Flint. April, 1940. 23 pp., frontis. + 19 figs. Contents: Termites and Sein habits; Structural control of termites; Control of termites wi chemicals ; Unified action against termites. xa / 38.—Windbreaks for Illinois Farmsteads. By J. E. Davis. February, 1942. (Secone printing.) 24 pp., frontis. + 19 figs. Contents: Introduction; Planning the windbreak: Planting the windbreak; Care of the wind break; What the windbreak trees are like; W indbreaks and wildlife. 39.—How to Collect and Preserve Insects. By H. H. Ross. June, 1941. 48 pp., frontiif + 53 figs. Contents: Where to collect; What to use; Special collecting equipment: Sending inseets for identification; How to handle unmounted specimens; How to mount and preserve Spee mens; How to label the specimens; Housing the collection permanently; Identifying specimens; Useful books; How to ship a collection; Where to buy supplies. C.—ILLINOIS NATURAL HISTORY SURVEY MANUAL. 1.—Fieldbook of Illinois Wild Flowers. By the staff. March, 1936. 406 pp., com frontis. + 349 figs., index. $1.50. Contents: Introduction; Key to families; Description of species (650). 2.—Fieldbook of Illinois Land Snails. By Frank Collins Baker. August, 1939. 166 pp. color frontis. -+ 170 figs., 8 pls. $1.00. Contents: Land snails, what they are and where they live: Land snails native to Illinois; Land snails introduced from foreign countries; Land snails of uncertain presence in Illinois; Bibliography ; Check list of Illinois species; Index. List of available publications, over 300 titles, mailed on request. Address orders and correspondence to the Chief ILLINOIS NATURAL HISTORY SURVEY Natural Resources Building, Urbana, Illinois Payment in the form of U.S. Post Office money order made out to State Treasurer of Illinois, Springfield, Illinois, must accompany requests for those publications on which a price is set. UNIVERSITY OF ILLINOIS-URBANA 570IL6C C006 CIRCULAR 37-44 1940-51 TOIT 30 91