: : wes Nin Bae) arenas : Ayia Ne aoningce inteae F f . # , ’ + AS} iatenchat Pe eA oree ‘ ; , . faith : : Ce aaa * * oie ve . « A ‘ ne ed he mh - ‘ of ay . Sarnia tt arrest Sante a rye Sey aS Eg Satria UTERO pane wise * tg : : aes : 7 Ar eat po Hes so gree siny, tate / ened : , : te, Gaia ee : ; 5 ca tefrersecea se eeaeey . oe tee Pa Po se ed i venee errekeran ey oe : F : Oe aa an a ase : . a uaieysscogt Perea Perea f iy wt , ey a Pere 7 sae ee epost a vues Owe NATURAL HISTORY SURVEY, \ BULLETIN of the ILLINOIS NATURAL HISTORY SURVEY HARLOW B. MILLS, Chief Contents and Index Volume 24 1947-1949 NATURA) HSTopy SURVEY 20 1969 UBRApy Printed by Authority of the STATE OF ILLINOIS ADLAI E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION NOBLE J. PUFFER, Director SALE Or SL EN Os AbLal E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Nose J. Purrer, Director INEAW TE WERO A el Ss In @OuRay, SS UP RAVer Yau ON VY LiSi@ iN Hartow B. Mitts, Chief Illinois Natural History Survey BULLETIN Volume 24 Printed by Authority of the State of Illinois URBANA, ILLINOIS 1947-1949 STATE OF ILLINOIS Apart E. Srevenson, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Nose J. Purrer, Director BOARD OF NATURAL RESOURCES AND CONSERVATION Nose J. Purrer, Chairman A. E. Emerson, Ph.D., Biology L. H. Tirrany, Ph.D., Forestry L. R. Howson, B.S.C.E., C.E., Engineering Georce D. Sropparp, Ph.D., Litt.D., L.H.D., LL.D., President of the University of Illinois Watter H. Newuouss, Ph.D., Geology Rocer Apams, Ph.D., D.Sc., Chemistry NATURAL HISTORY SURVEY DIVISION Urbana, Illinois SCIENTIFIC AND TECHNICAL STAFF Hartow B. Mitts, Ph.D., Chief Bessie B. Henpverson, M.S., Assistant to the Chief Section of Economic Entomology Georce C. Decker, Ph.D., Entomologist and Head J. H. Biccer, M.S., Entomologist L. L. Eneuisu, Ph.D., Entomologist C. J. Weinman, Ph.D., Entomologist S. C. Cuanpter, B.S., Associate Entomologist Wituis N. Bruce, M.A., Assistant Entomologist Joun M. Wricut, M.A., Assistant Entomologist H. B. Perry, M.A., Associate in Entomology Extension James M. Bann, B.S., Research Assistant Section of Faunistic Surveys and Insect Identification H. H. Ross, Ph.D., Systematic Entomologist and Head Mitton W. Sanverson, Ph.D., Associate Tax- onomist Lewis J. Srannarp, Jr., MS., Assistant Tax- onomist Leonora K. Gtoyp, M.S., Laboratory Assistant Puitip W. Suir, B.S., Laboratory Assistant Carotyn E. Suroyver, Technical Assistant Section of Aquatic Biology Georce W. Bennett, Ph.D., Aquatic Biologist and Head Wituram C. Srarrett, Ph.D., Associate Aquat- ic Biologist D. F. Hansen, Ph.D., Assistant Aquatic Bi- ologist R. We.tpon Larrimore, M.S., Research Assist- ant DanteL Avery, Field Assistant Section of Forestry Witter N. Wanve.t, M.F., Forester and Head Lawson B. Cutver, B.S., Associate in Forest- ry Extension Henret D. Crawtey, M.F., Funior Forester Technical Library MarcueEritre Simmons, M.A., M.S., Technical Librarian Ruru Warrick, B.S., Assistant Technical Libra- rian Section of Applied Botany and Plant Pa- thology Leo R. Teuon, Ph.D., Botanist and Head J. Cepric Carrer, Ph.D., Plant Pathologist J. L. Forsperea, M.S., Associate Plant Patholo- gist G. H. Boewe, M.S., Assistant Plant Pathologist Rosert A. Evers, MS, Assistant Botanist Joan H. Lause, B.S., B.M., Technical Assistant Section of Game Research and Manage- ment Tuomas G. Scorr, Ph.D., Game Specialist and Head Racpeu E. Yeatrer, Ph.D., Game Specialist Frank C. Bettrose, B.S., Assoctate Game Specialist Harotp C. Hanson, M.S., Assistant Game Specialist James S. Jorpan, M.F., Assistant Game Tech- nician Wiii1am Nuess, Laboratory Assistant Section of Publications and Public Rela- tions James S. Ayars, B.S., Technical Editor and Head Biancue P. Youna, B.A., Assistant Technical Editor Cuartes L. Scort, B.S., Assistant Technical Photographer Cooperative Wildlife Research (Illinois Department of Conservation and U.S. Fish and Wildlife Service, Cooperating) Paut J. Moore, B.S., Project Leader GeorGce C. Arrtuur, B.S., Project Leader Lyste R. Prerscu, M.F., Project Leader Joun C. Catuoun, B.S., Assistant Project Leader Witi1am J. Harru, M.S., Project Leader Leonarp Duruam, B.S., Technical Assistant Consuttant tn Herperotocy: Hosarr M. Smiru, Ph.D., Assistant Professor of Zoology, University of Tilinots. This paper is a contribution from the Section of Publications and Public Relations. (90443—800—11-49) CONTENTS ARTICLE 1—THE MOSQUITOES OF ILLINOIS (Diptera, Culicidae). By Herspert H. Ross. August, 1947. 96 pp., frontis., 184 figs........... 1-96 Biology 1, Seasonal distribution 8, Distribution pattern 8, Economic importance 9, Control considerations 9, Collecting and preserving 10, Study techniques 12, Rearing 13, Classification 14, Key to subfamilies 16, Literature cited 93, Index 95. ARTICLE 2—THE LEAFHOPPERS, OR CICADELLIDAE, OF ILLI- NOIS (Eurymelinae—Balcluthinae). By D. M. DeLonc. June, 19458. PS0ippetrontis: Ol fos aepo ne sinye clone ae eiqas cinsaneamee: 97-376 Biology 97, Ecological relationships 98, Economic status 105, Taxonomy 106, Key to subfamilies 108, Literature cited 357, Index 367. ARTICLE 3.—THE BASS-BLUEGILL COMBINATION IN A SMALL ARTIFICIAL LAKE. By Georce W. BENNeETY. December, 1948. 36 DEMON EIS ome Otis ese wernt mee Sie eyed iets otcn MEANS spews nee chs OMe Acknowledgments 378, Cropping procedure 378, Fish yield 381, Dam failure 382, Pond habitat 385, Vegetation vs. fish yield 387, Growth rates 387, Condition and growth 391, Scale analysis 393, Spawning and young fish 395, Sexual cycle 397, Foods 398, Discussion 407, Summary 411, Literature cited 412. ARTICLE 4.—THE PSEUDOSCORPIONS OF ILLINOIS. By C. Cray- TONS EORE-a alines 1949. eS pprmtromtis:. Dil f1PS..0.G shel ses ac ae 413-498 Biology 413, Habitat preferences 415, Distribution 416, Collecting methods 418, Prep- aration of material 422, Morphology 423, Acknowledgments 427, Classification 427, Key to suborders 428, Literature cited 494, Index 497. NID) EXO Wena ete re Nee 52k RRS. tcp Sheets aiisecsayaieveie suk Stee tas F siele wins ae 499 Page Page Page Page Page Page Page Page Page Page Page Page Page EMENDATIONS 182, couplet 5, line 9. For 35 substitute 36. 187, couplet 41. For line 3 substitute on the mesonotum, as in fig. 392..............++:- 42 Por line 5 substitute mesonotum®. ... 1 4().). v-naveee sore eae ee oe eee eee 43 188, 41. SCAPHOIDEUS Uhler. Correspondence between Dr. D. M. DeLong and Dr. P. W. Oman has revealed that the type series of Scaphoideus luteolus Van Duze is composd of at least two species and as a result there has been some confusion in the use of this name. Scaphoideus luteolus Van Duzee, as represented by the type female in the United States National Museum, is the same species as Scaphoideus baculus DeLong & Mohr. The species in this report identified as Scaphoideus luteolus, based on the paratype male in the Osborn collection at Ohio State University, is a different species from that of the type female of luteolus. The name motus DeLong has been proposed for the misidentified form /uteolus DeLong mec Van Duzee. This necessitates the first eight of the following changes. 188, couplet 5. For luteolus swbstitute motus. 189, fig. 248. For LUTEOLUS substitute MOTUS. 190, couplet 22. For baculus substitute luteolus. 191, couplet 34. For baculus substitute luteolus. 191, couplet 37. For luteolus substitute motus. 192, fig. 274. For BacuLus substitute LUTEOLUS. 197, 12. For Scaphoideus baculus DeLong & Mohr, substitute Scaphoideus luteolus Van Duzee. 202, 31, For Scaphoideus luteolus Van Duzee substitute Scaphoideus motus DeLong. 478, column 1, line 24 from top. For Toumey substitute Twomey. 481, column 1, line 21 from top. For Toumey substitute Twomey. BULLETIN of the ILLINOIS NATURAL HISTORY SURVEY HARLOW B. MILLS, Chief So a ee eee The Mosquitoes of Illinois (Diptera, Culicidae) HERBERT H. ROSS Printed by Authority of the STATE OF ILLINOIS DWIGHT H. GREEN, Governor ry MS rowe row =a = J aaeecelUrlC elw Oe -_ DEPARTMENT OF REGISTRATION AND EDUCATION FRANK G. THOMPSON, Director SiALt FOR ieee Nios Dwicut H. Green, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Frank G. THompson, Director NA DURAL HISTORY SURVEY DIVISION Hariow B. Mitts, Chief lume 24 BULLETIN Article 1 The Mosquitoes of Illinois (Diptera, Culicidae) HERBERT H. ROSS Printed by Authority of the State of Illinois URBANA, ILLINOIS August 1947 STATE OF ILLINOIS Dwicut H. GREEN, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Frank G. THompson, Director BOARD OF NATURAL RESOURCES AND CONSERVATION Frank G. THompson, Chairman Cart G. HartMan, Ph.D., Biology GrorGce D. Sropparp, Ph.D., President L. H. Tirrany, Ph. D., Forestry of the University of Illinois L. R. Howson, BS.C.E., C.E., Engineering Watter H. Newuouse, Ph.D. Geology ROGER Apams, Ph.D., D.Sc., Chemistry NATURAL HISTORY SURVEY DIVISION Urbana, Illinois SCIENTIFIC AND TECHNICAL STAFF Hartow B. Mitts, Chief Bessiz B. Henprrson, M.S., Assistant to the Chief Section of Economic Entomology Section of Aquatic Biology G. C. Decker, Ph.D., Entomologist J. H. Biccrr, MS., Weeuaiate Entomologist e L. EncuisH, Ph.D., Research Entomologist . C. CHANDLER, B.S., Southern Field Ento- Peioia James W. Appte, M.S., Northern Field Ento- mologist C. J. WEINMAN, Ph.D., Associate Entomolo- gist Joun M. Wricut, B.A., Assistant Entomol- ogist Wuuis N. Bruce, B.S., Assisitant Entomolo- gist H. B. Petry, Jr. M.A., Associate in Ento- mology Extension Georce F. Lupvix, M.A., Special Research Assistant Joun E. Porrer, M.S., Laboratory Assistant Crara Z. EISENBERG, B.S., Laboratory Assist- ant Section of Faunistic Surveys and Insect Identi- fication H. H. Ross, Ph.D., Systematic Entomologist Cart O. Moser, Ph.D., Associate Entomolo- gist, Artist (on leave) B. D. Burks, Ph.D., Assistant Entomologist Mitton W. SANDERSON, Ph.D., Assistant Entomologist Lewis J. STANNARD, JR., B.S., Assistant Ento- mologist ELizABeTH N. MAxweELl, mological Assistant Puyiuis A. Beaver, Laboratory Assistant B.A., Artist, Ento- Section of Forestry Wier N. WANDELL, M.F., Forester Lawson B. Cutver, B.S., Extension Forester Technical Library Marcuerite Simmons, M.A., M.S., Techni- cal Librarian CONSULTANTS IN HERPETOLOGY: Georce W. BENNETT, Ph.D., Limnologist D. F. Hansen, Ph.D., Assistant Zoologist Pau G. Barnickot, M.A., Ichthyologist ELIZABETH B, CHASE, Ph.D., Research Assistant Section of Game Research and Management R. E. Yeatrer, Ph.D., Game Specialist ; Dean H. Ecke, Assistant in Game Research Section of Migratory Waterfowl F. C. Bettrose, Jr., B.S., Associate Game Technician Harotp C. Hanson, M.S., Assistant Game Technician Cooperative Wildlife Research (With State Department of Conservation and U. 8. Fish and Wildlife Service) C. C. Swears, M.F., Project Leader Georce C. ARTHUR, B.S., Project Leader Paut J. Moors, B.S., Project Leader A. B. Cowan, B.S.F., Assistant Project Leader Section of Applied Botany and Plant Pathology — Leo R. TEHON, Ph.D., Botanist J.C. Carter, Ph.D., Associate Botanist G. H. Boewe, M.S., Field Botanist J. L. Forsperc, M.S., Research Pathologist Ropert A. Evers, M.S., Assistant Botanist Section of Publications James S. Ayars, B.S., Technical Editor Frances B. Kimprouch, B.S., Assistant Tech- nical Editor Rosert E. HesseLSCHWERDT, B.A., Assistant Technical Photographer Howarp K. Gtoyp, Ph.D., Director of the Museum, Chicago Academy of Sciences; Ciirrorp H. Pope, B.S., Curator of Amphibians and Reptiles, Chicago Natural History Museum. This paper is a contribution from the Section of Insect Survey. CONTENTS 7 LENG, 205) Baitltre GS FOG GENER DOD COCO oc Le BEMInG 06 COIN Oa Co nn UGnerdc Cn retinitis 1 Eggs.—Larvae——Pupae.—Adults.—H ibernation—Habitat Preferences. OO SINUAN IL: CDSN WOK ONS Coe Reena ode orp SOO nen Oster A nes homo cornet: 8 Seamrm said es WHET CO) Nga ey Ac Lcd ERIN cseree res chara ccheye cic tevolaiare IV tute AGHaw s fai Sinnoleyada/aus tejetereretere 8 MEST Ta Oar WV 112 ©) RATVAUNI GH otameaiay cles aceseleuare) cist sicin.ct alavebahela erie lave isuagvonote, afe-aoraaneys 9 ONTO Ike (COINSMIDIDRYA EONS SE ns oe tee a ar eb nnidor ea pmo peonon apo enc cnr 9 eee EKO STONING AGNI SPRUE SER VAD NIG tines ca vereiecosey alte: a ciate e's «lots wiereteitis o cimycesseus\scies« 10 Larvae.—Adults.—Labeling. MemLOn ID yeu Vid Hs CCE THINUOT CO) CU Sexe teen Shes, Sic si aucvat chet ore foieyone:ciifeseyse eye ole ei ole, sl0) ove ope.s) are alene sate olors 12 Larvae. —Adults. SEMEN NAILIN (Cr PTGS, Cole ICN Se aval D Pe Corot ACETAL le osehasicrsvoyev a isi aieialeis oialle) «lB tcece to analaree 13 Individual Rearings—Group Rearings.——Larval Food— Temperature, Aeration, and Sunlight. | ASSRIPIICI IDIOT ec 55 Cee dnl oie eer, eee ece cao Ale porno tee Ome aECRConE Oona On 14 Terminology—Literature—Material Studied —Acknowledgments. IRGrayceerT MES TIS HANTS soseret re crete ches cite) fo eke Lognt have) eevee eels Sop eae)s pie ale s/o na shelores 16 (RELA ORORUNUATE SP pence RS re cere Lape ites erate taza etc op aten av ayagararevenctorenacs 17 (CHT TONSENDS oo chee Boece Oo HES Utd bois BORE AGO 0 OB OLS COR terete Re eerie 17 IVIDSOMMEGeSMO Le llllino sincere iri accctcre, ortrae taken Paki Noles ose eh eoeneetah ove Goleus We ACEVA TOM ren era etme mene apie in cops trasercrerbae scioincia codes see arth on niarce 17 SGV AUMI ESS CSc mots OL Oe AIO PRTC A ACN OREO IEE EM ESRICNCaC os 24 VU LEE CSAIL, © A ry SERRE LPI PEROT OE SELLE aes ae REE RRS 32 QUATRE HTRAZ En Giga la oe ets BION, Che MC EE ICON EOL eR NOL ICR CIE ECR MECC IETe 33 [LISTED ETL De ace, Gay Maa ILE OTE EEN ECE RE Rainn HIE Eo re 34 LU ATR TRS A ey a ROR) CAO) PIS eGo nes RAE RO Ree CE eT EE eae ne REO OE 35 (O} NO) NEV ION/ RIO decree Ae AER IO RCLIG OIG TIED DITO ROIS e eR O 36 (MMOGs LAs PANS RRL ache U ONT is RLS! CEPOL REO LEER RSIS 37 (CRATERS Str CCB i AM ken ene er oRCR AE Cue he CHE Oe oi ar RA a ICR Ee ena UREN Citas 40, TENET ARR case EN ERS er A EU ey ROR RCRA LS Cs, Aare a Sala eC REE a 52 ASOT O PILOT Lone ee Sate ee atet a tech bine arated atone tars ei ay sha raileheniotey sy ePale Piece 82 am PWENERUAGT AH) FH ont OSTEO EDO) Seb eRe ve sea cas sha ede sars opty Ales insstreayes coleccaenShessuctovace ¢ bialele wah enete 93 One of the largest Illinois mosqui- toes is the “gallinipper,” Psorophora ciliata, which may attain a wingspread of 15 mm. (over half an inch). It is a vicious biter and is generally distrib- uted over Illinois. The larvae or wig- glers of this species breed in rain pools and have the habit of feeding on larvae of other mosquito species. The Mosquitoes of Illinois ( Diptera, Culicidae) OSQUITOES are midgelike insects of various sizes, some of them minute, some of them nearly a half inch long. They belong to the family Culici- dae, which belongs to the order Diptera, embracing the common housefly and other two-winged flies. Mosquitoes have aquatic larvae called wiggle-tails, wigglers, or wrig- glers, which transform to aquatic pupae ealled tumblers. The adults, which emerge from the pupae, are aerial. About 150 species of mosquitoes are known to occur in the United States and Canada, and 52 of these have been taken in Illinois. The Illinois mosquito fauna repre- sents a combination of the northern and the southern mosquito faunas, a combination not yet treated in the various reports giving keys to the faunas of limited regions. - Mosquitoes are a real nuisance in many parts of Illinois. Although some of the more intensively farmed areas are compara- tively free from all but local incursions of mosquito broods brought on by unusual weather conditions, in all other parts of the state mosquitoes are a perennial problem. An extremely vicious biter, the salt marsh mosquito, dedes sollicitans, has invaded a few Illinois cities. The malaria mosquito, Anopheles quadrimaculatus, is a menace to human health in some areas. To be eco- nomical as well as effective and thorough, a control program for these and other mos- quitoes must be based on accurate identifica- tions of the species involved and a knowl- edge of their peculiarities of life history and habits. The nation’s annual “mosquito bill” is igh—probably $100,000,000 due to mos- uito-borne diseases, and close to $50,000,- (0 for screening, pest control programs, and depressed real estate values. The object of this paper is to provide means for making mosquito control pro- grams more effective, first by furnishing illustrated keys and descriptions for the identification of mosquito species that occur in Illinois and states similar in climate, and HERBERT Ho ROSS second by summarizing information regard- ing the distribution, biology, and habitat preferences of the species. BIOLOGY Mosquitoes, in common with other groups of flies, have four distinct stages in their life history: (1) the egg, laid by the female; (2) the larva, wiggle-tail, wiggler, or wrig- gler; (3) the pupa, or tumbler; and (4) the adult fly. Eggs Eggs deposited by Illinois species of mos- quitoes fall into three fairly distinct cate- gories: (1) those laid singly on water; (2) those glued together in rafts that float on water; and (3) those laid singly in damp humus or other semidry material. Eggs Laid Singly on Water.—In this category belong the eggs of Anopheles, fig. 10. They are elongate oval, usually pointed at one end, and have a pair of lateral floats. From 100 to 300 eggs may be laid by an adult female after taking a blood meal; usually the eggs hatch in a few days. Little is known about the eggs of the tree hole genus Megarhinus except that they are laid singly on the surface of water. Anopheles and Megarhinus are the only genera in this class known to occur in Illinois. Eggs Laid in Rafts on Water.—The eggs of many mosquito genera are deposited side by side in such a manner as to form a raft, fig. 1d. This raft floats on the surface of water, and the eggs hatch in a few days, each larva escaping from its egg at the end that touches the water. The raft may con- tain a hundred eggs or more. In the genera Culex, Culiseta, Mansonia, and Uranotae- nia, eggs are deposited in rafts. The larvae of all these groups breed in permanent bod- ies of water. Eggs Laid Singly in Semidry Places.— In many genera of mosquitoes, including Aedes, Psorophora, Orthopodomyia, and pote Wyeomyia, the eggs are laid out of water, but they do not hatch until water has risen and inundated them. The eggs may be laid either just above the water line in such sit- uations as tree holes, various water contain- ers, and marsh edges, or in damp humus in the bottoms of recently dried-up pools that are subject to periodic flooding. The eggs of Aedes, fig. 1B, and Psorophora, normally a, en IIIA Ye HN ih \ ry) 7} PN WATT) i Fig. 1—Eggs of mosquitoes: quadrimaculatus. laid in damp humus, are adapted to with- stand desiccation and may lie dormant 1 or 2 years without losing their viability. MW ye- omyia lays its eggs above the water line in the pitcher plant, and these eggs do not hatch until the water within the pitcher rises. The same habit is a characteristic of the tree-hole mosquitoes, Orthopodomyia and Aedes triseriatus and aegypti, which lay eggs on the sides of tree holes or water contain- ers just above the edge of the water so that with a rise in the water level the eggs hatch. The species of Psorophora and Aedes, which lay their eggs out of the water, may be divided into classes with respect to sig- nificant differences in egg hatching. In one class the eggs hatch as soon as they are flooded; since in this species the life history is completed rapidly, several generations usually are produced in a summer as pools dry and flood with alternate dry and rainy periods. Species belonging to this class are Intino1is NaTturAL History Survey BULLETIN HY iM iN y Vol. 24, Art. 1) known as intermittent breeders. They in- clude all species of Psorophora and certain species of dedes: vexans, sollicitans, trivit- tatus, and many southern species. only one generation is developed each year, the eggs must be subjected to winter freez- ing before they develop. adults of one generation do not hatch with iW) Mahia Ny ) A, Culex restuans; B, Aedes taeniorhynchus; C, Anopheles (After Howard, Dyar, & Knab.) summer flooding but lie dormant through) the winter and hatch the next spring. To this class belong many species of Aedes, such as grossbecki, stimulans, and implaca- bilis. Larvae The mosquito larva or wriggler, fig. 2, has a distinct head, broad thorax, and tubu- lar abdomen. It lives only in water. The larval period is one of feeding, during which the small larva hatching from the egg grows to a size large enough to produce the adult’ fly. Unlike the adult, this larva has no beak and does not suck food; instead it has: a series of brushlike rakes in addition to the: grinding and grasping mouthparts, a combi- nation enabling it to strain, scoop, and ingest! small aquatic organisms and particles of plant or animal matter floating in or upon the water or resting on the bottom. In the In the: other class, called annual breeders, because: Eggs laid by the: August, 1947 few genera in which the larvae are preda- ceous on other mosquito larvae, the mouth- parts are sharp-toothed for grasping and swallowing the prey. Unlike fish, the wriggler does not obtain oxygen from the water by means of gills. When in need of air, the larva in most spe- cies swims upward until it is just below the surface of the water, if it is not already there, and sticks the breathing apparatus (in some species a tube and in others a plate), which is near the end of the abdomen, through the surface tension membrane into actual contact with the air, fig. 2. With the larva in this position, the air inside the body is exchanged for fresh air above the water. Among Illinois mosquitoes, only the larva of Mansonia does not come to the surface for air. In this species, fig. 18, the air tube forms a sharp, piercing organ, which is thrust into the air chambers in the under- water portions of marsh plants such as the eattail. The larva of Mansonia obtains its oxygen entirely from this source. Ross: Mosourrors oF ILLINoIs 3 The larvae of Illinois mosquitoes may be divided into two distinct types on the basis of breathing structures and feeding habits, the anopheline type and the culicine type. In the anopheline type (including only the genus Anopheles), the larvae normally rest paral- lel to the surface, touching the surface ten- sion membrane, fig. 24. They have no air tubes; the spiracles form a flat structure on the back of segment 8. The larvae normally twist their heads through a 180-degree angle and feed on microorganisms or other parti- cles at or on the surface, but occasionally feed below the surface much as do culicine larvae. When disturbed they swim to the bottom and hide. In the culicine type, the larvae normally feed on or near the bottom and come to the surface only periodically for air. This group includes all of the Illinois mosquitoes except Anopheles, and all of them have distinct air tubes. The predaceous species, such as Psorophora ciliata, do not feed on bottom microorganisms but usually cruise near the bottom and grasp their prey Fig. 2—Larvae of mosquitoes: A, Anopheles; B, Culex. (After King, Bradley, & McNeel.) 4 Intinois NaruraL History Survey BULLETIN Fig. 3—Pupa of mosquito. Bradley, & McNeel.) (After King, there. The curious genus Mansonia is also included in this group although, as mentioned above, it does not come to the surface for air. It is a true bottom feeder. Pupae The pupae do not feed but they breathe in the same manner as the larvae; the air tube is situated on the thorax, fig. 3, instead of near the end of the abdomen as in the larvae. The pupal stage, in which the mus- cular and other body structures of the larva Vol. 24, Art. 1 are broken down and reorganized into the structures of the adult, generally lasts only a few days. At the end of that time the mature pupa comes to the surface of the water, and the adult within it breaks the pupal skin, crawls out onto the surface of the water, and flies away. Adults Mosquito adults, fig. 4, are fairly small, delicate, winged flies, quite slender, and always with long, spindly legs. All the adults of the true mosquitoes have beaks. The visible part of the beak is a scabbard or sheath in which a group of extremely fine stylets makes up a needle-like piercing and sucking organ; it is the function of the sheath to keep this slender needle straight when it is thrust through the skin of the animal upon which the female mosquito feeds. Both males and females fly with a distinct humming or buzzing sound. Only the female mosquito “bites,’ or feeds upon animals; the male feeds on nec- tar and water. Whereas the female seeks. out her prey and may travel long distances to it, the male is relatively inactive, gener- ally hiding in grass or shrubbery except dur- ing the mating flights. There is evidence that the female does not bite for several , a / ie 8 August, 1947 days after she becomes an adult. Not all species bite humans. Some feed on nectar, and it is thought that a few others feed chiefly either on plant juices or the blood of birds and small mammals. Females of most species seek their blood meal during the dusk and night periods. Many of these same mosquitoes attack readily in the late afternoon or on cloudy days and during the dawn period. The woodland species almost invariably bite throughout the day, although their attacks are usually most vicious during the crepus- cular period. A few species attack readily in the open during the day time. Probably the best known Illinois species having this habit is Anopheles walkeri. Of unusual interest is the biting habit of Psorophora cyanescens, which attacks in the open and during times of bright sunlight. Flight habits of mosquitoes have been the subject of considerable study, in which marked or colored specimens have been released and their recovery in light traps or resting places has been plotted. A spe- cies of mosquito apparently will behave dif- ferently under different conditions. It is usually considered that malaria mosquitoes normally have a flight range of not more than 1 or 2 miles. Probably the longest flight ranges occur in species of dedes. It is not unusual for summer swarms of dedes vexans to migrate 2 or 3 miles and possibly up to 15 miles, and the salt water mosquito, Aedes sollicitans, has been known to migrate 40 or 50 miles. Many woodland species appear to be fairly restricted in their move- ments and seldom leave the piece of woods in which they have matured. The length of life of adult mosquitoes is not well known. Some of the Anopheles and Aedes females undoubtedly live 1 or 2 months during the summer period. The adults that hibernate have a much longer life span. Hibernation The great majority of Illinois mosquitoes, including most of the species of d4edes and Psorophora, hibernate in the egg stage. A few species, such as /V/yeomyia smithii, Anopheles barberi, and species of Orthopo- domyia, hibernate as larvae frozen in pitcher plants or tree holes in which they breed. Anopheles, Culex, and at least inornata ot Culiseta overwinter as fertilized. females. Ross: Mosquiroks or ILLINOIS The males die with the advent of cold weather. The females hide in hollow trees, cellars, manholes, and other sheltered places, from which they emerge in spring and lay eggs. Habitat Preferences The various species of mosquitoes differ greatly in the type of habitat frequented by the larvae. Some species breed in a great variety of situations, whereas others are extremely restricted in their breeding places. The following summary outlines in a general way the habitats preferred by the Illinois species. Running Water.—dAnopheles punctipen- nis usually breeds in small streams, fre- quenting the edges and shallow areas where the current is sluggish. ‘This species breeds with equal success in still water. A few species of Culex sometimes breed in moving water heavily laden with organic matter where the current is slow. These same species normally breed in still water. Still Water.—All Illinois species will breed in still water, and most of them only in still water, chiefly small ponds and pools of many types, the shallow edges of lakes, and the still water in shallow, dense weed beds along the edges of streams. Still water habitats are of several types and may be classified as permanent, temporary, special- ized, and semidomestic areas. PERMANENT AREAS.—AII species that lay eggs on the surface of the water, whether singly or in rafts, frequent permanent water areas. All prefer areas with shallow water and little wave action, abundant cover in the form of at least moderate aquatic vegeta- tion, and abundant food in the form of humus or other organic matter on the bottom and floating particles or microorganisms at the surface. Marshes, fig. 5, or shallow ponds with cattails, sedges, and associated aquatic vegetation are ideal for many mos- quito species. Temporary ArEAS.—In this category are ponds that fill with water intermittently for variable periods. In all these ponds one of the chief requirements for a good mosquito habitat is that they have ample organic matter (usually in the form of rotting leaves) on the bottom. In Illinois, temporary ponds are extremely varied with respect to how and when they are filled, where they are situated, and how 6 Intinois NaTurAL History Survey BULLETIN Vol. 24, Art. 1 Fig. 5—Marsh near Hinsdale, Illinois. In spring the more abundant mosquitoes at the marsh edge include Culiseta inornata, Aedes fitchii, Aedes vexans, and Culex apicalis. long they last. Most of them fall into one of four classifications: winter seepage ponds, flood plain ponds, summer rain ponds, and marsh edges. Winter seepage ponds fill up during the winter or early spring with surface or seep- age water from winter precipitation or the spring thaw. Ponds of this type, fig. 6, may have water in them for several months, but during much of this time the weather is too cold to allow mosquito development. They support many of our most vicious early spring Aedes, especially canadensis, stimu- lans, grossbecki, and implacabilis. The same species occur in flooded stump holes, fig. 7. Flood plain ponds form with the over- flow and retreat of streams that leave iso- lated pools of water scattered throughout the flood plain. ‘These are favorite places for many Aedes, especially the early spring species sticticus, and some Psorophora species. Summer rain ponds form in many depres- sions during heavy summer rains and remain for periods of a few days or weeks. In these breed dedes vexans and many species of Psorophora Fig. 6—Woodland pool, Bensenville, Illinois. This spring pool contains an enormous popu- lation of Aedes stimulans. It dries up in summer. August, 1947 Ross: Mosouiroes oF ILLINoIs Fig. 7—Stump hole, Bensenville. A favorite habitat of Aedes canadensis. Marsh edges that are alternately flooded and exposed by the rise and fall of water give the same conditions as temporary ponds, as far as mosquitoes are concerned. These marsh edges or margins, fig. 5, are impor- tant mosquito breeding grounds, especially for Aedes vexans. SpecIALIZED Hasirats.—Two situations of unique interest from the standpoint of the mosquito fauna are tree holes and pitcher plants. Each of these may harbor species of mosquitoes found in no other situation. Tree holes, fig. 8, include cavities within standing tree trunks and inside fallen trees (Jenkins & Carpenter 1946). Illinois mosquitoes that are restricted to this habitat include Megarhinus septen- trionalis, species of Orthopodomyia, Anoph- eles barberi, and Aedes triseriatus. The tree holes fill up either with rain water or with sap that has risen within the wounded tissues. Larvae that live in the tree holes develop much more slowly than is usual for species living in ponds. Only one Illinois spe- cies of mosquito, Wyeomyia smithii, breeds in pitcher plants; it is found in no other situation. Its larva feeds on decomposing animal material trapped in the pitcher. SEMIDOMESTIC SITUATIONS.—Several spe- cies of mosquitoes breed readily in situations around human habitations. They breed in the water that accumulates in fish ponds, tin cans, or almost any other type of container, fig.9. They may frequent also the accumu- lation in stopped-up eaves troughs, drains, and cisterns. In Illinois the chief species found in these situations are Culex restuans, pipiens, and quinquefasciatus. In contain- Pu’ en AM bey Fig. 8—Tree hole at Starved Rock State Park. This is the habitat for Aedes triseria- tus, Orthopodomyia species, and Anopheles barberi. 8 Irtrnois NatrurAt History Survey BULLETIN Fig. 9.—Refuse heap near Wilmette, Illinois. Water in the containers is a favorite breeding place for Culex pipiens and restuans. ers that are out of doors and that have in them an abundance of organic material (neglected fish ponds are the favorites), Anopheles punctipennis may breed in enor- mous numbers. Aedes aegypti also breeds in similar containers, usually those inside build- ings. SEASONAL DISTRIBUTION The various mosquito species appear in a fairly definite sequence as the season advances. The earliest species are Aedes, whose larvae develop in the spring pools. In southern Illinois the principal species are canadensis, grossbecki, and sticticus, through the central part of the state canadensis and sticticus, and in the northeastern part stim- ulans, implacabilis, fitchii, and others. In southern Illinois the first emergence may occur as early as April 1, in northern IIli- nois by the middle of May, but usually first emergence is about two weeks later than these dates. The early Aedes listed above are without exception annual breeders. They are followed in rapid succession by Culiseta inornata and Culex apicalis. A week or so after these appear, the large number of summer species begin to make their appearance. These include Anopheles, several species of Culex, and usually Aedes vexans and trivittatus. “The summer spe- cies continue to breed in suitable locations throughout the summer or intermittently with the summer rains. A third group of species, which includes Culex quinquefasciatus and Uranotaenia sapphirina, may be present early in the sea- son, but an appreciable population of this group usually does not appear until at least midsummer, Vol. 24, Art. : | es When the spring weather is uniformly cold well into May, and then is followed by” a series of warm weeks, early and midsea-_ son species come out together, and there is” little demarcation apparent between sea-_ sonal groups. DISTRIBUTION PATTERN The mosquito fauna of Illinois resolves itself into three well-marked groups: (1) species of wide distribution, which are gen- erally distributed in Illinois; (2) northern” species that have a range widespread to the north, and that occur in only the northern portion of the state; and (3) southern spe- cies that have a range extending only slightly into Illinois and that are only spo- radic north of the southern third of the state. The species that are generally distributed include some of our most abundant nui- sance species, such as Aedes vexans, trivit- tatus, canadensis, and sticticus, Psorophora ciliata and ferox, Culex pipiens, apicalis, and restuans, and Culiseta inornata. Northern species whose range extends into northern Illinois include many of the annual-breeding large 4edes found in the glacial bogs and marshes in the extreme northeastern corner of the state. These species are Aedes implacabilis, punctor, stimulans, excrucians, fitchii, flavescens, and cinereus. A few of these, such as flavescens and punctor, are rarities; excrucians is pres- ent in only moderate numbers; the other species breed tremendous populations. Other mosquitoes in this northern group include Culiseta morsitans, confined to the tamarack bogs, and Wyeomyia smithii, the pitcher plant mosquito, which also occurs only in tamarack bogs. On the basis of Illinois collecting, Anopheles walkeri appears to be in the same group, since in this state it is abundant only in the cattail marshes and bogs of the northern part; records from other states indicate, however, that its range extends far to the south where marshes are available. Another northern mosquito taken in Illinois is Aedes spencerii, for which our only record came from the northwestern corner of the state. Many southern species have been taken in the extreme southern tip of Illinois, most of them in the woodland pools of the post oak flats in the Mississippi River valley. The post oak flats list includes dedes fulvus August, 1947 pallens, dupreei, and grosshecki, Psorophora howardii, and Anopheles crucians. Aedes thibaulti has been taken near Carbondale, only 50 miles north of Cairo at the southern tip of Illinois. Psorophora discolor, varipes, and cyanescens, and Megarhinus septentri- onalis are southern species which often occur in the southern eighth or fourth of Illinois and sometimes sparingly north of that. Aedes aegypti is another southern mos- quito that has been taken in the St. Louis area and southward. Apparently it is unable to maintain itself there and occurs only as a temporary adventive during favorable years. The southern house mosquito, Culex quinquefasciatus, which has been taken in some numbers in southern Illinois, occasion- ally extends northward at least as far as Urbana. Present collection data are far from conclusive but suggest that unfavor- able winters push back the range of this species and that it migrates northward again during a succession of favorable years. Perhaps our most unusual record is that for dedes aurifer, a northern and eastern mosquito for which we have only one IIli- nois record, from the extreme southern tip of the state. Almost as unusual is the occur- rence of the northern Aedes cinereus in the same locality. Presence of these northern species in southern Illinois illustrates a tend- ency, which has been noticed in several other insect groups, for occasional northern spe- cies to occur in or near the Mississippi River region south of the main body of their range. ECONOMIC IMPORTANCE Mosquitoes cause an economic loss both as nuisances and as disease carriers. The nuisance category includes all those species that inflict painful bites but that are not known to carry diseases. Most impor- tant in this group are the various species of Aedes and Psorophora; in cities and towns, species of Culex are of prime importance. Mosquitoes in the nuisance group inflict financial loss in various ways. tions they restrict the vacation season, with subsequent loss of patronage to resort estab- lishments. They attack domestic animals and fowls and, when in large numbers, cause loss of weight and health. It has been esti- mated that 500 mosquitoes will draw one- twentieth of a pint of blood per day from an exposed animal. Sometimes mosquitoes In some sec- Ross: Mosourtors oF ILLINoIs 9 become so abundant as to interfere with or stop work by man, with a consequent loss of labor and accomplishment. Mosquitoes are among the worst nuisances of the out- of-doors and prevent enjoyment of recrea- tional facilities by many people seeking exer- cise and relaxation. Disease-transmitting mosquitoes are the sole vectors of malaria in human beings. Malaria is an endemic disease in southern Illinois. Only 50 miles to the south of Illi- nois, in the Mississippi River valley, occurs one of the high density areas of this disease in eastern North America. Anopheles quad- rimaculatus is considered the only impor- tant mosquito species capable of transmit- ting the disease in Illinois. Several other human diseases, such as yellow fever, filariasis, and dengue, are transmitted by certain species of mosquitoes that occur in Illinois. However, recent out- breaks of these diseases are so far removed geographically from Illinois, or the known mosquito vectors are so rare in this state, that the diseases are not considered a serious threat to Illinois citizens at the present time. Public health workers have pointed out that a number of the service men returning from areas in the Pacific and Oriental regions where many insect-borne diseases occur will have been infected with these diseases. It is entirely possible that, upon returning home, the men may be a source from which mosquitoes may become infected with some of the tropical diseases and trans- mit them to other persons resident in the same locality. There is little possibility of knowing when and where such situations will arise. At the present time this problem seems to resolve itself into one of early detection and accurate diagnosis of the dis- eases by local medical authorities. Up to the present time measures insti- tuted against mosquitoes in Illinois have been directed toward abatement of nuisance species or toward control of the malaria vector, Anopheles quadrimaculatus. CONTROL CONSIDERATIONS Control measures require consideration as individual problems in each community or locality. In different localities different species of mosquitoes are encountered, bring- ing into the control problem the treatment of different habitats, and involving differ- ences in number and seasonal timing of 10 Ittinoris NarurAL Hisrory Survey BULLETIN mosquito generations. Vagaries of precipi- tation or flooding frequently require rapid and unexpected changes in control plans. Control measures, to be both economical and thorough, must be based on data obtained by a collecting and identification program. It is wasteful to attempt control measures of every water surface within an area, because many bodies of water (and frequently the most extensive ones) do not serve as breeding places for mosquitoes. Before actual control measures are planned, therefore, larval collections should be made that will serve as a guide to the areas to be treated. To check the efficiency of control opera- tions, it is mecessary to supplement larval collections with biting records and adult collections throughout the season. These should include light trap collections and col- lections from resting stations. The persistence of adult mosquitoes in a control area (shown by collections and biting records) may indicate that breeding places within the area have been overlooked or that mosquitoes are coming in from sur- rounding territory. After overlooked sites have been eliminated, collection and identifi- cation of larvae from breeding places in surrounding territory will indicate addi- tional places which should also be treated. When adult mosquitoes are identified as to species, facts about them, fundamental in controlling them, can readily be ascertained: (a) the types of situations in which larvae should be sought and (b) breeding habits, that is, whether the mosquitoes are annual, intermittent, or persistent breeders. Such information is useful in searching out places where control treatments must be applied and determining whether the treatments need to be applied only once a year for annual breeders, following rains or floods for intermittent breeders, or at regular intervals for persistent breeders. COLLECTING AND PRESERVING Mosquitoes, both adults and larvae, are so delicate that their hairs and scales, upon which identification is based, are readily broken or rubbed off by careless handling. For this reason it is necessary to use great care in the procurement of material and in its subsequent handling and preparation for study. Vol. 24, Art. 1 Larvae A white enameled dipper, about 6 inches in diameter, is the most convenient utensil for collecting mosquito larvae. It may be used to dip up larvae from ponds and open water. The larvae can be removed from the dipper by one of two methods: (1) by pulling them into a wide-mouth medicine dropper and then discharging them into a vial of preservative or into a rearing cap- sule or (2) by pouring the contents of the dipper slowly onto a cloth strainer, picking the larvae off the cloth with forceps, and transferring them to a preservative or to a rearing vial. Hairs of the larvae are easily knocked off or the larvae mutilated in other ways if the transfer is made carelessly. 4 Alcohol makes a satisfactory preserva- tive; 80 per cent alcohol is strong enough if the larvae are transferred to it with forcepal If a medicine dropper is used to transfer the larvae, a few drops of water will be dis- charged into the preservative with each | larva, and a stronger solution of alcohol should be used. Not more than two live larvae should be placed at the same time | in a single vial. If many thrash around in the vial, they knock the hairs off each ell As many as 10 larvae may be put in a three= dram vial, but they should be put in one at! a time; the second and succeeding larvae should not be put in until the first and others. have died. The most satisfactory way to. kill a larva desired for a specimen is to place: it in a separate killing vial and transfer it to a stock vial after it has died. If larvae are handled in a vial only all tially filled with preservative, they will, jounce around, with a consequent loss oll hairs and tufts. If the specimens are in a: vial that is filled with preservative, without a single air bubble in it, they will move only) slowly, no matter how violently the vial is agitated, and suffer no damage. To preserve larvae in this way, the follow- ing procedure 1 is recommended. Put the dead larvae in a small shell vial; put this vial, open end up, in a larger vial containing, alcohol above the top of the shell vial. Now pick up a plug of cotton with a pair of for= ceps, soak the cotton with alcohol, and plug, the open end of the shell vial with the cot ton under the alcohol. Then take the shell vial out of the larger vial, put it in again plugged end down, and stopper the large’ vial, fig. 104. > | a August, 1947 GLYCERIN | 10.—4, vial with inner vial contain- B, mosquito mounted on Fig. ing mosquito larvae. crimped point and genitalia in microvial with pin through cork. The plug is prepared by rolling a small piece of cotton between the fingers until it is fairly hard; after a little practice, a plug can be gauged that will fit the shell vial tightly but that is not so large that the vial will be broken when the plug is forced in. For storage, the larger vial should be kept well filled with alcohol; no evaporation will occur from the inner vial until the alcohol in the outer one is almost gone. Adults There are three principal methods of col- lecting adult specimens: (1) by placing a killing tube over them as they sit in natural resting places or as they alight to bite, (2) by sweeping them from vegetation around their breeding places or sweeping them in the air as they swarm in mating flights, and (3) by attracting them to light traps. Killing Tube.— Collecting adults with a killing tube calls for the same careful indi- vidual attention as does collecting larvae. Seales of the adults rub off very easily. For this reason, a tube with a strong killing agent should be used and only one live mosquito should be placed in a tube at one time, never more than 6 to 10 dead ones. carry It is wise to with loose, rumpled cellucotton in the bottom and to transfer to these each dead mosquito from a killing tube. These boxes, which should have tight- fitting lids to prevent accumulation of dust on the specimens, should be so placed some- several boxes Ross: Mosouirors oF ILLINOIS 11 where in the vehicle used for transport that they will not tip. Sweeping.—Sweeping around vegetation does not net good study specimens of females, but it is valuable in collecting males. Fre- quently the males are present around a pond after all the immature it have matured. Collections of males often give an accurate clue as to the species that develop in the pond, and their proportionate popula- stages in tions. The type of sampling done by sweep- ing vegetation is especially valuable in scout- ing temporary pools. A standard sweep net can be used, and the males picked out of the net with If the collector desires to obtain, by using a net, female an aspirator. mosquitoes that are in good condition, it is advisable that the net bag be made of very fine, light material. For routine collections of males, it is more practical to use a heavy bag that will withstand the abuse involved in hitting shrubs, thick herbage, and the like. Light Traps.—A standard light trap used Fig. 11.—Light trap. (Photograph by cour- tesy of Bureau of Entomology and Plant Quar- antine, U.S.D.A.) 12 Ittinois NatTurAL History SurvEY BULLETIN for mosquitoes at the present time is the New Jersey light trap, fig. 11. This attracts mosquitoes by means of a low wattage elec- tric light bulb and is provided with a fan that blows them into a killing jar. The light bulb and fan are fastened to the inside of a large cover, which sheds rain, and a funnel is below the fan, fastened to three legs that support the trap when it is placed on the ground. ‘The standard trap has a handle on the top, so that in the field it may be hung in a tree or from some other sup- port. Mosquito specimens collected in this type of trap are usually in fairly good con- dition. Occasionally a swarm of beetles will be attracted to the light and blown into the killing jar. The beetles will crawl and thrash through the collection and mangle the mosquitoes. Individual catches from each trap should be placed, while still pliable, between layers of cellucotton in pill boxes. These layers should be thick enough to dry the insects thoroughly; otherwise mold may engulf the collection and render it useless for study. At the top of the pill box enough extra cot- ton should be added so that, when the lid is put on, the contents will be held firmly, but not so tightly as to crush the specimens. The container may then be transported with- out injury to the contents. A collection of pill boxes having different diameters and cardboard boxes 2 by 3 inches to 3 by 5 inches gives a good selection for handling catches of various sizes. hese containers should be packed with cotton in a larger box if shipped by mail. Labeling No matter what type of collection is made, each container, whether box, tube, or vial, should be labeled with station number, locality, date of collection, and name of col- lector. If the collection is of adults, note should be made of whether each container represents a biting record, a catch in a rest- ing station, a light trap catch, or a sweep- ing record. STUDY TECHNIQUES When the mosquito material, either larval or adult, is brought to the laboratory for study, the same care must be exercised in its further preparation as was expended in its collection. Vol. 24, Art. 1 Larvae In most instances it is satisfactory to pre-_ serve larval material in alcohol. Diagnos-_ tic characters in most groups are seen read- ily on specimens in fluid. For detailed studies of pecten and comb scales, a permanent mount is desirable. The larva should be dehydrated by being run. through the alcohols to 95 per cent, cleared in benzol or cedar oil, and then mounted in| Damar balsam. Each larva with an air tube - should be cut through the seventh abdomi-. nal segment and the anterior portion) mounted with the dorsum up and the poste-_ rior end with the left side up. This mount-_ ing will allow the study of the largest num- ber of characters to best advantage. Pieces. of broken slides should be placed around | the specimen in such a way that they prevent — the cover slip from flattening and distorting © the specimen. When the air tube is flat- tened, its proportionate length to width) becomes greatly distorted and cannot then) be used as an accurate guide for identifica- tion. Adults Material brought in from the field should | be mounted for study. A very satisfactory method of mounting is to glue the insects > on card points. If the end of the point is+ crimped down quite a distance, and moder-- ately thin cellulose cement is used for glue, . a neat mount can be made with the dorsum) of the specimen uppermost. Before being. pinned, adult specimens should be relaxed! for a short time. There is a tendency for: the specimen to become greasy if relaxed! too long, and care must be observed regard-~ ing this point. Full data labels should be» put on every specimen. Critical study of adult material frequently requires detailed examination of the geni- talia. A preparation of the genitalia may. be made as follows: snip or break off the posterior half of the abdomen and place it’ in a vial of 5 per cent caustic potash or caus-- tic soda solution; heat the vial in a boiling: water bath for about 5 minutes; remove the preparation from the caustic solution and! place it in distilled water; press it gently, with a needle to squeeze out dislodged vis-- cera and brush it carefully to clean off! lodged scales or dirt. “Transfer the prepa-- ration to fresh, distilled water, leave itt August, 1947 there for 15 minutes to an hour, and then transfer it to 80 per cent alcohol that is very weakly acidulated with acetic acid. After leaving it in this solution for a few minutes, transfer it to a drop of glycerin in a well mount on a slide. The preparation is then ready for microscopic examination. For preservation, place the preparation in a very small vial, about + by 10 mm., which has a droplet of glycerin about 3 mm. deep in the bottom. Cork the vial and then push the pin, on which the insect is mounted, through the cork sidewise, as in fig. 10B. In the case of heavily sclerotized genitalia, especially those of many dedes, it is neces- sary to use a caustic solution of 10 or 15 per cent instead of 5 per cent. For making large numbers of genital preparations simultaneously, it is conveni- ent to use a battery of small vials of cold caustic solution. Good results with the more heavily sclerotized genitalia, such as those of Aedes and Psorophora, can be obtained with about 12 hours of clearing in cold 5 per cent caustic solution. For the more weakly sclerotized preparations, such as those of Culex, 5 or 6 hours of clearing are usually ample. It is often necessary to tease apart vari- ous structures of the genitalia in order to see certain characters. For this purpose fine needles can be made from 00 insect pins. Snip off the head of the pin; then, holding the pin near the blunt end with pliers, force it bit by bit into a wooden handle whittled to suit the user. Large match sticks make fairly good handles for small needles. REARING Rearing is a necessary part of the mos- quito study program. There are many in- stances in which the larvae, or the males or females, of two species cannot be differenti- ated, so that for final identification it is nec- essary to have associated larvae and adults. Two types of rearings are useful, individual rearings and group rearings. Individual Rearings A single larva is isolated in a vial or dish, about half full of water, and food is added until the larva matures. When it molts to form a pupa, its cast larval skin is immedi- ately preserved in alcohol or mounted on a slide. At ordinary room temperatures the Ross: Mosquirogs oF ILLINOIS 13 pupa will mature in 3 or 4 days, and the adult will emerge. It is advisable to have some sticks or rumpled paper towel in the top of the dry part of the container so that the adult may rest there and harden for 2 or 3 days before being killed. Adults killed immediately upon emergence will shrivel. Frequently the adult can be transferred into a second container without free water and kept there for a few days to avoid the possi- bility of its drowning and disintegrating in the water. The pupal skin, larval skin, and adult should be preserved and mounted according to usual methods, and specimens of the same rearing associated by means of a distinctive accession number system. A con- venient system is to use a lot number for each collection and a letter for each indi- vidual of this collection. For example, speci- mens from collection No. 157, bear the accession designations 157C, 157D, 157E, etc.; the adult bearing the label 157C is associated with a larval skin and a pupal skin also bearing the accession designation 157C. No other specimen or skin in the collection has on its label 157C. With this method, it is possible to avoid getting the skins and adults of ditferent rearings mixed. Every skin and adult should be labeled promptly and clearly. Group Rearings In order to secure large numbers of study specimens in good condition, group rearings are of much use. Larvae may be placed in a large tube or mason jar and fed until they transform to pupae. For small cultures of less than 20 specimens, a cap vial about 114 inches in diameter and 2 or 3 inches long is very satisfactory. After a culture has pupated, the container should be placed in a large dry-battery jar or cage having a tight muslin top, and a liberal amount of crum- pled paper toweling placed in the bottom. The small container can be fastened upright on the inside of the large container by adhe- sive tape. After adults begin to emerge, water can be squirted through the muslin top onto the paper toweling, care being taken not to bathe the adults. This water will prevent desiccation of the adults and their premature death. In 2 or 3 days the adults will harden satisfactorily, and the entire cage can be treated with a fumigant to kill them. They may then be picked out of the cage and mounted. 14 Ittrnois Naturat History Survey BULLETIN Larval Food If larvae are collected when almost ready to pupate, a supply of the water in which they have been breeding and some of the organic matter from the bottom of the same pond will provide ample food to carry them to full development. If, however, they are collected at an earlier stage, it is necessary to add food. he safest type of food is fresh material from the bottom of a pond; this may be added to the rearing containers every 2 or 3 days. If this food cannot be obtained conveniently, various prepared foods, such as crumbled yeast, powdered dog biscuit, moldy corn, and gold fish food can be substituted. Because there is great danger that these concentrated foods will putrefy in the water, resulting in bacterial growth that will kill the mosquito larvae, they should be used in minute quantities. Temperature, Aeration, and Sunlight If the rearing is done indoors in hot weather, death of the larvae may result from too high a temperature or from insufh- cient aeration. Larvae that normally live in a cold water environment should be kept relatively cold. It is desirable to keep jars containing such larvae in a running water bath. This will generally keep the tempera- ture of the rearing medium below 75 degrees F. Good ventilation is necessary for indoor rearing of Anopheles larvae. Satisfactory results are obtained with these larvae by using rearing containers nearly filled with water and placed near or in an open win- dow; for adult emergence the pupae should be transferred to containers with 2 or 3 inches of air space above the water. Some exposure to sunlight gives good results, but in the heat of summer this exposure must be short to avoid overheating the water. CLASSIFICATION Mosquitoes belong to the order Diptera, or two-winged flies and to the family Culi- cidae. This family is characterized by the following adult structures: antennae, figs. 32-38, filamentous and slender, with 15 seg- ments, the first 2 forming the base and the last 13 forming the slender thread. Each segment has a whorl of hairs, which in the males are extremely long. ‘The eyes are large and conspicuous. ‘The mouthparts V ol. 24, Art. 1 a consist chiefly of a proboscis (which may be | either short and flabby, or elongate and | forming a beak) and a pair of maxillary palpi; the palpi are referred to in this report — as “palps.” The legs are long and spindly. The wings are fairly large; radial sector is 3-branched and Media is 2-branched; the branches of radial sector are either nearly straight or only slightly curved. The family is divided into two subfamilies, the Chaobo- rinae, or non-biting mosquitoes, and the Culi- cinae, the true mosquitoes. An adult of the Chaoborinae is readily distinguished from all adult Culicinae because it does not have a beak; each adult of the Culicinae has a well-developed beak or proboscis. The larvae of some Chaoborinae, however, might be readily confused with the larvae of true mosquitoes. Terminology Many special terms are employed for dis— tinctive parts of both adults and larvae of the mosquitoes, and these terms are used throughout the keys and descriptions. Fig. 12 is labeled to identify these distinctive parts of the larvae. Special parts of the + u WONT 7K ¢) ; . yj 7 fs reantennal i \S Ly pe ae Fa _anfenna lateral < airs \ \ eony! = ee ~ air fube Fk I fy x Ue tufts a era comb gills S yy) fax} -f- \ ee cfen =) pigs Fig. 12—Larval diagram, Culicinae. (After King, Bradley, & McNeel.) August, 1947 CLYPEAL HAIRS 4 ANTENNA FRONTAL HAIRS LATERAL HAIR ~ AMAL GILLS ~-..------ Fig. 13.—Anopheles larva. adults are identified on diagnostic draw- ings where they appear in the text associated with the keys. Distinctive structures of Anopheles larvae are shown in fig. 13. Literature Additional information about mosquitoes, especially species not contained in this report, will be found in the general mosquito reports listed below. Additional information con- cerning these reports is given in the section “Literature Cited.” Papers of more limited scope are mentioned later in the text in ref- erence to particular genera or species. 1928. The Mosquitoes of the Americas, by Harrison G. Dyar. Ross: Mosouitrors VENTRAL BRUSH . or ILLINoIs 15 SES MAIN 10, /9 POSTSPIRACULAR HAIR , SPIRACLE ‘ 1937. 1939. 1941. 1942. 1944, 1944, 1944. 1946, THORAX (VENTRAL) PECTEN DORSAL BRUSH * ie NAL > GiLLs Left figure, dorsal view of entire larva; upper right figure, details of thorax; lower right figure, apex of abdomen, lateral aspect. by courtesy of American Entomological Society.) (After Ross & Roberts, The Mosquitoes of Minnesota, by William B. Owen. The Mosquitoes of the Southeast- ern States, by W. V. King, GE Bradley, and T. E. McNeel. The Mosquitoes of Arkansas, by Stanley J. Carpenter. The Mosquitoes of Oklahoma, by L. E. Rozeboom. The Mosquitoes of Wisconsin, by W. E. Dickinson. Handbook of the Mosquitoes of North America, by Robert Mathe- son. The Mosquitoes of Texas, by Texas State Health Department. The Mosquitoes of the Southern United States, by Stanley J. Car- 16 penter, Woodrow W. Middlekauff, and Roy W. Chamberlain. Material Studied The major part of the material on which this study is based was collected by staff members of the Insect Survey Section, Illi- nois Natural History Survey. Various other persons or organizations contributed much valuable material, and I am greatly indebted to them for permission to use their records in this paper. J. Lyell Clarke, Des Plaines Valley Mosquito Abatement District, Lyons, Illinois, and M. A. Dobbs and J. M. Gilbert, East St. Louis Health District, contrib- uted extensive material. I wish to express my appreciation to officials of the Chicago Natural History Museum, who allowed me to study their mosquito collections; indi- vidual records from their material are marked in this paper with the initials cm. In addition, I am greatly indebted to offi- cials of the U. S. Public Health Service and the Illinois State Department of Public Health for permission to use their extensive records of Illinois mosquitoes; these records are indicated in this paper by the abbrevia- tion USPHS. Acknowledgments I wish to express my gratitude to several workers who were kind enough to check keys and to give advice on many questions which have arisen during the progress of this report. Captains C. F. Gerlach and F. Earle Lyman of the U.S. Public Health Service were very helpful in these matters. I am especially indebted to Dr. Alan Stone, U. S. Bureau of Entomology and Plant Quarantine, who was of the utmost assist- ance regarding the taxonomic problems which arose time and again. I wish to thank also the officers of the U. S. National Museum for the loan of considerable study material of critical species, especially larval material of rare Aedes species. Dr. C. O. Mohr, Dr. B. D. Burks, and Mr. G. T. Riegel were very active in the earlier years of this project, 1938-1942, in collecting and rearing material. In 1944 and 1945, Dr. Kathryn M. Sommerman and Dr. Milton W. Sanderson aided in this work. Dr. Sommerman and Mr. Riegel did the larger part of the rearing in the labora- tory. I am greatly indebted to Dr. Som- merman for the many original drawings © which she made for this report. Various individuals and organizations were extremely kind in either loaning draw- ings and cuts for use in this bulletin or in giving permission to reproduce illustrations Intinois Naturat History Survey BULLETIN Vol. 24, Art. 1 / 2 4 i ‘ appearing in their publications. On this score — I am especially indebted to Professor Robert Matheson and the Comstock Pub- lishing Company; the American Entomolog- ical Society; the Entomological Society of — Washington; the Bureau of Entomology and Plant Quarantine, U. S. Department of Agriculture; and the Malaria Control in ~ War Areas, U. S. Public Health Service. Key TO SUBFAMILIES LARVAE 1. Antennae arising close together on a mesal raised area or protuberance of the head, © fe l4e ioe eee Chaoborinae Antennae arising at sides of head, figs. 12, kK UE a erent pn 2 2. Anal segment with a sclerotized ring or plate, figs. 17-20; antennae without long, prehensile hairs............ Culicinae Anal segment without either a sclerotized — ring or plate; antennae with long, prehen- — sile hairs (Mochlonyx and Eucorethra), figs! 155) 1Giss. conta arena Chaoborinae ADULTS 1. Proboscis elongate, figs. 32-38, many times longer than depth of head..... Culicinae Mouthparts forming only short submem- branous lobes which are no longer than depth of head. >... 3.3. Chaoborinae © Fig. 14.—Head of larva of Corethrella. Fig. 15.—Larva of Mochlonyx (Redrawn from Matheson.) cinctipes. Fig. 16.—Larva of Chaoborus punctipennis, (Redrawn from Matheson.) August, 1947 Subfamily CHAOBORINAE The adults of this subfamily are midge- like ; their bodies usually are hairy but with- nut scales. Four genera comprise the North American fauna of the subfamily. Of these, Chaoborus, Corethrella, and Mochlonyx oecur in Illinois; the fourth genus, Eucore- thra, is widely distributed north of Illinois but has not yet been taken in the state. Larvae of Chaoborus, fig. 16, have no air tubes. Larvae of the other three genera have either air tubes (Mochlonyx and Core- thrella) or spiracular plates of the Anoph- eles type (Eucorethra); in these genera the larvae are predaceous and in gen- eral appearance resemble those of some biting mosquitoes. A synopsis of the North American species, together with keys and illustrations, is pre- sented by Matheson (1944). Subfamily CULICINAE To date, 10 genera of this subfamily, rep- resenting the true mosquitoes, have been taken in Illinois. It should be emphasized that this mosquito group includes all the Culicidae with well-developed beaks, many species that bite, and in addition a few spe- cies that do not bite. The subfamily Culicinae is frequently divided into two tribes, the Anophelini, in- cluding in the Illinois fauna only Anopheles, and the Culicini, including the other nine Illinois genera. However, the subfamily is sometimes divided into a large number of tribes. Since the final solution of this prob- lem in taxonomy will require a study of the world fauna, the most practical solution for the present report has been to avoid segre- gation into tribes and to treat the subfamily as a single unit. Mosquitoes of Illinois Aedes aegypti (Linnaeus) Aedes aurifer (Coquillett) Aedes canadensis (Theobald) Aedes cinereus Meigen Aedes dorsalis (Meigen) \dedes dupreei (Coquillett) \dedes excrucians (Walker) \dedes fitchii (Felt & Young) \dedes flavescens (Miller) \dedes fulvus pallens E. S. Ross : Aedes grosshecki Dyar & Knab Ross: Mosgutrors or ILLINoIs 17 Aedes implacabilis (Walker) Aedes mitchellae (Dyar) Aedes nigromaculis (Ludlow) Aedes punctor (Kirby) Aedes sollicitans (Walker) Aedes spencerii (Theobald) Aedes sticticus (Meigen) Aedes stimulans (Walker) Aedes thibaulti Dyar & Knab Aedes triseriatus (Say) Aedes trivittatus (Coquillett) Aedes vexans (Meigen) Anopheles barberi Coquillett Anopheles crucians Wiedemann Anopheles punctipennis (Say) Anopheles quadrimaculatus Say Anopheles walkeri Theobald Culex apicalis Adams Culex erraticus (Dyar & Knab) Culex peccator Dyar & Knab Culex pipiens Linnaeus Culex quinquefasciatus Say Culex restuans Theobald Culex salinarius Coquillett Culex tarsalis Coquillett Culiseta inornata (Williston) Culiseta morsitans (Theobald) Mansonia perturbans (Walker) Megarhinus septentrionalis Dyar & Knab Orthopodomyia alba Baker Orthopodomyia signifera (Coquillett) Psorophora ciliata (Fabricius) Psorophora confinnis (Arribalzaga) Psorophora cyanescens (Coquillett ) Psorophora discolor (Coquillett) Psorophora ferox (Humboldt) Psorophora horrida (Dyar & Knab) Psorophora howardii Coquillett Psorophora varipes (Coquillett) Uranotaenia sapphirina (Osten Sacken) Wyeomyia smithii (Coquillett) Key To GENERA LARVAE 1. Eighth segment with a flat spiracular plate, but no air tube, fig. 13..1. Anopheles Eighth segment with an air tube, figs. 17-20 2 2. Air tube short, with some of its sclerites at the apex forming long stout spurlike processes, fig. 18........ 5. Mansonia Air tube without stout processes, its apical sclerites flat or conical, figs. 17, 19, 20 by only an apical pair of double hairs, Sea det 4. Wyeomyia 18 Ittinors NaturAL History SurvEY BULLETIN Vol. 24, Art. Larval parts: A, apex of abdomen; B, dorsum of head. a Fig. 17—Orthopodomyia signifera. Fig. 19—Megarhinus septentrionalis. f Fig. 18—Mansonia perturbans (the air tube Fig. 20—Wyeomyia smithii. Note ventral only.) (After King, Bradley, & McNeel.) brush reduced to only four long hairs. August, 1947 Ventral brush of anal segment consisting of several tufts, figs. 17, 19......... 4 Anal segment with sclerotized plate not meeting ventrad, figs. 102-105. Many Reales OL ays 2 SySe ins. Se akties 9. Aedes Anal segment completely ringed by sclero- perm late, fig. 217 5.205 Ss cece nes 5 Air tube cylindrical and without pecten, MOS ue teh Pe Oe 8 6 Air tube either fusiform, fig. 175, or with a@epecten: figs. 75; 98, 172 02 ok ny 7 Abdominal segments 3—7 with three spine- bearing sclerotized plates on each side, fig. 194; head quadrate, with stout mouth brushes and only a few single dorsal setae, fig. 19B... .2. Megarhinus Abdominal segments 3—7 without lateral plates, sometimes segments 6 and 7 with dorsal saddle, fig. 174; head oval, with fine bushy mouth brushes and with most of the dorsal setae multiple, fig. 17B eh tae irssecad ok ....6. Orthopodomyia Comb teeth situated on the posterior mar- gin of a large sclerotized plate that cov- ers most of the eighth segment; head with four stout black spines; fig. 72 - LEE Ce ee 3. Uranotaenia Comb teeth either on a small, poorly de- fined plate, fig. 172, or not on a plate; head with slender hairs, no stout spines, ESS, 7 cet Ole ana Ag ne ee ee 8 Air tube with a single pair of ventral tufts situated at base, figs. 74, 75 = 6 O60) CO ene 7. Culiseta Air tube either without ventral tufts, or with tuft near middle or apex, figs. 98— 101, or with air tube having several Pairs of tufts, figs. 80-85.......... 9 Air tube with several pairs of ventral tufts of which some may be represented by single long hairs, figs. 79-85 Peretti Satie nicle Seeksue s ccets 8. Culex Air tube with only a single pair of ventral Mitte mOWewith. NONE: -. 2 Soca oe ee 10 Ventral brush of anal segment having sev- eral tufts that arise out of the sclerotized ring, figs. 172-174.....10. Psorophora Ventral brush of anal segment with all tufts situated posterior to sclerotized ring, fig. 111. Some species of. .9. Aedes ADULTS Fork of R»s close to margin of wing, cell Rz only half length of its petiole, Rz,:, Rial ete an Sed wars Fork Rs; much farther from margin of wing, so that cell R» is as long as its Beak curved almost into a quarter circle, palps of both sexes very long, those of female massive, figs. 33, 34; large spe- cies, wing length 6.5 mm............ - 6 C\en O EO eRaar eae 2. Megarhinus Beak only slightly curved, palps of both sexes short and abortive, fig. 32; small 6. a | 10. Ross: Mosourrors or ILLINors 19 species, wing length under 3.5 mm.... Potash MIG ORE A okie Ate 3. Uranotaenia Mesoscutellum with apical margin evenly rounded, the setae arranged evenly along it, fg. 24; male with clavate palps, fig. 37, and female with palps as long as beakyseie p38. a acne sve nrte 1. Anopheles Mesoscutellum with apical margin incised to form a mesal lobe and two lateral lobes, with the setae grouped on these three lobes, fig. 25; male palps not cla- vate and female palps short, fig. 35. . .4 Mesonotum with a mesal line of short setae and scales, and with a wide, pol- ished bare area along each side of the mesal line, fig. 26; hind femur with a tuft of projecting scales at apex, fig. 28. Large species of...... 10. Psorophora Mesonotum without linear, polished bare areas; hind femur with only a few pro- jecting hairs at apex, fig. 30........ 5 Hind tarsi with one or two segments en- tirely white, the remainder entirely blue or black. A few species of.......... eA ce Cae Ae pester 10. Psorophora Hind tarsi either with some segments banded, fig. 29, or all segments nearly phessame calor: cot. erws wee e ae 6 Hind tarsi with wide or conspicuous bands of white on most segments, fig. 29... .7 Hind tarsi with no bands or with only MNCONSPICUOS TONES e/s)- rane eae eel 13 Second, third, and fourth tarsal segments each with a narrow white band at each ENE A2 Dhar sa, ors, cee een ore te en Cte 8 Second, third, and fourth tarsal segments each with a white band at base only, JPET PGW emit ey Rd A ae 10 Beak black, with a definite white band in middle, as in fig. 35. The species tar- SAILS Ay tes ey akc tick erent ea 8. Culex Beak not banded, either all black, or mot- tled, or black with rows of white scales along its entire length............ 9 Mesonotum either without white lines, or generally cream in color as in fig. 119. Av few Species sOL=, 2 jr c)-e ee 9. Aedes Mesonotum nearly black, with a series of Whites linesmast1O) fies 27e. eetiewsiers chee nice Siewatelesre eet aesne sce 6. Orthopodomyia Post-spiracular area entirely bare; hairs on disc of mesonotum long, abundant, and venect, fig. 39/1: s4m)e rs 5. Mansonia Post-spiracular area with bristles or a patch of scales; hairs on disc of prono- tum much more appressed, fig. 41... .11 Outer faces of hind femora in general dark but each with a transverse band of white scales near apex, fig. 31. A few SPECIES OLt 3 Fs <4 horde ons ces 10. Psorophora Outer faces of hind femora without such [ete OR ator cic Micatec rene Gn aia cael a 12 20 Ittinors Naturat History Survey BULLETIN 12. Wings with either Costa banded with white-scaled areas and_ black-scaled areas, or anal vein white scaled for basal two-thirds with apical portion black scaled. A few species of...... ccs MA eaklfel Reval A she: te a cay oe 10. Psorophora Wings either almost uniformly white or — Vol. 24, Art. 1 dark scaled, or the two types of scales — mingled in a salt-and-pepper, patternless — mixture. Some species of...... 9. Aedes | 13. Mesonotum covered with a close mat of — blue-black scales, with bristles only around periphery; fork of Ras basad of © fork of Miz, fig. 22 ..... 4. Wyeomyia Adult Parts Fig. 21—Uranotaenia sapphirina, wing. Fig. 22.—Wyeomyia smithi, wing. Fig. 23.—Aedes vexans, wing. Fig. 24—Anopheles quadrimaculatus, meso- notum. Fig. 25.—A edes vexans, mesonotum. Fig. 26.—Psorophora ciliata, mesonotum. Fig. 27.—Orthopodomyia signifera, meso- notum. Fig. 28.—Psorophora ciliata, hind leg. Fig. 29—A edes canadensis, hind leg. Fig. 30.—Psorophora varipes, portion of hind lec. Fig. 31—Psorophora confinnis, hind femur. Fig. 32—Uranotaenia sapphirina, male: head. Fig. 33—Megarhinus septentrionalis, male. head. Fig. 34—Megarhinus septentrionalis, female: head. Fig. 35.—Aedes sollicitans, female head. Fig. 36.—Orthopodomyia signifera, female: head. Fig. 37—Anopheles quadrimaculatus, male: head. Fig. 38.—Anopheles male head. quadrimaculatus, fe- August, 1947 Ross: Moseurtoets oF ILLINOIS 21 Adult Thorax, Lateral Aspect. bristles or scales; s, spiracle; sb, spiracular bristles. Fig. 39—Mansonia perturbans. Fig. 40.—Culiseta inornata. 14. 15. 16. Mesonotum with several series of erect bristles extending above scales on disc, fig. 42; fork of Res at about same level as that of Mus, fig. 23............ 14 Mesonotum either with broad lateral bands or areas of white or cream scales, figs. 115, 120-123, or almost entirely covered with cream scales........ 15 Mesonotum mostly dark scaled, at most with a scattering of light scales, or with narrow weak lines of them........ 16 Hind tibiae enlarged and shaggy toward apex, with setae not longer than width of tibia at apex, fig. 30; spiracular bristles usually present, fig. 41. A few BHIGELESEOLGI a: > beret aac tare 10. Psorophora Hind tibiae slender to apex, not shaggy, often with a scattering of setae longer than width of tibia at apex, figs. 29, 125, 126; spiracular bristles absent. Many species of ........... 9. Aedes Post-spiracular area bare, and spiracular bristles lacking, as in fig. 39........ +g 2 Eo Se 8. Culex Thorax either with post-spiracular area having bristles or scales, fig. 42, or spiracular bristles present, fig. 40, or 1 EV, = Sk BC ga ne cee ee 17 Spiracular bristles present; post-spiracular area sometimes with scales but never with hairs, fig. 40........ 7. Culiseta Abbreviations: pm, pronotal bristles; ps, post-spiracular Fig. 41.—Psorophora confinnis. Fig. 42.—Aedes stimulans. ue Without spiracular bristles; post-spiracu- P P P lar area with hairs or hairs and scales, fig. 42. Many species of..... 9. Aedes MALE GENITALIA Dististyle with a contorted mass _ of branchesw tpse4-6\o-ceee eee 4. Wyeomyia Dististyle either unbranched, fig. 43, or with only one or two simple lobes, figs. HCI AJ pat, SANS Me Saale Mile pCa CuCrSear7 A pair of subcylindrical arms (claspettes) arising from dorsum of capsule, and tipped with a sclerotized filament, figs. 136-158. Most species of... .9. Aedes Claspettes absent, platelike, fig. 70, or each tipped with a cluster of spines, fig. 177 Dististyle bilobed, its mesal margin bear- ing a long hook and a large membranous lobe, fig. 178. The species howardii in She ertae anarotanaes. scenacane 10. Psorophora Dististyle without an accessory membra- MOUSMIODEN mipee-yens corer eae tae tate hat eira ates + Basistyle with an apico-mesal shoulder bearing a cluster of specialized, blade- like or spatulate spines, which are fre- quently complex in structure, figs. 88—95 Nc pate gs ie Reta er tsen ey eye ae 8. Culex Basistyle either without an apical shoul- der, or the shoulder bearing only nar- LOWS PLNEStece clone lokenese at chen crmmtaliseever arate 5 22 Intinors Natura Hisrory SurvEY BULLETIN Vol. 24, Art. 1 5. Apex of basistyle continuing as a pointed Claspettes absent or platelike, fig. 70, dis- lobe beyond insertion of dististyle, fig. tistyle of various shapes........... 3 135. The species cimereus in.......... 8. Basistyle with a stout peglike rod on mesal See eet acs AO mR OME TE Rog ci echale 9. Aedes face near middle; dististyle with apical Dististyle situated at apex of basistyle, half very wide, its apical seta forming Gi AS ie re EE he Mera tent py NUR eS eS 6 a stout spurlike tip, fig. 43.......... 6. Dististyle with a pointed lobe projecting .........0.ee eee eeaee 5. Mansonia beyond apical spur, fig. 133. The spe- Basistyle frequently with one or more CLES! PEMA Sle nele eo taeene eel wale 9. Aedes stout setae on mesal face, but never with Dististyle with apical style terminal, fig. a rodlike structure; dististyle either not 45, or apex round, fig. 47, or truncate, enlarged at apex or with a peglike or Thanet Rema te aces ARIE MI Batic, bARGi Oks Pitot 7 hairlike apical seta, figs. 45, 47...... 9 7. Claspettes each with a stalklike base, and 9. Basistyle short and ovate, with a pair of with a comblike cluster of spurs or setae large, stout spines dominating the ven- at apex, figs. 177, 179-182; dististyle tral aspect of the basal portion, fig. 70 sinuate, fig. 177, or bulbous, figs. 179— ee ee eee 1. Anopheles 182. Most species of. . .10. Psorophora Basistyle either long and slender, fig. 45, Male Genitalia Fig. 43—Mansonia perturbans, ventral as- Fig. 45.—Orthopodomyia signifera, ventral pect, and lateral aspect of dististyle. aspect. Fig. 44—Uranotaenia sapphirina; A, ven- Fig. 46—Wyeomyia smithii; A, ventral as- tral aspect, with lateral aspect of dististyle; pect; B, lateral aspect. B, mesal aspect of clasper, with mesosome and Fig. 47.—Megarhinus sedtentrionalis, ventral other mesal structures removed. aspect. August, 1947 19. or without a pair of isolated stout spines on basal portion of ventral aspect, fig. MERE Sn ibs 3 Aft nt ct i ahis"e lee e¥ane 10 Ninth tergite forming a large bilobed sclerotized plate whose lateral lobes are nearly as long as the basistyle, fig. 44. . 2 Sachse 3. Uranotaenia Ninth tergite forming at most a plate as SPR ACHING: 4-7-1. 5 ots. = eo Sass 5 tere 11 Apical seta of dististyle single, slender, and pointed at tip, figs. +7, 134..... 12 Apical seta of dististyle short and either divided, fig. 78, or truncate at tip, fig. SEMEN Nes ook! chic icus Reap ta leye sie: pet Je 13 Ross: Mosgurrogs oF ILLINOIS 12. 13 23 Base of basistyle with a mesal, arcuate pad bearing a crown of stout spines; dististyle cylindrical, with apical spine just before apex, fig. 47. .2. Megarhinus Base of basistyle without a mesal pad; dististyle tapering toward apex, apical spine issuing from tip, fig. 134. The species aegypti in.......... 9. Aedes Apical spine of dististyle double, each ray short and stout; mesosome without lat- eral teeth at apex, fig. 78...7. Culiseta Apical spine of dististyle cone shaped, wide and truncate at apex, and with what appears to be a minute fringe Female Genitalia: Fig. 48—Anopheles quadrimaculatus. Fig. 49 —Uranotaenia sapphirina. Fig. 50.—W yeomyia smithii. Fig. 51—Mansonia perturbans. Fig, 52.—Orthopodomyia signifera, A, lateral aspect; B, ventral aspect; C, dorsal aspect. ¢, cercus; p, postgenital plate; 7, insula plate. Abbreviations: Fig. 53.—Culiseta inornata. Fig. 54.—Culex restuans. Fig. 55.—Culex apicalis. Fig. 56.—Culex erraticus. Fig. 57,—Megarhinus septentrionalis, 24 Ittinois NaruraL History SurvEY BULLETIN Vol. 24, Art. 1 along the edge; mesosome with a few short, lateral teeth at apex, fig. 45.... AE UALS eh cry Cutis 6. Orthopodomyia FEMALE TERMINALIA 1. Cerci round and finger-like, wide apart and directed almost dorsad, fig. 48.... Sh ae epee St Ia Parnas 1. Anopheles Cerci either closer together, or leaflike and directed posterad, figs. 49-57........ 2 Fig. 58—Abdomen of adult female, lateral aspect. A, Culiseta inornata; B, Acdes aegypti; C, Psorophora ciliata. Abbrevia- tions: c, cercus; p, postgenital plate. 2. Eighth segment retractile, markedly nar- rower than seventh and joined to it by a wide band of membrane, figs. 58B, C; cerci either long and narrow, fig. 159, or extending far beyond postgenital plate, fie LUGO che tac aeatlent ee areen aOR Sae 3 Eighth segment not retractile, practically the same diameter as the seventh, joined to it by a narrow strip of membrane, fig. 584; cerci short and extending little if at all beyond end of postgenital plate, Tete OO /iea Berane Cuba Gee oaid 6.0 ooh 4 Ninth tergite consisting of a fairly wide, indefinitely outlined rectangular dorsal sclerite, figs. 159-167........ 9. Aedes Ninth tergite consisting of a heavily scle- rotized, longitudinal rod enlarged at apex and extending basally beneath eighth tergite, fig. 184. .10. Psorophora 4. Postgenital plate extending considerably es) beyond cerci, fig. 50..... 4. Wyeomyia Postgenital plate extending only slightly if at all beyond cerci, fig. 49........ 5 5. Eighth tergite long and wide, forming a flat hood that extends considerably be- yond sternite; ninth segment and cerci 5 ry flattened and horizontal, fig. 57...... i ch seed ny eer 2. Megarhinus Eighth tergite hemicylindrical, shorter than sternite and not at all hoodlike, fe SY AOE OE GG rc 3 alge 6 6. Cerci with base enlarged, middle con-— stricted, and apex expanded, fig. 52... . eee eee SO TS: a0 6. Orthopodomyia | Cerci with base not at all enlarged, but sometimes expanded at apex, fig. 51..7 7. Insula plate well developed as a sclero- tized, arcuate, cushion-like crescent, fig. 49; ninth tergite with apical margin rounded and sclerotized, slightly over- hanging base of cerci.......... es se ay Bags Lo toon de poe Sa 3. Uranotaenia Insula plate either entirely membranous — or forming a band that bears a small mesal tuft of setae, fig. 53.......... 8 8. Cerci from edge to edge almost vertical in position, the apex markedly widened ; eighth sternite nearly twice length of eighth tergite, fig. 51..... 5. Mansonia Cerci from edge to edge inclining to hori- zontal in position, the apex narrowed at least slightly, fig. 53; eighth sternite longer than eighth tergite, but not as much longer as in Mansonia.......- 9 ) 9. Postgenital plate parallel sided and trun- cate, with a long apical seta near each corner and many small setae on the cen- tral area, fig. 161; ninth segment nar- row. A few species of...... 9. Aedes » Postgenital plate rounded or pointed, with | a row or cluster of several scattered setae near apex, fig. 54; ninth segment WIE Soe ogtr en ae ace Chek id eee 10) 10. Postgenital plate very wide, as in fig. 56) area hae ony tae 8. Culex Postgenital plate much narrower, figs. 532255 ais cuecns rks eho chalet eae eee 11 11. A U-shaped internal sclerite present in) membranous folds of spermatheca, fig. © 54 scene yo aces ale cape Veta 8. Culex « No distinct internal sclerite evident in) folds of spermatheca, fig. 55....... 122 12. Ninth tergite forming a sclerotized, fairly | straight bridge, with a pair of clusters ~ of setae situated close together, fig. 53.._ SASL do A ees ee Oe eee 7. Culiseta | Ninth tergite consisting of irregular folds ~ at most scmisclerotized, with clusters of setae situated far apart near lateral | margins, fig. 55).))...\. sysname 8. Culex + 1. ANOPHELES Meigen Of the Illinois mosquitoes, Anopheles is- the most distinctive genus and the most’ important one. The larvae, fig. 13, are’ readily distinguished by the platelike aper- August, 1947 ture of the breathing apparatus, which in all other Illinois mosquito larvae is tubu- lar; the adults have the scutellum evenly rounded, not trilobed, and the males have the apical segments of the palps greatly enlarged, fig. 37. According to present information, Anopheles quadrimaculatus is the chief carrier of malaria in Illinois. In proportion to their size, few mosquito genera present so many difficulties regard- ing larval identification as the North Amer- ican Anopheles. There is undoubtedly much variation within many of the species, both Ross: Mosauirors oF ILLINOIS 25 in the hair arrangement of the larvae and in the details of the male genitalia. Conse- quently, in Illinois the main basis for identi- fication of the species in this genus should be the adult females. In other sections of the country the larvae may present the only reliable characters for certain complexes of the species. Many keys have been presented for the identification of males by means of the genitalia. The studies of Roth (1944), however, have substantiated my own obser- vation that the characters of the male geni- talia can be used only on an average basis Heads of Anopheles Larvae Fig. 59—A. barberi. (After Ross & Rob- erts.) Fig. 60—4A. occidentalis (inner clypeal hairs only). Fig. 61—A4. punctipennis. (After Ross & Roberts.) Fig. 62.—d. quadrimaculatus. & Roberts.) Fig. 63—A. walkeri. (After Ross & Rob- erts.) Hair numerals used on this plate are those currently employed in the taxonomic literature on mosquitoes. (After Ross 26 and cannot be used as a means of absolute diagnosis in all cases. The recent work of Ross & Roberts (1943) and Roth (1944) illustrates exten- sively many diagnostic and other structural features of this genus. Additional descrip- tions and a summary of distribution is given by King & Bradley (1941), and biological material by Bradley & King (1941). An interesting study of variation in-larval char- acters has been made by Roth (19456). To date, five species of this genus have been taken in Illinois. A sixth, occidentalis, has been taken in Iowa across the Missis- sippi River from Illinois. As it undoubt- edly occurs in Illinois, it has been included in the key. Key TO SPECIES LARVAE 1, Head hairs 5, 6, and 7 short and simple, fig. 59; lateral body hairs with only short feathering.......... 1. barberi Head hairs 5, 6, and 7 long and plumose, fig. 61; lateral hairs of thorax and first Ittinois NatruraAt History nN Sse Survey BULLETIN Vol. 24, Art. 1 three abdominal segments with long feathering, fig, 64.4). samen 2 Fourth and fifth abdominal tergites with hairs 0 and 2 plumose, fig. 65........ «Sales Sualal sue bese Gee 5. crucians Fourth and fifth abdominal tergites either with hairs 0 inconspicuous or with hairs 2 only single or double, fig. 64...... 3 Head hairs 3 very dense, fan shaped from base, so that no basal stalk is evident, fig. 63; head hairs 2 sometimes feathered at tip; prothoracic hairs 1 sometimes branched’. 5 oh.7 Wiel 3. walkeri Head hairs 3 less dense, the fan shaped portion beginning some distance from base so that a basal stalk is formed, fig. — 61; head hairs 2 never feathered at tip; prothoracic hairs 1 rarely branched... Second abdominal segment with hairs 1 well developed, sclerotized and palmate, MOAR AOS Sk en ne 2. quadrimaculatus Second abdominal segment with hairs 1 small, at most fanlike, fig. 65, not at all like the palmate hairs on segment 3. .5 Parts of Anopheles Adults 64 Fig. 66.—A. punctipennis, wing and mouth- parts. Fig. 67.—A. crucians, wing and mouthparts. Fig. 64—Anopheles quadrimaculatus, larva, Fig. 68.—A. quadrimaculatus, wing and portion of dorsum. mouthparts. Fig. 65—Anopheles crucians, larva, portion of dorsum. Fig. 69.—A walkeri, mouthparts. (Figs. 64— 69 after Ross & Roberts.) August, 1947 Ross: Mosourrors oF ILLINors 27 5. Head hairs 2 wide apart, fig. 62........ Wings without any pale patches, all scales 5 Sate oe eae 2. quadrimaculatus dark, fig. 68, except sometimes apical Head hairs 2 close together, fig. 61..... 6 POISE MALE a const rer of Satie oy ate er etrciw 3 6. Head hairs 2 always simple, fig. 61..... 2. Anal vein with 3 short dark bars sepa- PUTER soccer ss tye See 4. punctipennis rated by white bars; palps dark with At least one of the two head hairs 2 usu- white bands, fig. 67; Costa with a white ally with a conspicuous branch, fig. 60. . spot only at apex of wing. . .5. crucians BEEP ozs lel sisiw ssa d.si a occidentalis Anal vein with apical half and extreme base black, and with a single white area VUES between; palps black, unbanded, fig. 66; 1. Wings with spots or bars of white or yel- Costa with an apical white spot and lowish-white scales along anterior mar- usually also a preapical spot or bar... PUSAN A VEL NES! GO 10 hieevaie abana | 2. pllelel aiayokesseeuar deere) oh re 4, punctipennis 70 B BARBERI QUADRIMACULATUS Figs. 70-71—Male genitalia of Anopheles. A, phallosome; B, claspettes; C, ventral aspect of entire structure. Abbreviations: Bs, basistyle; Cl, claspettes; Ds, dististyle; [XT, ninth tergite; Pb-s, parabasal spine; Pi, phallosome; P-JXT, process of ninth tergite; Pr, proctiger. (After Ross & Roberts.) 28 Intinors NaTurAL History SurvEY BULLETIN 3. Tip of wing with a patch of silvery or golden fringe scales; dark wing spots very pronounced......... occidentalis Tip of wing with fringe not different from remainder; dark wing spots frequently ODSCUREN Mies etch oe stntecaael sore ve vousjfener eke ke 4 4. Palps narrow and filiform, fig. 38 (fe- ALES) Peete ated vert centers eheee enti 5 Palps enlarged into an oval apical club, SPS /AN (BLES) ceeaeiatapsPeteeiie mee petet ans uch 7 5. Palps black, with white rings, fig. 69.... Pech cane SR REN CM ree TCE Sa 3. walkers Palps entirely black, without rings, fig. 68 Ra et enade oR eNeT ee Ceeeateae ec aemeie tebe dc Geka t= 6 6. Wings without a trace of spotting; wing length about 3.5 mm........ 1. barberi Wings with definite darker areas giving a spotted appearance, fig. 68; wing length about 5.0 mm...... 2. quadrimaculatus 7. Mesosome without leaflets at apex, fig. 70; wing length under 3.5 mm...1. barberi Mesosome with a cluster of leaflets at apex, fig. 71; wing length over 3.5 mm. 8. Lobes of ninth tergite stout, apex wide, sometimes enlarged, fig. 71.......... DS ees EA HLA ae Ne 2. quadrimaculatus Lobes of ninth tergite narrower, usually tapered at apex.......... 3. walkeri 1. Anopheles barberi Coquillett Larva.—Fig. 59. Length 6 mm. Head with almost all hairs simple and unbranched, especially conspicuous being hairs 3, 5, 6, and 7. Thorax and abdomen with only short feathering on lateral major hairs. Segments 3-7 with a pair of palmate hairs, segment 2 with moderately developed pal- mate hairs. Pecten consisting of an irregu- lar series of long teeth, each tooth with ser- rations at base. FEMALE.—Wings with veins having almost uniformly dark scales, neither the field of the wing nor the fringe with dark spots or light patches. Mate.—Similar in color and general structure to female. Genitalia, fig. 70, with two large parabasal spines; mesosome tapered, without apical leaflets; claspettes with three setae on the ventral lobe and three broad scales arising in a compact group from the dorsal lobe. This species contains the smallest individ- uals of Anopheles in North America, mos- quitoes that in general appearance are easily confused with small dark Culex individuals. The setation of the larvae and structures of the male genitalia separate this species indu- Vol. 24, Art. 1 bitably from all other North American anophelines. It has been found in only a few of the many tree holes investigated and is either much more critical in its choice of breeding place or much less abundant than several other tree hole species such as Aedes tri- seriatus. As pointed out by King, Bradley, & McNeel (1939), this species has been proved susceptible to malaria parasites but is of doubtful importance in malaria trans- mission. It is widely distributed in the southern and eastern states. Illinois Records.—Six larvae, collected June 29 to July 6, and many males and females, col- lected May 25 to October 10, are from Alton (uspHs), Cahokia (uspHs), Camp Ellis (UsPHs), Carterville (UsPHs), Crab Orchard Lake (UsPHS), Des Plaines, East Alton (UsPHs), East St. Louis, George Field (uspHs), Hamp- shire (UsPHS), Johnston City (UsPHs), Marion (usps), Momence, Mount Vernon (usPHs), Onarga, Savanna (UspPHs), Scott Field (UsPHs), and Springfield (usPHs). 2. Anopheles quadrimaculatus Say Larva.—Fig. 62.—Length 8 mm. Head with hairs 2 long, simple and widely sepa- rated; hairs 3 plumose, branching some dis- tance from base; hairs 5, 6, and 7 long and plumose. Thorax and first three segments of abdomen with long feathering on lateral major hairs. Abdominal segments 4 and 5 with hairs 2 usually single, rarely double; of the total of four “hair 2’s” on segments 3 and 4, seldom is more than one double. Palmate hairs on segments 3 to 7, frequently also on segment 2. Pecten with a series of well-spaced long teeth, between each of which is a group of three or four short teeth. Body hairs shown in fig. 64. FemMALe.—General color dark brown. Palps entirely dark brown to black, with no annulations. Wings, fig. 68, uniformly dark scaled, the scaling slightly darker at the fork of Res, Miz, the base of Rs and the base of Rus. These darker scalings make four dark spots, sometimes very pronounced, sometimes scarcely perceptible. Mate.—Similar in color and general structure to female. Genitalia, fig. 71, with two large parabasal spines; mesosome slen- der, its apex with a group of three leaflets on each side; claspettes each with setae of dorsal lobe round at tip, those of ventral lobe sharp and pointed. The number of setae on each lobe varies considerably; if August, 1947 only two or three are present on the dorsal lobe, they may fuse at the tip. The diagnosis of this species is clear cut only in the female. The separation of the larvae of this species from those of puncti- pennis is frequently difficult. Nearly all the specimens I have seen from Illinois will key out without difficulty, but an occasional larva is encountered that falls squarely be- tween the two alternatives of couplet 5. In our series of associated larval skins, there is considerable variation in the branching of hair 2 on abdominal segments 4 and 5; the more reliable character seems to be the dis- tance apart of head hairs 1. The males are extremely close to those of walkeri, although in all of our specimens the separa- tion on the lobes of the ninth tergite is fairly satisfactory. The halteres of quad- rimaculatus are usually much darker than those of walkeri, but these characters vary somewhat, and, in preserved specimens, the difference tends to disappear with time. In Illinois, the breeding season of quadri- maculatus begins nearly a month after that of punctipennis in the south and of walkeri in the north, indicating a restriction imposed by water temperature. The preference for warmer water is further suggested by the abundance of quadrimaculatus in more open and still bodies of water during the heat of the summer when punctipennis is found only in more heavily shaded or mark- edly cooler waters. The habitat preference of quadrimaculatus, which is quite wide, includes small pools, backwaters, and shal- low basins of large lakes and marshes. Abundant populations of larvae are almost always associated with emergent vegetation, ranging from plants such as Jussiaea diffusa, which never extends more than a few inches above the water surface, to cattails, rushes, and shrubs reaching a height of several feet. We have a few records of guadrimaculatus living in running water, but these were in Situations where the water was shallow and warm, and the flow extremely sluggish. Biting records indicate that the females are crepuscular and nocturnal. On cloudy days we have noticed a tendency for the females to bite early in the afternoon, but normally they bite no earlier than shortly before dusk. Their bites are seldom painful and often go unnoticed. This species is considered the most impor- tant carrier of malaria in the United States east of the Rocky Mountains. Ross: Mosourrors oF ILLINOIS 29 Illinois Records——Many larvae, collected June 2 to October 1, and many males and females, collected May 16 to November 15, are from Algonquin, Antioch, Belleville (uspHs), Benton, Bonnie, Cahokia (uspHs), Cairo (usPHsS), Camp Ellis (UspHs), Camp Grant (uspHs), Carbondale, Carterville (UsPHs), Caseyville, Champaign, Chanute Field (uspus), Charleston, Crab Orchard Lake (uspHs), Dan- ville (UspHs), Decatur (uspHs), Detroit, Dubois, Dwight (UspHs), East Alton (uspus), East Hannibal, East Moline (uspus), East Peoria (UspHs), East St. Louis, Edgemont, Edwardsville, Elgin, Elsah, Evansville, French Village (UspHs), Galesburg (UspHs), George Field (uspHs), Gibson City (UspHs), Gibsonia, Glendale, Gorham, Grafton (uspHs), Grand Tower, Granite City (uspHs), Hampshire (USPHS), Havana, Hecker, Herod, Herrin, Hull, Johnston City (uspHs), La Rue, Law- renceville (UsPpHs), Makanda (uspHs), Marion (uspHs), Milford (uspHs), Mississippi Pali- sades State Park, Momence, Mound City (usPHs), Mount Vernon (uspHs), Mulberry Grove, Oakwood, Olive Branch, Olney, Omaha, Palos Park, Pere Marquette State Park, Port Byron, Rockford (uspHs), Rock Island (uspHs), St. Jacob, St. Joseph, Savanna, Scott Field (UsPHs), Seneca (UsPHs), Spring- field (UspHs), Starved Rock State Park, Thom- son, Urbana, Ursa, Vienna, Waltersburg, and Ware. 3. Anopheles walkeri Theobald Larva.—Fig. 63. In size and general color similar to quadrimaculatus. General structure of head and body as described for quadrimaculatus, except for the following difierences: head hairs 2 close together, in our Illinois specimens almost always single and very long, rarely with one or two fine branches near tip. Abdomen some- times with well-developed palmate hair on segment 2, segments 4+ and 5 with hair 2 usually single and very long, rarely double or triple. The best diagnostic character found to date is head hair 3, which is densely branched from the base and therefore lacks a basal stalk. FemMALE.—In color similar to guadrimacu- datus with the exception of the palps, fig. 69, which are black with a narrow white annu- lation at each joint. The wing spotting is identical with that of quadrimaculatus. Maxe.—Genitalia very similar to those of quadrimaculatus, differing in the more slender lobe of the ninth tergite; usually the ventral lobe of the claspette has only one stout and one slender seta. 30 Ittinois Narurat History Survey BULLETIN It is noteworthy that the diagnostic char- acters for the larvae of this species, which have been stressed by King & Bradley (1941) and by Ross & Roberts (1943), are not applicable to Illinois specimens. Fol- lowing are characters listed by these authors and, in parentheses, my own observations on Illinois specimens: head hair 2 finely branched at tip (only an occasional Illinois specimen has these hairs branched and then with only one or two branches); protho- racic hair 1 branched (this hair is usually single in Illinois specimens) ; and hair 0 dis- tinct and many branched (in only a rare Illinois specimen is hair 0 discernible). The densely tufted head hair 3, however, is an excellent diagnostic character, our associ- ated larval skins indicate. This same char- acter is well illustrated by Ross & Roberts. This species is abundant in the marshes of extreme northeastern Illinois. Outside of this area we have Illinois records from only three widely separated localities, all from the Mississippi River valley region. These three localities are Savanna and nearby Thomson (the northwestern corner of the state), East Hannibal (almost at the center on the western margin), and Scott Field (a short distance south of the St. Louis area). All our collections have been made in cat- tail marshes, to which this species appears to be restricted. In the northeastern cor- ner of the state this species is found in prac- tically every marsh and bog in which cat- tails are found. ‘The larvae have never been found there in abundance. Collecting which nets one larva per five dips is unusual; usually the proportion is closer to one larva per 20 dips. The marshes, however, are very extensive in this section, and the species is quite abundant. Unlike the females of quadrimaculatus, the walkeri females bite readily during the day as well as during the evening. In early summer they are espe- cially vicious and will attack a person in bright sunlight. In northeastern Illinois, adults and full grown larvae have been collected early in June and also late in October. The species has a great tolerance for cool water and is similar to 4. punctipennis and Culiseta inor- nata in this respect. It is interesting to note that walkeri is considered rare south of northern Illinois. In northern Illinois and northward, it is one of the dominant species of the anopheline populations, as shown by our Illinois collec- Vol. 24, Art. 1 tions and by studies in Minnesota and Wis- consin by Daggy, Muegge, & Riley (1941). Tllinois Records—Larvae, taken May 19 to September 15, and many males and females, collected May 19 to November 1, are from Antioch, Beach, Camp Grant (uspHs), Cary, East Hannibal, Fox Lake, Franklinville, Great Lakes Naval Training Station, Lake Bluff, Lake Zurich, Orland Park, Savanna (USPHS), Scott Field (uspHs), Thomson, Volo, Wau- conda, Waukegan, Woodstock, and Zion. 4. Anopheles punctipennis (Say) Larva.—Fig. 61. Length 8 mm. Color and general conformation of hairs on head and body as for guadrimaculatus. Diag- nostic characters as follows: head hairs 2 long and single, the pair close together at base; head hairs 3 each with multiple branching that begins some distance from the base, so that the base of the hair forms a distinct stalk; palmate hair of second abdominal segment reduced; abdominal seg-— ments 4 and 5 with hairs 2 usually double, occasionally single or triple, the single, dou- ble, or triple hairs occurring in almost any combination on different specimens. FEMALE.—Body dark brown, with the mesonotum clothed with grayish scales and the wings definitely patterned with dark and cream color. out white annulations. Typical wing pat- tern, fig. 66, having a white costal patch near apex and a preapical white patch one-third the distance between apical spot and base of wing, this preapical spot including adja- cent portions of C, R:, and Reais; in addition there are variable areas of white scales near — the base of Rs and M, Mi, Mz, and M2; a diagnostic and stable area of white scales occupies most of the basal half of the anal vein. Mate.—General structure and color, especially wing pattern, as for female. Gen- italia in general as for quadrimaculatus with the following average differences in the claspette: dorsal lobe usually with only ~ one seta, which may be round or pointed at apex; ventral lobe usually with only one stout and one narrow seta in addition to one or two short setae. Occasional larvae are found that seem to bridge the gap between punctipennis and quadrimaculatus. The number of such larvae, however, appears so small as to be of no statistical importance in proportional — Palps entirely dark with-— August, 1947 counts because 99 per cent of all the larvae taken can be identified with certainty. Extreme variation of wing pattern has been found in Illinois material of this species. Two wing spots appear to be con- stant, the apical costal spot and the white bar on the base of the anal vein. All the other spots vary greatly, and occasionally additional white bars appear on practically all the radial and medial veins. The pre- apical spot is subject to the most conspicuous variation. Usually it is about one-half as long as the dark bar separating it from the apical spot. In the light extremes, the pre- apical spot may be fully as long as this dark bar; in dark extremes the preapical spot may be only a quarter or a sixth as long as the bar; and in rare instances no preapical spot may be present. Our collections indicate that there is no particular significance to these variations. We have taken a wide range of these types in a single collection from one locality, and seldom does a large collection from one locality present even a reasonable homogeneity in regard to wing spots. In Illinois, punctipennis is undoubtedly the most widespread and common species of Anopheles. It breeds in a wider variety of aquatic situations than the other species in the genus. We have taken it in running streams, backwaters of lakes, cattail marshes, densely wooded cypress swamps, and open and practically barren pools. In southern Illinois, it is the earliest anopheline to make its appearance, the first adults usually emerging by about the middle of April. In the northern part of the state, mature larvae and pupae have been collected in the mid- dle of October. In early spring it shows a preference for open sunlit water. In the heat of summer, at least in southern Illinois, it leaves the open situations almost entirely and breeds in fairly densely shaded situa- tions, such as pools and creek beds, running streams, cypress swamps, or woodland pools. Both seasonal distribution and habitat indi- cate a preference for cooler water than that frequented by quadrimaculatus. In the northern part of the state this segregation is not so pronounced; here punctipennis and quadrimaculatus are frequently taken to- gether in the same body of water. Although punctipennis is extremely widely distributed, it has never been found in the tremendous local abundance that character- izes populations of quadrimaculatus. Evi- Ross: Moseuirors oF ILLINOIS 31 dence at present indicates that punctipennis is not an important carrier of malaria under natural conditions, although the species be- comes infected readily under experimental conditions. Illinois Records—Many larvae, collected May 14 to October 14, and many males and females, collected April 17 to November 29, are from Albion, Algonquin, Belleville (uUspHsS), Brubaker, Cache, Cahokia (usPHs), Cairo, Calvin, Camp Ellis (uspHs), Camp Grant (uspHs), Carbondale, Carterville (usPpHs), Champaign, Chanute Field (uspHs), Charleston, Council Hill, Crab Orchard Lake (uspHs), Decatur (UuspHs), Dixon Springs, Dwight (usPpHs), East Alton (uspHs), East Moline (uspHs), East Peoria (uspHs), East St. Louis, Edwardsville, Effingham, Elsah, Epworth, Florence, Forest Glen, Fox Lake, Fox Ridge State Park, French Village (usPHs), Fulton (uspHs), Galesburg (uspHs), George Field (uspHs), Giant City State Park, Gibson City (uspHs), Gorham, Gossett, Grafton (uspHs), Grand Tower, Granite City (USsPHs), Grantsburg, Greenville, Grimsby, Hamilton, Havana, Herod, Herrin, Joetta, Johnston City (usPHs), Jonesboro, Kankakee, Karnak, Keiths- burg, Laclede, La Grange, Lake Villa, La Rue, Lawrenceville (UspHs), Lima, Maroa, Marion (uspHs), McClure, Michael, Mill Shoals, Mis- sissippi Palisades State Park, Momence, Mount Carmel, Mount Vernon (usPpHs), Mulberry Grove, Muncie, Neoga, New Athens, New Haven, Nutwood, Oakwood, Oak Park, Olney, Omaha, Palos Park, Pere Marquette State Park, Pingree Grove, Pittsburg, Pittsfield, Quincy, Richmond, Ridge Lake, Rising Sun, Rockford (uspHs), Rock Island (UsPHs), Rock- ton, St. Jacob, St. Joseph, Salem, Savanna (uspHs), Scott Field (UspHs), Seneca (USPHS), Springfield, Starved Rock State Park, Sugar Grove, Thomson, Urbana, Ursa, Utica, Viola, Waltersburg, Ware, Waterloo, Wauconda, White Heath, White Pines Forest State Park, Willow Springs, Wolf Lake, and Zion. 5. Anopheles crucians Wiedemann Larva.—Fig. 65. Color, size, and general conformation of hairs on head and body as for quadrimaculatus. Diagnostic characters as follows: head hairs 2 long and single, the pair close together at base; head hairs 3 each with multiple branching that begins some distance from base, so that the base of the hair forms a distinct stalk; palmate hair of second abdominal segment reduced; abdom- inal segments 4+ and 5 with hairs 0 and 2 multiple and conspicuous. FeEMALE.—Body dark brown, the mesono- 32 Ittrnois NaturAL History Survey BULLETIN tum clothed with linear areas of grayish scales, and the wings patterned with dark and cream color. Palps dark, with the short apical segment white and with a conspicu- ous white band at the base of the third seg- ment. Typical wing pattern, fig. 67, having the costal margin entirely dark scaled except for a white patch at the apex of the wing; in addition there are areas of white scales on all the veins posterior to R:; a diagnostic feature is the alternation of white and dark- scaled areas on the anal vein. Mate.—General structure and color, especially wing pattern, as for female. Geni- talia very similar to those of punctipennis males. In Illinois this species has been taken in numbers only in the St. Louis area and southward. Two apparent stragglers have been taken north of this area, one at Havana and one at Peoria. The species is wide- spread south of Illinois, and our records represent probably the northern edge of its range. Our only larval records are from cattail marshes in the Mississippi River valley. In an extensive cattail marsh at La Rue, IIli- nois, this species was especially abundant. The larvae were taken in company with those of qguadrimaculatus, which outnum- bered the crucians larvae almost two to one. Light trap collections indicate that crucians is never a dominant feature of the mosquito fauna in Illinois. Illinois Records—Many larvae, collected May 22 to October 1, and many males and females, collected June 16 to October 4, are from Alton (uspHs), Cache, Cahokia (UsPHs), Carterville (UspHs), Crab Orchard Lake, East Alton (uspHs), East St. Louis, Granite City (usPHs), Havana, Herrin, Johnston City (uspHs), La Rue, Marion (uspHs), Mount Vernon (USPHS), Peoria (UsPHS), and Scott Field (USPHS). 2. MEGARHINUS Robineau-Desvoidy Individuals of this genus are among the most peculiar in the state. The adults are large and brilliantly colored. The probos- cis is markedly curved, as in figs. 33 and 34, not adapted for biting but for feeding on nectar. The larvae as well as the adults are very large and may be identified immedi- ately by the small sclerotized plates upon which many body setae are situated. The larvae are restricted to tree holes, in which they are predaceous upon other mosquito Vol. 24, Art. tm larvae. According to previous workers, the eggs are laid singly on the surface of the water. Only a single species, septentrionalis, has been taken in Illinois. The only other Nearctic species, rutilus Coquillett, is very closely allied and has never been collected north of the extreme southeastern United States. 1. Megarhinus septentrionalis Dyar & Knab Larva.—Fig. 19. Head quadrate, with well-developed mouth brushes; antennae very short, with only one or two minute setae; dorsum of head with only a few minor setae. Body hairs long and stout, each seg- ment of thorax with one sclerotized plate bearing the dorsal lateral tuft and another bearing the ventral lateral tuft. Segments 1—7 of the abdomen with the long seta situ- ated on tubercle-like sclerotized plates, the first segment with four on each side, the remaining segments with three, each bearing one to several long setae. Eighth abdominal segment with a large lateral sclerite bearing — several long apical setae and representing the lateral comb. Air tube short and stout, with a pair of ventral tufts near base. Anal segment large, completely enclosed in a heavily sclerotized ring, and having short budlike gills and hair tufts as in fig. 19. FEMALE.—Length of wing 7 mm. Body — and appendages with metallic iridescent scales. Palps and beak a mixture of bluish- purple and gold scales, dorsum of head greenish. Mesonotum with lateral and mesal stripes of greenish gold, the interven- ing bands black, purple, and green. Dor- sum of abdomen almost entirely greenish purple, apical segments with a few lateral patches of silvery scales; venter almost en- tirely creamy gold, with a mesal greenish- purple stripe. Legs, for the most part, pur- plish; the middle and hind tarsi with the — second, third, and fourth segments white; the hind tarsi with the fourth and fifth seg- ments white; the femora with the base and posterior face of each mostly cream. Wings entirely purple scaled. ‘The female geni- talia are dorso-ventrally compressed, fig. 57, and in this respect the species is quite unlike any other Illinois mosquito group. Mate.—In size and general color similar to female. The tarsi are black, except for the fourth segment of the hind tarsi, which ~. August, 1947 is clothed with dirty white scales. The palps are very long and black, fig. 33. Male genitalia, fig. 47, fairly simple in general structure, resembling in many respects those of Culiseta; differing most markedly in the shape of the dististyle and ninth tergite. We have only a few scattered records of this species, all from the southern third of the state. Our records from Carbondale are based on captures of free-flying adults; specimens from Scott Field and Edwards- ville were collected as immature stages in tree holes in oak-hickory woods. The spe- cies has been reported as widespread throughout the southeastern states. Illinois Records—CarBONDALE: Aug. 7, 1927, 19; 1941, 24 ; EpwarpDsviL_e: Sept. 24, 1943, from tree hole, 19; Scorr Fietp: Aug. 13, 1942, tree hole, 2 larvae; Aug. 24, 1942, fallen- tree hole, 14; Sept. 16, 1942, tree hole, 1 larva. 3. URANOTAENIA Arribalzaga Individuals in this genus are small. Both adults and larvae present a number of dis- tinctive characters that set them off readily from other mosquitoes in Illinois. Of the three species of Uranotaenia known to occur in North America, only one has been taken in Illinois. 1. Uranotaenia sapphirina (Osten Sacken) Larva.—Fig. 72. Length 5 mm. Head elongate, the upper and lower head hairs represented by long stout spines. Antennae short with a few sharp spines at apex. Thorax and first two segments of abdomen with long stout lateral hairs, abdominal segments 3—7 with only fine tufts of hairs. Lateral comb of eighth segment represented by a large sclerotized plate bearing a row of 8 to 10 teeth on its apical margin. Air tube elongate and slender, the pecten dis- tinct and containing about 15 spines, the ventral tuft large and situated at the end of the pecten. Anal segment longer than deep, completely encircled by the sclerotized ring, the anal gills finger-like, slender, but only about as long as the anal segment. FremMaLte.—Length of wing 2.5 mm. Palps minute and budlike. Head and thorax, in- cluding beak, dark-brown scaled; dorsum of head, antero-lateral lobe of pronotum, patches of scales on the pleurae, a narrow line on the extreme edge of the mesonotum, Ross: Moseuirors or ILLINoIs 33 and a narrow mesal line down the prono- tum, from near the anterior margin to the tip of the scutellum, bright iridescent blue. Abdomen dark brown with irregular apical patches of dirty white scales at the apex of some segments. Legs dark brown, each with a small conspicuous knee patch and a small patch on upper side of tip of tibia, each patch consisting of a cluster of white scales. Wings brown scaled, except for a line of blue scales covering the stem of Cubitus. All the brown scales of the wings and legs are iridescent, appearing greenish blue in certain lights. Mave.—Similar in size and general struc- ture to female; in this sex also the palps are small and budlike, fig. 32. Genitalia, fig. 44, with basistyle short and robust and with a cluster of five or six longer spines on the mesal face; dististyle short, the apex nar- rowed and hooked, without conspicuous apical seta. Ninth tergite developed into a very large bilobed plate that extends over the tenth segment and mesosome. The larvae of this species, which is wide- spread in Illinois, live in permanent or semi- permanent ponds, preferring weed-choked situations. In northern Illinois they occur in several cattail marshes and in southern Illinois are usually associated with dense marginal growths of Jussiaea, especially Fig. 72—Uranotaenia sapphirina, larva. A, apex of abdomen, lateral aspect; B, dorsum of head. 34 Intinois NaruraAL History Survey BULLETIN where this plant occurs in combination with cattails or other marsh plants. They are very much like anopheline larvae in peculi- arities of movement when diving or coming to the surface. The species appears fairly late in the season, apparently in response to the warmer waters of the summer season. The adults apparently do not bite. Pre- sumably they feed on nectar. The females lay eggs in irregular rafts on the surface of the water. This species has a wide range that em- braces most of the United States east of the Great Plains and has at least scattered rec- ords from Minnesota to the extreme south- ern states. It has been reported from south- ern Illinois by both Chandler (1920) and Matheson (1930) and from various local- ities in the Chicago area by Gerhard (1910). Illinois Records.—Larvae, collected June 3 to August 27 and many males and females, collected May 23 to October 21, are from Cahokia (UspHsS), Cairo (UspHs), Camp Grant (uspHs), Carterville (uspHs), Chanute Field (uspHs), Charleston, Crab Orchard Lake (uspHs), East Hannibal, East St. Louis, Edwardsville, Effingham, Elgin, Elsah, Fox Lake, Fox Ridge State Park, Gibsonia, Gossett, Grafton (UsPHs), Granite City (USPHS), Great Lakes Naval Training Station, Havana, Hecker, Herod, Herrin, Homer, Johnston City (uspHs), Lake Glendale, LaRue, Marion (uspHs), Mount Carmel, Mount Vernon (usPHs), Muncie, Oakwood, Omaha, Ottawa, Peoria (USPHS), Putnam, Raymond, Salm, Savanna, (UsPHS), Scott Field (UsPHS), Seneca (UsPHS), Springheld (uspHs), Starved Rock State Park, Sugar Grove, Thomson, Urbana, Volo, Wauconda, and White Pines Forest State Park. 4. WYEOMYIA Theobald This genus is represented in Illinois by only the pitcher plant mosquito, smithit. The males are readily identified by the curious shape of the dististyle, fig. 46. The larvae, fig. 20, have very distinctive charac- ters in the structures of the terminal seg- ments. 1. Wyeomyia smithii (Coquillett) Larva.—Fig. 20. Length 6 mm. Head longer than wide, somewhat ovate, antennae short, without conspicuous lateral tufts. Dorsum of head with only a few indistinct hairs. Body hairs very long. Eighth seg- ment with a lateral comb consisting of about eight scales arranged in a straight 3a Vol. 24, Art. 1 a row. Air tube small, slender, with about 15 pairs of long single hairs scattered along its length. Anal segment almost ringed by the sclerotized plate. The apex of this plate bears dorsally two pairs of long dou-— ble hairs and a single pair of lateral double hairs; at the postero-ventral corner of the plate is a pair of double or triple hairs. No ventral brush is present. The anal gills, two in number, are large and sausage shaped; a second pair of gills may be represented by a pair of small swellings above the base of the conspicuous gills. Femate.—Length of wing 3 mm. Beak, — dorsum of head, mesonotum, and dorsum of abdomen almost uniformly covered with a mat of iridescent bluish-black scales, — Pleurae and venter uniformly covered with — creamy or silver scales. Scales of mesono- tum forming a dense appressed mat with- out setae projecting above it, but with setae projecting from beneath it at the sides and along the posterior margin. Postnotum with a small cluster of minute setae. Legs, for the most part, blue black, whitish blue be- neath, iridescent; the middle pair may have the apical two or three segments predomi- nately white scaled, at least on the outer face. Wings uniformly deep bluish-brown scaled. Mate.—Similar in size, color, and struc- ture to female. The palps are short and abortive as in female. The male genitalia, fig. 46, have a long slender basistyle and are distinguished from those of all other Illi- nois mosquitoes by the curious processes of the dististyle. In Illinois this little mosquito is found only in the tamarack bogs of the northeast-— ern corner of the state. The larvae live in the water contained in the pitchers of the pitcher plant, Sarracenia purpurea Linnaeus. The species overwinters as larvae in the pitcher plants, and the adults emerge the following summer. The females, which lay eggs in the pitchers, apparently do not bite. The adults are quite active during the day, — flying around the pitcher plants. They are very difficult to follow in flight; they have an irregular and slow flight pattern that combines with the gangling legs and irides-~ cent color to make it difficult for an observer to be sure just how far away they are. The development of the larvae is apparently very slow. In this respect the pitcher plant mosquito resembles the tree hole species. The range of the species includes most of © August, 1947 the northeastern states, wherever the pitcher plant occurs. Two other species in the genus occur in southern Florida. A key to the females is given by Roth (1946). Illinois Records.—Cepar Lake: in bog, Aug. 3-6, 1906, Shobe, 32 ; Aug. 6, 1906, 1¢ ; Aug. 7, 1906, 78, 222. McHenry: Nov. 10, 1927, in pitcher plant, H. H. Ross, 3 larvae. VoLo: in pitcher plant, July 1, 1942, Ross & Mohr, 3 larvae; July 3, 1942, Ross & Mohr, 15 larvae; July 8, 1942, Ross & Mohr, 2 Q, 2 pupal skins; July 19, 1942, Ross & Mohr, 124, 12 ; Oct. 27, 1943, Ross & Sanderson, 14. 5. MANSONIA Blanchard Modifications in the larva make this genus of unique interest. The larval air tube forms a sharp piercing structure that is inserted into the roots or underwater stems of vascular plants; it pierces the air chambers of these, and the larva draws on the air in these chambers for its respiration. Thus, the larva does not need to come to the surface for air. Otherwise the larva and the adult are very similar to those of allied mosquitoes. The eggs are laid as rafts on the surface of the water. A single species, perturbans, occurs in Illinois. The only other United States species are the tropical f¢itillans (Walker) and indubitans Dyar & Shannon, which are found in south- ern Florida (Pratt 1945). The species perturbans is placed in the subgenus Cogquil- lettidia Dyar. 1. Mansonia perturbans (Walker) Larva—Fig. 73. Head wider than long, antennae slender and long, with a fan- shaped tuft near middle; dorsum of head with many multiple tufts. Thorax and abdo- men with many long setae. Eighth segment with an irregular row of scales forming the comb. Air tube, fig. 18, with a wide base, the apical sclerites long and sharp, forming a stout piercing organ. Anal segment fairly narrow, completely encircled by a sclero- tized ring; anal gills pointed, shorter than segment. FemMate.—Length of wing 4.5 mm. Beak with a mixture of brown and pale scales, the latter forming an indistinct central ring. Dorsum of head and mesonotum with brown scales and hair, the mesonotal setae abun- dant, long and recurved. Abdomen with a mixture of pale and brownish-blue scales, the former predominating at the base of the Ross: Mosaurrors oF ILLINOIS 35 segment, the latter predominating at the apex. Femora and tibiae with an irregular mixture of brown and pale scales, the poste- rior face of femora chiefly cream scaled; tarsal segments 2-5 each having the basal half white scaled, the apex black scaled; basitarsi with a narrow basal band of white scales and an irregular central band of white scales. Wings with an indiscriminate mix- ture of white and brown scales, the scales all broad. Matve.—In size, color, and general struc- ture similar to female. Palps longer than beak, the apex of the second segment and the entire third and fourth segments with a ventral brush. Genitalia, fig. 43, with ninth tergite strap shaped and having a pair of conspicuous ventral lobes. Basistyle fairly stout, its mesal face with few setae and with a single long stout beaklike spine. Disti- style twisted and angulate at base, narrow, expanded, and bladelike at apex, its apical spine forming a stout sharp tip. Lobes of tenth sternite moderately long and evenly toothed. Mesosome short and stout, with a row of stout but minute dorsal teeth. Wy \\I/ Wy Lal 7 / Fig. 73.—Mansonia perturbans, larva. (After Matheson.) 36 Ittinois NaturAL History Survey BULLETIN Taken in only a few areas of the state, this species is most commonly encountered in the marshes of the extreme northeastern corner and south to the Chicago area. A few other records have been taken extend- ing to the southern third of the state. Adult records occur from June through August. Males have been taken only in the early part of this period and suggest that there is only a single generation per year in IIli- nois. ‘The species is associated chiefly with cattails and aquatic sedges. In the southern states, pickerelweed, arrowhead, and other plants are frequently preferred for larval attachment. The females are voracious biters, espe- cially in the cloudy afternoons and the cre- puscular periods. Gerhard (1910) recorded this species as common and annoying in tracts of woodland in the Chicago region and encountered rarely on the south side of the city. Specimens from Roxana, Danville, and also Algonquin were recorded by Matheson (1930). J. Lyell Clarke has told me of occasional swarms of this species which were very annoying to the workers in several industrial plants on the south side of Chicago. The species is widely distributed through- out the eastern United States, from Minne- sota to Florida. Illinois Records.—Adults, collected May 21 to September 19, are from Algonquin, Beach, Belleville (UspHs), Cahokia (UsPHs), Camp Grant (UsPHS), Carterville (UspHs), Danville, East St. Louis, Elsah, Grand Tower, Granite City (UspHs), Great Lakes Naval Training Station, Herrin, Johnston City (UsPHs), Marion (uspHs), Oak Park, Peoria (UsPHs), Pere Mar- quette State Park, Roxana, Savanna, Starved Rock State Park, Volo, and Zion. 6. ORTHOPODOMYIA Theobald The Illinois species of this genus are char- acterized by the curious mesonotal pattern of the adults, fig. 27, and by the air tube, basal sclerite, and anal segment of the larva, fig. 17. Two species are known from IIli- nois, both of which occur only in tree holes. The status of these two species is very puz- zling. To date no distinguishing characters have been discovered either in coloration of the external areas or in the structure of the male genitalia. The larvae, however, differ quite markedly both in color and in the average sclerotization of the seventh and eighth abdominal segments. Larvae of both Vol. 24, Art. 1 species are practically identical in chaeto- taxy and formation of the lateral comb. It has been suggested that the color of the base of the abdomen would separate these two forms in the adult stage. Isolated rearings have demonstrated that this differ- ence does not hold, at least for Illinois speci- mens. It is therefore impossible at present to give a key for the specific diagnosis of males or females. Key To LARVAE Head medium to dark brown, body pink; segments 6, 7, and 8 usually with dorsal sclerotized plates, the plate of segment 8 frequently extending ventrad to the ventral margin of the comb, fig. 17; these sclerotized plates may be entirely absent=:.).25...).s) eee 1. signifera Head capsule very pale yellow to white, body white to straw color; segments 6, 7, and 8 without sclerotized plates... . iW oieelere keke ela venend ae 2. alba 1. Orthopodomyia signifera (Coquillett) Larva.—Fig. 17. Length 7 mm. Head dark brown, somewhat oval, slightly longer than wide; upper and lower head hairs multiple and fan shaped, the lower hairs close to the uppers and more laterad than anteriad; between them is a pair of shorter fanlike tufts. Thorax and abdomen with many long hairs. Seventh abdominal seg- ment frequently with a large dorsal sclero- tized shield, which may be reduced to a pair of small dorsal sclerites or even be entirely absent. Eighth segment usually with a large dorsal sclerotized shield; this may be so large that it extends to the ventral end of the lateral comb but it may be much smaller or in rare individuals practically absent. Lateral comb consisting of two distinct series of scales, an anterior row of 15 to 20 small scales and a posterior row of about 5 very large long scales. Air tube about three times as long as wide, having no pecten but having a large ventral tuft just before mid- dle. Anal segment with a basal barlike sclerite, the main portion of the segment completely surrounded by the sclerotized ring and with pointed gills, the upper pair much longer than the segment, the lower pair about as long as the segment. FemaLe.—Length of wing 4 mm. Entire body principally dark brown to black scaled, dull and velvety. Beak and palps with irreg- ular rows of white scales, dorsum of head August, 1947 with scattered white scales and a prominent row around posterior margin of eyes. Meso- notum with narrow but sharp lines of white scales, fig. 27. First abdominal tergite and base of second usually white scaled. Femora with a scattering of white scales, tibiae with irregular lines of white scales. Tarsi black, the anterior pair with a minute white patch at end of basitarsus, the middle pair with patches of white at base of apex. Basitar- sus and the hind pair with basal apical patches on the first four tarsal segments and on the dorsum of the last segment. The white bands on only the first two tar- sal segments of the hind legs are wide enough to form conspicuous bands. Wings with a conspicuous mottling of white scales that form definite patches on the base of the anal vein and around the point where Res and Re: divide from each other. Mave.—Size, color, and general struc- ture essentially as for female. Palps elon- gate, as long as beak, black scaled, without tufts, but apical segment with 15 or 20 fairly long stiff setae projecting irregularly on all sides. Male genitalia as in fig. 45. Ninth tergite mostly membranous, without definite ventral lobes. Tenth sternite of medium length, ending in a series of three or four closely appressed teeth. Mesosome about as long as tenth sternite, with short lateral teeth near apex. Basistyle elongate, with a ventral mesal cluster of stout setae; at its base is a mesal arcuate lobe that bears an even cluster of stout setae. Dististyle slen- der and elongate, tipped with a short stout seta that is truncate at apex, the end appar- ently with a cone-shaped hollow. Widely distributed over Illinois, this spe- cies breeds exclusively in tree holes. The egus are laid singly at the water’s edge and hatch in a few days. As seems true with all the tree hole mosquitoes occurring in this latitude, the larvae apparently grow rather slowly. Emergence of adults begins toward the end of June and continues through the summer. Apparently females of the species bite humans only on rare occasions and are not a pest. Superficially the adult resem- bles the yellow-fever mosquito, dedes aegypti. The adults can usually be found most readily sitting in and around tree cavi- ties. The species is widely distributed through- out many of the eastern states, although it does not occur much farther north than Illinois. Ross: Mosquitoes oF ILLINOIS 37 To date, all but one of the larval colonies of this genus that we have encountered in Illinois have been those of signifera. For this reason we have tentatively considered all field-collected adults of Orthopodomyia to be of this species. This species was reported from the Chi- cago area by Gerhard (1910) as Bancroftia signifera and from Urbana by Matheson (1930). Illinois Records.—Larvae, collected June 29 to July 3, and adults, collected June 5 to Sep- tember 30, are from Cahokia (uspHs), Des Plaines, East St. Louis, Galesburg, Glencoe, Havana, Mahomet, Onarga, Ridge Lake, Scott Field (uspHs), Thebes, and Urbana. 2. Orthopodomyia alba Baker Similar to signifera in adult characters and in general characteristics of the larva; differing as outlined in the key. Only a single colony of this species has been encoun- tered in Illinois. It was found in a tree hole —in a soft maple tree at Onarga, where it occurred with signifera. This dual colony has persisted for several years, the alba larvae slightly more abundant than the szg- nifera larvae. Individual rearings from this colony established the similarity in color of the adults of the two forms. 7. CULISETA Felt Only two species of this genus have been taken in the state. A third species, melanura (Coquillett), is widespread to the east and south. he few remaining species of the genus are northern or western in distribu- tion. The eggs are laid in rafts on the sur- face of the water. The adults resemble large specimens of Culex, but the larvae are read- ily distinguished from other mosquito larvae by the large basal tuft on the air tube. Key 10 SPECIES LARVAE Tube short and stout, fig. 74......- 1. inornata Tube longer and slender, fig. 75. .2. morsitans FEMALES Tarsi without pale rings on the segments... . Be are Ciok notes Sine ee 1. inornata Tarsi with faint whitish rings at both ends of the: segments. ....5..-.--- 2. morsitans MALES Mesosome consisting of a pair of long, slender black rods tipped with a small membranous PIECE MPA 7 Shera faite where Hledehace 1. inornata 38 Ittinors NarurAt History Survey BULLETIN Mesosome wide, bulbous in central portion and only lightly sclerotized, fig. 77....... er REEOECICT a DLT Pea Ne AOR Rear 2. morsitans 1. Culiseta inornata (Williston) Larva.—Fig. 74. Length 10 mm. Head capsule wider than long, upper and lower head hairs fan shaped, the lower ones usu- ally quadruple, the upper ones with about eight rays; in front of the upper hairs is an accessory pair of tufts, each with about four hairs. Hairs of thorax and abdomen of only medium length. Eighth segment with a tri- angular comb consisting of about 50 scales. Air tube fairly long, a little over three times Vol. 24, Art. 1 as long as wide; pecten long, the basal 10 to 12 scales sclerotized and dark, the re- mainder longer, hairlike, and almost color- less; ventral tuft composed of about eight long stout hairs situated near the base of the air tube on the ventral aspect mesad of the pecten. Anal segment completely en- circled by sclerotized ring; anal gills long and tapering, longer than segment. FEMALE.—Wing length 6 mm. _ Beak, head, mesonotum, and most of legs a mix- ture of brown and gray scales; pleurae, ven- ter of abdomen, and ventral face of most of legs with gray or cream-colored scales predominating. Dorsum of abdomen with basal bands of cream and tawny scales, apical Larvae of Culiseta Fig. 74.—C. inornata: A, dorsum of head; B, apex of abdomen. Fig. 75.—C. morsitans: A, dorsum of head; } B, apex of abdomen. August, 1947 portion brown scaled. Wings mostly brown scaled but with a mixture of tawny scales along most of the anterior veins. In some specimens Costa and Radius almost entirely tawny scaled; in these the legs may be pre- dominantly tawny scaled throughout. Mave.—Form slender compared to that of female. Pattern in general similar to ‘Gas 76C IMPATIENS 77¢ MORSITANS - 77B INORNATA of Culiseta. Figs. 76-78.—Male genitalia A, genital capsule, ventral aspect; B, meso- some, dorsal aspect; C, lobe of tenth sternite, lateral aspect. that of female but with the cream and tawny scales replaced almost entirely by lemon scales, with little or no banding on the dor- sum of the abdomen but with the eighth tergite almost entirely yellow scaled. Palps longer than beak, slender, and without con- spicuous brushes, both palps and beak largely yellow scaled, except at tip. Genitalia, fig. 78, with basistyle fairly long, robust, and tapering, with a small meso-basal area bear- ing a dense patch of setae. Dististyle slen- der, tipped with a pair of short stout tooth- like setae. Lobes of tenth sternite ending in a few sharp teeth, much fewer than in impatiens (Walker), fig. 76. Mesosome Ross: Moseurrors oF ILLINOIS 39 composed of two long sclerotized plates with a slender membranous tip. One of the common marsh mosquitoes in Illinois, this species is most abundant in the northeastern quarter of the state, where it is found in numbers in almost every marsh. Farther south it occurs in marshes, sink holes, stump holes, and artificial ponds. In Illinois the species apparently has an early spring and late summer generation with a fairly definite period of inactivity during the hottest period of the summer. The two- brooded condition is especially pronounced in southern Illinois, where the first wave of adults comes out in April and early May and the next in September and October. The eggs are laid as rafts on the surface of the water. The adults apparently overwin- ter and are frequently encountered entering houses, presumably to hibernate, during warm days of November and December. In early spring the overwintered females bite ferociously, but during the summer this species does not seem to constitute much of a pest even in those regions where it is abundant. Very common throughout almost the en- tire United States, the species is essentially a winter form in the extreme southeast, according to King, Bradley, & McNeel (1939); in higher elevations of the Rocky Mountains it is primarily a midsummer torm. Illinois presents an interesting inter- mediate between these two extremes. The species was recorded from the vicin- ity of Chicago under the name Culiseta con- sobrinus (Robineau-Desvoidy) by Gerhard (1910). Matheson (1930), who recorded it as common and widespread in Illinois, listed several localities. In the same paper he listed a male from Carbondale, Illinois, as Theobaldia impatiens (Walker); the cleared genitalia of this specimen show that it is a typical specimen of Culiseta inornata. Illinois Records.—Larvae, collected April 6 to October 22, and adults, collected March 16 to November 16, are from Algonquin, Alton, Amboy, Antioch, Cache, Cahokia (UsPHs), Cairo (usPHs), Camp Grant (UsPHS), Carbon- dale, Carterville (usPHs), Cottage Grove, Crab Orchard Lake (UspHs), Dupo, Durand, East Moline (uspHs), East Peoria (UsPHs), East St. Louis, Effingham, Eldorado, Elk Grove, Elsah, Farmer City, George Field (uspPHs), Gilman, Glencoe, Grand Tower, Granite City (uspHs), Grantsburg, Great Lakes Naval Training Station, Harrisburg, Havana, Hazel- crest, Herod, Herrin, Highland, Hinsdale, Kan- 40 Intinors NarurAL History SurvEY BULLETIN kakee, Karnak, Keithsburg, Makanda, Marion (uspHs), McLean, Mazon, Mill Shoals, Mis- sissippi Palisades State Park, Momence, Mount Vernon, Mount Zion, Muncie, Neoga, New Boston, Orland Park, Palatine, Palos Park, Pere Marquette State Park, Ravinia, Rockton, Roxana, St. Jacob, Savanna (USPHS), Scott Field (uspns), Seneca (USPHS), Spring- field (uspus), Starved Rock State Park, Urbana, Wadsworth, Waltersburg, Ware, Waukegan, White Heath, Willow Springs, Wolf Lake, Woodstock, and Zion. 2. Culiseta morsitans (Theobald) Larva.—Fig. 75. Length 9 mm. Head very wide, almost rectangular. Upper head hairs usually four or five branched, lower head hairs double and extremely long; be- tween them is a pair of extremely minute hairs. Antennae long and curved with a large tuft near apex. Thorax and abdo- men with many very long hairs. Eighth segment with large triangular lateral comb consisting of about a hundred minute scales. Air tube extremely long and slender, nearly seven times as long as wide; pecten consist- ing of only a few flat teeth on basal fourth; ventral tuft on ventral margin at extreme base. Anal segment entirely enclosed by sclerotized ring, with hairs of ventral brush arising through ring; anal gills slender and pointed, about as long as segment. Femae.—Length of wing 5 mm. Color dark bluish brown, the dorsum of head mostly gray scaled, mesonotum with a few small spots and lines of gray scales. Dorsum of abdomen with a basal gray band on each segment, the apical portion of the segments brown scaled. Legs almost entirely bluish- brown scaled with faint but distinct narrow rings at the base of most of the tarsal seg- ments. Wings entirely blue-brown scaled. Mate.—Similar in size and color to female. Palps elongate, differing markedly from those of inornata in having long ven- *tral brushes at the apex of the second and on all of the third and fourth segments. Genitalia similar in general outline to those of inornata, differing markedly in the shape of the mesosome, which is bulbous, sinuate, and not heavily sclerotized, fig. 77. This is a northern species, which we have taken in Illinois only in a tamarack bog near Antioch. A single larva was taken on the edge of the bog, June 4, 1943, Ross & Sanderson; subsequent collecting during the same year failed to disclose additional Vol. 24, Art. 1 specimens. The next year the bog was vis- ited on April 19, and scattered specimens of the larva were found in the cool, shaded pools around the base of the old tamarack hummocks. Efforts to rear some of these — specimens were not successful. The speci- mens were transported to Urbana, where at the time fairly high temperatures pre- vailed, and all the larvae died. It is interest- ing to note that larvae of several species of Aedes, brought back at the same time and given the same treatment, emerged without difficulty. On a subsequent visit to the bog on May 19, 1944, larvae were found in the same place and apparently completely full grown. On this occasion, jars in which larvae were placed were wrapped in moist cloths for the trip to Urbana and after- wards were kept in a water bath at a tem- perature of about 60 degrees F. These larvae matured and transformed slowly but successfully. Although no other records for Illinois have been taken, we have in the collection a female from Lake Delavan, Wisconsin, and two females from Minocqua, Wisconsin, which are of this same species; these were incorrectly recorded as impatiens (Walker) by Matheson (1930). 8. CULEX Linnaeus The eight species of this genus that occur in Illinois have a continual series of gener- ations throughout the warmer months of the year. The females lay their eggs in rafts on the surface of the water. The species frequent still or semistagnant water of all types and may be found even in lakes of some size, the larvae breeding in masses of float- ing or emergent vegetation. Usually the larvae are taken in association with anoph- eline larvae. The genus as a whole is tropical or sub- tropical in distribution. Many North Amer- ican species occur in the southeastern states, southwest Texas, and southern California. In the Neotropical region, the genus is rep- resented by a very large number of species. During the period 1941-1945 concerted investigations of the mosquito fauna of the southern areas of the United States led to the discovery of several species of Culex hitherto recorded only from the Neotropical — region. A digest of these and allied Nearc- tic species is given in two papers, one by W. W. Wirth (1945) and the other by August, 1947 Ross: Moseuitrors oF ILLINOIS 4] ZBI J; ff \ . y, | / l | APICALIS HAL || A BIA TARSALIS Figs. 79-81.—Larvae of Culex. A, apex of abdomen, lateral aspect; B, dorsum of head. In figs. 81 and 85, the ventral tufts are shown for both sides of the air tube. In other illustrations, tufts of only one side are shown. | i | Ittinois Natura Hisrory Survey BuLLETIN Vol. 24, Art. 1 , 82A PIPIENS = \ Ez = \ QUINQUEFASCIATUS \ 84A SALINARIUS Figs. 82-84,—Larvae of Culex. 4, apex of abdomen, lateral aspect; B, dorsum of head. q August, 1947 Pratt, Wirth & Denning (1945). These papers supplement the work of Roth (1943) on the Nearctic species of Culex. The genus is divided into many subgenera, three of which are represented in Illinois. Key To SPECIES LARVAE 1. Antennal tuft near middle, fig. 79...... oo aR Gn Rs pena 2. restuans Antennal tuft considerably beyond middle, ROPEMRR ec ne Grote sie actos ais cians GlaeaeeD Ross: Mosourrors oF ILLINOIS 43 Comb scales forming a patch; body only sparsely spiculose; upper head hairs doublevor triple... <2 «%' 8. peccator 5. Air tube very long and slender, fig. 84, from six to eight times as long as width at end of pecten; tufts scattered and Vl Sr ean rc eemehs Crem aeeei 5. salinarius Air tube either not more than five times as long as wide, fig. 82; or with strong, clustered tufts, fig. 81...... 6. Air tube usually six times as long as width at end of pecten, sinuate but of almost uniform thickness throughout, and with Fig. 85.—Culex erraticus, larva. 2. Both pairs of head hairs long and single, an occasional hair double, fig. 80..... RS os Sete aie ii co's tatedcve oe ee 1. apicalis One or both pairs of head hairs either multiple, fig. 82, or very short, fig. 85 3. Lower head hairs long and single, uppe1 short and double to multiple, fig. 85. . .4 Lower head hairs triple to multiple, similar to upper head hairs, both pairs long, “SIE, SDN Beg Aba Ooh het 5 4. Comb scales arranged in an irregular single or double row; body densely spiculo-pilose; upper head hairs each with four or more branches; fig. 85... > 2 SENSES enantio be aye 7. erraticus A, apex of abdomen; B, dorsum of head. all tufts near ventral margin, fig. 81.. Soi ORAS Cle XE ey BEA DIO 6. tarsalis Air tube usually three and one-half to five times as long as width at end of pecten, somewhat vasiform, definitely thickest near end of pecten; penultimate tuft distinctly more dorsal than, and out of 7. Air tube usually four to five times as long as wide; two basal pairs of hair tufts with a maximum of three or four branches each, fig. 82....... 3. pipiens Air tube usually less than four times as long as wide, two basal pairs of hair tufts with 5-to 10 branches each, fig. 83 RE ae eles onerssduarane 4. quinquefasciatus 44 FEMALES Beak and hind tarsi with white bands; mesonotum with white lines, fig. 864. . PSE ruc ec ae een OSES 6. tarsalis Beak and hind tarsi entirely dark; meso- notum with pale dots but without white lines on central portion............2 Dorsum of abdomen with apical white bands or apical lateral spots on some of the segments, and without basal bands. a ahiesapel afar ues stca any haseh Gahanna cas 1. apicalis Dorsum of abdomen with basal bands but Soya Fig. 86.—Dorsum of Culex females. A, C. tarsalis, thorax and abdomen; B, C. pipiens, abdomen; C, C. quinquefasciatus, abdomen. Fig. 87—A, Culex restuans, scales on wing vein R.; B, C. erraticus, scales on wing vein Ry and R2. Ittinois NaturaAt History us Survey BULLETIN Vol. 24, Art. 1 Scales of veins Rz and Rs very long and slender, fig. 874, similar to scales on stem of R, (examination of wing mount under a compound microscope is best method for seeing this character)... .4 Scales of veins Rz and Rs; shorter and wide, fig. 87B, contrasting with long, slender scales on stem of Rs........ 7 Abdominal tergites with dingy basal bands of yellowish or brownish scales, the bands usually irregular and narrow... ola a al sc Sch aie) ale ons eee 5. salinarius Abdominal tergites with bright and con- spicuous basal bands of white scales, the central bands wide, fig. 86B, C...5 Abdominal dorsal white bands usually deep and crescentic, the bands not ex- tending to edge of dorsum, fig. 86C.... Se Asa oe ee ke ee 4. quinquefasciatus Abdominal dorsal white bands usually shallower, fig. 86B, or with posterior margin straight, extending to edge of dorsum Mesonotum usually with a pair of central pale:spots. .. )<22s)an see 2. restuans Mesonotum always without any pale spots J oyiedhe auw Sono Soe eos 3. pipiens Occiput with a large mesal triangle of narrow scales, the area between this tri- angle and eyes covered with wide, over- lapping scales........... 7. erraticus Occiput entirely covered with wide over- lapping scales except occasionally for a narrow mesal line of narrow scales... DOR Uae a 8. peccator MALES Basistyle globular and _ short; subapical lobe divided into two or three individ- ual long stalks, figs. 94, 95......... 2 Basistyle elongate, tapering at apex; sub- apical lobe only slightly, if at all, sub- divided, figs. 88-93............-. 3 Dististyle narrow and only slightly curved ; subapical lobe with upper stalk slender, leaflet regular in shape and of moder- ate) size, fig. 9955s" hyeteuemene 7. erraticus Dististyle wide, abruptly angled just be- yond middle; subapical lobe with upper stalk stout, leaflet very large and with irregular outline, fig. 94... .8. peccator Middle mesosomal plates armed with a cluster of stout sclerotized teeth, figs. 92 O38 esvecs ao) alletetel e Somh ble eta eee 4 Middle mesosomal plates not toothed, in some species not evident, figs. 88—91.. Inner mesosomal plates with apical half expanded; middle plates with basal projection, a, curved back and up under teeth, fig. 92, and without a ventral blade paralleling inner plates........ Be Pai area D IS C 5. salinarius August, 1947 Ross: Mosguirors oF ILLINOIS 45 “if --5N'- 90B QUINQUEFASCIATUS | ie TARSALIS vl i 94A , ERRATICUS Figs. 88-95.—Culex, male genitalia. 4, claspers, lateral aspect; B, mesosomal structures, dorsal aspect; C, ventral view of capsule. Abbreviations: s, apex of tenth sternite; r, basal arm of tenth sternite; m, middle and, m, inner mesosomal plates; a and 4, as in text. 46 Intinois NaturAL History SurvEY BULLETIN Inner mesosomal plates narrow and blade- like, apex curved laterad and paralleled by a ventral blade of middle plates; middle plates with basal projection, a, projecting only laterad, fig. 93....... FL Cah CaCO Ota CE 6. tarsalis 5. Inner mesosomal plates forming a V- or U-shaped structure, middle mesosomal plates also well developed, terminating in a sickle-shaped process, figs. 89, 90 Inner and middle mesosomal plates not separate from each other, together rep- resented by a single structure, figs. 88, I Deg Sail So Ie EMC ty- a CuEPER SACRE PIS ttre Uh 6. Rods of inner mesosomal plates divergent, forming a V-shaped structure, fig. 89. . RC CP On cpa ea RO AD 3. pipiens Rods of inner mesosomal plates conver- gent, forming a U-shaped structure, fig. D0 ienctag tan ays akc ehoes 4. quinquefasciatus 7. Inner mesosomal plates with apexes form- ing a pair of stout rods curved laterad at apex, fig. 91; brush of tenth sternite bushy eiteecty gies alin wheneceteeue 2. restuans Inner mesosomal plates with apexes form- ing a pair of round serrate lobes; the entire structure forms a_ sclerotized oval; brush of tenth sternite comblike, LEB Beh chad Sate sense sieienatete 1. apicalis Subgenus Neoculex Dyar This subgenus is characterized by the api- cal abdominal bands on the abdomen. The male genitalia have the basistyles elongate, and the middle and inner mesosomal plates are represented by a single structure, fig. 88. 1. Culex apicalis Adams Larva.—Fig. 80. Head broad and short, antennae long, with long apical setae and a large tuft situated close to the apex. Upper and lower head hairs single and very long. Eighth segment with a triangular comb of about 50 scales. Air tube long and slender, at least 10 times as long as width near the middle of pecten; pecten composed of 10 or more weak scales, beyond which are six or seven ventral tufts. FEMALE.—Length of wing 2.5 mm. Head and thorax almost entirely light brown. Abdomen dark bluish brown with, usually, a narrow band of white scales along the apical margin of each segment; these bands may be interrupted in the middle of the seg- ments, or completely absent on the basal four or five segments, but are always dis- Vol. 24, Artin tinct on the sixth. Legs with tibiae and tarsi entirely bluish brown, femora chiefly cream color with dark scaling on the upper surface. Wings entirely bluish-brown scaled. Mave.—Similar to female. Palps long and with an extensive apical brush. Male genitalia as in fig. 88. Basistyle slender, with a distinct subapical lobe bearing a pair of long sinuate narrow processes and a pair of shorter spurs. Tenth sternite with an apical row of truncate comblike setae. Mid- dle and inner mesosomal plates apparently fused to form a heavily sclerotized oval structure beyond which project serrate edges of the ends of the middle plates. Of the Illinois species of Culex, this is the earliest. The larvae are to be found soon after the early spring dedes emerge; in southern Illinois in the latter part of April, in northern Illinois in early June. Appar- ently a cold water form, the species practi- cally disappears during the hot summer weeks but reappears during the cooler weeks of late summer and early autumn. The larvae show a decided preference for open marshes or moderately shaded pools with clear water. The species is found through- out Illinois and has a wide distribution over most of North America. It is seldom noxious to man. Illinois Records.—Larvae, collected April 17 to October 17, and adults, collected April 28 to October 6, are from Albion, Algonquin, Alma, Belleville (UuspHs), Cache, Cairo (uspHs), Calvin, Camp Ellis (uspHs), Camp Grant (uspHs), Carbondale, Carterville (uspHs), Central City, Chanute Field (UsPHs), Clinton, Cottage Grove, Crab Orchard Lake (uspHs), Dixon Springs, Downs, Dupo, Durand, East St. Louis, East Dubuque, Ed- wardsville, Effingham, Eichorn, Elsah, Ep- worth, Giant City State Park, Gorham, Gossett, Grafton (uspHs), Grand Tower, Granite City (uspHs), Grantsburg, Great Lakes Naval Training Station, Halfday, Herod, Herrin, Joetta, Johnston City (uspHs), Kappa, Kar- nak, Keithsburg, Lake Villa, Lake Zurich, La Rue, Lawrenceville (UsPHS), Marion, Michael, Mill Shoals, Morris, Mount Carmel, Mount Vernon (uspHs), Mulberry Grove, Mun- cie, New Boston, New Haven, Oakwood, Olney, Omaha, Palos Park, Pere Marquette State Park, Princeton, Raymond, Rockville, Rockwood, Rosecrans, St. Jacob, St. Joseph, Savanna, Scott Field (UsPHs), Seneca (USPHS), Shawneetown, Springfield, Starved Rock State Park, Sugar Grove, Thomson, Urbana, Utica, Vienna, Volo, Wadsworth, Waltersburg, Ware, Wauconda, West Vienna, White Heath, Wil- low Springs, Yellow Springs, and Zion. August, 1947 Subgenus Culex Linnaeus In this subgenus the scales on vein R: and Rs are slender and elongate, similar to the scales on the stem of R: and Res, fig. 874. In the males, the genitalia usually have the basistyle elongate and the middle and inner mesosomal plates differentiated as two pairs of processes. 2. Culex restuans Theobald Larva.—Fig. 79. Head moderately long. Antennae shorter than head, each antenna having short apical spines and a short tuft situated near middle. Preantennal tuft short and multiple. Upper and lower head hairs multiple and long. Eighth segment with triangular comb of about 30 or 40 scales. Air tube elongate, nearly five times as long as greatest width, slightly enlarged near middle and tapering to apex; pecten composed of 10 or more weak scales, beyond which there are two long setae and a short tuft on each side. FemMALe.—Length of wing 4+ mm. Head and mesonotum bright brown. Mesonotum usually having an indistinct band of cream scales around anterior and lateral portions and around scutellum; usually with a pair of spots of cream color about the middle of the sclerite. Dorsum of abdomen bluish brown, each segment with a basal bright cream band which has a nearly straight pos- terior margin. Legs with tibiae and tarsi entirely dark, femora cream, frequently with upper and outer areas dark. Wings entirely dark scaled. Mave.—Similar in size, structure, and general color to female. Palps elongate, with an extensive apical brush. Male geni- talia, fig. 91, similar in shape of basistyle, subapical lobe, and dististyle to those of pipiens, fig. 894. Tenth sternite with a dense brush of narrow setae and with a moderately developed basal arm. Middle and inner mesosomal plates apparently fused, each side with a broad base, with one or two lateral bumps, and with a long apical proc- ess curved sharply laterad at tip. In Illinois this species is one of the most common mosquitoes in unstocked fish ponds, rain barrels, semidomestic water holes, and pools of many types, especially those with abundant humus. It is distributed over the entire state. It occurs nearly as early in the season as apicalis and continues breeding Ross: Moseurrors oF ILLINOIS 47 throughout the summer and into early autumn. Although it has been recorded as a painful biter, some observers believe that it bites little. Judged from our own experi- ence, this species is seldom annoying; cer- tainly it is not such a persistent and vicious biter as erraticus. Widespread throughout the eastern and central states from the Atlantic seaboard to the Rocky Mountains, restuans extends southward to the Gulf. Illinois Records.—Larvae, collected April 17 to October 14, and many males and females, collected April 19 to November 23, are from Algonquin, Alton, Anna, Aurora, Belleville (usPHS), Cahokia (uspHs), Cairo (USPHS), Calvin, Camp Ellis (uspHs), Camp Grant (usPHS), Carbondale (uspHs), Carmi, Carter- ville (USPHS), Chanute Field (UspHs), Charles- ton, Chester, Clinton, Cottage Grove, Crab Orchard Lake (uspHs), Danville (uspPHs), Durand, East Peoria (usPHs), East St. Louis, Elk Grove, Epworth, Forest City, Forest Glen, Fox Lake, Galesburg (UspHs), George Field (usPHS), Gorham, Grafton (usPHs), Grand Tower, Granite City (uspHs), Great Lakes Naval Training Station, Halfday, Havana, Herrin (uspus), Hoopeston (UsPHs), Johnston City (uspHs), Kappa, Karnak, Keithsburg, Lake Villa, La Rue, Lawrenceville (uspHs), Marion (uspHs), Maroa, Milford (uspHs), Mount Vernon (uspHs), Mount Zion, Muncie, New Haven, Oakwood, Olney, Orland Park, Palos Park, Pere Marquette State Park, Pitts- burg, Pittsfield, Princeton, Ravinia, Reynolds- ville, Ridge Lake, Rising Sun, Riverside, Rock- ford, Rock Island (uUspHs), Roxana, Russell- ville, Salem, Savanna (uspHs), Scott Field (USPHS), Seneca (USPHS), Shawneetown, Sko- kie, Springfield (uspHs), Starved Rock State Park, Summerdale, Urbana, Vienna, Wads- worth, Waltersburg, Ware, Waterloo, White Heath, Willow Springs, Winnetka, Wolf Lake, and Zion. 3. Culex pipiens Linnaeus Larva.——Fig. 82. Head moderately wide, with fairly long apical bristles and a thick tuft situated near apex. Upper and lower head hairs multiple, as long as, or slightly longer than, the preantennal tuft. Eighth segment with triangular comb composed of 30 or 40 small scales. Air tube nearly four and one-half times as long as its width at end of pecten; pecten composed of about 10 weak scales; between the end of the pecten and apex of tube are four tufts on each side, one of them considerably more dorsad than the others; these tufts are long and usu- ally composed of three hairs. 48 Ittinois NaturAL History Survey BULLETIN FEMALE.—Length of wing 3.5 mm. Head dark bluish brown with scattered gray scales on dorsum. Mesonotum entirely brown. Dorsum of abdomen bluish brown, each seg- ment with a basal band of white scales; these bands moderately narrow, usually ex- tending the full width of the segment and having the posterior margin irregular or nearly straight across; the bands on seg- ments 3-6 should be used as examples. Legs with tibiae and tarsi black or dark, femora cream with dorsal or outer portions dark. Mate.—Size, color, and general structure as for female. Palps elongate, with an extensive apical brush. Male genitalia, fig. 89: basistyle slender, its subapical lobe prom- inent, with a short leaflet and several bristles and spines; dististyle slender and curved. Tenth sternite with an apical brush of fairly short pointed spines, its basal arm slender and short, sometimes poorly devel- oped and inconspicuous. Middle mesosomal plate with two lobes, an irregular sclerotized basal lobe, a, and a sickle-shaped apical lobe that has a sclerotized apical edge and a membranous area below this. Inner meso- somal plate composed of a single straight blunt blade on each side, the two forming a V-shaped structure. Known as the northern house mosquito, this species is common over all of Illinois. The larvae frequent practically all types of domestic and semidomestic pools, such as rain barrels, tar buckets, fish ponds, clogged drains, and containers of various descrip- tions. The adults are persistent but wary biters, especially annoying at night in gar- dens or houses. The species occurs through- out the season, from late spring until early autumn. In garden pools it frequently occurs in company with restuans and quin- quefasciatus. It is one of the easier species to control by the use of clean-up measures directed against the semidomestic type of water containers in which this species breeds. The northern house mosquito is widely distributed over most of the temperate regions of the world having at least moder- ate rainfall. In the eastern states it extends south of Illinois into the northern portion of the southern states. Illinois Records—Larvae, collected from May 3 to September 15, and many males and females, collected from May 6 to November 15, are from Algonquin, Belleville (USsPHs), Cahokia (UspHs), Cairo (UsPHs), Camp Ellis (UsPHS), Carbondale (UspHs), Carmi, Carter- Vol. 24, Art. 1 ville (uspHs), Central City, Chanute Field (uspHs), Charleston, Chicago, Clinton, Cottage Grove, Crab Orchard Lake (UsPHs), Danville (UsPHs), Decatur (UsPHs), Dwight, East St. Louis, Edwardsville, Elsah, Forest Glen, Gales- burg (uspHs), George Field (uspHs), Gibson City (uspHs), Grafton (UsPHs), Granite City (uspHs), Great Lakes Naval Training Station, Havana, Herrin, Hoopeston (UsPHs), Johnston City (UspHs), Lawrenceville (UsPHs), Marion, Metropolis, Mound City, Mounds, Mount Car- mel, Mount Vernon (usPHs), Palos Park, Peoria (usPHS), Ravinia, Raymond, Rockford (usPHs), Rock Island (usPHs), St. Jacob, St. Joseph, Savanna (uUsPHS), Scott Field (UspHs), Seneca (usPHs), Springfield (UsPHs), Urbana, Vienna, Ware, Willow Springs, and Zion. 4. Culex quinquefasciatus Say Larva.—Fig. 83. Very similar in size, shape, and general structure to larva of pipiens. ‘There is often considerable dif_f- culty in separating specimens of the two species. Material of guinquefasciatus col- lected in Illinois is distinguished by the fol- lowing combination of characters: air tube only about three and one-half times as long as its width at end of pecten; tufts on air tube usually with four or more branches and usually markedly shorter than greatest width of air tube. The gills of both species vary in length. ADULTS.—Similar in almost all respects to pipiens adults. The female usually has definite-shaped basal bands on the abdomi- nal tergites; in quinquefasciatus the bands are deeper than in pipiens and taper off com- pletely at the edge of the dorsal aspect. Female specimens are encountered, however, in which it is difficult to distinguish between the two species either on this character or any other. The male genitalia are very sim- ilar to those of pipiens in general conforma- tion. Those of quinquefasciatus are dis- tinguished as follows, fig. 90: the distal lobe, b, of the middle mesosomal plates is larger and extends farther laterad than in pipiens; and the arms of the inner mesosomal plates make a U-shaped structure with converging arms (diverging arms in pipiens). Culex quinquefasciatus, the southern house mosquito, occurs regularly in the southern third of the state but has been taken only sporadically northward. Light trap collec- tions indicate that this species does not appear in numbers until July or August and usually disappears soon after the first August, 1947 cool weather in September. The larvae frequent the same types of domestic and semidomestic containers as those of pipiens and the two species are usually represented in mixed cultures in Illinois. C. quinque- fasciatus is distributed throughout most of the tropical and subtropical regions of the world. The Illinois records appear to be on the extreme northern edge of its North American range, which extends southward to the Gulf of Mexico. In much of the literature, this species has been recorded under the name fatigans Wiedemann. Edwards (1932) prefers to refer guinquefasciatus Say to the list of dubi- ously known names. Since quinquefasciatus has been used consistently as at present, there seems no valid reason for discarding this name in favor of fatigans; quinquefas- ciatus was described in 1823, fatigans in 1828. Illinois Records—Larvae, collected from September 15 to October 1, and adults, col- lected from June 17 to November 23, are from Belleville (uspHs), Cahokia (UusPHs), Cairo (uspHs), Carterville (UspHs), East St. Louis, Edwardsville, Grafton (UspHs), Granite City (uspHs), Herrin (uspHs), Johnston City (uspHs), Marion (uspHs), Mount Vernon (uspHs), Scott Field (UspHs), and Urbana. 5. Culex salinarius Coquillett Larva.—Fig. 84. Head moderately wide, antennae of moderate length, with long apical bristles and a stout tuft near apex. Upper and lower head hairs long, with at least four branches. Eighth segment with a triangular comb of about 50 small scales. Air tube very long and slender, about eight times as long as greatest width, pecten com- posed of about 10 weak scales and with sev- eral pairs of tufts irregularly placed between end of pecten and apex of tube. FemaLe.—Length of wing + mm. Head and mesonotum bright brown, dorsum of abdomen bluish brown with narrow basal bands yellowish scaled on each segment, the bands frequently indistinct on the basal two or three segments and frequently broken up with brownish scales, giving them a muddy appearance. Legs with tibiae and tarsi entirely dark, femora mostly yellowish with upper and outer surfaces frequently dark. Wings entirely dark-brown scaled. Matve.—Similar in size, color, and general Structure to female. Palps long, having Ross: MosquiTorEs oF ILLINOIS 49 extensive apical brushes. Genitalia, fig. 92: basistyle long and slender, its subapical lobe with a leaflet and several bristles and spines. Tenth sternite with a dense irregular apical brush and with a long stout basal arm. Middle mesosomal plates with a dorsal cluster of 8 or 10 stout teeth and a sharp upturned stout ventral arm. Inner meso- somal plates divergent, their apexes expanded and sinuate. Although the species occurs generally throughout Illinois, individuals are present usually only in small numbers. Breeding commences fairly early in the season and continues at a fairly uniform rate through- out the summer and into the autumn. The larvae have been taken in a variety of habi- tats including swampy edges of lakes, oxbow pools, marshes of various types, ponds and cattle tracks, cattail bogs, stump holes, and polluted ditches. The females are said to bite readily, but in Illinois they are not suffi- ciently abundant to be a nuisance. The species breeds in the eastern United States westward into the Rocky Mountains, and south to Florida and Texas. Illinois Records—Larvae, collected April 16 to October 15, and adults, collected May 5 to November 23, are from Alton, Belleville (usPHs), Cahokia (uspPHs), Cairo (UsPHs), Camp Ellis (uspHs), Camp Grant (USPHS), Carbondale (uspHs), Carmi, Carterville (UsPHS), Chanute Field (usps), Cottage Grove, Dupo, East St. Louis, Edwardsville, Equality, Fox Ridge State Park, George Field (UsPHS), Gorham, Grand Tower, Grafton (usPHs), Granite City (uspis), Great Lakes Naval Training Station, Havana, Herrin, Jacksonville, Johnston City (Usps), Karnak, Lake Glendale, La Ruz, Lawrvncevilie (usPHs), Marion, Maroa, Mount Vernon (uspHs), Mun- cie, Olney, Orland Park, Palos Park, Ridge Lake, Rock Island (uspHs), Roxana, St. Charles (UsPHS), Savanna, Scott Field (UsPHs), Seneca (UsPHS), Springfield (uspHs), Urbana, Ware, Willow Springs, and Zion. 6. Culex tarsalis Coquillett Larva.—Fig. 81. Head moderately broad, proportioned much as in pipiens, fig. 82B. Antennae elongate, with long apical bristles and with a tuft near apex. Both upper and lower head hairs multiple and about as long as preantennal hair. Eighth segment with a triangular patch of about 50 small scales. Air tube slender, usually over six times as long as its width at end of pecten; pecten 50 composed of about 10 weak scales; beyond this are about five pairs of tufts arranged very irregularly but all near ventral mar- gin; the basal three pairs are long and each one has three to six hairs, the apical two short and usually having two to four hairs. FemaLe.—Length of wing 4.5 mm. Beak and palps dark brown, beak with a white band just beyond middle, palps with extreme apexes tipped with white scales. Dorsum of head with a mixture of brown and gray scales. Mesonotum brown with narrow grayish-white lines as illustrated in fig. 864. Dorsum of abdomen brown with basal patches of white scales. Legs with posterior aspects of femora and tibiae cream, anterior aspects dark brown, each with a central stripe of white scales extending down the middle of this brown area from base to apex, the white line on the anterior legs broken into a series of white bars; tarsi dark bluish brown, all segments of hind tarsi with a white ring at both base and apex of segment, tarsi of front and middle legs with white bands indistinct on, or absent from, the apical two or three segments. Wings dark scaled except for a scattering of white scales on the costal region of each. Mave.—In size, color, and general struc- ture similar to female. Palps longer than beak, apical two segments with a long brush. Genitalia, fig. 93: basistyle elongate, with a pronounced subapical lobe bearing a small leaflet, a pair of stout spurs and a pair of more slender spines. Dististyle curved and narrow. ‘Tenth sternite with a large apical lobe, the lateral series of teeth truncate and flattened. Middle mesosomal plates with three distinct processes: (1) a large blunt basal tooth, (2) a series of five or six long large sharp teeth, and (3) a curved ventral blade that is closely appressed to the inner mesosomal plate. This last forms a long curved slender blade. In the plains states this species occurs in very large numbers; in Illinois it has been taken in widely scattered localities over the entire state and only rarely in large num- bers. The adults occur chiefly in middle and late summer, with a few persisting into early autumn. The larvae have been found in a wide variety of situations, including hoof prints, pools, stream beds, marshes, and backwaters. A colony at Cahokia, IIli- nois, occurred in a drainage backwater hay- ing a very high pollution by sulfuric acid waste. Intinois NaturaAL History SurvEY BULLETIN Vol. 24, Art. J The species is said to hibernate as ferti- lized adult females; the males apparently die at the advent of winter. Breeding be- gins in early spring and continues until autumn. The range of the species includes most of the semiarid regions of the west coast and the great plains. Illinois seems to be near the eastern edge of the range. Adults of this species have been found naturally infected with the virus of western encephalomyelitis. The females, which attack men readily, are on the wing chiefly at dusk or after dark. They invade houses often and are fierce and painful biters. Illinois Records.—Laryae, collected June 11 to October 15, and males and females, collected June 21 to October 28, are from Algonquin, Belleville (uspHs), Cahokia (uspHs), Camp Ellis (uspHs), Carterville (UuspHs), Chanute Field (uspHs), Des Plaines, East Peoria (usPHs), East St. Louis, Edwardsville, Fox Lake, Granite City (uspHs), George Field (uspHs), Great Lakes Naval Training Station, Greenville, Havana, Hoopeston (uspHs), John- ston City (UsPHs), Marion (uspHs), Milford (usPHs), Savanna (usPHs), Scott Field (UsPHs), Seneca (UsPHs), Springfield, Urbana, Water- loo, and Zion. Subgenus Melanoconion Theobald This subgenus is characterized by the wide scales on veins Rz and Rs, which are in marked contrast with the long slender scales on Rs, fig. 87B. In the Illinois species, the males have the basistyle almost globular, and the middle and inner mesosomal plates not differentiated from each other. 7. Culex erraticus (Dyar & Knab) Larva.—Fig. 85. Head moderately wide. Antennae long, with long apical bristles and with a long tuft situated near apex, prean- tennal tuft long and dense, lower head hairs long, single, and bristle-like. Upper head hairs very short and multiple, with at least four and usually six hairs to each bristle. Abdomen with most of the segments spicu- lose, having a covering of extremely fine spinules giving it a dense, pilose appearance. Eighth segment with comb consisting of an irregular single or double row of 12 to 15 scales. Air tube only moderately long but narrow, about six times as long as its width at end of pecten; pecten composed of about 12 weak scales; beyond this are four or five > August, 1947 pairs of long multiple tufts situated very close to ventral margin. Femace.—Length of wing 3.5 mm. Head, mesonotum, and dorsum of abdomen almost entirely purplish-brown scaled; abdo- men usually with narrow basal bands of cream scales, usually with brown scales intermingled so that the bands are indistinct and muddy. Dorsum of head having a wide triangular mesal area with narrow scales, the area between this and the eye covered with broad overlapping scales; these are in addition to the erect scales that stand up like a comb above this area. Legs dark except for usually creamy portions of femora. Wings entirely dark scaled. Mate.—Size, color, and general struc- ture as for female. Palps long, with exten- sive apical brushes. Male genitalia, fig. 95: basistyle short and almost globular; apical lobe produced into three long stout stalks, the two lower ones each bearing a stout flat- tened process, the upper one bearing a leaf- let and three spines; dististyle sinuate, with the end ridged and produced into a pair of minute teeth. Tenth tergite bearing a row of flattened teeth and a stout basal lobe of moderate length. Middle mesosomal plates bladelike and each divided at apex into a short sharp mesal point and a wider blunt lateral triangle. Inner mesosomal plates apparently not differentiated. Abundant and widespread in southern and central Illinois, this species is a comparative rarity in the northern part of the state. The larvae frequent marshy areas at the edges of lakes, pools, and ponds in which there is abundant emergent vegetation. They are especially numerous in ponds with growth of cattails and water primrose. In addition to ponds, they frequent vegetation-choked shallows along the edges of sluggish streams and ditches. They are usually taken in com- pany with dnopheles, and frequently with Uranotaenia, also. In Illinois, adult emer- gence begins in the southern part of the state, usually early in June, and continues until early autumn. The adults attack with per- sistence and inflict painful bites. The species is widespread throughout the southern states. Illinois is near the north- ern edge of its range. It was recorded from Illinois by Matheson (1930) under the name inhibitator Dyar & Knab. At that time erraticus was generally considered a direct synonym of inhibitator. King & Bradley (1937) have shown, however, that inhibita- Ross: Moseuirors or ILLINoIs 51 tor and erraticus are distinct species. The name inhibitator should be applied to a Santo Domingan species, whereas erraticus is the name to be used for this small dark Illinois mosquito. Illinois Records——Larvae, collected from June 29 to October 3, and males and females, collected from June 2 to November 4, are from Alma, Belleville (UspHs), Benton, Caho- kia (uspHs), Cairo, Carbondale, Carterville (uspHs), Charleston, Cottage Grove, Coulter- ville, Crab Orchard Lake (uspHs), Decatur (uspHs), East Hannibal, East Peoria (uspHs), East St. Louis, Edgemont, Edwardsville, Effingham, Elsah, Fox Ridge State Park, George Field (uspHs), Gibsonia, Gossett, Grafton (UspHs), Grand Tower, Granite City (UsPHs), Grayville, Greenville, Hannibal, Havana, Herod, Herrin, Hull, Johnston City (uspPHs), Karbers Ridge, Lake Glendale, Marion, Maroa, Momence, Mount Vernon, Neoga, Oakwood, Olive Branch, Omaha, Peoria (UspHs), Pere Marquette State Park, Pike, Ridge Lake, Rock Island (uspPHs), St. Joseph, Salem, Seneca (UsPHS), Springfield (UsPpHs), Ware, West Vienna, and Willow Springs. 8. Culex peccator Dyar & Knab Larva.—very similar to larva of errati- cus, differing as follows: upper head hairs short as in erraticus but only double or triple; body only sparsely spiracular; comb with the scales forming a definite patch rather than an irregular line. Aputts.—Similar in size, color, and gen- eral structure to those of erraticus. Both sexes differ in having almost the entire occi- put covered with appressed and overlapping scales, at the most with a narrow mesal line of narrow scales. Males differ in characters of the genitalia, fig. 94: the basistyle is nearly globular, as in erraticus, the subapical lobe is very definite, the leaflet large, irregular, and expanded, the stalks thicker and defi- nitely proportioned; dististyle very thick, sharply bent at nearly a right angle with a series of concavities and brushlike lines of minute setae. Like the preceding, this species occurs throughout the southeastern states, where it is usually a rarity. In Illinois, we have taken only a few records of the species and most of these are in the southern fifth of the state. The larvae presumably frequent woodland pools with emergent vegetation. King, Bradley, & McNeel (1939) note that the larvae, when found, are almost always associated with those of apicalis. Cg 52 Intinois NaturaAL History SurvEY BULLETIN Vol. 24, Art. 1 Illinois Records——CarBonDALE: June 22-23, Ventral tuft situated beyond end of pecten, 1942, 16, 29; October 19, 1943, 16. CARTER- fig. 98.) oss bo. ee ee 3 VILLE: Aug. 13, 1942, 1g. Gossetr: June 3, 3. Gills budlike, much shorter than anal scg- 1942, Ross & Mohr, 3 larvae. GRANTSBURG: ment» fig. 98'> tcc... eee 4. sollicitans June 10, 1941, Ross & Mohr, 1 larva. La RUE: Gills at least as long as anal segment, fig. Oct. 1, 1942, 16. OLNey: June 10, 1941, Ross 99, frequently very long and pointed at & Mohr, 1 larva. Scorr Fievp: Sept. 10, 1942, tip, fig. 100... See 4 light trap, 12. 4. Gills extremely long, two or three times length of air tube, and with prominent — 9. AEDES Meigen tracheae, fig. 111; pecten with only a few scales... 22 07 See 20. dupreei To this genus belong nearly half of the Gills shorter than air tube, without tra- cheae, fig. 106; pecten with about 15 Scales)... 3.03 4... ee 5 5. Air tube short, not more than two and one-half times as long as wide, and pec- ten with several widely detached teeth Illinois mosquito fauna, with records for 21 species, which include nearly all of the truly nuisance species and both early spring and temporary summer pool species. One or two of the species transmit mammalian dis- F howe lee bie er 5. nigromaculis eases. Either air tube over three times as long In all species of the genus, as far as as wide, or pecten without detached known, the eggs are laid on moist soil or teeth iy. so eer 6 humus, or just above the water line in tree 6. Comb consisting of about 12 scales or less holes or artificial containers. They hatch forming a single row, fig. 106....... Fr) only after they have been flooded. Some Comb either consisting of 15 or more species, in which a desiccation and cold scales or forming a double row or tri- period is necessary for hatching, have only angular patch, fig. 108............ 8 7. Comb with 6 evenly spaced teeth; apico- dorsal tuft of anal segment represented by a pair of long, strong setae, as in a single generation per year, the adults emerging in early spring. Other species are intermittent breeders and usually have two fig 106i ote 22. implacabilis or three generations per year, depending on Comb with about 12 teeth forming an the rains. irregular line; apico-dorsal tuft of anal Certain taxonomic difficulties were encoun- segment many haired, fanlike, fig. 107 tered in studying the genus. The most 2 29 -++++eee see eete reese 23. punctor important resulted in the discovery that in 8. Air tube with ventral brush two-thirds many of the species the head hairs of the distance from base to apex, fig. 108... larvae were extremely variable, with the ey Oa SS SES Sens ag eae aa pe ‘ ee Air tube with ventral brush midway be- result that often in the then existing keys feed hasclandi apes ane 6.-mitchellal each side of the head of a single individual 9. ye 3 ‘ Head with preantennal hair delicate and would key out to a different species. Fre- single, fig. 112; anal segment with pre- quently, on this same basis, specimens of a apical dorsal tuft only three-branched, pure culture would key out to several spe- but as long as apical tuft... .2. aegypti cies. With the Illinois species it was possi- Head with preantennal hair divided into ble to circumvent this difficulty by introduc- a 4 to 15—branched tuft, fig. 113; anal ing new key characters especially concerning segment with preapical dorsal tuft 8- the relative positions of various stable hairs. to 15—branched, much shorter than api- Supplemental material regarding extra- Uc 10 10. Pecten with one or more apical teeth spaced fairly wide apart, appearing detached from row, figs. 101-103...11 Pecten with all teeth close together and limital species may be found in all of the comprehensive treatments of the family listed under the heading “Literature” on page 15. forming an even row, figs. 104, 105. .16 Key 10 SPECIES 11. Head with lower head hair considerably LARVAE laterad of, and only slightly anteriad 1. Anal segment completely ringed by sclero- of, upper head hair, fig. 100....... 12 tized plate ign 96ry aac tisu-eers skeen 2 Head with lower head hair only slightly Anal segment with sclerotized plate not laterad of, but considerably anteriad meeting on venter, frequently forming of, upper head hair, fig. 102........ 13 only a dorsal saddle, fig. 99........ 9 12. Antennae fairly thick at base and long, 2. Pecten extending beyond ventral tuft, tuft beyond middle, fig. 100; upper and Soy RA per meanie at etn ao 21. fulvus pallens lower head hairs double, occasionally — August, 1947 Ross: Mosquiroes or ILLINors 53 10OB AURIFER . SA \" TRISERIATUS U3 IOlA CY MK Yo \ Figs. 96-101.—A edes larvae; A, apex of abdomen, lateral aspect; B, dorsum of head. Inset are details of pecten and comb scales. On these and succeeding larval head drawings of Aedes, the mouth brushes are omitted. 54 ILLINOIS Natura. History SurvEY BULLETIN Vol. 24, Art. 1 XZ = a lO3A EXCRUCIANS Figs. 102-105.—Aedes larvae; Ad, apex of abdomen, lateral aspect; B, dorsum of head. Inset are enlarged drawings of pecten and comb scales. August, 1947 Ross: Mosquitoes oF ILLINOIS 55 Bar iat ie: ee (14 bot 107A STICTICUS “ wee ' lO9A FITCHII Figs. 106—110.—4edes larvae, apex of abdomen. All are the lateral aspect except fig. 110B, which is the ventral aspect of A. spencerii showing one or two anal hair tufts anterior to the barred area at base of gills. 56 Ittrnois Natura History Survey BULLETIN V ol. 24, Art. 1 OUPREE! AEGYPTI! GROSSBECKI 3B Figs. 111-113—Aedes larvae; A, apex of abdomen, lateral aspect; B, dorsum of head. Inset are enlarged drawings of pecten and comb scales. (Fig. 111 redrawn from Dyar.) August, 1947 one of the four triple; clypeal bristles moderately far apart....... 15. aurifer Antennae not enlarged at base, tuft below middle, fig. 101; upper and lower head hairs triple to multiple, at least two of the four with four to six branches; clypeal bristles much closer together. . 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McAtee (1924) learned of one pair of Canada geese that were mated for 42 years and another pair for over 20 years. Wilfrid (1924) reported a gander he believed to be at least 40 years old at the time of the bird’s death, and Leffingwell (1890) reported “as a matter of history” a captive bird that was killed when it was 80 years old. Doubtless there are other records in the literature that compare with these. Several instances of Canada geese, once used for decoys and later kept as pets, that attained ages of at least 20 years have been reported to the authors of this paper. In the wild, few Canada geese approach these ages. The greatest age attained by a wild Canada goose, to our knowledge, is at least 22 years. This goose was banded at the Miner Sanctuary in the spring of 1923 and retrapped in the spring of 1932 and again in the spring of 1944. The life span of the average wild Canada goose after banding, however, proves to be only a few years, generally less than 3, but as Austin (1942) has pointed out, “Tt is of little importance biologically speaking how long members of a species live providing their life span is long enough for a generation to reach and main- tain sexual maturity in order to duplicate the achievement of its predecessor.” In most instances, our data are inade- quate to compute average longevities with accuracy. ‘The complete recovery series, table 35, are of limited usefulness, since the geese involved were of unknown age when banded. ‘These data are further complicated by the fact that the number of recoveries during the season of banding are not representative of usual first-year mortality. Average longevities calculated from data collected for the present study would be misleading. While average longevities derived from adequate data would serve ideally to compare the survival of individuals of different bandings, for the present study the survival indices shown in tables 29, 32, 40, 41, and 42 are useful and are more appropriate. From these indices and from other data, it seems obvious that few Mississippi Val- ley Canada geese live longer than 3 or + years after being banded. Vol. 25, Art. 3 An approximation of the longevity of juvenile geese banded at Horseshoe Lake in the years of this study may be obtained through computations beginning with the following formula: f, yi + fe yo + fy Ys etc. N S stands for average survival after band- ing; f,, f., etc. represent, for each age- class involved, the mortality frequency in each of successive years as computed from the survival series on page 174: 26,46, 11.53, 3.90, 3.73, 1.99 (mortality fre- quencies:* 73.54, 14.93, 7.63, 0.17, 1.74) ; Yy, Yo, etc. represent the number of years (1 through 5) following banding applica- ble to each mortality frequency; N rep- resents the sum of the mortality fre- quencies. “The mean death date of geese banded at Horseshoe Lake was about mid- way between mean banding dates.t Hence, the value calculated for S, 1.4 years, is cor- rected by subtracting 0.5 to give average survival after banding, 0.9 year. As juveniles at Horseshoe Lake were — about 0.5 year old when banded, this figure is then added to 0.9 to give the average longevity, 1.4 years. Thus, it might be said that the average banded juvenile goose and presumably the aver- age juvenile in the unbanded Horseshoe Lake population in the years of this study — did not live long enough to produce one brood of young. DISCUSSION It is axiomatic that the sound manage- ment of a wildlife species must in the last analysis rely on carefully gathered scientific data. Waterfowl studies usual- ly concern migratory species for which it is difficult to secure adequate data from all parts of the range. The range of most waterfowl species is immense, and some populations shift their distribution within a flyway from year to year because of changing food, water, and weather con- ditions. The aim of most broad studies of water- fowl species probably would be to gather * Derived by subtraction: 100.00-26.46, 26.46-11.53, 11,53-3.90, etc. + Mean banding date about December 1. March, 1950 information that would allow manage- ment of the species concerned on a flyway basis, as recently suggested by Gabrielson (1944). Because Canada geese tend to exhibit a greater adherence to their ances- tral range than do ducks, management by flyways for this species is more suitable than it would be for most other waterfowl. In fact, the fairly restricted range of the various Canada goose populations in eastern North America, as shown earlier, suggests the need for certain management measures for individual population ranges rather than for an entire flyway. Al- though additional information concerning the Mississippi Valley goose population is needed, enough is now available to per- mit this population to be managed pri- marily as individual population units. Status In 1946, 14 states of the Mississippi flyway (Michigan, Wisconsin, Minnesota, Ohio, Indiana, Illinois, Iowa, Kentucky, Tennessee, Missouri, Mississippi, Ala- bama, Arkansas, and Louisiana) were closed to the hunting of Canada geese. The closed season of an entire flyway was the first of its kind in the history of this species of waterfowl. The only similar actions ever taken were those closing the shooting seasons on snow geese and brant in the Atlantic Coast states. Snow-goose hunting has been prohibited there since 1931, and brant hunting for more than half of the years since 1933. The closed season on Canada geese in the Mississippi flyway in 1946 was believed necessary for a number of reasons: an alarming decrease in the number of these geese in the Mississippi fyway from 1940 to 1945, as indicated by January inven- tory data; markedly increased kills be- ginning in 1939, particularly in the region of Horseshoe Lake; a disproportionate kill of juvenile birds and an apparent de- creased productivity in 1945, as indicated _ by research at Horseshoe Lake. The peak number of geese at Horseshoe Lake dropped from about 50,000 in 1943— 44 to 26,000 in 1945-46. That this de- crease represented a real decrease in the flyway population and was not due to by- passing of the area by flocks is shown not only by flyway censuses but by band-re- covery records. These records indicate Hanson & SmitH: Canapa GEESE 189 that since 1932 many of the geese that formerly used the Mississippi River from Cairo, Illinois, to Baton Rouge, Louisiana, have concentrated in a much smaller area centering on Horseshoe Lake, probably because of the refuge there and the large amount of grain available to the geese. Known bags and careful estimates of kills indicate that, in the years just pre- vious to 1946, an average of about 20 per cent of the Canada goose population wintering at Horseshoe Lake was bagged annually, and that the total annual kill in the area averaged about 27 per cent of the population. In view of the fairly low productivity of the Canada goose, it is obvious that a reasonable kill in this area was greatly exceeded. Population declines at Horseshoe Lake and in the Mississippi flyway as a whole showed that flock mortality from all causes combined had been excessive, and, as hunting losses are one type of mortality that can be con- trolled, it was evident that closing the en- tire flyway to shooting was the most effective management measure that could have been employed. Evidence of increased shooting pressure on Canada geese in years just previous to 1946 is illustrated by the survival curves, fig. 77, representing data computed from band recoveries from geese banded at the Jack Miner Bird Sanctuary, Kingsville, Ontario. These data show that the an- nual survival rate for that portion of the population migrating through the Kings- ville area was lower in the 5 years be- ginning in the fall of 1940 than in any comparable period in the previous 15 years, fig. 77. Chiefly responsible for this lower survival rate were the heavy kills made at Horseshoe Lake; band recoveries show that the survival rate of the Horseshoe Lake flock was well below the average for the entire Mississippi Valley population. In fact, the survival series for the Horse- shoe Lake flock was lower during the period 1940-1945 than it was in the entire Mississippi Valley population in the years in which baiting and the use of live decoys were permitted, tables 10, 37, and 38. Moffitt (1935) was concerned over the future of a flock nesting in California when he realized an 11.5 per cent first- season recovery rate from his bandings. Unpublished studies by Cecil S. Williams 190 of the United States Fish and Wildlife Service at the Bear River marshes, Utah, indicate that the Great Basin population he dealt with could show a first-year band- recovery rate of 16 per cent and a total band-recovery rate of 25 per cent and still increase. Total recoveries from Horseshoe Lake bandings were at only about half the rate of total recoveries re- ported for the Great Basin, but other data indicated a heavy kill rate and a decline in the Horseshoe Lake population in the years just previous to 1946. While Wil- liams’ data establish the fact that the Canada goose could withstand heavy shooting losses in the Great Basin, con- ditions vary too widely in the various fly- ways to predict on the basis of data from one area (Utah) what the conditions are in another (Horseshoe Lake). Interpolating from fig. 74, curve I, which is based on a survival series ob- tained for the Horseshoe Lake flock, it appears that only about 16 per cent of the juveniles reaching Horseshoe Lake Table 43.—Juvenile-adult ratios of Canada geese at Horseshoe Lake, 1942-43 through 1946-47, arranged to show the effect of a differential kill on survival. ; Ittrnois NaturAL History SuRVEY BULLETIN Vol. 25, Art. 3” during the period of field work for this study lived long enough to see a brood of their young on the wing. When a major portion of the annual ~ kill of a Canada goose flock is at the ex- pense of one age group, data on the total — number of birds bagged do not reveal the true impact of the kill upon the total population. At Horseshoe Lake the juve- — niles made up the major part of the kill in the period covered by this study, tables In the autumn of 1943, the — juveniles made up 56 per cent of the population, while 91 per cent of the hunt- In that year, 37 per cent of the juvenile popula-— tion at Horseshoe Lake was bagged. The — following year, the 1943 generation (then — yearlings) comprised only about 29 per — The effect — of this differential kill is also shown by ~ trap-age ratios of banded survivors in In table 43, returns for the — years 1943-1947 of geese banded during the autumn and winter season previous to 43 and 44. er’s bag consisted of juveniles. cent of the total adult birds. later years. (See table 23.) Numper Returnine To Traps 1 Year Later JUVENILES JUVENILES SEASON Per 100 Per 100 : Aputts Banpep| ADULTs In BaG Age Num- Per Cent of Yearlings Class ber | Original Banding | Per 100 Adults 1942-43. . 153 259 Juvenile 67 10.82 137 Adult 32 7.92 1943-44. . 145 1,053* Juvenile 87 6.31 56 Adult 107 11.26 1944-45... 246 942 Juvenile 106 17.46 173 Adult 25 10.08 1945-46. . 172 410 Juvenile 39 19.90 87 Adult 26 22.81 * Although this figure is based on a smaller sample than in most other years, field observations and data collected subsequently indicate that it is a close approximation of the actual kill ratio. Table 44.—Calculated kill of juvenile Canada geese at Horseshoe Lake, 1942-43 through — 1945-46, exclusive of crippling losses. E Per Cent oF yee anes Per Centr or} CatcuLareD |ToraLt JUVENILES Seaean tReR LOGE ikaw Bac Mabevp| NumsBeror_ {in FLocks BAGGED (Sze AviiNeos OF JUVENILES By Hunrers Tape 27) JuvENILES tn Bac NEAR Horses I 949-45) 22 32,450 6,529 72.1 4,707 14.5 1943-44... 0... 29,680 12,062 91.3 11,013 37all 1944-45 | 22,316 7,807 90.4 7,058 31.6 1945-46. ....... 10,534 5,244 80.4 4,216 40.0 March, 1950 each of these years are given. In the autumn of 1942, when only 2.59 juveniles were shot for every adult, the survival rate of juveniles was evidently favorable to this age class as 10.82 per cent of the total banded juveniles returned to the traps in the following year as compared with 7.92 per cent of the adults, or a ratio of 1.37 juveniles to 1.0 adult. In contrast to this survival picture is the highly differential kill that occurred in 1943 when the ratio of juveniles to adults shot at the hunting clubs surround- ing the refuge was 10.53 to 1.0, table 43. ‘The next year the return to the traps was only 0.56 juvenile (then yearling) to 1 adult. Despite the fact that juveniles bore the brunt of the kill in 1944, table 44, the net loss to the juvenile segment of the population was somewhat less, with the result that the ratio of juvenile (then yearling) to adult returns in the traps a year later, in 1945-46, was 1.73 to 1.0, table 43. A relatively high kill of juveniles coupled with a year in which productivity is low is almost certain to place a goose population in a hazardous position. Band- ing at Horseshoe Lake indicated a de- crease in productivity in 1945 from the productivity in 1944, table 43. The rel- atively small number of young produced in 1945 may have been related in part to the cold weather in the spring of that year; the productivity of mallards also was greatly reduced in that year. A depres- sive effect on the intensity of mating or on nesting success in many species of birds has been attributed to late and cold springs. The following species said to be affected thus might be cited: Canada goose (Johnson 1947); arctic tern (Lack 1933); eiders and loons (Bird & Bird 1940); moor hen (Huxley 1932); and house wren (Kendeigh 1942). However, it is conceivable that part of the decrease in productivity in 1945 may _ have been apparent rather than real. .Un- doubtedly juveniles: contribute a larger proportion of the kill during migration than do the adults, but the extent to which shooting north of the Horseshoe Lake Game Refuge is selective of juveniles is not known. Because the kill between the refuge and the Canadian border in 1945 was much larger than usual, the age ratios Hanson & SmitTH: CANADA GEESE 191 in the southward-bound flocks may have been significantly altered by shooting in that particular year. The subject of cycles in waterfowl is still largely an unexplored field. It does not appear to be known generally that, in the arctic, geese, ducks, and loons may be subject to nonbreeding years (Man- niche 1910, Bertram, Lack, & Roberts 1934, Bird & Bird 1940). Keith (1937) writes, “. . . . 1936 was a ‘non-breeding year’ [in Northeast Land, Spitzbergen Archipelago] when large numbers of Ducks and Geese failed to nest; and in other parts of the Arctic it had always before been found that the Divers [loons ] were also affected by these years and that of them too only a small proportion were breeding.” As nonbreeding of waterfowl has been reported only from high arctic areas, it is debatable whether the Canada goose populations dealt with here are similarly affected. At present, low productivity in blue geese and snow geese appears to be con- fined to summers in which inclement weather directly affects the success of nesting (Soper 1930). In the opinion of Berry (1939), “climate is of the utmost importance in limiting the survival rate of goslings on the northern breeding grounds.” A year of low productivity in Canada geese should be of particular concern to the administrators who seek to influence the kill by hunting regulations, for the reason that the young birds bear a double responsibility. Being more vulnerable to shooting than the adults, they must con- tribute a disproportionate share of the kill, and, secondly, they must survive in sufficient numbers to help reproduce an equivalent of the annual loss in the breed- ing population. Even in a year when the production of young was not significantly low, 1943, shooting losses in the Horse- shoe Lake area were so severe and so greatly at the expense of the juveniles that only a small proportion of this generation survived to reach the minimum breeding age of 2 years. Management What can be done to insure the future of the Mississippi Valley geese? Until recent years, two prime measures for con- 192 Ittinots NaturAL History Survey BULLETIN serving waterfowl, hunting regulations and refuges, have been fairly successfully used in the management of this group. As applied to the population of geese dealt with in this report, it is apparent that these measures were not very effective in the period of field work. In Canada.—Several factors minimize the need for any immediate change in measures relating to the Mississippi Valley population while in Canada. The relatively inaccessible nature of the Cana- dian breeding grounds insures adequate protection for the flock during the actual breeding season. The kill in Canada is not excessive, and a reduction of the early spring kill on the breeding grounds would be difficult be- cause much of this kill is virtually neces- sary for the survival of native Indians. Furthermore, our kill and population data indicate that the annual rate of kill (the percentage of birds taken from the re- turning population in the spring) by the Indians is relatively constant. In general, only when there is an actual increase in Vol. 25, Art. 3 the Canada goose population does a signif- icant increase in the number of these geese bagged by Indians occur. This relatively constant relationship is evidence that the goose kill by natives cannot be considered ~ the direct cause of any considerable popula- tion decrease that might be reported in the United States from any of the annual January inventories. In the United States.—In 1944 and 1945, when season bag limits were im- posed for Alexander County, Illinois, table 10, it was a relatively easy matter to limit the kill of geese in the Horseshoe - Lake area to approximately the predeter- mined figures. The facility with which © the day-to-day kill can be tallied is perhaps the outstanding advantage of en- couraging a portion of the flock to utilize the refuge there. “The season bag limit in the above instances was determined by the trend of the population in prior years, — but, to be fully effective, management should anticipate future trends based upon the current composition of the population. With the data at hand on the Canada Table 45.—Calculated losses and reproductive gains for the Horseshoe Lake Canada — goose flock between the autumn of 1944, and the autumn of 1945.7 oi Tora, ADDED] ToraL BALANCE CLASSIFICATION (Youne Lost (Toran Propucep) Survivine) Flock arriving at Horseshoe Lake in the autumn of 1944 (in- cludes 6,885 yearling and older females)................. 40,500 Number lost from hunting at Horseshoe Lake (includes 525 yearling andyadulttemales)).cce12-.jse = ee mies tee een 10,550 Maximum number flying north in spring (includes 6,360 fe- males older than 114 years of age)....................--- 29,950 Kill by Indians in the Hudson-James Bay area? (includes 277 females 2 or moreyeatsiol age)! hee eae ere nes 2,100 Natural losses for year at 18 per cent of 40,500 (includes esti- mated (.000ladult feniales)*:, 32 st eee 7,290 Total yearlings and adults alive after breeding season (in- cludes‘5,083 adult females)2/e (oe ne eee ent 20, 560 Number of young brought to flying stage (3 per adult female). 15,189 Approximate total at start of autumn migration............ 35,749 Kill by hunters in flyway north of Horseshoe Lake (at 6 per cent of southwardiflicht)®. 9) 8s .eeeeee eee 2,135 Number calculated to arrive at Horseshoe Lake in 1945...... 33,614 Actual number to arrive at Horseshoe Lake in 1945 (inven- tory figure, January, 1946, plus total hunting loss in area)... 29,100 1In most cases calculations are based on actual data, in others on estimates. 2 Proportional share of total kill suffered by the Horseshoe Lake flock. § ean eity of yearlings 2.8 times that of older geese; kill of adult females should not exceed 13 per cent of e tota OSS. 4 The loss rate from natural causes tends to be inversely related to the losses from hunting. ©The kill of Canada geese between the Canadian border and Horseshoe Lake was particularly heavy in 1945; hence, the actual kill for that area probably exceeded 6 per cent of the southward flight. For reasons explained im footnote on page 150, the actual kill rate in this area in most years is probably closer to 8 or 10 per cent of © the southward flight. March, 1950 goose in the Mississippi River valley, it is possible to arrive at a practical estimate of the maximum kill that can be tolerated. A method by which management of the Mississippi Valley population might pro- ceed is best illustrated by a concrete example, table 45. Similar calculations based on sex and age ratios from trapping, and made by the authors in the spring of 1945, forecast a decreased population for the autumn of 1945. Censuses during the autumn and the inventory of January, 1946, proved the accuracy of this pre- diction. Since the autumn flight in any year depends to a large extent on the produc- tion of young in the spring of that year, it is necessary to know the approximate number of breeding females and to have some measure of the nesting success on the breeding grounds to predict the autumn flock population with reasonable accuracy. Inventory on the breeding grounds would be difficult because of the nature of the terrain, but the use of planes would aid tremendously in such work, For the present, and until more data are available, the average produc- tivity of the population might be calcu- lated on the basis of three young (brought to flying stage) per adult female. If the flock population has been fairly stable for several years or is on the in- crease, a bag of 10 per cent of the number wintering in the Horseshoe Lake area might prove to be within the limits of what the flock could stand without decreasing in size. Even this kill might be too high if kills north of Horseshoe Lake were un- usually large in a given autumn, if nesting success was low the previous spring, or if sex and age ratios were seriously un- balanced. When the population is very low, the kill of a single bird constitutes overshooting. A reduction in the crippling loss would allow the season bag limit in the Horse- shoe Lake area to be increased. The num- ber of geese crippled and lost to hunters each year in the area is needlessly high. An estimate of cripples not retrieved and soon dying is placed at 30 per cent of the number of geese bagged. Certain ad- ministrative measures can be taken to re- duce the per cent of cripples not retrieved. For instance, adequate spacing of pits to Hanson & SmitH: CANADA GEESE 193 reduce competition among hunters would materially aid in reducing crippling losses. But a large share of the responsibility will rest with the hunter himself, who must restrain the natural desire to “give a high one a ride.” Some hunters hope to bag geese with greater ease by using magnum shotguns. However, it is open to debate whether more geese are bagged than crippled by such guns because of the out- of-range shooting their possession en- courages. At least in one instance a 10- gauge magnum shotgun is known to have failed to live up to its owner’s expectation; a tally of empty casings from this shot- gun in one pit, presumably fired to bag the limit of two geese, was 22, as against the average of 9 cartridge casings per hunter for all pits inspected. It is clear from tables 15 and 10, show- ing kill and hunting regulations in the Horseshoe Lake area, that hunting restric- tions were not always successful in re- ducing the kill to the desired extent, but, if various measures instituted to lower the annual kill had not been taken, it is probable that a large proportion of the Canada geese using the Horseshoe Lake area would have been shot by the end of 1945. Under normal conditions, the duration of the hunting season can be expected to show a fairly direct relationship to the kill, but, when the natural wariness of the geese has been reduced, as at Horseshoe Lake, the length of the hunting season may show no correlation with the kill, figs. 52 and 53. Pirnie (1939) has emphasized that “Changing habits of these birds [Canada geese] may create new hazards for them and require even more stringent regula- tions.” The behavior of the Horseshoe Lake flock in recent years and its relation to shooting has already been discussed, but it should again be emphasized that restric- tions alone cannot be expected to safe- guard it. Refuges form an important part of our system for the preservation of waterfowl. Whether or not any individual refuge proves of value will depend to a certain extent upon its management and also upon its size. Leopold (1931) stated the chief problem in regard to the Horseshoe Lake Game Refuge soon after this refuge was 194 created. ‘The question of whether public refuges should be surrounded by public shooting grounds is frequently debated. Horseshoe Lake in Alexander County, Illinois, is a good place to study the ques- tion.” Twelve years after this statement was published the answer was torcibly given by Gabrielson (1943). “Because of its [Horseshoe Lake Game Refuge] attrac- tiveness to Canada geese, small size, lack of food, and peculiar relation to surround- ing lands, it has become a slaughter pen rather than a refuge.” The breakdown in wariness that oc- curred was perhaps more serious to the future of the Horseshoe Lake flock than the reduction in its size. ‘The steps be- lieved necessary to re-establish wildness in the flock were as follows: (1) Establish refuge areas on the nearby islands and bars of the Mississippi River or on lands adjacent to the river; (2) disperse the geese from Horseshoe Lake to these bars and islands; that is, drive them back to their original habitat; (3) insofar as possible, reduce contact between human beings (both the public and refuge per- sonnel) and the geese. In the past years in which the geese used both the river bars and the refuge, they retained their natural wildness; coin- cident with their almost complete depend- ence on the refuge for food and grit, they lost much of their wildness. The river refuge might act as a final sanctuary for the flock should it be disturbed for any reason at Horseshoe Lake, and ideally it should contain the bulk of the flock at most times. Canada geese will feed by moonlight, at daybreak, or at dusk, if they are disturbed while feeding during the day. ‘This fact may offer a partial solution to the Horse- shoe Lake problem. If the geese were permitted to feed at the Horseshoe Lake Game Refuge only during the hours of dawn and dusk, the re-establishment of wildness might occur and with it a reduc- tion in the rate of kill. We have a prece- dent for such a course of action in the operation of the Miner Sanctuary, where the geese feed only in the early morning hours and at dusk, spending the remainder of their time roosting out on Lake Erie. State regulations just previous to 1946 I_tinois Narurat History SurvEY BULLETIN Vol. 25, Art. 3 prohibited the placing of shooting pits within 75 to 150 yards of the boundary of the Horseshoe Lake Game Refuge. This buffer zone, which was intended to allow the geese to attain safe heights before — reaching the shooting pits and blinds was unquestionably insufficient, since many of the geese leaving the refuge encountered shot pellets 75 yards away from the first line of pits. Although the Miner Sanc- tuary consists of only 400 acres and sup- ports an even greater density of geese than — is ever experienced at Horseshoe Lake, excessive kills have not occurred near this Canadian refuge in late years. Responsi- ble in part for the small kills reported in — the vicinity of the Miner Sanctuary is a buffer zone that surrounds the ponds and feeding grounds for a distance of a mile. When geese leave the refuge, they have sufficient space in which to gain altitude before passing over the shooting grounds. The present food resources of the Horseshoe Lake Game Refuge are insuffi- cient to winter more than 20,000 geese, and probably only 15,000 can be accom- modated to best advantage. When the corn crop and wheat browse on the re- fuge are exhausted, and sometimes before this occurs, the flock feeds on unharvested and waste grain and on the green plants Se eT ee ee eee of winter wheat in fields of the surround- — ing countryside—occasionally at a con-— siderable loss to farmers who do not rent their fields to hunters. is broken up and scattered to other areas in the flyway, the local food conditions must be improved, either through the ac- quisition of more land or by an artificial — feeding program. ‘The artificial program is wholly undesirable unless it is carried Unless the flock — out on an isolated tract of land. On the B 3 other hand, the development of a river refuge would certainly increase the flock’s usage of natural foods—the grasses, sedges, and switch willows on which the geese es formerly fed. The present size of the Horseshoe Lake Game Refuge is woefully inadequate for ba the geese using the area, as experiences there and elsewhere have demonstrated. A program involving purchase of additional lands has been planned by the State De- partment of Conservation for several years, but has been blocked by the in- flated prices of lands in the area—inflated March, 1950 prices resulting in part from the commer- cialization of goose hunting. Census data showed that, between 1942 and 1945, the Canada goose in the Mis- sissippi River valley suffered a marked decline in population. Kill records showed an increase in the annual bag beginning in 1939, and banding data revealed a con- current decrease in goose survival for the same period. The conclusion must be reached that the Mississippi Valley Canada goose population was shot too heavily in that period and that stringent protection was necessary to insure perpet- uation of this population. PRESENT SITUATION The time lapse between completion of the field work reported here and publica- tion of this article has been sufficient to permit an evaluation of some of the meas- ures recently taken to assure the future of the Canada goose population of the Mississippi River valley. The decision to close the valley to Canada goose hunting in 1946 was based partly on evidence gained from banding that the geese winter- ing at the Horseshoe Lake Game Refuge were suffering unprecedented losses from hunting and were being killed at a rate far greater than the flock could stand and still maintain its numbers. In addition was the evidence from annual inventories that the flyway population was at an alarmingly low level. In 1947, the shooting of Canada geese Was again permitted in the Mississippi River valley, but on a restricted scale. The season opened on November 4 and closed on December 3. The bag limit was reduced to one bird per day and the possession limit was also one bird. ‘To in- sure against a return of heavy kills in the Horseshoe Lake region, an area in the region totaling approximately 15,000 acres was declared closed by proclamation of the President of the United States with the joint support of the Governor of Illinois. By this action, a buffer area, roughly 2 miles in depth, was created around the Horseshoe Lake Game Ref- uge. In 1948, the hunting season opened on October 29 and closed November 27. During this 30-day season, hunters were permitted to bag two Canada geese per Hanson & SmitH: Canapa GEESE 195 day and were allowed a possession limit of two birds. The response by the geese to greater protection has been most heartening, their comeback demonstrating both that the kill by hunters in the United States was a major suppressive factor on the popula- tion, and that this population, given op- portunity, possesses strong recuperative powers. With a capital investment of 49,000* birds in the Mississippi flyway in the winter of 1945-46, interest in the form of 1946 reproduction was reinvested as capital gain by virtue of the closed season. Inventory in January, 1947, re- vealed a capital gain of approximately 25 per cent, table 7. This recovery by an almost bankrupt population so encouraged the committee on regulations that a dividend, in the form of an open season, was declared permissible for the autumn of 1947 and again for the autumn of 1948. The dividend in the Horseshoe Lake area in 1947 was 1,644 geese bagged by hunt- ers; in 1948 it was 2,587 geese bagged by hunters. In addition to this number, other geese, estimated at 2,000, were shot illegally within the buffer area closed to hunting outside the refuge. We do not have the data at hand to show what the profits were to hunters in other states in the flyway, but that the goose business could afford the dividends is shown by the recent summary of capital stock given in table 46. The recovery made by the Mississippi Valley population has not gone unnoticed by the Indians who trap and hunt on the breeding grounds before the actual com- mencement of nesting. In August, 1949, the senior author learned at Fort Albany that the Indians there had observed more geese in the spring of 1949 than at any other time in recent years. Similarly, questionnaire answers received from Ray- mond M. Alaine of Weenusk, September 21, 1949, stated that the Indians at that post had not seen as many geese in any other years of the last 10 as they did in the fall of 1948. Future management of the Horseshoe Lake flock by the United States Fish and * This figure includes geese from western Louisiana, birds that possibly belong to the Eastern Prairie popula- tion and that should not be included in the Mississippi Valley population. Hence, it exaggerates the size of the Mississippi Valley population for 1945-46. 196 Ittinois NaturAL History Survey BULLETIN Table 46.—Population of Canada geese in the Mississippi River valley in 1947-48 and 1948-49, from January inventory, except as noted. SEASON SraTe or OTHER AREA 1947-48] 1948-49 pecans s2 5,000} 6,000 Wisconsin. 4,200) 4,760 Indiana. 1,679} 7,449 Illinois (total). 57,205] 90,414 Mason County... as ; = 960 Horseshoe Lake... = 46,000 Craborchard Lake, William- son County.... . — 30,000, Lyerly Lake, Union County — 12,450 Miscellaneous areas. | = 1,004 Kentuaeyacvss coke oe 1,500} 7,200 Mississippi. ....---- 5,500} 7,250 Tennessee. .........--- 2,500} 9,450 Arkansas. saisiaciernie is 9,000} 12,000 Missovnis i.e ssmote eee — 5,000* Weouistanaerc, eee tee 10,000) 10,000 Moral eet ae eee 96 ,584|159 523 * Most of these geese were a part of the flock wintering in the Horseshoe Lake area. Wildlife Service and the Illinois Depart- ment of Conservation envisions the break- ing up of this concentration and dividing it among four other refuge areas: Crab- orchard National Wildlife Refuge, Wil- liamson County, Illinois; Lyerly Lake State Refuge and Public Shooting Grounds, Union County, Illinois; the Mingo National Wildlife Refuge, Mis- souri; and the Kentucky Woodlands National Wildlife Refuge bordering the Tennessee River south of Paducah, Ken- tucky. To implement the dispersal of geese from Horseshoe Lake, planes, guns, bombs and various other pyrotechnic de- vices were used to frighten the geese in 1947, 1948, and 1949. That this dis- persal program is meeting with success is evident from the data presented in table 46. Provided with these other areas, an ample food supply, and adequate legal pro- tection, the Canada goose population in the Mississippi valley faces a future that seems assured for some years to come. SUMMARY The Horseshoe Lake Wildlife Ref- uge, located at the southern tip of Illinois near Cairo and created in 1927 by the Illinois Department of Conservation, totals approximately 3,700 acres. Vol. 25, Artogs 2. Soon after the refuge was formed, increasing numbers of Canada geese, de- coyed from their traditional wintering grounds along the Mississippi River by the food and protection offered, began to use this refuge. In most recent winters the refuge has attracted about 50 per cent of the Mississippi Valley Canada goose population. With the increase in the size of the flock at the refuge, there was a loss of wariness on the part of the geese, ; accompanied by a tremendous increase in the annual kill. 3. In the eastern half of the United States there are two subspecies of Canada geese. The easternmost race, Branta canadensis canadensis, comprises the geese of the North Atlantic population. The other race, Branta canadensis interior, which breeds principally west, south, and east of James and Hudson bays, is com- — posed of four subgroups, each of which — constitutes a separate flyway population, © The four subgroups are as follows: the South Atlantic, the Southeast, the Mis- sissippi Valley, and the Eastern Prairie. 4. The main breeding range of the ~ Mississippi Valley geese is believed to lie within the western limits of the Paleozoic Basin west of James Bay and south of — Hudson Bay. The majority of the nest-_ ing geese of this population are found in relatively restricted areas of the vast, low- lying, muskeg-covered plain of the region. 5. Aerial observations revealed that the type of muskeg attracting the greatest numbers of geese is one that is studded with potholes of a few acres to about 30 acres in size, so closely grouped that often only a narrow strip of land or floating vegetation separates one from another. 6. Most nesting pairs of Mississippi Valley geese are concentrated in produc- tion centers, but, as most of these produc-_ tion centers are of considerable size, scattered nesting, with one or two pairs” to a small lake, seems to be the rule west of James Bay and south of Hudson Bay. - 7. Before the southward migration of Mississippi Valley geese begins, about August 15, some family groups and small flocks begin a series of local flights, the termini of which are favored feeding grounds along the west coast of James” Bay and the south coast of Hudson Bay. the tundra of Cape Henrietta Maria and the coastal marsh of Akimiski Island. The March, 1950 tundra of Cape Henrietta Maria is favored because of the quantity of berries usually available there. 8. At least half of the Mississippi Valley geese do not fly to the coastal areas before migrating, but leave directly from their muskeg breeding grounds and strike south on a broad front. ‘These are be- lieved to be the geese that cross the Canadian border into eastern Minnesota and the upper peninsula of Michigan. 9. While probably at least a few Canada geese in migration pass over most areas of the Mississippi flyway each year, band recoveries and observations indicate that the following routes are most fre- quently used: from the Miner Sanctuary to Horseshoe Lake via Lake St. Mary, the Wabash and Ohio rivers; from Saginaw Bay southwest across the lower peninsula of Michigan to the W. K. Kellogg Bird Sanctuary area and the lower Kalamazoo River; southward along both shores of Lake Michigan. Migration through Wis- consin is principally in the eastern half of the state. The west shore of Lake Michi- gan is followed by appreciable numbers of geese. Two other routes appear to be favored: (1) the valley of the Wisconsin River; (2) Green Bay south to Lake Winnebago, the flight probably splitting south of Lake Winnebago, one section going to the Lake Geneva area, the other following the Rock River valley. Migra- tion through Illinois appears to take place on a fairly broad front although the Illinois River valley is particularly favored. 10. Band-recovery data indicate that turnover in the population wintering at Horseshoe Lake is negligible. Geese that are decoyed into this refuge usually re- main there for the rest of the season. 11. A portion of the Mississippi Valley geese migrating through the Kingsville, Ontario, region do not visit the Horse- shoe Lake Refuge but by-pass it to the east, probably via the Tennessee River, and winter on the lower Mississippi. 12. The northward migration in spring is more nearly on a directly north and south axis than routes taken in the autumn. The flights of Mississippi Valley geese that stop at the Miner Sanc- tuary in the autumn do not reappear there in the spring in appreciable num- bers; presumably they return to the breeding grounds by a more westerly Hanson & SmitH: CANADA GEESE 197 route. The spring flights through the Kingsville region are comprised chiefly of South Atlantic geese. 13. Autumn migration of Mississippi Valley geese occurs over a 3-month period ; the last geese to reach Horseshoe Lake in appreciable numbers arrive in_ early December. Much of the late flight rep- resents the exodus of geese from the Miner Sanctuary when feeding there is curtailed. 14. The southward movement of the Canada geese from the breeding grounds may be compared with a segment of the concentric waves produced by an object striking the surface of a body of water. Geese that leave the breeding grounds earliest are believed to winter in the most southerly areas of the flyway. Those that leave the breeding grounds last are be- lieved to winter in the most northerly areas of the wintering grounds. 15. In spring, the first flocks generally arrive on the breeding grounds between April 15 and 25, 2 to 3 weeks before the breakup of the major rivers. 16. Winter concentrations of Canada geese occur in the region of Kingsville, Ontario, westward to southern Wisconsin, and south to the Gulf Coast. 17. Although the Canada goose is widely reputed to be an extremely wary and difficult species to hunt, the behavior of this species at Horseshoe Lake in re- cent years has contradicted this reputa- tion. Believed responsible for the high vulnerability of Canada geese to shooting in the vicinity of this refuge are the psychologically pacifying effect of large numbers of geese at rest on a relatively small area; the frequent sight of man in a benign role; and the decreased mobility of the flock when food is abundant on the refuge, as well as on adjacent hunting areas. 18. Goose hunting in Illinois, once a sport carried out in widely scattered areas of the state, is now confined largely to the Illinois River valley and the Horseshoe Lake region. 19. In the period 1944 through 1947, the kill of Canada geese of the Mis- sissippi flyway by Canadian Indians is computed to have been between 4,000 and 5,500 or from about 8 to 10 per cent of the number of birds that attained the breeding grounds in the spring. Approxi- 198 Ittinois NaturAL History SurvEY BULLETIN mately 25 per cent of the total number of Mississippi Valley Canada geese bagged in recent years have been taken by Indians. 20. The waterfowl kill made by the Indians of the James Bay region is some- times vital to actual survival of the In- dians. Blue geese and snow geese greatly outrank the Canada goose-in importance during the fall hunt along the coastal marshes; in spring, when the Indians are trapping inland along the rivers and creeks, the principal kill of Canada geese occurs, while relatively few blue geese and snow geese are shot at this time. 21. The restocking of beaver in some areas of the Canadian goose breeding range is beginning to relieve some of the hunting pressure on Canada geese. 22. The kill in the Horseshoe Lake area first began greatly to exceed what the flock could stand in 1939 when a kill of 17,300 geese was made. The average number of geese bagged in the Horseshoe Lake area in the autumns of 1939 through 1945 was about 9,800. In the autumns of 1943, 1944, and 1945 the bag amounted to 23, 19, and 18 per cent, respectively, of the number of geese that arrived at the refuge in those years. 23. The annual bag of geese in Illinois in areas other than Horseshoe Lake averaged approximately 1,100 birds in the period covered by this report. 24. Next to Illinois, Michigan made the largest kills of Mississippi Valley geese, 1938-1944; the annual bag was probably between 1,000 and 3,000 birds. 25. Bag inspections at hunting clubs near Horseshoe Lake showed that juvenile geese made up a high percentage of the total kill, 1940-1945. In 1943, juveniles were about eight times as vulnerable to hunting as adults. 26. Crippling losses among geese at Horseshoe Lake in recent years are esti- mated to have been equivalent to about 30 per cent of the annual bag. 27. Causes of death among Canada geese at Horseshoe Lake include lead poisoning (from ingestion of lead pellets), bound crop (perhaps a result of lead poisoning), tracheitis, and aspergillosis. 28. Sex ratios obtained from trapping geese at Horseshoe Lake show that there were slight, but statistically significant, larger numbers of males than of females Vol. 25, Art. 3 in the juvenile and adult age classes, 1940-1946. Bag-inspection figures showed © no significant preponderance of either sex — in either age class, 1940-1945. 29. Nesting success of geese is not ap- preciably affected by the Canadian Indians, since the bulk of the kill is made in early — spring before geese have begun to nest. Foxes may have a slight effect on nesting - success when their other prey species, which — appear to be cyclic, are low in numbers. 30. In 7 years of trapping and bag inspection at Horseshoe Lake, the age ratios obtained varied from 57 to 204 juveniles per 100 older geese. In 1944— 45, trapping indicated that 55 per cent of the population consisted of juveniles. Trapping in the following year indicated © that the proportion of juveniles had dropped to 36 per cent. " 31. Average flock size, computed from — frequency counts of flocks of nine or fewer geese on the wintering grounds, — may provide a quick means of appraising — breeding success of geese in the previous — spring. & 32. Low survival of Canada geese banded at the Jack Miner Bird Sanc- — tuary, 1940-1944, is believed to have been — brought about chiefly by the tremendous — increase in the kills made in the region of Horseshoe Lake. 7 33. Mortality data calculated from trap- ping and band-recovery figures show that ~ the Horseshoe Lake flock had a lower sur- vival rate during the period of this study than did comparable banding classes from the Miner Sanctuary. 34. Mortality indices, the average of mortality rates for three years after band- ing, provide a possible basis for com- ~ paring mortality between different popu- lations and banding classes of geese. 35. Survival data for the Horseshoe Lake flock, 1941-1945, indicate that the average juvenile did not live long enough to produce a brood of young. 36. In 1946, no open hunting season on Canada geese was permitted in the Mississippi River valley. In 1947, shoot- ing on a restricted scale was permitted. : 37. Increased protection of the Mis- — sissippi Valley Canada geese plus certain other management practices resulted in an appreciable gain in the population by the fall and winter of 1948-49. APPENDIX A THE SOUTHEAST POPULATION NE of the important findings from our O study of the Jack Miner banding data, as they relate to the Horseshoe Lake prob- lems, is the existence of a distinct and here- tofore unrecognized group of Canada geese that winter in the inland areas of Virginia, North Carolina, South Carolina, Georgia, and Alabama and on the Gulf Coast of Florida. Because management of the Mis- sissippi Valley goose population should be guided to some extent by a knowledge of neighboring goose populations, it seems desirable to include in this paper a brief summary of the breeding and wintering ranges, as well as the migration paths, of the Canada geese of the newly defined group, to which we have given the name Southeast population. Breeding Range To date there have been no recoveries of Horseshoe Lake goose bands in the Moose River district of James Bay or at the extreme south end of this bay, while fair numbers of bands have been recovered in that region from geese banded at the Jack Miner Bird Sanctuary near Kingsville, Ontario. Large numbers of Miner bands from the autumn flight have been recovered in the inland portions of the southeastern states. It appears from band recoveries that the Southeast geese nest from the coun- try drained by the Moose River, south and east to the Nottaway or Rupert river country. In an area north of the Moose River, the breeding grounds of these geese merge with those of the Mississippi Valley population; east of the Nottaway River, or Rupert River, they merge with the nesting grounds of the South Atlantic geese, most of which migrate through the Kingsville area only in spring. Census data on the flyway of the South- east population are meager. Because the scattered flocks were not recognized as components of this distinct population, their significance was lost in the usual method of lumping census figures by states. Popula- tion figures presented below are from three sources: letters to Jack Miner from local sportsmen or officials; personal conversation with W. P. Baldwin, Jr., United States Fish and Wildlife Service biologist, stationed at Port Wentworth, Georgia; and records in the files of the Division of Refuges, United States Fish and Wildlife Service. Following is a summary of the wintering grounds of the Southeast population, as in- dicated by band recoveries and other data. Migration Routes In the autumn migration, the range of the Southeast population overlaps that of the Mississippi Valley population between James Bay and the Miner Sanctuary. At the latter point, however, band recoveries indi- cate that the birds of the Southeast popula- tion split off from the Mississippi Valley population and fan out south and southeast over a number of courses. The paucity of recoveries between the Miner Sanctuary and the eastern and southern slopes of the Appalachian Mountains suggests that most of the geese of the Southeast population make few stops en route to their wintering quarters. The routes taken by these geese on their northward migration are probably mainly to the west of their autumn migration paths, as band recoveries show that comparatively few of the birds retrace their autumn flight through the Kingsville, Ontario, region. Winter Concentrations The wintering grounds of the geese of the Southeast population lie mainly in the Piedmont region east and south of the Appalachian Mountains, and in some parts of the coastal plain. The wintering range can be better understood if the distribution of the recoveries from the southeastern states in figs. 12-21 is compared with the physiographic features of these states shown in fig. 81. Band recoveries show that geese resort to nearly every river of appreciable size that dissects the Piedmont and the coastal plain, but that the numerous reser- yoirs are particularly favored. The coastal [ 199 ] Ittinois Naturat History Survey BULLETIN Vol. 25, Art, 3 wintering range of the South Atlantic geese and the inland wintering range of the South- east population are clearly indicated in figs. 6, 12, and 14-21. Virginia——Band recoveries from Canada geese banded at the Miner Sanctuary in the autumn indicate that the Southeast flyway geese wintering in Virginia concentrate in certain counties bordering the James River: chiefly Fluvanna, Goochland, Henrico, and Charles City. To a lesser extent these geese use the Mattaponi, Pamunkey, Roanoke, and Rappahannock rivers. In a letter to Jack Miner, January 8, 1945, A. W. Smith of Richmond, Virginia, stated that about 2,000 geese frequented the James River, and another flock of about 1,500 were to be found on the Pamunkey River. As many as 15,000 geese have spent the winter in the region of Hopewell, Prince George County, according to A. P. Cutchin, a deputy warden of the United States Fish and Wildlife Service in 1939 (letter to Jack Fig. 81—Map of the wintering grounds of the Southeast Canada goose population. Miner from A. P. Cutchin, Atlanta, © Georgia, December 9, 1939). 4 North Carolina—In this state, the coun- ties adjoining the reservoirs on the Yadkin (chiefly High Rock, but also Narrows Lake and the Norwood dam impoundment), the Catawba (Oxford reservoir), and the Rocky rivers are the principal wintering grounds of the Southeast population in North Carolina, as band recoveries indicate. According to Pearson et al. (1942), the reservoirs of the Yadkin River form the most important of these water areas. They report that William Birsch of the United States Fish and Wildlife Service has esti- mated that in one year 10,000 geese win- tered in that section of the state (year of report not stated). } The Canada goose population using High Rock Lake in recent years has numbered about 600, according to W. P. Baldwin, Jr., of the United States Fish and Wildlife Sery- ice. He reports that the flock wintering March, 1950 along the Great Pee Dee River and at Ansonville has recently totaled about 3,000 (personal communication, March, 1949). South Carolina.—Pickens (1928) re- ported the Canada goose to be a common winter resident in upper South Carolina, a statement that is amply supported by the Miner returns of autumn-banded geese. According to Ernest F. Holland, manager of the Carolina Sandhills National Wildlife Refuge (letter to the Jack Miner Bird Sanctuary, December 18, 1946), about 5,000 Canada geese used this refuge and the adjacent Great Pee Dee River basin in the late autumn of 1945. An additional 2,500 were reported using the private waterfowl refuge of Lockhart Gaddy, lo- cated near Ansonville, North Carolina. Judged from band recoveries, Lake Murray, an impoundment of the Congaree River, is probably one of the more important bodies of water for Canada geese in South Caro- lina. Wateree Pond, a much smaller res- ervoir on the Wateree River, appears to be second in importance. Other rivers used by geese are the Broad, the Saluda (Lake Greenwood), and the Savannah (from Anderson to Aiken counties). In several years prior to the winter of 1948-49, about 200 Canada geese wintered in the vicinity of McBee in Chesterfield County and about 250 on Lake Murray (W. P. Baldwin, Jr., personal communi- Hanson & SmiTH: CANADA GEESE 201 cation, March, 1949). Another 300 fre- quented the section of the Savannah River bordering McCormick County. The Santee Cooper Reservoir area harbored about 250 Canada geese, the Cape Romain sector of the Atlantic Coast about 500, and Winyah Bay a small but unknown number. The Winyah Bay flock may be only a segment of the Cape Romain flock that segregates out from time to time. Data on populations at the Santee Cooper and Cape Romain National Wildlife refuges in other recent years are given in table 47. Alabama.—According to Howell (1924), Canada geese in Alabama are “probably most abundant on the Tennessee River in the vicinity of Muscle Shoals.” They are “numerous every winter in the vicinity of Montgomery. On the coast they apparently are not common, though found occasional- ly.” Since 1942, 300 to 900 Canada geese have been reported wintering in the vicinity of the Wheeler Reservoir, according to data in the files of the United States Fish and Wildlife Service. Sixty per cent of the Miner-banded geese reported killed in Alabama were shot in Tallapoosa, Coosa, and Elmore counties. Over half of the recoveries from these three counties are from the vicinity of Mar- tin Lake, an impoundment of the Tallapoosa River; the remaining returns from these counties are from areas adjoining the Coosa Table 47—Numbers of Canada geese wintering at three national wildlife refuges in the Southeast flyway, 1934-1945. REFUGE YEAR St. Marks Cape Romain Santee Cooper Season Number Season Number Season Number | DLS ee ee Winter 5,000 -} Winter MEA eine a 5A oes Shire, ons Winter 6,000 NES a Winter 9,500 Eh ae Winter 13,500 RN erotic) Seis sia 4 Sins baits Winter 13,500 | Winter 300 EL A rr Winter 6,500 | Winter 27 isa a er Winter 11,500 | Winter 50 REO Sane «oe vs 2 ais Winter 12,000 SUR Ae ae Winter 11,000 | Winter 60 Fall 10 Spring 20 Sh Winter 13,000 | Winter 83 Fall 120 Spring 50 | Shs Sah ese Winter 15,000 | Winter 196 Fall 80 Spring 50 202 Ittrnors NaturAvt History Survey BULLETIN River impoundments (Lay, Mitchell, and Jordan lakes). The flock wintering on Martin Lake numbered about 400 in the winter of 1939-40 (letter to Jack Miner from C. Robinson of Alexander City, Ala- bama). Georgia.—Band recoveries from Georgia are spotty, suggesting that no great con- centrations of geese occur anywhere in the state, possibly in part because of the com- parative lack of large reservoirs or natural lakes. The Savannah River from Hart County to Richmond County appears to be a favored wintering area; the Ocmulgee (Lloyd Shoals Reservoir between Jasper and Butts counties), the Oconee (Washing- ton and Laurens counties), and the Flint River (Pike, Upson, Taylor, and Craw- ford counties) are other sectors used by Canada geese. Many of the recoveries from Georgia, however, may be from migrating geese rather than from wintering flocks. As a number of the recoveries are from areas of the state directly north of the St. Marks National Wildlife Refuge on the Florida Gulf Coast, it seems likely that birds en route to St. Marks contribute appreciably to the kills made in Georgia. In 1941, 150 to 200 Canada geese were reported using Lake Harding, an impound- ment created by Bartletts Ferry dam on the Chattahoochee River near West Point (letter to Jack Miner from William B. Fuller, West Point, Georgia, January 10, 1941). Florida—tThe St. Marks National Wild- life Refuge, consisting of 54,681 acres, is believed to contain the greatest single con- centration of geese in the Southeast popu- lation. Although between 11,000 and 15,000 geese have wintered at this refuge since 1941, table 46, there have been singularly few band recoveries from Miner-banded geese in the surrounding country. This fact suggests that either the bulk of these geese by-pass the Miner Sanctuary on their southward migration, and hence are not banded, or that the kill in the St. Marks area is relatively small. From about 10,000 geese wintering along a 100-mile stretch of coast during the late twenties, the annual kill was said to be several hundred (letter to Jack Miner from R. G. Vol. 25, Art. 3 Porter, Apalachicola, 1927-28). Florida, winter of © Future Status Although the Canada geese of the South- east population winter over an enormous area, extending from Virginia to Alabama — and the Gulf Coast of Florida, their total number is not large. With the exception of the flock in the St. Marks area, most of the concentrations can be classified as being — either small to medium in size and, in the — aggregate, may match the St. Marks flock in — size. Therein may lie the security of the Southeast population. The small concentra- tions, by virtue of their size, do not attract other than local hunters, whose kill is probably fairly light. The paucity of band recoveries from the St. Marks area suggests — the possibility that the flock there is afforded adequate protection by the St. Marks Na- tional Wildlife Refuge. a In any management measures involving — the Southeast population, recognition should be given to the fact that the scattered flocks — are but segments of a more or less con- tiguous population on the breeding grounds. — These segments should be carefully censused at the time of the annual January inventory and the extent of the kill in each wintering — area should also be determined within fairly — close limits. To help insure the perpetua- tion of this population, it may be necessary — to declare at least a portion of all reservoirs important to wintering geese, and some ad- — jacent land areas, inviolate to hunting. Insofar as their habitat requirements in winter are concerned, Canada geese can be They are quick considered adaptive birds. to respond to changing agricultural prac- tices, to the creation of reservoirs, and to the formation of new refuges by changes in their habits and their local distribution. — W. P. Baldwin, Jr., reported (personal communication, March, 1949) that in- ~ creasing numbers of Canada geese are win- tering in northern Georgia, where they are resorting to the cultivated fields. At least — some of these geese in former years must — have migrated down to the St. Marks area. © Such ‘“‘reshuffles” in the population and the — problems that arise from them should be recognized in any attempts to manage the Southeast geese. APPENDIX B CLASSIFICATION OF THE CANADA GEESE OF THE GENUS BRANTA ROBABLY few other groups of North American birds have presented the taxonomists with greater challenge than the white-cheeked geese of the genus, Branta. Before the distribution and the relationships of the various races can be fully understood, much collecting and banding will have to be done on the breeding grounds. The com- plexity of the problem is apparent when it is realized that the race Branta canadensis interior alone can be broken down into four fairly distinct breeding populations. As might be expected, the literature on the genus is fairly voluminous and often con- tradictory. Some plumage variations once thought to have taxonomic significance have been shown to be merely variations within single populations (Taverner 1931, Elder 1946, Hanson 19494). In the latest re- vision of the genus by Hellmayr & Conover (1948), the characters of the downy plum- age were taken into consideration. This factor considerably enhances the reliability of their study over studies previously made. They list the various members of the genus as follows: Branta leucopareia leucopareia (Brandt). Tundra goose. [The lesser Canada goose of Kort- right (1942) and others. ] Branta leucopareia occidentalis (Baird). West Coast goose. [The Western Canada goose of Kortright (1942) and others. ] Branta minima Ridgway. Cackling goose. Branta canadensis parvipes (Cas- sin). Lesser Canada goose. [See Aldrich (1946) regarding the res- urrection of parvipes. | Branta canadensis moffitti Ald- rich. Great Basin Canada goose. Branta canadensis interior Todd. Todd’s Canada goose. Branta canadensis canadensis (Linnaeus). Eastern Canada goose. Branta hutchinsii (Richardson). Richardson’s goose. [Branta cana- densis hutchinsi of Kortright (1942) and others and sometimes known as Hutchins’s goose. ] Taverner (1931) has pointed out that several of the races are markedly distinct in the field, but as skins in the laboratory they are separated only with difficulty. According to James Mark, an Indian living at Eastmain, four different kinds of Canada geese are recognized by the James Bay Indians. The bird called Muskego nisku by the Cree Indian, meaning “large swamp goose,” is the breeding goose of the muskeg, Branta canadensis interior, fig. 82. The “coast goose,” Winnipego nisku, is restricted to the James Bay coasts and observed only while on migration. It is reported as being smaller than the swamp goose, more vociferous, and having a rela- tively shorter neck, a description that fits the lesser Canada goose, Branta leucopareia leucopareia. Richardson’s goose, Branta hutchinsii is called Apichishkish, meaning literally a small goose that has attained its full growth, fig. 82. The fourth kind recognized by the Indians on the south and east coasts of James Bay is described as being the largest of the group and possessing a brown breast, a feature from which it has derived its name, Kaoosoupasawat nisku. Geese of this kind are reported to breed farther north and are called the Fort George (Quebec) geese by the Moose Indians. The brown breast may represent staining by iron-rich waters of the areas frequented by this bird, which may possibly be B. c. interior. It is of interest to note that Blakiston (1863) also reported that an Indian on the Saskatchewan River described four dif- ferent kinds of “grey geese,” the common gray goose, a short-necked goose, a small goose, and a large goose, descriptive names that roughly fit the forms described by the Indians of James Bay. The chief of the Indians around Lake St. Martin, Manitoba, told Taverner [ 203 J 204 Ittrnois Natural History SurvEY BULLETIN Vol. 25, Art. 3 Fig. 82.—Profile views of (upper head) an interior Canada goose, Branta canadensis interior and (lower head) a Richardson’s goose, Branta hutchinsit. (Shortt & Waller 1937) that three kinds of Canada geese visit their area. The descrip- tions of these three varieties fit canadensis, leucopareia, and hutchinsti. According to Taverner’s unpublished notes, which Shortt & Waller quote, an immense kind of Canada goose is also traditional with these Indians and “is so rare that it is known only by report. It is probably mythical.” Despite Taverner’s disbelief at one time in the reality of a very large goose, Mer- shon (1925) leaves little doubt that a very large variety of honker existed. McAtee (1944) has also commented on records of large geese from the Plains region. Ald- rich (1946) has now recognized this large race of Canada geese, giving it the name moffitti. Individuals of this race, presum- ably adult males, are known to range as high as 14 to 16 pounds, and even greater weights than these have been reported. Elder (1946) weighed 2,179 geese and the senior author weighed several thousand more geese at Horseshoe Lake, Illinois, Both specimens are juvenile males. without encountering an individual that at- tained the weight of 12 pounds. In the light of our present knowledge, the very large, almost legendary Canada goose known to many Indian groups in the boreal forest of Canada might be explained by individuals of the race Branta canadensis moffitti that have been occasionally taken north of their normal range. Such occasional invasions of the breeding grounds of one subspecies of Canada geese by nonbreeding members of another adjacent subspecies would not be unexpected. (In the above case the invasion of the range of B. c. in- terior by individuals of B. c. moffitti or an even larger extinct variety.) In the summer of 1949, Peter Scott, British ornithologist, and the senior author observed several flocks of nonbreeding “honkers,” B. c. moffitti or interior, in the Perry River (Northwest Territories) breeding grounds of the smaller tundra Canada goose, skins of which have been identified by the senior author as those of Branta leucopareia leucopareia. : Pipe AME ORE so is] ~~ te HOE AI Addnamada —_—_———OororSr Sr Komi al HAM OMG aAaaIaaaa Om OD anaaaa NOOSE SSE raNnNsorAaNdra NHOODNDOME ANANAIMANAIAAA = (¢ ) Tee | (Zz) Bie | (49 ) 0 = () ste | (ef ) soe | (ZI ) £6°7% = cael (ESSA ABE My = (GST fn -Y a SOY a = (1 ) 9F€ = os = (8) ZOE | (F ) 86% | (€ ) EL Z (1) se°€ (8) Le°€ | (€l ) 6t € | (cI ) €6°% = (ons s = Gy) Mie = = AGE ON AS A G7 4a 6 = (IT) die | (€ )80'€ | (Ss ) 87 = ({)90'¢ | (L ) 167% | (IT ) 98% = (tC) 95% | (SE )t9'Z | (HE ) 89'S (Z) $6°T (C1) #L°% | (IZ )9L°t | (Le ) OLT = (91) €6°7 | (€O1) LL 7 | (SL ) 69% = (¢ )#L'€ | (ce ) 80'€ | HF) 967 = (¢ ) 1g | (€9 ) 60°€ | (9E ) 06% (1) 9t°€ (LI) Les | (791) 9%’ € | (9TI) €0'e — (f) sre | (88 ) 6c € | (S9T) LTE = (IL) cF'€ | (LOT) 2° € | (56 ) ZOE = = (9 )#0'¢ | (FI ) 90°¢ = = GSE GR) AS = = (I )£5°% | (81 ) #0'¢ = = (GEO cala(Ga eske = Tt) 187 (Gl MOSscate (Se ALL G (1) £5°% + )9E (CG Nistor, NP MG (ele) 6 = [ed AUS: (91 )O1'E | (th ) £67 ll 6 8 L {SHHON] ‘HLONAT GYVAGNVLS epee tp caer at tare GU ofor PC-LI “uel 8EOI Iz 2°d Ee 7% “3dag FI-8 3dag atte ap ctetia steaite a] ie veo Ge: G=0 Ajnf NOILOATIOY 40 ALYG *suouioads yO siaquinu juaseidas sasayjzuesed ur soinsi.y “7 “SY Ul pa3zj}0;d o1e Byep asaqy JO @WIOG ‘sasse]o YISUa] PsepuEIs JUSIAOHIP Jo sarddes9 9314M IN}eOIq] axe] Ul (Y) UOIIpUOD Jo JUaTOWJa0D ay} UT sUOIENJONH [eUOSeag—'}] 2/qeT, on N BioLoGy oF THE WHITE CRAPPIE HANSEN: August, 1951 (“PL ajqea wos BIEC]) “IN}LIAC] aye] 3B Sasselo yysua] jue Se6l PlGaNPiOy Sy iP aC AW seél |Z RIN oneal Cin NavOmeSean aa (pert a NGe Ww. NG desi Gi INI tO Saas cia tN, Jafip jo soiddei9 aIYM 10F (™) uOT}Ipuod FO JUdTOYJaAOD AY} UL suonenjony [BuOSBag—yZ “Sy £6! Le6l YyNLvVD35d 4YV 1 Y—NOILIGNOD 3O LN3IDISsI3059 238 crappies. White crappies over 7 inches (standard length) may be regarded as mature and those under 5 inches as imma- ture. The seasonal changes may be sum- marized as follows: Large sizes, crappies 7 inches standard length and smaller: Condition values in- creased rapidly through middle and late summer, reached a yearly peak in late fall or early winter, remained at a high level through the cold months, dropped sharply during the spring, and reached the lowest point in early summer. Small sizes, crappies 5 inches standard length and smaller: Condition values in- creased from the middle of spring through early summer, reached a yearly peak in midsummer, fell off through late summer and fall, remained stationary through the cold months, and fell again through early spring. Condition changes of crappies in the 6-inch class were approximately inter- mediate between changes described for fish of the two size classes discussed above. Differences between large and small fish with respect to condition changes may be summarized as follows: The small crappies began to fatten earlier in the growing season than the large crappies, reached peak condition in midsummer rather than late fall or early winter, and lost condition in spring and again in late summer and fall, rather than only in the spring and early summer. In fish that were less than 5 inches long at the start of the growing season and that grew to a length greater than 7 inches, the fall and subsequent spring changes in condition followed those de- scribed for the larger fish. Increases in K values occurred only during the annual growing period. Upward and downward trends in large and small fish described above for various seasons of the year have, for the most part, been based on observations made during 2 calendar years. The evidence of Winter-to-spring drop in condition in large fish rests mainly on observations in 1937 when large sizes were abundant; winter observations were lacking for 1935-36, and large fish were scarce in the first half of 1938. Fish of given sizes did not always show the same K _ values in corresponding Ittinois NaturAL History SurvEY BULLETIN months of different years. The 8-inch and 9-inch classes showed more uniformity in this respect than the smaller fish. ; A tendency for large fish to have higher K values than small ones was observed the smallmouth bass by Bennett (1938), in the largemouth bass by Thompson | Bennett (1939), and in the bluegill | Bennett, Thompson, & Parr (1940). Such a relationship was also found in the Lake Decatur white crappies but was unappar- ent or inconspicuous at certain times of | the year—especially in June and July. Ae ascribed to two things: (1) Late winter: and early spring weight losses were re a tively greater in large fish than in sma ones (compare the changes in K values in: the 6-inch to 9-inch classes from Mareh™ to June, 1937) and (2) summer gains in K values started earlier in small fish than) in large ones. Adequate data on the spread) of K values are not available for June an July, 1938, because no collecting was at tempted in June, and the July collection: included only a few large fish. is A limited number of comparisons be-\ tween K values of males and females of various lengths, table 16, indicates that: the seasonal changes in condition occur in) both sexes and that throughout the year | K values tend to be a little higher in males: than in females. Stroud (1948) found no) important difference in plumpness between the sexes of black crappies in Norris Reser- voir, Tennessee. Bt In black crappie collections made at sey-’ eral different times of year, Stroud (1948) | did not find important differences in| plumpness among four age categories Or among size groups ranging from 4 to 12 inches. The failure of his data to show im-| portant differences is perhaps explained the fact that most of his collecting was done in the spring, which, as indicated observations at Lake Decatur, is a time year when large and small crappies are of similar plumpness. Bad Changes in the average K value for members of various broods taken in the nets between early April, 1936, and early January, 1939, may be seen in table | and fig. 8. Broods represented in the n by only a few specimens have been om August, 1951 HANSEN: BioLtocy oF THE WHITE CRAPPIE 239 yeriod of observation of any brood was semblance may be seen between the curves about 2 years. A certain amount of re-_ in figs. 7 and 8. In general, the seasonal ~*~ _ Table 15.—Examples of the distribution of coefficient of condition (K) in white crappies of ur size categories, 6-9 inches standard length, at Lake Decatur, March 1-4, and June 24, . These dates were arbitrarily selected. ————————————— , | Sranparp LencrH* or Fisu Sranparp Lencru* or Fisu Cottecrep, Marcn 1-4, 1937 Co.tectreb, June 24, 1937 K VaLue eee b | Rrenlined 1) 28 i): oral WP re fone Pipes fae! Pas 9 ; Inches | Inches | Inches | Inches | Inches | Inches | Inches | Inches ee... Te ae | a ; oo o— —_ — = = SSS = = 1 2 a ae oar 0 eee 1 = 2 3 a er _— — | = a 2 4 8 = Se ll 2 = Zs 2 8 6 2 BE see 9 5 — — 3 8 14 5 es 5 11 2 — 2 7 16 4 aes ul 27 6 fe Be ln te 1 ee 4 16 11 1 = Pagan te) 3 Se 4 23 a3 = ee (a 2 ll Ce ~ = 1 a Meese sess. = 16 24 3 _ 1 = a — 2 30 6 —— _ = ES Eee 1 1 16 3 — = a — Se — 1 7 2 — as x aS — 1 3 1 — — = aoe ae 48 116 161 17 9 37 an | 12 Breerage KR... ....-.. 2.84 3.93 3.26 Ses Ys 2.67 2.70 2.76 2.74 * Class center; for example, the 6-inch class includes fish of 5.6 through 6.5 inches in length. Table 16—Coefficient of condition (K) in Lake Decatur white crappie males and females of different length categories. Walues of K were not computed where the sexes were not repre- sented by at least 16 specimens. Figures in parentheses represent numbers of specimens. Sranparp LENGTH* AND SEx Date or = | CoLtection 5 Inches 6 Inches 7 Inches 8 Inches ne Nl ] Male / Female Male Female Male | Female | Male | Female 1936 | | | / May 29-June4) — = 2.69 (16)} 2.6419) — | — | — -- July 31—Aug. 3 | 2.95 (26)| 2.88 (19)) — = = = = Oct. 24-27..... —- | — | = — 3.09 (51)| 2.94(37) | 3.29 (53)| 3.19 (52) a _ = 2.90 (18)} 3.00 (20)| 3.20 (94)| 3.12 (72)) 3.31 (38)| 3.25 (50) 1937 March 1-4..... _ — —_ 3.04 (66)) 3.01 (36)| 3.27 (69)| 3.25 (86) (0 —_ — — _ 3.01 (16); 2.82 (20)) 3.16 (18)) 3.05 (45) June 24....... _ — — — | 2.78 (20)] 2.60 (17)| 2.85 (26)| 2.71 (45) July 10-16..... — = = = 2.77 (16)| 2.57 (16) - = 1939 / a _ _ 2.74 (23)| 2.75 (22)| 3.00 (37)| 2.97 (28) — — | | * Class center; for example, the 6-inch class includes fish of 5.6 through 6.5 inches in length. Vol. 25, Art. Ittrnois NaruraL History Survey BULLETIN 240 rig NO Ss VF FWWY W 4 FIG N O CLI 9[qe} Worf eJeq) ‘SaAINd 9y} Duoje s[eArajur je dvadde yorym sainsy y}sua] ay} ur Uaas aq ABU SUOT}BAIaSgO jo potiad c=} Surinp spoo1q 9y} FO S[eNpPIAIPU! Fo Sy}SuUa| adeIaAe UT SadueYD Iofew ay, *LE6I-EL61 ‘INJeIaq aye] 32 payo}ey spoorq snore 0} Sursuojaq satdde1zd aj1yM Toy (3) UONIpuod Fo JUaTOWa09 ay} UT SUOHENJONY [eUOSeaGC—'g “$17 Seven ry WN oven ING aie eal eG NiIOl Sa iV eee UN eV: ald iS BV ues 2¢6| —#— 9e6l —e— seé6l —v— q beé6l —- ee6l —O— Sdgooud uMlvosd. snV7 v¢ 92 ee M-NOILIGNOD dO LN3IDI44909 ve August, 1951 fluctuations in condition summarized for small fish were similar to those occurring in young fish, and the fluctuations sum- marized for large fish were similar to those occurring in old fish. Differences in condi- tion between adjoining broods were, as a rule, small, unless members of the adjoin- ing broods differed considerably in length. Late-summer trends in condition were especially variable from year to year in second-year fish, fig. 8. A late-summer rise in condition was observed in broods mak- ing good or moderately good late-summer growth (1935 brood in 1936, and 1937 brood in 1938), but a late-summer loss of condition was observed in a brood whose latesummer growth was small (1936 brood in 1937). The amount of late-sum- mer growth can be seen from the average lengths of fish printed along the curves in fig. 8. With reference to the condition HANSEN: BIoLoGy oF THE WHITE CRAPPIE 241 changes in the 1935 brood in late summer of 1936 and the 1937 brood in late sum- mer of 1938, it is apparent that while each brood, taken as a whole, showed a rise in condition, fig. 8, the smaller (4-inch and S-inch fish, fig. 7) were losing condition. Eschmeyer, Stroud, & Jones (1944) ob- served condition changes in white crappies which they refer to as 2-year-olds (appar- ently the 1940 brood) at Chickamauga Reservoir, Tennessee, from March to October, 1942. This brood of white crap- pies reached peak condition in June and showed little change in condition from June to October, thus following the trends observed in Lake Decatur crappies of simi- lar age and making the same sort of poor late-summer growth. Measurements of condition of white crappies in three other Illinois lakes may be seen in table 18. Generally, fish from Table 17.—Seasonal fluctuations in average coefficient of condition (K) in several broods of Lake Decatur white crappies. Figures in parentheses represent numbers of specimens. Dare or CoLLecrion 1933 Broop | 1934 Broop | 1935 Broop | 1936 Broop | 1937 Broop [936 ee | 2.80 (152) | 2.28 (168) -- = 5 2.73 ( 18) | 2.50 ( 44) — —_ _ May 29-June 4.............. 2.71 ( 59) | 2.70( 24) a= = SS 3.01 ( 5) | 2.99 ( 36) _— — | EG S205i() 4) >|) 3.02.6 27)) "| 2°90: 51) -- _ (sh a ee 3.47 ( 2) | 3.15( 11) | 2.99 14) _ — 0 seo || 2597 (10)! |) Q697¢ 49) — — a S207) = oes (139)e4) 2293 69) — — Dec. 21 3.18 ( 18) | 3.22 (107) | 3.14 (171) — (937 0 Se 322016 53) | 3.161220) | 295 ( 67) _ — LL 2 SON £4) 193202" 67)! | 279. (. 85) = — EE sich. voce are was SOME) |) S207 39)! fe 2.95:(37) — — Ee 2.79 ( 32) 2.72 (116) 2.66 ( 62) —_ -= a Desi 27) W227): | 2eth( 27) — — July a 2.65 ( 15) Pe Gs 32) 2.69 ( 29) 2.66( 6) FO eID) (ee PON en ON (ee eB | 2ath() LS) 2 20u 45) = - BLOOM ez) 2a70 (2 2)r| 28OKC <2) 2 59"(206) Re ene — Sri (aee ieee Oe Gems yal) 2045, (065) - (938 OE Sn. wtecicex ne = STE US)) — 2.47 ( 12) —_ S| = 3.22 ( 14) | 3.15 (16) | 2.40 (181) | — a — 3.06( 8) | 3.05( 4) | 2.26( 84) | = Mr ees ne | — | 2.74)( 4) — — rr | = — — 2.54 ( 24) — ee — | — [re Oe 2) 2s 7 S(O)! | 2258556), a — -= | = 3.05( 9)°| 2.68 (59) = — — = 2.89 ( 17) | 2.67 (49) (939 MEM cies oes esas - — _ 3.06 ( 71) | 2.70 (77) * Sample obtained from anglers. ww N = i) > Intrnois Narurat History SurvEY BULLETIN 242 “yaBuay ul saypur g°g YySnoryi 97S JO Ysy sapnpur ssejo YyDUI-g ayi ‘ajdurexe Joy ‘191Ua9 Sse[D % aa Fe = =I (F ) TL € | (I) OIE | (Ft) SBT | (Se) 99°C | (F ) 787 | EEO “CI-1 390 ima ye aa a3 = (6 ) 80 € | (€1) 78°C | (FR) C87 | (8 ) S9'T | EL6I “6C-Ie ydag = a > a a7 (§ )S6 7 | (11) €6 T | (61) #87 | (ID) $8 7 £61 ‘9T-1 “das = See <4 = = (€ ) 667 | (8 ) 167 | (BE) #8 °c | 19T) $87 | ELOr “Te-81 “BMY (Ajunos weujng) SUIMYIVUIG oa (Z) €0°F | (F) ste | (#) 99°] (€) OLE ai a = ax | AST ASO PREIINE | (juno uosuety! AA) paeyoioqeag (5) LI¢.| (01) tee | (9) C0'e | (5) ZL] (%) 9LT] (2) CHT | (9) BRT | (TE) SL°e ae “*SE6I “87-61 “GPA | ({QunoD Jepurxaly) a0ysasiopy cl Il OL 6 8 fe 9 S F a1vqd ayvy] 4STHONT “HLONAT GUVaNVLG ‘suaujoads yO siaquinu juasasdes sasayjueied Ur SoINsIy “axe suIMYoRUag pur ‘axe ] pseyosoqesry ‘axe soysessOF] 3e satddeso ay1yM Jo sdnos$ yISue] psepuvys snolseA 10¥ (Y) WOWTpuoD FO yua!oWya09 asPIOAW— RI PIG L August, 1951 HANSEN: these lakes show an increase in K with in- srease in length. An exception may be sited in the Horseshoe Lake data, where the K value of the 5-inch class was con- siderably higher than the K values for the b-inch and 7-inch classes. The condition values of 13 white crap- pies taken at Craborchard Lake in March, 1944, were much higher than the values observed in crappies of the same size else- where in Illinois. In these Craborchard specimens, high condition had accom- panied rapid growth. Craborchard Lake was new in 1939. These large Craborchard specimens were observed to be deep bodied in proportion to their lengths and unu- sually plump in their abdominal regions. The body cavities of dissected specimens contained exceptionally large deposits of fat. No such large deposits were seen in the white crappies of Lake Decatur. In the same Craborchard collections, fish of small sizes appeared to be much less plump than those of large sizes, but they were not weighed and their K values were not de- termined. While working for the Natural History Survey at Senachwine Lake on July 31, 1933, Lyle E. Bamber measured and weighed 16 white crappies which ranged from 35 to 49 mm. (1.4 to 2.0 inches) standard length. From their lengths and the absence of annuli on their scales, they were judged to be about 2 months old. They were the only young-of-the-year crappies studied. Their K values varied from 2.01 to 2.46 (average 2.20). Length and weight measurements were made with the degree of accuracy desirable for such small fish, as described in the section “Methods and Techniques.” Collections of 4- to 7-inch white crap- pies measured at Senachwine Lake during the period August 18 to October 13, 1933, showed changes in condition that approxi- mately corresponded with the autumn changes in condition in 4- to 7-inch crap- pies at Lake Decatur; the +, 5-, and 6- inch classes showed a loss in condition and the 7-inch class a slight rise in condition from August to October, table 18. Possible Reasons for K Loss The fact that spring was a time of sharp decline in plumpness of Lake Decatur BioLoGy oF THE WHITE CRAPPIE 243 white crappies suggests a possible connec- tion between weight loss and spawning. The major weight loss in mature white crappies occurred over a 2-month period preceding the nesting season. It appears likely that, in the years we are dealing with, most of the nesting took place within the period May 15 to June 15. Russell (1914+) suggested that a prespawning con- dition loss in the haddock was caused by diversion of food materials to the ripening sex organs. But since two other species, the sardine studied by Clark (1928) and the bluegill studied by Bennett, Thompson, & Parr (1940), showed a rise in con- dition just before spawning and also since there was a spring loss of condition in im- mature crappies, it is appropriate to look for other explanations than the one offered by Russell. Clark (1928), Mottley (1938), and Bennett, Thompson, & Parr (1940) all observed a loss in condition after spawning. The condition losses in mature white crappies are too large to be accounted for by reduction in weight of the ovaries and testes after spawning. Weighing of the gonads of a few white crappies ranging from 6.5 to 10 inches standard length showed that just before the spawning sea- son the ovary weight amounted to 6 per cent of the total body weight, and the testes weight amounted to less than | per cent of the total body weight, while the average winter-to-spring weight loss of the entire fish amounted to about 15 per cent in both sexes. It was found, as already mentioned, that small white crappies underwent a loss in condition in late summer and fall when they were increasing slowly in length. The possibility can be disregarded that the spring condition loss of larger fish was brought about by growth in length of the crappies without sufficient gain in weight to maintain K values at a constant level. Annulus formation studies showed that only a few of the mature Lake Decatur white crappies had started their 1937 growth by early June, and that the major- ity delayed their 1937 growth until July or August. Thus, at the time of their spring loss in condition, the large crappies were not growing in length. Other possible reasons for spring con- dition loss among white crappies include 244 disease, seasonal scarcity of fattening foods (or food in general), and difficult feeding conditions resulting from high turbidity. Disease as a possible reason for weight loss is suggested by the apparent high summer mortality of Lake Decatur crappies, a mortality indicated by low net catches in summer, table 20. No data are available on seasonal variations in crappie foods at Lake Decatur. It is not known that high turbidity in spring seriously in- terfered with crappie feeding. On the con- trary, crappies caught in the spring of 1937 seemed to be having considerable success in capturing gizzard shad. The reason for late-summer loss of con- dition in small crappies remains as obscure as the reason for their condition loss in the spring. AGE AND GROWTH The uses to which growth data on fish may be put depends in large measure on the accuracy of age determinations. In many instances, annual rings on the scales of white crappies appear to give only ap- proximations of age, and the practical ap- plication of the scale method of age deter- mination in these fish has been limited in Illinois mainly to detection of stunted populations. Age Determination Evidence was obtained at Lake Decatur during studies on date of annulus forma- tion in white crappies that the age rings, fig. 9, are not invariably formed at the rate of one ring for each year of life nor at exactly the same time of year. This evi- dence may be summarized as follows: 1. In 1935 and 1937 some individuals failed to form annual rings because they did not grow in those years. While the observed cases of failure to form these rings appeared to include only a small proportion of the total population, there seemed to be a possibility that the percent- age of cases was high in certain broods, 2. In the collection of September, 1937, 65 per cent of the members of the 1936 brood had two annuli, one of which was necessarily false. The false annulus, or the one thought to be false, while com- paratively inconspicuous in some individ- Ituinois NaruraL History Survey BULLETIN Vol. 25, Art. uals, was well defined in others; some a a close resemblance to the rings ordinaril considered to be true year marks. : 3. In many scales collected at Lake De-; catur the first annulus was indistinct an in some scales it was missing. Commo the first annulus was present on so scales but absent on other scales of same fish. A similar variation in visibi of supposedly first rings was commonly served in collections from other Illinois localities. 4. Annulus formation occurred in di ferent individuals at quite different times in the spring or summer from early M period in which different fish in the po lation were forming annuli lasted fro weeks in some years to 10 weeks or long in other years. White crappies collected during under rather unusual circumstances as 4 Lake Decatur, the fish can be assigned broods on the basis of scale patterns, fi for determining in all cases whether ginal growth represents growth of current season or of the previous seaso While absorption at the edge of the wi crappie scale (in summer collections) parently indicates that the new yeal growth has been delayed (Hansen 1937) the lack of absorption may not mean tha growth of the current year has alreadi started. Absorption seems to be of irreg and unpredictable occurrence. Sum then, is not the most favorable time fo collecting scales for age studies. ; From the Lake Decatur collection appears, in spite of many exceptions, formation of one ring for each year of is at least usual in white crappies. But fact that many departures from a strict annual rate were found, and the additio fact that the scale reader would not | dinarily be in position to detect those partures, tends to limit the confider which can properly be placed in any s reading. Adding greatly to the diff of scale reading is the imprecise manner which many of the rings are formed determination in the white crappie is n August, 1951 } s e. - _ HaNnseN: Biovocy or THE Wuire Crappie 245 Fig. 9.—Scale from a white crappie that measured 10.1 inches when captured from the Rock River at Lyndon, Illinois, March 14, 1931. Cutting-over is unusually conspicuous in one of the lateral fields of annulus 3. The annulus or annual ring (five annuli are shown in the scale pic- tured) is a mark separating successive zones of annual growth. It makes its appearance on the seale when the fish begins a new season of growth rather than at the termination of a season of growth. The successive dark lines between the annuli represent ridges termed circuli. The dis- tances between adjacent annuli are approximately proportional to growth increments of the fish in the years represented. The fish from which this scale was taken was not of known age, but its age is estimated to have been about 534 years. Its age was greater than that of most crappies taken from Illinois waters. Relatively few crappies live longer than 3 or 4 years. 1933 Scale Growth * 1934 " " 1933 Brood 1935 6 1936 ” * 1934 Scale Growth a 1935 " “ 1934 Brood 1936 : ; (sara an j 1935 Scale Growth 1935 Brood 1936» ” 1937 ” ” “ Fig. 10.—Annual ring patterns, that is, ring spacing, of white crappie broods hatched at Lake Decatur in the years 1933, 1934, and 1935. se ring patterns served to make individu- als of the broods recognizable in later years. a simple process of counting clearly de- fined marks of uniform appearance but in- stead is one which usually involves picking the true marks from an assortment which, to the scale reader, may seem to include some true rings, some false rings, and some rings which might be either one or the other. Because of these several possible sources of error in aging white crappies through scale reading, the handling of the scale reading for the present paper needs ex- planation. Reading was carried on from the point of view that the scale method of aging fish should be used even though in many instances the age read might be only an approximation of the true age. How- ever, it is believed that in only relatively =a sa sa 46 Intinors NaruraL History SurvEY BULLETIN Vol. 25, Art. 4 “ x 4 ry) 4 5 6 78 O20 12 3 ia 20 v io i ee 1935 5 20 re SPRING, 1936 : Ge SUMMER, 1936 20 10 20 8 Le WINTER, 1936-37 PF 10 2 oe a SPRING, 1937 Ki as SUMMER, 1937 20 io FALL, 1937 ee SPRING, 1938 ' 5 ——$<—<——————————__— — 20 e Pr SUMMER, 1938 20 10 Oe aia 'FALL, 1938 20 10 eae WINTER, 1938-39 20 FALL, 1936 PER CENT OF EACH SEASON'S COLLECTIONS IN VARIOUS LENGTH CLASSES 10 SPRING, 1939 20 10 SUMMER, 1939 is 20 7 10 FALL, 1939 5 20 : 10 WINTER, 1939-40 4 5 6 7 8 9 10 mM 12 13 14 TOTAL LENGTH IN INCHES Fig. 11—Length-frequency distribution (by half-inch classes) of Lake Decatur white crap~ pies collected during the period 1935-1940. (Data from table 19. Some seasons omitted from graph because of meager data.) August, 1951 HaNsEN: BrioLocy oF few cases of age approximation did the age read deviate from the true age by more than a year. Few scales were discarded for lack of their easy readability. If, on an individual scale, a ring was present that was believed to be false, the ring was omitted from the count. Conversely, a ring was sometimes counted, though imperfectly shown, or even entirely lacking, if supplementary in- formation, such as length of fish, indicated that it should have been present. How- ever, no addition was made to the count in the case of an unformed ring of the current year in a fish collected within the period of annulus formation. The lack of a thoroughgoing study of age reading in crappies of positively known ages means that it is not yet possible to judge the success with which ages usually have been puzzled out or to appraise the effect of errors introduced either by faulty ring formation or faulty scale reading. The Lake Decatur white crappie scales studied intensively for several years were THE WHITE CRAPPIE 247 usually more easily understood and prob- ably read with a greater degree of ac- curacy than the scales from other places in the state. Favoring accurate determina- tions in the Lake Decatur scales were wide fluctuations in annual growth, which produced ring spacing patterns that were generally diagnostic for the various broods. Fig. 10 shows these patterns in three broods. ‘wo later broods were separated on a length basis. Size and Age Distribution The size distribution in net catches of white crappies at Lake Decatur changed considerably from year to year, table 19 and fig. 11. Catches in some years included many large crappies; in other years mostly smal!. Moderate to large sizes, 8 to 11 inches, were prevalent in the nets at two periods (in alternate years) during the 4+ years of study: from the fall of 1936 to the summer of 1937 and from the fall of 1938 to the spring of 1939. Occasional Table 19.—Length distribution of white crappies caught in hoop nets at Lake Decatur; col- lections are grouped according to 3-month periods—spring: March, April, May; summer: June, July, August; fall: September, October, November; and winter: December, January, February. The same data expressed as percentages are plotted in fig. 11. m~| io) Dp > Tora. sulk aKa oda Pee eal tee Pa fel eee Via et Lencrn, Petal iene ls alm loele oles oles ale olealaS IncHes* [S| SQ/ED/ SAI ZAHA SA/ SA ZA SAR|SH AA ZAG A/S alIalza Beja ae © ia ia ff iF ks ja le is is e F . aa = fay es | 1 1 1 . ae = Pas ee 2} —|—|—|— (NY art Weg eh ee Mar emer PSU) . TAT) yh ES SEE Ry ed aes Lastolite Seen eae S5lh tole at ae eee re een Oe ONE ar 29) Tl LO) cy Dl 2h O95) oder 38 . an 8] 65} 7] - 1— 1} 18} 70) 1) 79) 22) 23} 4) 15) 54) 27) 58 . a NG 29) 25) 22} — 2} 17| 125} 7) 67| 20) 18] 8] 13] 43] 83] 260 / 18] 53) 47| 12} 1) 2] 16) 121} 4) 51} 16) 15) 9} 21} 33) 90) 298 ee... 12} 41] 26] 14) 8] 17] 16] 35/—¥J| 25] 9} 10! 14] 44] 20) 39] 102 : 7| 52) 18| 40} 22) 28) 24) 10/ —| 14] 3] 12] 21) 77) 21) 7} 40 a 3). 40] 30) 45) 66] 40) 58| 3) — Sfeeece il 871106] ee Alene Slaett —| 10} 17} 39} 66) 70) 57; 4| — Sir 2h ei] 26) 98/7] lel a 3} 19} 12) 80) 57| 101) 122} 4|—1) 7) — 1} 14 67; 5) 4| 17 i ae 3} 9| 2) 44] 148] 117] 95) 1] —] 11) — Bl oee7 Sl neal enol ey | ral ate 36| 22lSsi) 59) 31 — TAN AS) EE od ipl b Sail hy Sr hata? i as eS) — 9} 4) 17) 21) — LOATH Pe Sinai oes) ec7 Pane dt ad 11%... 1] ATW SS |) FOS | a 8 fl Sea | 2a | See eS 2} 4 15| 12% ie == 2 2; — | — 1 4 16 6 1; — ee... ... —|/—/}—}—|— 1} 4 7 4 —|— ee... == || 34) | 2 1 =|) Se ae - }—|—| i} —}|—|—|-| | | } | | | | | Total. | 78] 428| 197| 326) 294) 454) 541) 388| 18) 320, 110) 143) 153) 579) 619| 260) 817 * Class center; for example, the 6-inch class includes fish of 5.8 through 6.2 inches in length. 248 observations of fishermen’s _ stringers showed that nets were good indicators of the sizes likely to be caught by anglers. Changes in Size Distribution — Three separate factors enter into the changes in size distribution in the net samples: (1) availability in summer of broods hatched in the previous year; (2) summer growth of individual fish; and (3) periodic large-scale, and somewhat sud- den, natural mortality of large fish, leav- ing for a time mainly fish of small sizes. The removal of large crappies by anglers is believed to have been a minor factor contributing to the periodic scarcity of large fish in the net samples. Table 20.—Number of white crappies of various broods taken in hoop-net catches : number caught per net-day at Lake Decatur. Ittinors Naturavt History Survey BULLETIN Vol. 25, / Conspicuous changes in size distribut in white crappie populations were served by Thompson & Bennett (193 in an Illinois lake and by Wickliff et (1944, 1946) in several Ohio lakes. § distribution changes in a black crap population were observed by Thomps (1941). Thompson suggested that a sing successful brood of black crappies hatel at Senachwine Lake in 1 year was able consume most of the young crapf hatched for 3 or 4 years thereafter. W] this first brood reached an age of 4 o1 years, its members were sufficiently duced by mortality that another bre survived in abundance. There is no e 1933 Broop}1934 Broop|1935 Broop|1936 Broop|1937 Br Dare or CoLLection! Hoo es 3 3 z 3 3 a 3 3 z 3 3 KS z 3 3 E he Q Re: £ fe Sis 2h SS ea en een E \§é 5B js es) 3s is Oo) Ss |S Sosa Se ee ZZ ZIiGIA Zia |A Za 1936 eh EUS ee Ok peer ter asi rer 16 152) 9.7 | 168) 10.5 | — _ — — — Wie h pC alse err e nicks mene tas 4 18} 4.5 44, 11.0 | — — — — May 29 June 4.0. eo 7 59}° 823 | 24) 3245) el Julyas; leer 6 51 8.3 36} 6.0 | — — — — —_— July 31=Aug..3 .. .=--- 7. 5 4, 8.0 27| 5 4 51] 10.5 | — =— — Septr Sal 4a tees recess 6 22083) Lees: 14, 2.3 | — _ — tS Le] Lea aeprat tes Nena e Saie Ar 4 1} 0.2 Ll) S27 49) 12.2 | — —_ _ Oct. 24-27 12 57] ee: a OSS) i Ur ) 69} 5.7 | — _— _ Decs QU See Ceca 15 18} 1.2) 107) 97 A |) 17a) TEs _— _ 1937 Marchil=49 3 c.. tectk 16 SS ES Su 220 liSee, 67| 4.2 | = _ —_ Aprili2 a ries etiaiats pays ticta 6 14, 2.3 67| 11.2 35} 5.8 | — —_ => | [ST een reel ars meio 12 2) a2 aly MUG eer 62) 5.2 | — —= — June 246 Sh ceaeccaee ee 9 27; 3.0 EN ew) 27; 3.0 | — _ = July 10-16 27 15} 0.6 37} 1.4 29 eal 6} 0.2 | — Aug: 6-14.65 275 22) cies 30 2) 0.1 8} 0.3 13} 0.4 45) 1.5 | — Septs22. 4. necro eee 6 210.3 DORs 7) 1:2.) 206345 Nov. 3.... 6 Oe 2) 03 3] 0.5 | 165) 27.5 | — 1938 Jani W724. J eee 17 0) = 3) 0.2 0} 0.0 12) 0.7 | — March 405 i csaiiar 9 Oo} — 14] 1.0 16] 1.8 | 184) 20.1 | — May 28 8 Oo} — 8} 1.0 4, 0.5 84) 10.5 ualy: TVs ort cuca 9 oOo} — Oo) — 4. 0.4 24, 2.7 Ag. 25:07 cing aun ones 14 oOo — Oo} — p) Oe 19) 1.4 56) 4 OEE IG. ciicctas Vraseteey See 10 0). = Oo} — 0) = 9)" =0 39) 59) 3 Novi4alln nhc ere 20 Oo} — Oo} — o| — 17| 0.9 | "4m 1939 {Xo OR an eng Mi 12 Oo} — (0) 0} -= 71; 5.9 Tie 1 June 22, 1936, data omitted because of uncertainties in age determination. 2 The number of hoop-net days was obtained by multiply they were fished. ing the number of nets by the number of (24-hour August, 1951 dence that one brood dominated later broods in this manner at Lake Decatur, where strong broods were produced each “C nges in Age Distribution.— The entry of young broods into the net samples and the dropping out of older ones at Lake Decatur is shown somewhat roughly in table 20 by changes in the rate of catch in nets. The relatively short lite span of broods was an outstanding char- acteristic of the Lake Decatur white crap- pie population. Assuming that June 1 was the approximate hatching date for all broods, it may be determined from table 20 that the 1933 brood disappeared from the net samples at an age of about + years and 4 months, the 1934 brood at + years, and the 1935 brood at 3 years and 3 months. But each of these broods showed a major decline in numbers a full year preceding its final disappearance from the samples, table 20. Longer life spans were observed in some broods in Lake Decatur, table 24, and in a number of other localities, table 28. It may be noticed, however, that fish with more than three annual rings were frequently scarce in Illinois collections. The highest number of annual rings, ob- served among several thousand age read- ings, was eight, table 28. Influence of Periodic High Mortal- ity on Size and Age Distribution.— The sharp drop in summer netting rates, table 20, suggests that heavy mortality eceurred at Lake Decatur in one or more broods during the summer months in 1936, 1937, and 1938. Most broods, how- ever, showed a certain amount of recov- ery in rate of nettability from summer to winter, indicating that the depressed sum- mer rates were, in part, the result of low efficiency of summer netting operations. There is no clear indication of high sum- mer mortality in these broods during their nd summer of life—the first summer f net capture. Lack of age readings prevented inclu- ion of most of the 1939 catch figures in able 20. However, there is evidence of nsiderable summer mortality among arge crappies in 1939 from the fact that sh of the larger sizes were relatively ore abundant in the spring than in the = seasons of that year, table 19 and fig. HANSEN: BroLtoGy oF THE WHITE CRAPPIE 249 Normal variations in net catches make it impossible to give the exact date of highest summer mortality. It is suspected that highest losses may have occurred in June or July when the older crappies were at the lowest point in the annual condition cycle, although inquiries among lake-shore residents failed to show that dead crappies were more abundant along shore in June or July than at other times of the year. Annual Growth Period The beginning of the annual growth period of white crappies is marked by formation of the annual ring or annulus, fig. 9. Data on the time of annulus forma- tion in white crappies at Lake Decatur in 1935 and 1936 have been published (Han- sen 1937). Data for 1937 and 1938 are given in tables 21 and 22. A summary of data for the + years is given in table 23. The method of determining the time of annulus formation in crappies of 1937 and 1938 collections was more precise than the method used with the 1935 and 1936 collections. Because of the distinctive ring patterns of most broods of Lake Decatur white crappies in 1937 and 1938 collec- tions, fig. 10, individual fish were assigned to their respective broods. Scales were then examined for presence or absence of annuli of the current growing season and for marginal growth beyond the new an- nuli. On the basis of these studies, it is apparent that some white crappies of Lake Decatur started their annual growth much earlier than others, as much as 6 weeks earlier in one season to 10 weeks earlier in another. Generally, small, sexually imma- ture fish formed their annuli earlier than large, mature ones. The end of the annual growth period is estimated from the data on average length of fish in the various age classes in successive summer, fall, and early winter collections, table 24+. Judged by length ob- servations in well-represented age classes —classes with one or two annual rings— the fish of most Lake Decatur broods stopped growing about the latter part of September. However, there is indication that members of some broods may have continued to grow, but at a very slow 250 Ittinois NaruraAL History Survey BULLETIN Vol. 25, rate, during the months of October and completely. First, there were gaps November. month or more between collections. § For two reasons it is not possible to ond, the length averages calculated state with certainty when growth stopped some broods tended to be erratic; for Table 21.—Data on annulus formation in white crappies at Lake Decatur in 1937. 1935 Broop 1934 Broop 1933 Broop Dare or Num- Num- Cottection | Total ber oe Cent Total ber Be cat Total Num- | Having |), 1937 Num- | Having ae 1937 Num- ber |the 1937| ne ber |the 1937 pone ber Caught | Annu- eee Caught | Annu- j Caught lus mS lus us Welt 1-4.. 67 0 0.0 220 0 0.0 54 0 April 24...... 34 0 0.0 67 0 0.0 14 0 May 16....... 37 0 0.0 39 220) 0.0 10 0 June: 3=Ses05 2): 71 8 TS 117 0 0.0 36 0 June: 2452528): 27 3 Tel 74 1 1.3 26 0 July 10-16.... 30 ie 40.0 37 1 pies 15 0 Aug. 6-14..... 15 15 100.0 9) 8 89.0 1 1 SEptae2 vaceins 5 SF 100.0 2 2% 100.0 — oo Noyce oie: 2 ps 100.0 2 2 100.0 — — * One of these fish showed an incomplete stage of annulus formation where new circuli were present on some of scales but not others, or where new circuli were Present only in certain areas of some scales. Table 22.—Data on annulus formation in white crappies at Lake Decatur in 1938. 1936 Broop 1935 Broop 1934 Broop Dare oF Num- Num- Cottection | Total ber Cent Total ber tee Cent Total Num- | Having is oy og8 Num- | Having ah 1958 Num- ber the 1938 es ber |the 1938 rs z ber Caught | Annu- ee Caught | Annu- | nu- | Caught lus us lus as March 14..... _— — — 12 0 0.0 13 May 28....... 69 0 0.0 5 0 0.0 5 Julyale eee 4 2 50.0 2 0 0.0 2 July 14....... 24 6 25.0 — —_ —_— 1 ATIC oo ela soe 18 18* 100.0 2 1 50.0 1 OBENGH tien - 2 2 100.0 = Nov. 4-11. - 4 4 100.0 1 * One of these fish had the annulus on only a part of its scales; of those scales which did not have the am seme showed absorption and some did not. Table 23—Approximate periods of annulus formation in white crappies at Lake Deca 1935-1938. _ YEAR OF Approximate Dares APPROXIMATE OaseRVATION or AnNuLus Formation* Lenctu oF PE LOSS ae roche Early May to early July or later..<..0..7.....5. 0s. neues 2 months or lo HOR se scale ne Early May to/early, July. ie) a See ee ee 114 to 2 months ORY Et ster eres Mid-May to early August or later.................2-8 0s 2% months or OS Ree senna. Early June to late August or later................---+-:- 21% months or lot “The term “or later” is added when some individuals had still not formed the annulus at the approxima of the period. ; tuayey Bulag sajros Jo painsesur Bulaq InoyIIM PapsEIsip BAM ‘Suo] soyoUT J] O2 H] ‘selddrs> osse] sOW xIs INOgY ¢ “suajdue Aq iyanes ; *siau Yysaul-y>uI-[ Ur 1YysNe dam dnois — ay Jo seareiuasosdas qsadiey aya AyUO _ a es aes (1) 0'€1 = (S)GOD s|a(ca) Se Oem CDA Ono ee) Ree (5) I’ GST Me ae hems ae eed tae ee eae 6 uel ofol = (Qo) raara COAOD piMCGGcOTian) (ODM On I AChR iaz (1) 8°€ (fei Naar tae We el 2 eee cores ae II-# “AON = = = (I) sor | (6 )68 | (us siz = VT eae dh here Ss SE ergs oar ek ae He 9°20 = = = (GE O0e |) CGT ONE 3 85. 1059 = Cline Weare Cyn ge a eee tee ie Nat mec St “sny a = mA Gee At) See | eee ys = GRA atest ices tek Sake taekies Te agen ll obT Ant : = ay ats Se. 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GN) 208 H yur] TL6I1 ‘6 [dy | -1€61 ‘97 29d : = Se NON UL NGC onl sCDiGa8 (7)96| (2) 6'6 == cl H Your | TSGI8Oe 48H | y ee aypiaurg ‘sdom = = = a oa CDOS Zan AUG) Rs yon eel ORG 8 S yout 9/T €£L61 “IZ-L “deg g = = se = == (I)€L} (81)19 | (91)0°9) se § youl 9/T CL6T “BI-T “any a ~ -- — = = (PI O'L | Ge) b'9 | (81I)69] 99 S youl 9/1 CL6l “bC-L AML, 2 = = = = — (€)69] (S1)8°9] (SI)e9] ee § youl 9/T CLGI “PT-11 oun{ |*- °° yowoyvyA “puuvyo r9Ary “i 4anty uouDvsuDy a = GOP 2PM ee (€)66) (4)0°6| (9)78)| (1)69)| 81 H yout | Se6l ‘TI-s eunf Ces n tAD] is “NGtd] PUD AdIY aUuTYS WIno'T x = SC) BELT OD) Seat MEM GnTn) Cec) IBIG |) CLDIEs8 = +9 H youl 31 | O€ol ‘8I-c1 [udy | odyoorg “oye] uewouury = = a = (9)6°6| (€%) £6} (6) 9°8 = 289 H youl 41 O¢6l + [udy—6z Your roth aN quod yooig Oyu] Pl = = — = (01) 0°6 | (JOT) S°Z | (8)OL| (FrS| Lor H yout | - SE6L “IT-1 Av | “UMoJaUMVYS “oUULYS 19AlYy SdyV'T MOGXC PUuv 4901 01/0) ww = = st a = = GENEL CHO EA G19) 7 OTT ay H your | 6761 “EZ-1 “Bn | Par seats *-3]A[IBD 5 H : 0} UvATTINS ‘jauULYD JAY g Aanigy DIYSDYSVN 1) 4 1) 5 6 "7 Bibs (6) Gis ee H yur BE6l ic |udy cease sjoed Burpiaas Di i .8°Oll G a oa Ol |) 6B yoUrT “***uosjaN ‘Jood Surpiaag Vol. 25, Art. 4 In tn 0 '1N 00 soele a wim ew ECON “67-1 ‘sny "e661 “IZ-L “3dag --$e6l ‘Tc-1 API inate “Secor ‘cI [dy pie ae 861 ‘OC APTN aPeeusgay ean ver epee w'e! Sy «| SE6l 9 dag BEEP PSS aTApIVD 0} UBATT[NG “TAALY vIyseysey EG sche eeapeeys e ke Jowoyryy] “aaAny uoulesurs ea ERA ee ee UMOJIUMEYS “IIA O1YO Bap pe eee Injeoaq ‘aye7] poomawofy SO Sonera naan aPC ujosury ‘saxe'y ujooury ee Gia ACE uOppeM ‘exe7] ssutadg uopjaA, (Yimoly mojy sussjiqryxy suouvjndog) (t ) 8°01 (Ga aGea (€f) 6° IT (8€) 9°€T Sea cae I€6T “61-7 “AON eae cea PLOT “67-81 APN oe) 20S6r. Si-Cmey. Fe aot BEL “FT WIEN Se ee ee LE61 8 judy ore rae ae) eae yjeg “juuryS JoAry siourlyy "- + = -Blsoparayy] ‘Avg vIsopasayAy Ea Se oe a jiodyooig ‘aye] uvuaUUTy Pe ate eae amqeaaqy {nqe2aqy 24k] lien Ber nate Pe gE SAC SRST oles axe] 20Ysasiopy (yimo1y pidvy Surnquyxgq suourjndog) SSVI) ONIY TVONNY NOILOATTO?) AO ALVC NMO]T LSTUVEN GNV YILVAA JO Aadog Irtinois NaturaL History SurvEY BULLETIN So[qe} Woy b3eC7) 258 *sayour Ul SysUa] [2}0} peAsasqg *suowiseds jo staquinu Jueseide1 sasayjueied ut soinsty (‘gz pue Fz ‘soiddeso az1YM STOUTT]] Ul yIMOIs MOTS pue YIMOIS prides jo sajdulexe pazoa[es— G7 P1921 August, 1951 HANSEN: BIoLoGy oF THE WHITE CRAPPIE Fig. 13.—Illinois localities represented by age determinations of fish included in table 28. 59 260 Ittinois NAtuRAL History SurRvEY BULLETIN In Illinois waters other than Lake De- catur, study of growth in fish more than a year old was based on’ scale samples from lakes or streams in 33 localities in widely scattered sections of the state, fig. 13h engths of fish having a like number of annual rings were averaged for each collecting period at each locality, table 28. Table 28 shows wide differences in sizes of fish having a like number of an- nual rings. Some of these averages are not subject to direct comparison, since small fish in the samples were not always adequately represented. Especially was this true in several samples collected in 1931 and before (footnote 3, table 28). Some collections were made during the active growing period of the fish collected, while others were made between grow- ing periods. In the case of summer col- lections, it was not known whether the outer ring on a scale was the ring of the current year or of the preceding year. Data on some of the outstanding ex- amples of white crappie populations con- taining fast-growing and slow-growing fish are recorded in table 29. Popula- tions containing slow-growing fish like those found in Weldon Springs, Lincoln, and Homewood lakes are termed “‘stunt- ed.” Such populations contain only a small percentage of crappies over 8 inches in length even though a large percentage are 3 to 5 years old. Growth in these populations is not so abnormally slow dur- ing the first 2 years as during the third year and later. Of all Illinois waters sampled, Horse- shoe Lake, in Alexander County, con- tained the largest white crappies. In this lake, annual growth increments were es- pecially large among fish that had lived beyond the third year. Also, the rate of survival of fish beyond the fourth year ap- pears to have been exceptionally high. The Horseshoe Lake population has been analyzed previously by Thompson & Ben- nett (1938). Probably the good growth observed in this lake was due to the recent origin of the population. The lake was drained in 1930 and refilled and restocked in 1931. Lake Decatur, where growth was rapid, and Homewood, where growth was slow, table 29, are in the same central Illinois locality; Homewood Lake was formed by Vol. 25, damming one of the small valleys t tri tary to Lake Decatur. Growth Rates in Out-of-St Waters.—Growth of the white crappic has been studied in three neighbori states: at Reelfoot Lake, Tennessee, Schofiman (1940); at Lake of the Ozarks, Missouri, by Weyer (1940) ; Indiana lakes by Ricker & Lagler (19 and Johnson (1945); and in three T reservoirs, two in Tennessee and one North Carolina, by Stroud (1949). growth rates observed in these bodie water fall approximately in the ran served in Illinois waters. Eschmeyer & Jones (1941) found th in the early years of impoundment ¢ Norris Reservoir, the black crappies the grew at a much faster rate than has’ been observed in Illinois white crap The first brood of black crappies hat in Norris Reservoir (in 1937) aver. 11.5 inches (total length) when they I completed two summers of growth. (1 best recorded growth for an ade sample of Illinois white crappies with completed summers was found at Lake catur in the winter collections of 1936 The fish of these collections averaged inches in length.) The third broo¢ black crappies hatched at Norris R voir (in 1939) grew at about the sa rate in their first summer as I[I]!inois crappies of the same age, but the ra’ growth in their second year, when reached 8.9 inches, was faster than best average for Lake Decatur. Eschmeyer & Jones (1941) attributed the good growth in the early years ai Norris Reservoir to abnormal richness 6} the lake in basic food elements and lac of severe competition. , SUMMARY This paper is based primarily on an intensive study of the white crappi Lake Decatur, Macon County, Illi where sampling was carried on at I- month intervals the year round from | 1935 to late 1939. It is based in pai additional information obtained from ious fisheries investigations carried on members of the aquatic biology staft the Natural History Survey during an 18-year period beginning in 1927. HANSEN: BIOLOGY oF ugust, 1951 “The white crappie and the black crap- . both important as sport fishes in IIli- are abundant throughout the state. white crappie generally outnumbers lack in small streams or creeks and rtificial lakes of all sizes. The black to be the more common species in ie deep glacial lakes of northeastern IIli- nis. In the larger rivers and in the bot- miand lakes preponderance of one cies over the other varies from lake to ke and from one part of the channel to 1other. At the time of this study, fishermen used urious methods of angling, some uncom- on, and various kinds of baits in fishing 3 white crappies in Illinois. At Lake lecatur they caught white crappies prin- pally from March 1 to June 1. In year-round hoop-net fishing at Lake lecatur, the poorest catches were made | the summer. White crappies require 2 years or, metimes, 3 years to reach sexual matu- ty. The smallest ripe female observed : Illinois measured 5.6 inches total ngth. Dark breeding coloration was yund in most males of breeding size from pril to June (or July) and was seen in ne female. Ripe females (with mature sgs) were found in Illinois as early as Tay 6 and as late as July 13; ripe males s early as May 16 and as late as June +. The height of the Illinois spawning ason is probably late May or early June. t appears that only a portion of the eggs | ripe females are laid and that perhaps considerable number of unlaid eggs are sorbed. Crappies spawn under a variety of ynditions of bottom, water depth, and roximity to vegetation, embankments, nd wooden structures. They seem to low a preference for depositing their eggs n plant material, but they do not require juatic plants for that purpose. Net samples showed a predominance f males among young white crappies, a redomimance of females among older hite crappies. They showed a temporary arcity of males in late spring and early immer. Lymphocystis, the most common disease bserved in white crappies, was found in 9.5 per cent of the white crappies in one cality. THE WHITE CRAPPIE 261 Comparisons in the relative plumpness of the members of different length classes and broods were based on the coefficient of condition, K. Small fish usually began their annual growth before large fish and showed earlier summer gains in condition. Large fish reached peak condition in late fall or early winter; small fish reached peak condition in midsummer. Small fish showed condition losses in late summer and ad- ditional losses in early spring. Large fish suffered condition losses mainly in spring and early summer. At most times of the year the K values were higher in large white crappies than in small ones. Differences in K values were least apparent in June and July when the large fish were at the low point in the condition cycle and the small fish were nearing the top of the cycle. K values were approximately the same in males and females of the same size cate- gories, irrespective of time of year. Evidence obtained at Lake Decatur in- dicates that the annual rings on the scales of white crappies are not invariably formed at the rate of one ring for each year of life and that the rings are not formed at exactly the same time of year. The sizes of white crappies caught in the nets at Lake Decatur fluctuated strongly from year to year. Large sizes were abundant only in alternate years. Disappearance of large sizes is believed to have been due to large-scale summer mortality (heavier some summers than others). Lake Decatur crappie broods were generally short lived. Broods were usually not conspicuous in net catches beyond the second or third year of life. One brood disappeared completely at the age of 3 years and 3 months; another brood at 4 years and + months. Dates of annulus formation were ob- tained for + consecutive years at Lake Decatur. Start of growth ranged from early May in some fish to late August or later in others. The annual growth period at Lake Decatur varied for most individual fish from about 2 to 6 months. Some individ- uals failed to grow at all in 1935 and 1937. The average observed lengths of white crappies falling into various annual ring classes were recorded for Lake Decatur 262 and 33 other Illinois localities. The an- nual growth increments of the white crap- pies at Lake Decatur varied widely from year to year. This was true particularly of fish in the second and third years of life, Ittinois Narurat History SuRVEY BULLETIN which grew exceptionall. made little or no growth Only small differe rates of males and fe LITERATURE CITED 1919. Crappie spawn in Washington Aquarium. Aquatic Life 4(10) : 137. 1948. A list of common and scientific names of the better known fishes of the United States and Canada. Am. Fisheries Soc. Spec. Pub. 1. 45 pp. nnett, George W. 1938. Growth of the small-mouthed black bass, Micropterus dolomieu Lacépéde, in Wisconsin waters. Copeia 1938(4) : 157-70. 1943. Management of small artificial lakes. A summary of fisheries investigations, 1938- 1942. Ill. Nat. Hist. Surv. Bul. 22(3) : 357-76. snnett, George W., David H. Thompson, and Sam A. Parr 1940. Lake management reports. 4. A second year of fisheries investigations at Fork Lake, 1939. Ill. Nat. Hist. Surv. Biol. Notes 14. 24 pp. eder, C. M., Jr. 1936. The reproductive habits of the North American sunfishes (family Centrarchidae). Zoologica 21: 1-48. wn, Carl B., J. B. Stall, and E. E. De Turk 1947. The causes and effects of sedimentation in Lake Decatur. Ill. Water Sury. Bul. 37. 62 pp. ark, Frances N. 1928. The weight-length relationship of the California sardine (Sardina caerulea) at San Pedro. Calif. Div. Fish and Game Fish Bul. 12. 58 pp. dy, Samuel 1932. The plankton of the Sangamon River in the summer of 1929. III. Nat. Hist. Sury. Bul. 19(5) : 469-86. dy, Samuel, and Thaddeus Surber 1947. Northern fishes, with special reference to the upper Mississippi valley. (Rev. ed.) University of Minnesota Press, Minneapolis. 276 pp. chmeyer, R. W. 942. The catch, abundance, and migration of game fishes in Norris Reservoir, Tennessee, 1940. Tenn. Acad. Sci. Jour. 17(1) : 90-115. chmeyer, R. W., and Alden M. Jones 1941. The growth of game fishes in Norris Reservoir during the first five years of impound- ment. N. Am. Wildlife Conf. Trans. 6, 1941:222-40. chmeyer, R. W., and C. G. Smith 943. Fish spawning below Norris Dam. Tenn. Acad. Sci. Jour. 18(1) : 4-5. chmeyer, R. W., Richard H. Stroud, and Alden M. Jones 11944. Studies of the fish population on the shoal area of a TVA main-stream reservoir. Tenn. Acad. Sci. Jour. 19(1) : 70-122. ermann, Barton Warren, and Howard Walton Clark 1920. Lake Maxinkuckee. A physical and biological survey. Ind. Dept. Cons. Pub. 7, vol. 1. 660 pp. rbes, Stephen Alfred, and Robert Earl Richardson 11920. The fishes of Illinois. (Second ed.) Illinois Natural History Survey, Urbana. 358 + 136 pp. rsbacher, Willard M. 937. Development of stream bottom communities in Illinois. Ecology 18(3) : 359-90. ymph, Louis M., Jr., and Victor H. Jones 937. Advance report on the sedimentation survey of Lake Decatur, Decatur, Illinois, April 8—July 3, 1936. U.S. Dept. Ag. Soil Cons. Sery. Sedimentation Studies. Div. Res. SCS- SS-12. April, 1937. 23 pp. eenbank, John 937. A chemical and biological study of the Elephant Butte Reservoir as related to fish culture. Thesis on file in University of New Mexico library. 102 pp. [263] oe 264 Irtinois NaturAL History Survey BULLETIN Vol. 25, A Hansen, Donald F. 1937. The date of annual ring formation in the scales of the white crappie. Am. Fishe Trans. 66:227-36. 1942. The anglers’ catch at Lake Chautauqua near Havana, Illinois, with comparative on hoopnet samples. Ill. State Acad. Sci. Trans. 35(2) : 197-204. } 1943. On nesting of the white crappie, Pomoxis annularis. Copeia 1942(4) : 259-60. Harper, D. C. 1938. Crappie and calico bass culture in Texas. Prog. Fish Cult. 38:12-4, Hile, Ralph 4 1931. ‘The rate of growth of fishes of Indiana. Ind. Dept. Cons. Div. Fish and Game. In Ind. Lakes 1(2) : 8-55. 2 Hubbs, Carl L., and Gerald P. Cooper 1 1935. Age end growth of the long-eared and the green sunfishes in 1 Wachee Mich. | aa Sci., Arts and Letters, Papers 20: 669-96. Hubbs, Carl L., and Karl F. Lagler 1947. Fishes of the Great Lakes region. Cranbrook Inst. Sci. Bul. 26. 186 pp. James, Marian F. 1946. Histology of gonadal changes in the bluegill, Lepomis macrochirus Rafinesque, a and largemouth bass, Huro salmoides (Lacépéde). Jour. Morph. 79(1) : 63-86. ‘ Johnson, Wendell L. i: 1945. Age and growth of the black and white crappies of Greenwood Lake, India Dept. Cons. Div. Fish and Game and Ind. Uniy. Dept. Zool. Invest. Ind. Lake Streams 2(15) : 297-324. ; Jones, Alden M 1941, The length of the growing season of largemouth and smallmouth black bass in Reservoir, Tennessee. Am. Fisheries Soc. Trans. 70: 183-7. Luce, Wilbur M. 1933. A survey of the fishery of the Kaskaskia River. Ill. Nat. Hist. Surv. Bul. 20(2) Artec — aetna Shite IN AC OO = TB Miller, Lawrence F., and Paul Bryan 1947. The harvesting of crappie and white bass in Wheeler Reservoir, Alabama. Tenn. A Sci. Jour. 22(1) : 62-9. ; Mottley, Charles McC. a 1938. Loss of weight by rainbow trout at spawning time. Am. Fisheries Soc. Trans. 67:207 Nelson, T. F. 1941. Fertilizing bass ponds. Prog. Fish Cult. 56:28—9. Nigrelli, Ross F., and G. M. Smith p 1939. Studies on lymphocystis disease in the orange filefish, Ceratacanthus schoo ‘@ baum), from Sandy Hook Bay, N. J. Zoologica 24(2): 255- 64. Pearse, A. S. : 1919. Habits of the black crappie in inland lakes of Wisconsin. U. S. Commr. Fisheries for 1918 (App. 3). Bur. Fisheries Doc. 867. 16 pp. Richardson, R. E. ; 1913. Observations on the breeding habits of fishes at Havana, Illinois, 1910 and 191 1. State Lab. Nat. Hist. Bul. 9:405-16. Ricker, William E., and Karl F. Lagler 1942. The growth of spiny-rayed fishes in Foots Pond. Ind. Dept. Cons. Div. Fish and € and Ind. Univ. Dept. Zool. Invest. Ind. Lakes and Streams 2(5) : 85-97. d Russell, E. S. J 1914. Report on market measurements in relation to the English: haddock fishery during years 1909-1911. (Gt. Brit.) Min. Ag. and Fisheries Fishery Invest. Ser. 2, 5(1):1 Schoffman, Robert J. ; 1938. Age and growth of the blue-gills and the largemouth black bass in Reelfoot Lake. I foot Lake Biol. Sta. Rep. 2:5—27. 1939. Age ea growth of the red-eared sunfish in Reelfoot Lake. Reelfoot Lake B Rep. 3:61-71. 1940. Age and growth of the black and white crappie, the warmouth bass, and the ye bass in Reelfoot Lake. Reelfoot Lake Biol. Sta. Rep. 4:22-42. ugust, 1951 Hansen: Biotocy or THE WHITE CRaApPiE 265 troud, Richard H. 1948. Growth of the basses and black crappie in Norris Reservoir, Tennessee. Tenn. Acad. Sci. Jour. 23(1) : 31-99. 1949. Rate of growth and condition of game and pan fish in Cherokee and Douglas reservoirs, Tennessee, and Hiwassee Reservoir, North Carolina. Tenn. Acad. Sci. Jour. 24 (1) : 60-74. ester, Albert L. 1932. Rate of growth of the small-mouthed black bass (Micropterus dolomieu) in some Ontario waters. Toronto Univ. Studies, Biol. Ser. 36:205-21. mpson, David H. 1933. The migration of Illinois fishes. II]. Nat. Hist. Surv. Biol. Notes 1. 25 pp. 1941. The fish production of inland streams and lakes. Jn A symposium on hydrobiology, pages 206-17. University of Wisconsin Press, Madison. 405 pp. pson, David H., and George W. Bennett 1938. Lake management reports. 1. Horseshoe Lake near Cairo, Illinois. Ill. Nat. Hist. Surv. Biol. Notes 8. 6 pp. ; 1939. Lake management reports. 3. Lincoln Lakes near Lincoln, Illinois. Ill. Nat. Hist. Surv. Biol. Notes 11. 24 pp. Irey, Lorraine, Clifford Risk, and Will Scott 1938. The number of eggs produced by some of our common fresh-water fishes. Ind. Dept. Cons. Div. Fish and Game and Ind. Uniy. Biol. Sta. Invest. Ind. Lakes and Streams 1(6) : 73-7. alker, E. D. 1949. The story of a Lake. Ill. Ag. Ext. Serv. Cire. 644. 12 pp. eissenberg, Richard 1939. Studies on virus diseases of fish. II]. Morphological and experimental observations on the lymphocystis disease of the pike perch, Stizostedion vitreum. Zoologica 24(2) :245-54. eyer, Albert E. 1940. The Lake of the Ozarks. A problem in fishery management. Prog. Fish Cult. 51:1-10. ickliff, E. L., Mark White, George Messerly, Jack Rodebaugh, Lee Roach, Elwood Seaman, and C. S. MaclIntire | 1944. Ten year summary of fish management activities for the Muskingum watershed con- servancy district lakes. Ohio Div. Cons. Bul. 171. 50 pp. 1946. 1945 Supplement to the ten year summary of fish management activities for the Mus- kingum watershed conservancy district lakes. Ohio Div. Cons. Supplement to Bul. 171. 6 pp. ~ Recent sinsietis's A—ILLINOIS NATURAL HISTORY SURVEY BULLETIN. il Volume 22, Article 1—The Plant Bugs, or Miridae, of Illinois. By Har September, 1941. 234 pp., frontis. + 181 figs., bibliog., index. $1.25. Volume 22, Article 2—Studies of North ‘American Plecoptera, with sp the fauna of Illinois. By T. H. Frison. September, 1942. 122. PP-s fr bibliog:, index. $1.00. \ Volume 23, Article 1—The Caddis Flies, or Trichoptera, of Tiingist Ross. August, 1944. 326 pp., frontis. + 961 figs., bibliog., index. $1.50. Volume 23, Article 3 —Overfishing i in a Small Artificial Lake: Onized Illinois. "By George W. Bennett. May, 1945. 34 pp., frontis. + 15 figs., Volume 24, Article 1—The Mosquitoes of Illinois (Diptera, Culicidae). i H. Ross, August, 1947. 96 pp., frontis. + 184 figs., bibliog. 50 cen Eu Volume 24, Article 2.—The Leafhoppers, or ‘Cicadellidae, of Illinois — hese Balcluthinae). By D. M. DeLong. June, 1948. 280 pp., frontis. ++ index. $1.25. fe Volume 24, Article 3—The Bass-Bluegill Combination in a Small At George W. Bennett. December, 1948. 36 pp., frontis. + 10 figs. — aN Volume 24, Article 4—The Pseudoscorpions of Illinois. By C. Claytor 1949. 86 pp., frontis. + 51 figs., bibliog., index. 50 cents. , Volume 25, Article 1.—Characteristics of Residual Insecticides Toxic to By Willis N. Bruce, July, 1949. 32 pp., frontis. fae 14 figs., bibliog. ; By Lee E. Yeager. " August, 1949. 32 pp., frontis. + 21 figs., bibliog. — Volume 25, Article 3.—Canada Geese of the Mississippi Flyway, with to an Illinois flock. By Harold C. Hanson and Robert H. a Mar frontis. + 82 figs., bibliog. B—ILLINOIS NATURAL HISTORY SURVEY CIRCULAR. 36.—Planting and Care of Shade Trees. By J. S Davis. Septembe printing, with additions.) 28 pp., frontis. + 20 fi 38.—Windbreaks for Illinois Farmsteads. By J. E. Davis. soe 1951. ( with revisions by L. B. Culver.) 33 pp., frontis. + 27 fi 39. Tees to Collect and Preserve Insects. By H. H. Ross. 4 uly, 1949, a 41 Corer to Recognize and Control Termites in Illinois. By B. G. Be 1947. (Reprinted without text revision, April, 1950.) 44 pp., frontis. 42.—Bird Dogs in Sport and Conservation. By Ralph E. Yeatter. Decembe pp., frontis. + 40 figs pik 43.—Peach Insects of “llinois and Their Control. By Stewart C. Chandle 1 1950. 63 pp., frontis. + 39 figs ne 44,—The Drug Plants of Illinois. “By Leo R. Tehon. July, 1951. 122 pp fr ntis, figs., index. Ua C.—ILLINOIS NATURAL HISTORY SURVEY MANUAL. hata *2.—Fieldbook of Illinois Land Snails. By Frank Collins Baker. August, color frontis. + 170 figs., 8 pls. $1.00. ie 3.—Fieldbook of Native Illinois Shrubs. By Leo R. Tehon. December, 1942, 4 color pls. + 72 figs., glossary, index. $1.25. List of available publications, about 400 titles, mailed on reque. Single copies of ILLino1s NATURAL History Survey publications for which no will be furnished free of charge to individuals until the supply becomes low, nominal charge may be made. More than one copy of any free publication m without cost by educational institutions and official organizations within the St prices to others on quantity orders of these publications will be quoted upon reque Address orders and correspondence to the Chief Itirnois Natura History SURVEY _ Natural Resources Building, Urbana, Illinois Payment preferably in the form of U.S. Post Office money order made out to State Illinois, Springfield, Illinois, must accompany requests for publications on which a rice ‘Eda re By ae B ULLETIN Bi bas of the ae ILLINOIS NATURAL HISTORY SURVEY ee HARLOW B. MILLS, Chief 4 ‘Commercial and Sport Fishes of the Mississippi River 4 Between Caruthersville, Missouri, " and Dubuque, lowa "PAUL G. BARNICKOL eh iAM C. STARRETT Printed by Authority of the STATE OF ILLINOIS ADLAI E. STEVENSON, Goverser DEPARTMENT OF REGISTRATION AND EDUCATION C. HOBART ENGLE, Director SLATE OF ILLLINOWS ApLat E, STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION C. Hoparr ENG, Director MenamwAL HisTORY SURVEY DIVISION Hariow B. Mirus, Chief BULLE EUN Article 5 bo on Volume Commercial and Sport Fishes of the Mississippi River Between Caruthersville, Missourt, and Dubuque, lowa PAUL G.-BARNICKOL WEE ELAM CG. STARRETT Printed by Authority of the State of Illinois URBANA, ILLINOIS September 1951 STATE OF ILLINOIS Avxal E. Srevenson, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Hosarr Enc te, Director BOARD OF NATURAL RESOURCES AND CONSERVATION C. Hosart Encie, Chairman A. E. Emerson, Ph.D., Biology L. H. Tirrany, Ph.D., Forestry RoGER gear Ph.D., ’D. Sc., Chemistry Georce D . STopparD, ’Ph. D., Litt.D., L.H.D., LL.D., President of the University of Ilinois DELYTE W. Morais, Ph. D., President of Soathera Illinois University ; can ee 2: NATURAL HISTORY SURVEY DIVISION é Urbana, Illinois Py ScIENTIFIC AND TECHNICAL STAFF i Hartow B. Mitts, Ph.D., Chief + Bessie B. East, M.S., Assistant to the re x Section of Economic Entomology Georce C. Decker, Ph.D., Entomologist and Head J. H. Biccer, M.S., Entomologist L. L. Eneutsu, Ph.D., Entomologist Gay: Weinman, Ph.D., Entomologist S. C. Cuanpter, B.S., ” Associate Entomologist Wixuts N. Bruce, M. A, Associate Entomologist Joun M. Wricxt, M.A., Assistant Entomologist W. H. Lucxmann, M.S., Assistant Entomologist H. B. Perry, M.A., Associate in Entomology Extension James M. Bann, B.S., Research Assistant Pau Suranyi, Ph.D., Laboratory Assistant Sue E. Warkins, Technical Assistant Section of Faunistic Surveys and Insect Identification H. H. Ross, Ph.D., Systematic Entomologist and Head Mitron W. Sanverson, Ph.D., Associate Tax- onomist Lewis J. Srannarb, Jr., M.S., Assistant Tax- onomist Leonora K. Grioyn, M.S., Laboratory Assistant Puitip W. Smitu, M.S., Laboratory Assistant Wicuram R. Ricuarps, B.S., Laboratory Assistant Grace H. Hutt, Technical Assistant Section of Publications and Public Rela- tions James S. Ayars, B.S., Technical Editor and Head Biancue P. Younc, B.A., Assistant Technical Editor Wituram E. Crark, Assistant Technical Pho- tographer James W. Curran, B.S., Technical Assistant Section of Forestry Witter N. Wanpve tt, M.I’., Forester and Head Lawson B. Cutver, B.S., Associate in Forestry Extension Ross J. Mirrer, M.S., Field Ecologist CHARLOTTE ASCHBACHER, B.A., Technical Assist- ant Consuttant in Herperotocy: Hosarr M. Smirx, Ph.D., Associate Professor of Zoology, Universi Illinois. trative and technical supervision. tEmployed by the Illinois Department of Conservation under terms of the Federal Aid in Wildlife Restoratio and assigned to the Natural History Survey for administrative and technical supervision. This paper is a contribution from the Section of Aquatic Biology. (30208—3M—5- Section of Aquatic Biology 51) ais = Wa ter H. Newuouse, FOR Geology L. R. Howson, B.S.C.E., C. Engineering thology f Leo R. TEnon, Ph.D., Botanist and Head A J. Cepric CarTER, Ph. D., Plant Pathologist a) J. L. Forsserc, MS., Associate Plant Path 0 @ J. Sressex, M.S., Assistant Plant Pathologist B. M. ZuckerMAN, MS., Assistant Plant P. os ogist § Rosert A. Evers, M.S., Assistant Botaniell G E. A. Curt, M.S., Special Research Assistant © Sytvia Wotcyrz, M. S., Special Research Assist- ant Rovenia F, Firz-Geratp, B.A., Technical As- sistant a Georce W. Bennett, Ph.D., Aquatic Biologist and Head Wixitam C. Starrett, Ph.D., Associate Aquatic Biologist Donatp F. Hansen, Ph.D., Assistant Aquatic: Biologist R. W. Larimore, Ph.D., Assistant Aquatic Bi - ogist Wa ter H. Hart, Field Assistant Leonarp Duruam, M.S., Technical Assia P. L. McNe1, BS., Technical Assistant* Section of Game Research and Manage- » ment T. G. Scorr, Ph.D., Game Specialist and Head Rateu E. YEATTER, ’Ph. D., Game Specialist F. C. Betxrose, B.S., Associate Game Specialt H. C. Hanson, M. S., Assistant Game Special J. S. Jorpan, M.F., Assistant Game Technte: Wiiiiam Nuess, Field Assistant GeorceE C. ARTHUR, B.S., Project Leader Lyste R. Prerscu, M.F., Project Leadert Joun C. Catuoun, B.S. , Assistant Project Lender Technical Library MarcuerirE Simmons, M.A., M.S., Tech ical Librarian Rutu Warrick, B.S., Assistant Technical Lire rian y CONTENTS Vib se OOSs2io bad Fag SOR OOH On ake One en ae ey 269 MTOM OOO SRE Ly oar ce rsih en's Wiasnceini oe AU ES Oreis.o Pa Ooclcc a ciwielajlele Seizes 269 provements LGNE IN ENTE GTi cae OO aes BORG cy SR RCT ace ae ee ree ae 271 MAPEER MENTE LISS ONL ss Mel oho arora oid Gin ore te aeNe oo atye.sel aie Saw Eee See 273 saary iddississipy ay) fo Y91D9 JvIIZLAUUOD aY4 07 JuDJLOgut Satzags ayy fo auo “ysIfjv9 jauuvy’) 4 Commercial and Sport Fishes of the Mississippi River Between Caruthersville, Missouri, and Dubuque, Lowa’ : TN December, 1943, conservation rep- resentatives from the states of I 1linois, Towa, Missouri, Minnesota, and Wis- consin, from the United States Fish and Wildlife Service, and from other inter- ested agencies met at Dubuque, Iowa, and formed the Upper Mississippi River Con- servation Committee (Smith 1949). This froup was organized for the purpose of sponsoring studies of the fishery and wild- life resources of the Mississippi River from Caruthersville, Missouri, to Hast- ings, Minnesota. The studies were de- signed to serve as a basis for making scientifically sound recommendations for the management of these resources. At that time the fish and game codes of the member states were at variance with one another in certain provisions, and some practices that were legal in the waters of the Mississippi bordering one state were illegal in the waters within the jurisdic- tion of another immediately across the river. To facilitate the actual projection of biological investigations, two technical committees were formed within the Con- servation Committee. These were the Technical Committee for Fisheries and the Technical Game Committee. To them were assigned the duties of planning research and reporting the progress of re- search to the Conservation Committee at its annual meetings. * This investigation was conducted under the auspices of the Technical Committee for Fisheries of the Upper Mississippi River Conservation Committee. 7 Formerly Ichthyologist, Illinois Natural History Sur- vey; now Chief Biologist of the Fisheries Section of the uri Conservation Commission. F Associate Aquatic Biologist, Illinois Natural History Survey. PAW a aG (BAUR NTI@ KOU, Wink A Mi Cx ST ARR E babe Basic to a sound management pro- gram for the upper Mississippi fishery was a knowledge of the status of various species of fish present in the river. Com- mercial fishery statistics were not adequate because they included several species under single groupings, as buftalofishes and cat- fishes, and because in recent years they failed to include sport fishes and other species closed to commercial fishing. Because state agencies were restricted in their research activities by state bound- aries (the United States Fish and Wild- life Service was the only agency involved that was free to finance projects without regard to state boundaries), it became necessary to subdivide the upper Missis- sippi. River fishery investigations into upper and lower co-operative units—the upper unit involving Wisconsin, Minne- sota, and northern lowa, and the lower unit involving Missouri, southern Iowa, and Illinois. Actual field operations were begun in the Missouri-Illinois part of the southern unit in March, 1944, with the Conserva- tion Commission of Missouri, the Illinois Department of Conservation, and the IIli- nois Natural History Survey participating. Two years later, in March, 1946, field operations were begun in the lowa-lllinois part of the river with the lowa Conserva- tion Commission and the two Illinois agencies co-operating. The entire investigation reported here was conducted under the auspices of the Technical Committee for Fisheries. This paper is based on an analysis of the data relative to the species composition [ 267 | 268 of the fishes appearing in test-net collec- tions taken in 1944 and 1946 with various types of commercial gear at 31 sampling stations between Caruthersville, Missouri, and Dubuque, lowa. The gear included types that could not be used legally by commercial fishermen in some or all of the co-operating states. The discussion is limited largely to the commercial and sport fishes of the river. The smaller-sized fishes, such as the min- nows (Cyprinidae), seldom occurred in the test-net collections, as the minimum mesh used was 1 inch square. Minnow collections were made at many of the stations, and a list of the species appear- ing in these collections was recorded but is not presented here. The writers believe that, regardless of any shortcomings of the sampling methods employed in this study, the data are exten- sive enough to allow a rough estimate of the status of the various commercial and game fishes now occurring in the Caruth- ersville-Dubuque section of the Mississipp1. Acknowledgment is made to the follow- ing persons for their various contributions to the progress of the researches reported in this paper: Mr. W. E. Albert, Mr. Daniel Avery, Mr. James S. Ayars, Dr. Reeve M. Bailey, Dr. George W. Bennett, Mr. Leonard Durham, Dr. T. H. Frison (now deceased), Dr. B. Vincent Hall, Dr. Don- ald F. Hansen, Dr. G. B. Herndon and associates, Mr. Don W. Kelley, Mr. Jacob H. Lemm, Dr. Harlow B. Mills, Mr. Sam A. Parr, Dr. Hurst H. Shoemaker, Mr. Everett B. Speaker and associates, and Dr. David H. Thompson. Financial support of this investigation was given by the conservation departments of the states of Illinois, lowa, and Mis- souri, and by the Illinois Natural History Survey, all co-operating under the Upper Mississippi River Conservation Commit- tee program. THE MISSISSIPPI RIVER The length of the Mississippi River from its source at Lake Itasca to its mouth at Head of Passes is 2,470 miles ( Missis- sippi River Commission 1940:1). This great river and its tributaries drain a total area of about 1,244,000 square miles, in- cluding all or parts of 31 states and 2 Ittinors NaturAL History Survey BULLETIN Vol. 25, Art, Canadian provinces: New York Pennsylvania farthest east, Wyoming Montana farthest west, Alberta and katchewan farthest north. The iny gation reported here covers that pa the Mississippi River between Caruthi %, % STAN. ce ae oS jp SAVANNA ULA STA‘ » 134 10.WA stay 14gf0 CORDOVA sta, ISR S/PVEASANT VALLEY, STA, 9 Big SANDALUSIA\ STA FAIRPORT o. STA. MUSCATINE 9 STA. Al7. NEW BOSTON STA. i, CfBoovawka sta. fis Se, “BURLINGTON STA, -\% on ve. =A19 A\/* warsaw)sta. 204 CANTON STA. A2i —Ff? QUINCY sTaA. HANNIBAL STA, p22 (0 N@CINCINNATIIL ANDING TA. LOUISIANA STA : 24 B HAMBURG STA, WINFIELD STA. GRAFTON STA. MISSOURI gS pee , ; 1. 9 MOUTH, MO\RIVER’ TAZ SS0u,; & SST. Louisg CLIFF CAVE STA. ~ CRYSTAL CITY STA. STE. GENEVIEVE STA MISSISSIPPI RIVER FIELD STATIONS LEGEND @ 1944 ILLINOIS - MISSOURI STATIONS © 1946 ILLINOIS -1OWA STATIONS ® 1946-47 POISON CENSUS OF BACKWATER 4 LOCK AND DAM sl CARUTHERSVILLE STA.) TENNESSEE AG Fig. 1—The Mississippi River between Caruthersville, Missouri, and Dubuque, low shown is the location of field sampling stati used during the fisheries survey of 1944 1946. The river distance between Caruthers: ville and Dubuque is 689 miles. Missouri, and Dubuque, lowa, a ce of 689 miles or 28 per cent of the al length of the river, fig. 1. This sec- on of the river includes 306 miles of the ywer Mississippi, designated hereafter as R-C (mouth of the Missouri River to aruthersville), and 383 miles of the ipper Mississippi, designated as D-MR Dubuque to the mouth of the Missouri rT). Early Descriptions The Mississippi River was discovered jin the sixteenth century by an expedition headed by Hernando de Soto. Later ex- plorations were made on the Mississippi by such well-known historical personages s D'Iberville, Joliet, Marquette, and La e. ‘The “Gentleman of Elvas,” a Portu- suese member of the De Soto expedition, jstated that “The river was of great depth ‘and of a strong current. The water was always muddy. There came down the river continually many trees and timber, which the force of the water and stream jbrought down. There was a great store of Mfish in it of sundry sorts, and most of it \differing from the fresh water fish of \Spain” (Saxon 1927:78). | Thomas Jefferson (1801:11) wrote the ‘following description of the river in about 11780: “The Missisippi, below the mouth Jof the Missouri, is always muddy and jabounding with sand bars, which fre- jquently change their places. However, it carries 15 feet water to the mouth of the Ohio, to which place it is from one and a jhalf to two miles wide, and thence to Kaskaskia from one mile to a mile and a quarter wide. Its current is so rapid, that it never can be stemmed by the force of the wind alone, acting on sails. Any ves- sel, however, navigated with oars, may jcome up at any time, and receive much jaid from the wind.” Reclus (1859:262) in his paper on the Mississippi mentioned the yellow water of \the Missouri River and the blue water of “the Mississippi at the confluence of the | two rivers. Priur to the construction of locks and jdams, two rapids were present in the }river between Dubuque and the meuth jof the Missouri River. The upper were | | FISHES OF THE Mississippr River 269 between Le Claire, lowa, and Rock Island, Illinois, and the lower at Keokuk, lowa. Glazier (1891:314) in describing his trip down the Mississippi in 1881 stated that “We found the current of the Mis- sissippi below the mouth of the Missouri much stronger than we had observed it to be since passing the Keokuk Rapids.” Floods and Levees Floods along the Mississippi have been reported since the river’s discovery. A member of the De Soto expedition in 1543 wrote the first description known of a Mississippi flood. The flood began about the tenth of March and reached its peak about +0 days later. “The inun- dated areas are said to have extended for twenty leagues on each side of the river” (Mississippi River Commission 1940:8). Jefferson (1801:11-2) wrote the fol- lowing regarding floods on the Missis- sippi: “These floods begin in April, and the river returns into its banks early in August. The inundation extends further on the western than eastern side, covering the lands in some places for 50 miles from its banks. Above the mouth of the Mis- souri, it becomes much such a river as the Ohio, like it clear, and gentle in its cur- rent, not quite so wide, the period of its floods nearly the same, but not rising to so great a height.” The delta with its fertile land early at- tracted many settlers. This alluvial valley extends up the river as far as Cape Girar- deau, Missouri. “In the Alluvial Valley the Mississippi River is an aggrading, or soil-building stream. In time of flood the river goes out of its banks, dropping its load of sediment as it goes. This action is due to the slowing up of the waters as they leave the river’s channel; and the larger share cf this material settles on or near the edges of the stream. For this reason the banks are generally from 10 to 15 feet above the lowlands away from the river. The slope away from the river is usually steepest for the first mile away from the river banks’ ( Mississippi River Commission 1940:9). For more than two centuries man has used levees in defense of his rich soil and cities against the flooding torrents of the Mississippi. By 1727, a levee along the 270 Table 1.—Stations where fish collections were taken during 1944 and 1946 on the Mississ River between Caruthersville, Missouri, and Dubuque, Iowa, with inclusive dates, pool numb number of net days at each station, and river stages in feet.* 4 Ivtinois NaturAL History Survey BULLETIN Vol. 25,088 STATION | Inci.ustve Dates 1944 Caruthersville, Mo........... April 6-12........ Tiptonville, Tenn... ..../.... April 15—May 10. Cairo, aus aceite May 18-24....... Cape Girardeau, Mo......... May 26-31....... Grand: Tower, Je oes bas June 29k as wees Chester, IIL. Basie tere (el Rb bal ond Plead Wye es Ste. Genevieve, Mig eae June 18-24....... Crystal City, Mo............ June 25-30....... Cliff Cave, Mo Pictiui aman July 2-8 Mouth Missouri R., Mo...... Jy lO Hse eee Graitony Wilke scaseee oe March 22-30. . Grafton, tli Ses ea las ee Grafton lisence Sept. 22-270 10. ade, Winfield, Mo... 0.2.2.0. e. July 27- Aug. pipet lambpureaull eres eets fae ee Auge SOF ee ieee Wowisiana, Ware Seti es Aug. 12-17......: Cincinnati Landing, Ill....... Aug. 19-23....... Hannibal WMio-e siemens ceed Aug. 25-30....... Quincy. also a tae sie and et Sept. 2-61 Sanne an Canton Mlosaes eta hee SEptyor lo saseere Wrarsawectlicee sae eeee ee Sept. 14-19)...... 1946 Burlington, lowa............ April 10-22....... Ogniawy ka, lll sere seve New Boston; [llc 22 2 8 May 7-18 Muscatine, Ilowa............ May 19-30....... Rainport; lowases me qeetuesn June 2S ae cae Andalusia; Uses tne Gaye | pA DEM lee eam Andalusia, Ill.. June 18-26....... Andalusia, Il. ee ae. Gl (SED ical Oo amet se Pleasant Valley, lowa.. June 28-July 9..... Cordova, sees Julyss 228 On Fulton, Ill... ..........,| July 24-Aug. 4 Sabulas Towa he ia eee ae. ANiES 6— lk] mee ents: Bellevue; lowass entree sen Aug. 19-30....... Dubuque, Iowa...) .....5.4% Septet Oem eee April 24—May 5.... Biss a Rayee Ke ELOW NumBer| STAGE TAG Dv- pee or Ner AT | AT BUQUE °- | Davs | Musca- Gi SraTion TINE DEA 689 — 42.54 SG 665 ETO) TS 573 = 54.10 14.2 529 = 61.94 16.7 499 = PSrLs 12.3 468 _ 38.99 NES) 454 = 46.14 LSS 429 are 62.19 WeS) 412 == 61.36 15.0 383 — 62.86 10.8 358 26 42.64 Ouse 358 26 74.30 9.4 358 26 93.31 aay) 337 | 25,26} 85 92 ii) 320 25 96.60 6.9 295 24 66.71 6.6 281 24 64.90 6.3. 267 22 82.97 Sth 256 22 105.20 6.2 236 21 100.82 5S 218 20 95599 6.0 178 19 143.72 10.2 159 18 135,80 Wo) 143 18 | 155.00| 6.4 134 17 160.00 8) 118 16 | 158.85 6.8 103 16 98.18 15.0 103 16 | 155.67 11.4 103 16 196.53 6.0 87 15 151.68 10.0 75 14} 150.17 x2) 57 14 | 152.39 5.6 44 13 160.31 5.3 17 12 | 188.40 5.0 0 12. | 192.83 6.1 * The ae river stage data from the United States Department of Commerce (1946) ; furnished by Ray K. Linsley, Jr., Flood stage is 32 feet at Cape Girardeau, Mo.; Mississippi at New Orleans had been com- pleted to a length of 5,400 feet (Missis- sippi River Commission 1940:10). In 1850 the Federal Government ap- proved an act which encouraged the re- claiming of the alluvial land along the Mississippi below the mouth of the Ohio River (Saxon 1927:261). In 1879 the Mississippi River Commission was created and placed in charge of flood control on the Mississippi (Saxon 1927:266). In that part of the Mississippi River covered by the present investigation, levees Acting Chief of Division, Climatological and Hydrologic Services, Washingto 15 feet at Muscatine, Iowa. the 1946 river s and drainage districts border much stream up as far as Muscatine, low the mouth of the Missouri Ri levees are more apparent than al upper river and they give the ob impression that the river is hemi by them. High-water conditions pre throughout the 1944 investigation MR-C section of the river, as shoy table 1. In several instances duri survey, test-netting was done over land formerly planted in corn or ~I september, 1951 FISHES OF THE Mississippi RIVER 2 Improvements for Navigation boats are being replaced by diesel-pow- ered towboats capable of pushing huge The exciting days of steamboating on barges loaded with coal, grain, oil, and sippi described by Mark Twain other commodities. During the period of und others are just about gone. Steam- World War II approximately 1,980 war Fig. 2.—Lock and Dam No. 25 just above the Winfield, Missouri, sampling station. ‘The swiftness of the current below the dam is quite perceptible. Photo by courtesy of the United States Army Corps of Engineers, Upper Mississippi Valley Division, St. Louis, Missouri. Fig. 3.—Lock and Dam No., 24 just below the Louisiana, Missouri, sampling station on the Mississippi River. Photo by courtesy of the United States Army Corps of Engineers, Upper Mississippi Valley Division, St. Louis, Missouri. 272 Ituinois Naturat History SuRvVEY BULLETIN Vol. 25, Art. 5 Basu RRR ie caren s, Fig. 4.—Lock and Dam No. 22 just below the Cincinnati Landing, Illinois, sampling station. Photo by courtesy of the United States oS Corps of Engineers, Rock Island District. Fig. 5.—Lock and Dam No. 11, and Pool No. 12, from Eagle Point Park, near Dubuque, Towa. Photo by courtesy of the United States Army Corps of Engineers, Rock Island District, vessels were passed through the lock at Alton, Illinois (War Department Corps of Engineers 1946:7). These vessels were constructed inland and outfitted for sea at New Orleans, Louisiana. The use of the river for navigation and the construction of levees for drainage districts and flood control have brought about many changes on the river. As early as 182+ an act was passed by Congress appropriating $75,000 for the improve- ment of the Mississippi by ‘“‘snagging” from the mouth of the Missouri River to New Orleans. The first permanent im- provement on the river came in the build- ing of a pier at St. Louis, Missouri, ‘to give direction of current. This construc tion was authorized by acts passed in 1836 and 1837. Later, the Keokuk and Rock Island rapids were improved for naviga- September, 1951 tion. An act in 1872 authorized improve- ment of the river between Alton and the mouth of the Meramec River by obtaining channel depths through revetments, solid dikes, and dams. A comprehensive project was approved in 1881 for continuous im- provement of the river between the mouth of the Ohio River and St. Louis to secure 4 minimum depth of 8 feet by using revet- ments, permeable dikes, and contraction of the low water channels to an approxi- mately uniform width of 2,500 feet. This project was modified by acts passed in 1895 and 1896 providing for the maintenance of a channel 250 feet wide and 9 feet deep by regulating works and dredging. The project was again modified in 1905, providing that the use of regulating works be supplanted by extensive dredging oper- ations. Later, dredging alone proved un- satisfactory; in 1910 regulating works were again approved, and channel depths of 6 feet from the mouth of the Missouri to St. Louis and 8 feet from St. Louis to the mouth of the Ohio were authorized. In 1927 and 1930, acts of Congress au- thorized a channel depth of 9 feet between St. Louis and the mouth of the Ohio, with a channel width of 300 feet, and a chan- nel depth of 9 feet from the mouth of the Illinois River to St. Louis, with a chan- nel width of 200 feet (War Depart- ment Corps of Engineers 1940:5-6). A project for the improvement of the Chain of Rocks Reach in the St. Louis area was approved in 1945. In this 7-mile reach, at low water the stream gradient averaged approximately 1.5 feet per mile in contrast to 0.5 foot above the Chain of Rocks and 0.6 foot from St. Louis to Cairo, Illinois (Smyser 1947:5). General improvement of the upper Mis- sissippi for navigation between the mouth of the Missouri and St. Paul, Minnesota, was authorized by Congress in 1878. This was to be accomplished by the use of wing dams and closure of chutes to secure a depth of 4.5 feet, eventually to be in- creased to 6 feet. In the period 1888 to 1906 “the rock cut through Rock Island Rapids was improved to a width of 400 feet and a depth of 6 feet.” In 1965 an act was passed to replace the locks and lateral canal at Keokuk with a power dam and navigation locks (War Department Corps of Engineers 1940:6). FIsHES OF THE Mississipp! RIVER 273 This project was practically completed in 1913 (Coker 1914:5). An act passed in 1907 provided for a 6-foot channel from Minneapolis, Minnesota, to the mouth of the Missouri River to be accom- plished by contraction works, as in the project of 1878, supplemented by dredg- ing and a lateral canal with a navigation lock around the upper portion of the Rock Island rapids at Le Claire (War Depart- ment Corps of Engineers 1940 :6). The Board of Engineers for Rivers and Harbors concluded after an investigation that canalization of the Mississippi from the mouth of the Illinois to Minneapolis was the most feasible and economical method of obtaining a dependable 9-foot channel for navigation; plans included the construction of approximately 2+ locks and dams (United States 72d Congress, Ist Session, 1932:2, 27). An act of 1930, as modified in 1935, authorized improvement of the Mississippi River from Minneapolis to the mouth of the Missouri River by means of locks and dams supplemented with dredging to provide a channel 9 feet in depth (War Department Corps of Engi- neers 1940:6). The upper Mississippi from Alton north was canalized by the time the present investigation was started in 1944, figs. 2, 3, +, and 5. In the Alton- Dubuque section there were 1+ locks and dams (Nos. 12-26, excluding 23). Influence of the Missouri In the above discussion the descriptions of several early writers were quoted re- garding the confluence of the Missouri and Mississippi rivers and the influence of the Missouri on the Mississippi. Prior to agricultural development of the prairies, the upper Mississippi was apparently a relatively clear river, and below the mouth of the Missouri it was always muddy. The D-MR section of the Mississippi was found by the survey party in 1944 and 1946 to be quite muddy; however, it ap- peared less muddy than the MR-C section. In 1944 Platner (1946:16) found that the turbidity of the Mississippi just above the mouth of the Missouri averaged 300 ppm, whereas, below the mouth of the Missouri it increased to an average read- ing of 1,880 ppm. At Caruthersville, 306 miles below the mouth of the Missouri 274 this high turbidity had diminished only slightly. The turbidity of the Mississippi, according to Platner (1946:12), is caused largely by erosion silt with some detritus. In 1921 Galtsoff (1924:371) found the water in the upper Mississippi muddy even at low water stages and progressively more turbid as he moved downstream. The current of the Mi€ississippi is swifter below the mouth of the Missouri than above. This difference in current was apparent before canalization, as evi- denced by Glazier (1891 :314). According to the War’ Department Corps of Engineers (1940:3) the veloci- ties in the current of the Mississippi between the mouth of the Wisconsin River and Alton may vary from about 2 miles per hour at usual pool stages to about + miles per hour at high water. In the uncanalized or open-river section below Alton, the velccities range from 2.0 to 5.5 miles per hour, except through the Chain of Rocks near St. Louis. In this region velocities as high as 8 miles per hour may occur at both extreme high- and extreme low-water stages. In the pools formed by the locks and dams in the Alton- Dubuque section, the swiftest current appears in the upper parts of the pools. The bottom of the river proper in the MR-C section is largely sand with occa- sional silt or mud. The flooded areas in which netting operations were’ conducted had chiefly mud bottom. The bottom of the canalized D-MR section of the Mis- sissippi varies with location in the pools. In the upper parts of the pools where the current is swift, the bottoms are sand and gravel, whereas, in the middle and lower reaches of the pools, the bottoms are largely silt. The silting in the canal- ized section of the river is a result of re- duction in current caused by the dams. Ellis (1931:4-5) made oxygen determi- nations of the Mississippi River in the Keokuk area prior to the canalization of the river above the dam at Keokuk (Lock and Dam No. 19). He found that the water before reaching the Lake Keokuk basin was carrying over 20 per cent more oxygen than after it was impounded in the basin. Some 30 miles below Dam No. 19, at La Grange, Missouri, the oxygen content of the water was 10 to 15 per cent less than above the impoundment. Ittrnors Naturat History Survey BULLETIN Vol. 25, Ar Platner (194+6:26) found that the ri has a distinct seasonal oxygen pulse. midwinter, when the river was fro; over with + to 8 inches of ice, the d solved oxygen ranged from 12.40 pp to 14.95 ppm. During times of low w. in August and September, it ranged fr 3.00 to 7.10 ppm. In periods of h water it ranged from 4.30 to 11.50 pp The flooded bottomlands in the can ized D-MR section of the river are le encroached upon by drainage districts, a they seem to provide more suitable ba water and sloughs for spawning, than th bottomlands in the extensive levee a drainage districts of the MR-C secti On the silt bottom of Lake K (Pool No. 19), Ellis (1931:8-9) f a. few fresh-water mussels near s otherwise, on this bottom he found lit besides sludge worms, bloodworms, Co thra (Chaoborus), a few snails of th monate group, tiny bivalves of the Musculium, and several species of le In the area free of silt, such as on_ci stones, and water-logged portions of tr he found large numbers of caddisfly a Neuroptera larvae, flatworms, beetle | vae, and occasionally a few specimens crayfish, gomphids (dragonfly nym and leeches. Pollution Erosion silt is a constant form of P lution in the Caruthersville-Dubuque s tion of the Mississippi River. Althou this form of pollution has long been ciated with that part of the Mississippi below the mouth of the Missouri, it was not generally noted in the upper p the river until after the developme intensive farming in the Middle Wi That silting tends to limit the duction of aquatic life has been d strated previously. Silting was pointe out as having a detrimental effect on trout and salmon eggs (Smith 1940:229) an on aquatic insects and other invertebra (Ellis 1931, 1936). In the Des Moin River, high water combined with 1 river’s increased silt load in a period flood was shown to be an important lin ing factor in the spawning success Of minnows and other kinds of fishes (St rett 1951:23). eptember, 1951 | The impounding of the upper Missis- tippi with a series of dams created favor- ble conditions for silting in that section the river. This impounding was done yely during the thirties, and the pres- investigation was made perhaps too n following this period to demonstrate possible maximum effects that siltation Platner (1946:71-2) found pollution on the Mississippi limited largely to local areas below cities and industrialized sec- s. “Even though the volume of water large enough and the dilution is great ough to render these pollutants harm- ess to the present fish fauna of the Mis- issippi River, one must remember that sach small amount of material narrows the safety margin of the river.’’ Platner con- uded from his chemical studies that the iver was not in a critical condition. He rther concluded that in the upper sec- ion of the river, that is, north of the +20- ile mark above the mouth of the Ohio River (about + miles above Oquawka, Illinois), a more ‘favorable position” ex- sted than in the lower section below mile $20. “Comparing the water quality of the Mississippi River with waters producing zood fish fauna, it would be rated as Ellis (1943) conducted a pollution study on the Mississippi River between Chain of Rocks (St. Louis area) and Cairo. He made this study in relation to zarbage introduced into the river at St. Louis. In September of 1931 and 1934, Juring periods of low water, he found that he Mississippi lost a considerable portion of its dissolved oxygen load in the imme- liate vieinity of St. Louis. Below the city t made a temporary recovery, and be- ‘ween Crystal City, Missouri, and Cape Girardeau it again lost a large amount of ts oxygen load. Between Crystal City ind Claryville, Missouri, Ellis (1943:8) ecorded a maximum of 3.86 ppm of total immonia. He stated that “This total am- nonia of approximately + p.p.m. represents i considerable nitrogenous load and shows lefinitely that the nitrogenous wastes from he St. Louis area are projected down- tream 65 or 70 miles before the maximum immonia production is reached.” Below he mouth of the Ohio River, at Wickliffe, 5 609 oa aa 67 raat O8S aa (hs ee 6 DE Ricont | eee! Cie Saeki ay Tae ‘Vy SAa]UA JuLsLa|q & L90°T om L91 See 69 96% Sh $7 Lo el CBee | eatime hat bate (3dag) “IT eIsnEpuy é 096 = 101 9S = S08 = tl 06 og 19s Se tab eet (eunf) “[T] “eisnjepuy bs IL¥ a = OF oa Sct oa S 87 9 S]: Xin pall Stes te ge emer (tudy) “TI 5 6 mA $8 69 = ise 2 ag 6s i rr vy Quodag 6 896 at eel C9T a els x Icl 9% 9 OCR ene ane Nae ane car ae vy “ouLvosnyA] 3 Lie c Os I = Peo I ae cs $s ee 5210) A | ie gil ine gn Ha ie II] “Woasog MON ee a eee ae = ozs ae bar she ee P en I eyaenbo 690'T = aa ‘ey ‘uO }Buyng — SNaW errr sawing | “atl | Sony soo | Soon | asim | Sood sores , vers | ree [aout [ows] aR | ak | are | Seen Vol. 25, A ILtinoris NaruraLt History SurvEY BULLETIN 30) ? =< 5116 Le 969 Tl 859 PL 76E ‘1 81 9LL L8°£S8 $0 S$9°T £6 L8h 1 6b bLb 69 806 OL tcr I t9 8601 S8 6FS OT CC6 es 6L est le £9 OFT $0801 OL SOT FL 681 Ct LP 99° $58 ct 18 8€ P61 $8 O61 78 LPS 81 9IT (06° TOL OL th 88 6FS #6 SLS $9 908 $s" 90S IT 087 £8 P19 8L CES CT 886 $8 6FS L9°069 SLIN doo ONIM TV.LO T, $9987 'T 18 61€ 1 GNV SLANY \o"1st |z6-911 oe-9 96: 9¢F Vere ebeeeseereeeesees ss sayy nbngng $8:9c1 _ |zo°1S 67:01 $5°SSz eats ra ee tosses ey OnaaTpg 90°#91 26’ EF 08° IZ ol-oze Sor epee eee tees caceeseess ogy Syngeg 166r¢ _|zh601 |08'8s Is99, [oo Shira an Meas Rr Sos Ty aoa z9'691 leo IL 98°91 eecte [occ tresses essay uAOpso5 eC Iho 8600 CIT eee) SER OTRO le a sores sees sss sey Kaye A WUSEaTT OL cL Oe £8 8% 0C 622s iain | ea ipl Aen Ya (adag) “TIT “eisnjepuy 98 ILh jcc OPT 69 8E WAT (AY soeee esses Qunf) y[p ‘eisnjepuy €L 6 tc L8 90°C SOC Death na aki ae eee (udy) TT visnjepuy It ZEl CL Pcl =|81 0 PRE CS Shee Met Ga aie 2 tReet Pee ry ‘wy Qaodury J IF'99¢ = |9L'S9 6t T GOBCO poly irey wa Se age i “Vy “auVosnyy Ip 6ST Ts C9 LP OI SSR COMM ier wal dos ale aa Wha II “UoIsog MON 91 6e1 €8 Pcl 0S Tl 9€ PLC cng neo a es actos a TTT eyanunbo Lc 91t 16 S9l 10° CI bse SUNS» oll eo ene 2 A a ga vy ‘uoouINg SLION ‘SLANT SLANT SLIM d00H] ONIAA doo ONIM NOLS HSA] HSaTL HSaJ] HSA] HON]-%Z | HON]-&%{Z | HON]-T HON]-T “SUI[ANG] WOT SUOT}EIS JB JBATY IddIssisstfy 94} Ur suOIzBIado ‘aaisnjour ‘eaoy ‘anbnqng 0} ‘emoy ‘u0} JOU-3S9} OF6[ Ul Jeas Surysy yo sadA} snorsea yA JYsnBo YsY JO spunog—s a/qey. ptember, 1951 FisHes OF THE Mississipe1 River 281 Fig. 6—Commercial fishermen setting a trammel net around a school of carp on the Mis- sippi River. This type of net was used at several test-net stations. cal commercial fishermen often proved value in locating a good fishing ground id in selecting effective types of fishing ar. The best available fishing sites were lected, rather than particular types of bitat at each station. Hoop nets and wing nets usually were ted after one overnight set. The num- r of nets used varied with fishing con- tions and season. Trammel-net sets were made at several ations primarily for taking carp and iffalo, fig. 6. Trammel-net floats were made at sta- ms having smooth bottom and_ sufh- ent current to float the nets downstream. hese proved to be effective for catching urgeon. Basket traps, usually baited with cheese rapings, were not very satisfactory since Was necessary to take the traps from e water when moving upstream to a new ation. “The traps are considered by me fishermen to be effective for cat- h when left in the water over long tiods. Seines could be used only at stations wing sufficient beach to permit efficient nding. The difficulty of obtaining bait discour- aged the use of trotlines. Two rowboats powered with outboard motors were used in carrying out fishing operations from the dnax. When the survey party was traveling between sta- tions these boats were loaded with fish- ing gear and towed astern of the dnax. Effectiveness of Gear Each of the various types of gear em- ployed by commercial fishermen is designed for use in a particular type of habitat and for catching a selected kind of fish. The effectiveness and selectivity of gear are mentioned here merely to manifest some of the difficulties encountered in deter- mining the species composition of the fishes in the river, on the basis of catches taken with commercial gear. The efficiency of hoop nets and wing nets in catching fish decreases during the warm months of the year. The actual poundages and numbers of fish taken at the various stations in the Caruthersville- Dubuque investigation are therefore not indicative necessarily of the abundance of a species at a particular station. Perhaps Vol. 25, Art ILttinois NaturAL History SurvEY BULLETIN Nn N a} t Jayons padins dayons payvos-auy “axons UOUTUIOD Jayonsdivs ‘dvd s9ats ‘divs Jaayig Jayonsdivs ‘divs 134]1S divs Jaye Mpyoo ‘1ayonsdivo ‘diva 194]1g opeyNg yoeqi[inb ‘opeyng 19] ‘ojeyng jauuvys ‘ojeyng yovqduiny ‘ojeynq yovqyovor ‘oyeyYNG yYovqIiozey oyeyng anyq ‘ojeyng pyaysdaays ‘ojzyng punos “1aj901 “193001 “sajsnq “opeyN [e15u0T oyeyng yoduiny ‘ojvyng ysnoys ‘ojeynq ssoul[ng ‘ojxynq YoU [Ng ‘ojwyNG Pesy][ag “peoy -1t03 ‘ojeyNnq uMosq ‘o[VYNg Preypuno. ‘ojeyNg asouqnys ‘ojeyNg YNoWpsy Jayons paaspinos ‘aszoyyxov|q “ysyanyq “rayons 1Nossiyy ]92 JoyeMYsory peys Asoxsipy Sulsay sn]q “sulsay IaAls “peys uepfoy aAQuooyy Prys a31yM “Suliay psy30o 7, ysypnur ‘nowy ssaidAo ‘aypuras “ysysoq 4v5 s0,eS]e tddississtypy qe3 pqongd awd Aqyiq “ysyyiq “eydren Auoods x9 |[1quoodg uoadsInjs puvs “[eIYOIIMS “YOVqa;yoeEY - qpyimur z24y1S | senna -(anbsaugey) wnansiup pucossoxoyy ~sssesses-s +> (anbsauyey) sdounjaue DuaSUuLy srtssssssss(gpadgory) suuossauimos snuojsojy) rae te sssss2->*s-(anbsauyey) 9/7790 sapord.ivg Be ee a (enbsauyry) o1d.409 sapordvy Gears ep ene ak ***(amang aJ) szurid ds sapordivg eC aT epee! pe *(anbsouyey) snjogng snqousy wee wee pete tee on ‘(enbsauyvy) 4asiu Snqou ry ees (souuatouaye A) veut sngojoumossvsayy ea Oe “= *(anang aq) suvsuoza snpdajak) Seep ge Sep (anang aJ) szsuaiuojsog vypinsup ine ee ree nod (anang ay) wnuvipadaa vutososog oar “-+ >>> sonbsauyey s1.407yI0Sh1yI snqgojowod Se eae ap as anbsauyey saprosojy uoporydup pos toe, anor “**amang a] sns134ay UOpoL yy Sates Saute Noe eg ae es snavuury 20/02 viupy eRe eras apedgov'y wpnyods snapsosidaT er ee anbsauyey snuossojnjd snapsosidaT et Na rt et **(snavuury) suasso snazsosidaT Ae Spe vesess ss ss(uneqreaa) onysods uopojog “+ +++**(anbsouyey) suysuciojyd snysucy.aydvog cee Zi eee eee -ass0ypas J2A|IS_ Sara eth a ata +> -Jayons pajjodg bes ceeseese sss yoyons any AA, Pr qayons uyysipy Se ARN ea Joyonsdivo IaAry BESTS ae ote eL per uarS S “YEG ING “+99 === ory ynouTTEWS Raden stuhcaitcabaarat oyeyng 3oRI_ a reach pace ojeyng yynowsig rim ico Re eae se ““Tayons an[g ei aute ate tepen a eey alte arets [ee URILIOWIY miketai =| Wess alenwiupy xt «3% peys paezziny CeO pent) Cee cathe ica Gyno youfdryg Pa Gee ah one Rae Peas aAapjoy Psat eee ene Tae 3) ADUOOT] a eh eerie Rene SEAR Yai NS qe 9s0u}10YS I SpRRA shan ane Ta 4v5 asousuo’] Pes Nisnt tbe Gee tsa seers ysyaipPed eae RE uoasin}s asoujaAoysS SANVN 1V90'T aWNVYN OIILNAIOS aWVN NOWNO’) ddtd go00y uaaMjeq <9F6 PUB PHET ‘BMO] ‘onbnqnq pue ‘t4nossij ‘g]|rAssayynaer Su01}09]]09 A@AINS 19430 10 joU-3S03 JAATY Iddississtp] UI FuTJINI00 soysy yo seweU [BOO] puB ‘oYTZUaIOS ‘UOUIUIOD pazdax0y¥—9 91421 283 FIsHES OF THE Muississipp1 RIVER sptember, 1951 “(CLe61) 42]4e'7 8 Sqqn}y wos die AOUIOOJ JYyI UI saweu oyloadsqns WOW F(§PHl) AlM90g solaysiy UvowaWYy ay JO | “ON Unayng [eloadg wos ose ayqei ayn SoUBU SYTUaIs puke UuoUE “Wo? paidaxy *][!den[q UoUWOD ‘anbsauyeY snsiy204IvM Sn4iyIOsVIMU StuOdIT :ssLq A2L]q panods UsayOU ‘(ANbsauyeY) snyopnjoaund snyomnjound snsajdosnpy isseq Yorjq YyNouypeus wo -yuou ‘apadgoe] N2UuOj]Op Naiwmojop snsidostpy :49INeS UsJIISEA ‘(YINWS) IuspoUuYI asuapoUudI Worpsrjsozys + peayl[ng Yq wsayyou ‘(anbsauyey) svjam spp snaniup Speaqynq umoiq *(yoosq]op]) SNIVLOWM AVIA SNSOINGIUu sSninigup *peEayl[ng MO][PA usayiou ‘(ainang ay) SU]DJDU SIVJOU snaniaup SYsyIwo anjq ‘(seuuaioualEA) sujyooin{ snyvran{ SNAN]DIIT (Syaes pauuPYy wo -Yinos *(anbsauyey) snjojzaund sisjsnov) SHANIDJIT + AIULYS uapjods wlaysam ‘(anbsouyey) sagosnn SDINI}OSKII SNUOTIMAION S49YINS II ‘(apadgor’y) MUUOSAPUUUOI UUUOSIIUILOI SNULOISOID) sayonsdird wsayiou ‘(anbsouyey) ordavs ordsvr sapoidiv:) :aed asouduo] Usoyiou ‘anbsauyry snandkxo snasso snajysosidaT |e eS a 524 Sw wloePeler = ee = a4o|f&®2=}]r>=wr D2 a Ow oH to WwOs>oo <= 2 eee ss Ww se fe eet ee OO > o2i%=bov2¢ > wW x Oo wWaZo ot2@eq247,235~0F®54>24552 -= OFC, SFuFHD—-Z2EFZo0otfe0tT905UHVOGQI4uU9 SCCuwzH O48 S6>uLO®5Z2SEV5I4_ S824 40545 eFfadwu>*t*sts0aqzE592E2ee5F9COneiMgID q%aqqerreedwomeciagotzas at sow2gZz4u05y aud SOFOOOOHNOOMOKCOFTIOLTCG0oFemOZzSutdtaounaa Fig. 9—The relative weight and the relative abundance of each of several groups of fishes taken in test-net collections in the Caruthersville-Dubuque section of the Mississippi River. The curves are based on the per cents of total weight and of total number of all the fish collected at each station. Sampling was conducted at stations between Caruthersville and Warsaw in 1944 and between Burlington and Dubuque in 1946. Vol. 25, Art ETIN Natura History Survey BULL ILtuiNors } 300 75 16.3 a aithalreonie | |S) |. || 5 Of 56 OV ae] cae 2 ‘OW STVSINNVHL Aiaict | i] | | | | | | | | | | a z - aaAANrS Sie eee A Tp | ie 2 | itso” TT g ILWNNIO Sei tian titine onto = e Ache eile gia — (eee 25) OW YNTESIIOT ene fy fe fay “9 so ss ee a eae eee 3 “T'T] SOWIWD pes (fae | | | | | | be He ud Bue SOUS NS) Nes ele) r 3% OL AVIA-S] Thay | [aaa a =a g8 Re Pd TT 11 11 1a SS sale “ATTIAN ay 3 25 ‘TI-9 Thad y Menem eases Se) ae |e Digs =e FPol rare [ealea} een a) : : ee : LAUV ole = 3 a2 -SUdHL 2) Moe Ss oe oS vo > SSS ASSESS & has at fe Wee bea a peits iG ne ANtHO Teese 1 Nya Lares eae -=3 ug o& cB TMA Oreo AS DT TT = ob 62 ob ab 0 Ge ob 3 : ASAAS ZS — kh e ee =a fleece le ik SCA RG NSH SS ee] ONS ars q xo Sarre Pebeicschch tat dt SN SS SS SS) Sc eA — oo co TAM HN man BS = ANSON AAS Te ae eae - 3 0 4OVUaAY YO 1VLO], at “as “¥y ‘aadagaqg fn Os-6F “On “y] ‘anagi1ag aS Be “yy ‘vTaavS + oay-Fo Atal “IT] ‘NOLTOYY TE-1 A1nf “ViIy ‘vAoauosd es 6 Atof[-gz axof / ‘vy ‘ASTIVA i LNVSVI 1g Woosp HAs5 “I1] ‘VISQTVaNY 9¢-81 aNaf | “Vy ‘visnivany L-] 1niay j| 11] ‘visaivany E | gi-z anal | "W] “Luoduivy ia Of-61 AVI “YY “ANILVOSAT T 8rLayw i “11] || ‘xousog man |) $ AYN TRey { A ttl ‘YXMVI0O |) oF. [o) oO oO TOTAL LENGTH IN INCHES 3 ie} 2 4 6 FisHes OF THE Muississippr RIVER 307 5 years old. The size at which they attain maturity was found to vary considerably. A few mature female flathead catfish less than 15 inches total length were noted; however, the majority of mature females were 18 inches or more in length. The Increment 8 10 12 14 AGE IN YEARS Fig. 14.—Average growth rates of flathead catfish taken in the Missouri-Illinois and Iowa- Illinois sections of the Mississippi River as determined from test-net collections, 1944 and 1946. than 50 years ago that at Morgan City and Melville, Louisiana, the blue catfish and the flathead catfish constituted prob- ably 98 per cent of the entire catch. Later Gowanloch (1933:421) mentioned that blue catfish weighing 150 pounds were caught occasionally and quoted Evermann as having been informed of one specimen weighing 185 pounds and another 250 pounds. Reports by commercial fishermen of 75- and 90-pound blue catfish were not uncommon in the section of the river near Caruthersville. No catfish of these large sizes were taken in the test nets. Age determinations of the channel cat- fish and flathead catfish were made from specimens collected during the survey; they were based on the number of rings or annuli on the vertebrae. The number of annuli on the vertebrae of the blue catfish could not be discerned with any de- gree of accuracy. From the growth studies it appears that channel catfish and flathead catfish do not mature until they are + or channel catfish was found to mature at lengths between 12 and 15 inches. Too few blue catfish were examined to de- termine maturity size for this species. Growth of the channel catfish and flat- head catfish was faster in the Missouri- Illinois section of the river than in the lowa-Illinois section, fig. 14. The length-frequency distribution of the catfishes from the test-netting collections is given in table 14. A line of demarca- tion is drawn on table 14 to set off the approximate size at which maturity is at- tained among the catfishes. The 15-inch set-off for the blue catfish is purely arbi- trary. Three species of bullheads were taken from the river during the 2 years of test- netting. As shown in table 15, the black bullhead (4 meiurus melas) made up 5.6 per cent of the total number of all fishes taken in the MR-C section in 1944. In that part of the D-MR section sampled that same year the black bullhead dropped 308 to an insignificant 0.6 per cent and in that part sampled in 1946 to 0.5 per cent. Black bullheads were taken in numbers at only four of the stations in the MR-C sec- tion, Appendix B, table 1. The black bull- heads taken at these stations represented 82 per cent of the number of this species Table 14—Length-frequency distribution of Mississippi River between Caruthersville, Missouri, and Dubuque, Iowa, in 1944 and 1946. horizontal broken rule marks the approximate dividing line between immature and mature the line for the blue catfish is based on little evid Intinois NATURAL Hisrory SuRVEY BULLETIN Vol. 25, the black bullheads taken in the entire vey. At the six stations immediate low the canalized section of the river tions south of Grafton) only five bla bullheads were caught, numerically 1.6 cent of the 1944 catch of black bullhead the catfishes in test-net collections from th ence and is therefore questionable. CHANNEL CATFISH FLATHEAD CatFIsH Biue Carrisu Tora. Lencru a in INCHES MR-C |} D-MR | D-MR | MR-C | D-MR | D-MR | MR-C | D-MR Section | Section | Section | Section | Section | Section | Section | Se 1944 1944 1946* 1944 1944 1946* 1944 DI Te Tag AE ee ae a — 1 6 — 7 — — ER Fe Oa 7 Brera Rel: Teta — — 3 — — 1 — BeBe Sa eo ome ees — 1 2 — = 2 = SURE dined Aoki ot cary — 4 99 — — 2 i OE AEN felt Rec ion eas 4 14 221 — 3 12 15 TES ON vik Vaaesttse 24 14 228 5 6 3 22 BoB De] ee tech acusiess 34 20 210 5 2 11 30 ONS=LO Maman se 15 29 111 7 @ 11 40 LOAS=U 7 waar cece 11 42 69 9 8 17 41 1) AE Je7 coe Bee ieee 5 60 34 13 13 20 23 bP Aes USN fis rae team 4 32 Di, 18 19 20 13) jG SRES SS bs ae RS cong Be 8 23 32 22 15 17 9 14 B15 lien eo ee ney: 11 26 33 35 29 22 13 PASI bile ee ate eee 4 15 18 42 28 22 4 WOR SU eaten hotest 11 14 10 46 28 26 6 DBL ON hie etre ae oe 3} 7 12 42 24 18° 1 HERS Ko Ee one ea 6 8 2 34 lg 5 3 LOE REDO He recat! was 1 4 a 17 12 11 2 PAV EL EONS Te emceie aaa s 1 2 1 17 5 12 — TAG FP JG [ie ee eden 2 i 2) 12 6 3 — PPD ORS Mean Sent an tae et 1 1 2 11 2 7 1 PB a yg (Bees See una 3 _ 3 8 1 3 — DA BA 25. Fee le en ners — _ 1 7 4 11 —_— DESIGN INR tae oe eee — 1 — 5 7 7 — PAS PM ie Dae 2 cs a — _ 5 1 4 — DH ABR Rii]enterden see ke ee -- a 1 2 1 5 — DSP 8200 cent Recents _ — — 2 1 1 — OLAS Une es Soneie Sere _ 1 1 3 _ 1 — BQ; 8-S1C Fa: res, et aoe -- — 1 1 1 1 — PACs PART AE ae rae — — — _ 1 5 1 SEG HSS site aout — _ — 1 2: — BSES=S4 ya roy eran ee — — — — — 1 — A TEE Lan dies A eae aetna _ — — 1 1 2 — B58 36M) aise ee ees — — D — 2 — Sb ee- Sie ie eee — — — 1 1 5 — S838 “lieder ane — — — — — 1 — GER S=SO/ le sete hs es — — _— — D) — SOS AD chines tet neces — — — — —_ — FAO): Yeap on ey —_— — — 1 = —= Total number...........| 148 320 1,136 372 245 295 231 Average length......... 12.3 12.8 9.6 14.9 17.0 17.5 11.3 Per cent mature length. .......... 29.1 25.0 8.3 45.7 35.5 36.9 13.4 * The 1946 D-MR data include 24 channel catfish and 2 Kurrle, a commercial fisherman. flathead catfish caught near Burlington, Towa, by.J._ 0 — stember, 1951 Fisues oF THE Mississippi River 309 Table 15.—Species composition of Mississippi River fishes taken above and below the mouth he Missouri River between Caruthersville, Missouri, and Dubuque, Iowa, 1944 and 1946. Movr Missou 5 | a ov eS coe RI | Warsaw to Mouts | os Dust Qt iE ro Li "iy Basti or MiEsOURTRIVER. | URLINGTON (ABOVE ARUTHERSVILLE, 1944 *ky | Mourn or Missourt 1944 | River), 1946 Meee. ie she ee ae 2 Species $s é ea oe S| |S Ss re hess SoBe lew lege Isa |pae ol c= SERS ane ee rs Inte eee o fee poate loy [Scael se los [Soae| Sales Bn) soe | oo [ection Nase eto SOR hap cee) (tS TN EH 365.8) 9.28 | 8 £219 96-8 BE|ES |§ 55.8) sf | 5+ 5527) 24 Sbacs2i| FE CssCeze| FECES F [paral Ba \S“"|Saea| Za sae REED) 2a \ EAE z } | 4 — = ~ Commercial FisHes | aphirhynchus album..... = Oo} — 8 1 0.01) Ola h a sturgeon....-.-- — =| 0) - 8 3 | 0.03 29| 281) 2.24 Gddlefish..........------- 40| - 24) 0.51 SO SDs |e Sloe in 17 i . eA SSE 30, 4 0.21) 1 2 : al 79} 17| 0.14 mesucker. ..------+-°-:: - — 0, 1 5} 0.0 Bathibufalo........-- 70} 48) 1.02 92} 61) 0.69 100) 277 es lack buffalo... 0. ..-- 60} 30! 0.64 re) OS 86, 29) 0.23 mallmouth utalos yw s2 = 80 127| 2.69 100) 341 3.88 93 486) 3.88 sarpiodes Spp--..------- >>> 100} 334) 7.08 100| 605 | 6.88 100) 1,491} 11.90 eo. -sieeesennee — — — e _— fe 6, 0.05 ach.. eee — = = — 2} 0.02 = redhorsé..:....----> —_ Oo} — — 0o| — 7 1) 0.01 Northern redhorse..---.--- 10 7; 0.15 58) 1S) 10.05 93| 104) 0.83 Bets. 100) 1,311) 27.80 100|1,014 | 11.53 100) 1,347) 10.76 ee cattish ease ae hee ed He a0 ate an 3 a 100} 1,115) 8.90 MEGATISH. wc oc ees A 3 ( 0. _ 0 — Yellow bullhead........--- 20 4) 0.08 50| 24) 0.27 29 10| 0.08 mn bullhead.......----- 10 1; 0.02 17 5 | .0.06) — 0) — es bullhead........---- 70| 262| 5.56 50) 48] 0.55 79 65| 0.52 Flathead evens eestor a" < => 100 S2\) elnoo 92| 245 2.78 100 294; 2.35 Freshwater drum......---- 100 348 7.38 100| 768 8.73 100\ 1,088) 8.69 Meubfolal......-----+++-°- 3,257\ 69.08 3,638 | 41.35 6,618)\ 52.85 . Sport FIsHES a: ; Re ales s.ciererts te — a = — : 4 ae 2 36 35} 0.28 Gi pickerel.......-.---- oS = } 02 — (= Yellow pikeperch........-- — fe a aoe uy ie a 57 17| 0.14 MMMDCL, = 2.2. .--6 2-2-2 tees 21) 0. 6 0,52 vA 68) 0.54 black bass. ..-..---- 10 310.04). = 0 — 7 9 0.02 ie sepeett black bassaveh. =i. 50) 10} 0.21 $Y) sella Pee nese 64 18} 0.14 Green sunfish........-----> 20) 18} 0.38 —_— 0o| — 21 3} 0.02 os 2 Up ee eee 70 39| 0.83 67| 556 | 6.32) 86) 308) 2.46 oo eee ts ee 30 15} 0.32! B51 859) 1, (OUSD} 36. 10) 0.08 Ss agora 10 1) 0.02 —_— 0 — = 0 — White crappie.......------ 70| 119) 2.52) 100} 879 | 9.99) 100| 2,677) 21.38 Black crappie.......------ 70| 123) 2.61 100|1,392 | 15.82 100) 1,452) 11.60 Mwghite bass.....«---------- 50| 24) 0.51 G8), 195) ea? 93} 162) 1.29 Wellow bass........--.---- 20 2) 30.04 83 |0 4s 0,05 57| 258) 2.06 WP Subtotal.........°.--.--- 374) 7.93 3,249 | 36.93 5,010) 40.00 ‘ Prepatory FIsHes | ‘Longnose gar.....-.------- 90) 51| 1.08 100; 143 | 1.63) 93; 38) 0.30 Shortnose gar....-..------ 100} 602) 12.77 100} 809 | 9.20 100) 209) 1.67 “Alligator gar......-------- 40) 84) 1.78 8 1 0.01 — oj; — Miowiin........---------- 50 29} 0.62 67 81 0.92 93} 154) 1.23 MiSubiotal.....-.-.++--+++- 766| 16.25 1,034 | 11.75 401| 3.20 -- ForacE FisHes | y Bee | 70 43) 0.91) 92| 66} 0.75} 79| 174) 1.39 Meoldeyet.....-----------: = = —— —— _ — 64) 84, 0.67 ert eee gains 30 11] 0.23] 17 A \eaOr OS se 0 oe “og Misdgl ttre ek. electri e = 6 70 264| 5.60 100, 805 9.15} 86 237) 1.89 Golden shiner......------- = = 8 2 \OVO2 — ae oj — 141071 ee ee rn | 318| 6.74 877 | 9.97 495) 3.95 i | 4,715 100.00 8,798 \100.00 12,524\100 .00 | | | | " # Includes one specimen of an undetermined species of redhorse (Moxostoma). £ + The goldeye is included with the mooneye in the 1944 collections. 310 Ittinois NATURAL History SurvEY BULLETIN In July, 1944, at the Grafton station, 14 specimens of black bullheads were taken, Appendix B, table 1. As mentioned in Appendix A, some of the sampling done ~ at this station was in the lower part of the Illinois River and adjoining bottomland lakes, and the catch there may not have been typical of the fish population in the Mississippi. At the next station above Grafton on the Mississippi, five black bull- heads were taken, and at the next four sta- tions none was caught. In the aggregate only four specimens were taken at the remaining three uppermost stations used in 1944. The number of black bullheads was low throughout that part of the D-MR section investigated in 1946. The largest number caught at one station in 1946 was 16, at Andalusia in June. The data for the various stations are contained in Appendix B. The yellow bullhead (dmeiurus nata- lis) was taken at less than half of the sta- tions and was plentiful at none, Appendix B. More specimens were taken at the upper than at the lower stations ; however, considerably more than half of the yellow bullheads taken in the survey were caught at the Grafton station, and, as suggested aboye, the sampling there was not confined to the Mississippi. Only six brown bullheads (4 meiurus nebulosus) were taken in 1944 and none in 1946, Appendix B. Of these only one was taken in the lower river and the re- mainder were caught at the Grafton sta- tion. The scarcity of bullheads in the D-PMR section of the river is reflected by the Iowa commercial catch between 1944 and 1948, table 16. For a few years following canal- ization of the upper Mississippi the com- mercial catch of bullheads increased, and it did not show a severe decline until 1944— 45. The reason for the decline is not known. The test-net catch of bullheads in 1944 was low at the six sampling sta- tions below the canalized section of the river. According to E. B. Speaker of the Iowa Conservation Commission (let- ter, August 19, 1949) there again is ap- parently some increase in the bullhead population in the Iowa section of the Mississippi. Since so few bullheads were taken in 1946, the length-frequency data of only Vol. 25, Art. § y Table 16—Commercial catch of bullhea from the Iowa section of the Mississippi Rives 1938-1948.* YEAR Pounps Caucur 1938-39 74,246 1939-40 98,577 1940-41 189,129 1941-42 215,675 1942-43 203,040 1943-44 138,385 a 1944-45 52,158 Bs 1945-46 7,679 a 1946-47 15,618 i 1947-48 20,306 * Data furnished by E. B. Speaker, Superintendent Biology Section, Iowa Conservation Commission. Table 17.—Length-frequency distributi of bullheads in test-net collections from Mississippi River between Caruthersville, M souri, and Warsaw, Illinois, in 1944. The hori- zontal broken rule marks the approximate dividing line between immature and mature fish. ToraL Buiack YELLOW Brown — LencTH Buit- Buut- Buti- 1n INCHES HEAD HEAD HEAD — 5.8- 6.7 4 — ae 6.8- 7.7 9 1 = 7.8- 8.7 28 2 1 8.8- 9.7 52 2 — 9.8-10.7 98 13 2 10.8-11.7 68 6 _— 11,.8-12.7 35 3 1 12.8-13.7 11 1 1 13.8-14.7 3 — 1 14.8-15.7 1 — =_ 15.8-16.7 1 _ — Total number 310 28 6 Average length 10.4 10.5 11.4 5 the 1944 catch are included in table 1 In Illinois the present minimum leg length for bullheads is 9 inches. A determinations made from vertebrae of t Mississippi River bullheads taken in 19: tend to indicate that the majority of the black bullheads did not reach the maturity length of approximately 10 inches before the age of 3 years. The yellow bullheads, however, seem to have a more rap growth rate and attained this length within 2 years. In the 1944 test-net sam= ples, 70 per cent of the black bullhea were 10 inches or more in length. Of the 28 specimens of yellow bullheads taken, 82° September, 1951 per cent equaled or exceeded 10 inches in length. The catfish and bullhead fishery be- tween Caruthersville and Dubuque as demonstrated by the 2 years of test netting is largely a channel cat—flathead fishery. The only other important species of this group, the black bullhead and the blue catfish, are more numerous in the MR-C section than above. The great abundance of the channel catfish in the upper river perhaps compensates somewhat for the small numbers of bullheads in that section and the scarcity of the blue catfish in the river above Warsaw. Yellow bullheads and brown bullheads are too scarce in the river to be of any commercial importance. Freshwater Drum SCIAENIDAE In the Midwest commercial market the freshwater drum is usually called white perch. In the Mississippi River this fish is of great importance commercially and of some value as a sport fish. According to Forbes & Richardson (1920 :324), weights of 50 to 60 pounds were in their time not uncommon for this fish. In the opinion of these writers the freshwater drum “be- comes tough and strong with age, but is at its best when weighing from three-quar- ters of a pound to three pounds. .. . This fish is of a sluggish habit, living on the bottom of muddy waters, where it feeds especially on mollusks, the shells first being crushed by the powerful, paved, millstone- like, pharyngeal jaws. Often the stomach contains only the soft bodies and opercula of gastropod mollusks, the crushed shells evidently having been thrown out. Craw- fishes are also sometimes found in the food. Half-grown specimens feed largely On aquatic insects, especially the larvae of May-flies, mingling larger and larger proportions of mollusks with this food as they increase in size, until they come finally to depend almost wholly upon wa- ter-snails and the relatively thin-shelled clams.” Although the increased silt load and canalization have modified the Mississippi as an invertebrate habitat, the freshwater drum has evidently been able to withstand the changes and is still one of the most abundant fishes in the river. In the test- FISHES OF THE Mussissirpp1 RIVER 311 netting study the freshwater drum was found to be abundant at all the sampling stations between Caruthersville and Du- buque. In 1946 the freshwater drum ranked fourth in weight of catch among Missis- sippi River fish groups reported by com- mercial fishermen of Illinois, Iowa, and Missouri, table 7. It ranked second among species in the test-net survey, as the buf- falofish, carpsucker, catfish, and bullhead groups were each composed of more than one species. Its relative abundance in the three sections of the river indicated in ta- ble 15 did not vary appreciably. The average weight of the freshwater drum in the survey catches was 0.67 pound, Appendix B. As shown in table 18 the average length for individuals of this species varied somewhat in the three sec- tions indicated. Many more large indi- viduals, that is, fish 1+ inches or more in length, were taken in 1946 than in 1944. Table 18.—Length-frequency distribution of the freshwater drum in test-net collections from the Mississippi River between Caruthers- ville, Missouri, and Dubuque, Iowa, in 1944 and 1946. The horizontal broken rule marks the approximate dividing line between imma- ture and mature fish. Tora. | MR-C | D-MR | D-MR LENGTH Section | SECTION SECTION IN INCHES 1944 1944 1946* 3.8- 4.7 — 12 25 4.8-5.7 | 4 36 eel 5.8= 6.7 DBP Ca Ade PHS 6:8— 7.7 4] 34 117 | 80 7.8-8.7 | 24 99 lay 122 8.8- 9.7 36 82 | 129 9.8-10.7 43 80 70 10.8-11.7 39 69 70 11.8-12.7 58 99 77 12.8-13.7 | 51 81 92 Coe EE A LEER ae RSIS Le ees] ee 13.8-14.7 | 11 40 hes 14.8-15.7 | 10 | LO see 15.8-16.7 “= a 54 16.8-17.7 | 4 20 7aS= UR ina 1 = 7 18.8-19.7 | — 7 21.8-22.7 | — _ 1 Total number 339 lL WewE 1,145 Average length 10.5 9.9 10.6 Per cent ma- | } ture fish 6.5 75 26.2 * The 1946 D-MR data include 58 specimens caught near Burlington, Iowa, by J. O. Kurrle, a commercial fisherman. 312 Ittinois Narurat History Survey BULLETIN Studies made on the scales of the fresh- water drum from the Mississippi indicate that, on the average, the drum does not attain a length of 14 inches until it is 5 years of age in the LIllinois-Missouri sec- tion and 6 years of age in the Illinois-lowa section. The minimum legal length limit of 10 inches, which has been in effect for some time in the state of Illinois, appears to have allowed a favorable take without seriously depleting the population. The length at which the freshwater drum matures was found to be variable. A female 10.5 inches in length was found spent, and individuals of 15.0 and 15.5 inches were determined as immature or de- veloping. Probably length variation within a group is associated with the age of that group, since a wide length range for each age group was common. In 1946 the freshwater drum com- manded a price along the Mississippi about equal to that of the buffalofishes, approxi- mately 10 cents a pound, undressed weight. In that year, undressed carp brought about 5 cents a pound and undressed catfish ap- proximately 20 cents a pound. Table 19—Relative abundance of individuals of the several groupings of Mississippi R fishes associated with upper, middle, and lower reaches of navigation pools between Bur and Dubuque, Iowa, in 1946, expressed as per cents of total numbers and total weights of fi Vol. 25, SPORT FISHES The sport fishery of the Missi River between Caruthersville and buque is confined largely to the D-M section. There sport fishing is, fo most part, conducted in the pools im diately below the dams and in backw and bottomland lakes adjoining the ri Bluegills (Lepomis macrochirus) crappies were by far the most abu species of sport fishes in the test-net lections. Black basses, pike, sauger, yellow pikeperch (walleye) were t in only limited numbers. Experience demonstrated that the black basses’ not so susceptible to being caught in and seines as are most of the other This possibly explains the scarcity of b basses in many of the collections. Fig. 9 portrays the abundance of spe fishes in the collections from test-n tions in the Caruthersville-Dubuque tion of the river. In this figure it ma’ clearly seen that the sport fishes mad a smaller part of the total catch in MR-C section of the river than in CoMMERCIAL Sporr PREDATOR ForaGeE Per Per Per Per Location 1n Poot Per Per Per AND STATION oa Cent Cent Cent Cent Cent Rent o of of of of of © Total Total Total Total Total Total Total um- |Weight| NU lweight| Nu™ |weiehe| Num ber = ber 8 ber = ber Upper Part 35.91) 67.25) 57.56] 23.03) 3.14] 8.55) 3.39 (New Boston, IIl., Pleas- ant Valley, Ia., Fulton, Ill., Dubuque, Ia.) Middle Part , 67.57| 89.19) 28.45} 5.48) 2.95} 5.08} 1.02) 0.25) 6,537|7,935.97 (Burlington, Ia., , Oquawka, III., Musca- tine, Ja., Andalusia, Ill., Cordova, Ill., and Sabula, Ia.) Lower Part oA 60.22) 88.96] 34.28] 5.69) 4.72) 5.321 0.79} 0.03) 1,272)1,625.16 (Fairport, Ia., and Bellevue, Ia.) September, 1951 D-MR section. Because of the scarcity of adjoining backwaters and bottomland lakes, together with a high degree of tur- bidity in the channel, the MR-C section is visibly less satisfactory as a_ habitat for most of the sport fishes than the D-MR section. A much more favorable habitat for these fishes is provided by the D-MR section; however, the increased silt load of the river, silting above the dams, and the draining of adjoining bot- tomland lakes have contributed toward re- ducing the potentialities of this section of the river for sport fishes. Netting operations in the various parts of the pools formed by the dams in the D-MR section revealed that the game fishes were most abundant in the upper reaches. The catches of all fishes in the upper, middle, and lower reaches of the pools are summarized in tables 19 and 20. A relative increase in the catch of commercial fishes occurred in the middle and lower reaches as the intensity of fish- ing was increased there, although the total FIsHES OF THE Mississippi RIvER 313 catch (all species combined) per net-day actually dropped. The relative increase in the catch of commercial fishes as reflected by table 19 is due partly to the scarcity of sport fishes in catches from the middle and lower reaches. The upper reaches of the pools provide a more favorable habi- tat for sport fishes than the middle and lower reaches in that the bottoms in the upper reaches are comparatively free of silt. Here probably more food is available in the form of aquatic insects and minnows than over the silt-covered bottoms in the middle and lower reaches of the pools. Deep holes and shallow sand bars are rather numerous in the upper reaches of the pools, and this type of habitat is usual- ly considered favorable for sport fishes. Early in this century, and before, sport fishes were taken commercially from the Mississippi. During the year 1899, Town- send (1902:681) reports, 18,744 pounds of “black bass” were caught commercially by Illinois fishermen from the Mississippi and 102,579 pounds from the Illinois Table 20—The 1946 hoop-net and wing-net catches expressed in average numbers and weight of fish per net-day in relation to location in navigation pools of the Mississippi River between Burlington and Dubuque, Iowa. 1-Inch Mesun | 2!4-IncH MEsH 1-IncHh Mesu 214-Incu MEsu Wine Net Wine Ner Hoop Ner Hoop Ner | | | oo iN Poot Averaze | Average | Average | Average | Average | Average | Average | Average Soa TAEION Number! Weight |Number| Weight Number, Weight |Number) Weight of Fish | of Fish | of Fish | of Fish | of Fish | of Fish | of Fish | of Fish per Net-|per Net-|per Net-|per Net-|per Net-jper Net-|per Aeros Net- Day Day Day Day Day Day | Day | Day Upper | New Boston........... 17.66 | 10.09 1.68 5.07 4.12 13 0.98 3.01 Pleasant Valley........ 7.71 Tals ibe 4.22 1.14 0.84 1.04 4.38 Ve Cae 24.91 12259 | 911-33 3155 6.05 73 2.30 6.60 NEIENT ESO ord. ive + « 10.16 | 5.97 0.91 3.68 2.22 | 0.70 0.59 2.42 Average for upper part...\ 15 11 8.95 ti ePeEISE | Wt S.cd0! 2.60 | 1.23 4.10 } Middle Burlington............. 13.92 BeSohe en 5.29 4.21 10 | 1.13 2.64 BemaWKa.. si. ccs ee 7.58 5.05 1 4 58 0.73 1.89 eee 2.92 BEREAN. eee 6.56 3.09 0. 2.05 0.75 0.28 2.16 4.75 i 11.01 | 5.04 0 139 ele 2.39 0.47 2.91 Andalusia (April).......| 6.99 | 4.43 | 1.44 | 4.50 1.18 0.40 0.15 0.30 Andalusia (June)....... 9.02 9.16 DS ey 533 6.87 | 4.45 8.53 Andalusia ieee 6.32 S14) 0. le 2eG5an | ek. 70 2.128) OSIEL |S LESS Cordova. . TeASe |5,40 0: 29451) 4.499) (2G O87 | 2B,e Average for middle part. 8.61 | 5.20 1 S79 2.52 2.35 | 1.33 3.34 Lower MEMETOE ees. 6 635-2 << less 5.54 Ey 3.89 0.11 0.02 0.55 52, Bellevue. . 6.76 S77 0.43 1.47 0.80 1.18 0.47 2.49 Average for lower part...| 6.13 4.66 1.07 2.68 0.46 0.60 0.51 2.51 314 River; 33,641 pounds of “sunfish” were taken from the Mississippi and 507,680 pounds from the Illinois. These statis- tics indicate that the section of the Mis- sissippi bordering Illinois was not then a great producer of sport fishes, at least when compared with the Illinois River. Pike and Pickerel EsocIDAE Pike are often referred to by Midwest fishermen as pickerel. In the Mississippi River a species of pickerel, as well as the pike (Esox Jucius), was taken in the test nets. The grass pickerel (EHsox vermicu- latus) seldom attains a length over 15 inches. This little pickerel was taken in the test-net collections only at the Graf- ton station and it is of no importance as either a commercial or sport fish. Pike, popularly known as northern pike, did not appear in the test-net collections below the station at New Boston, where a single specimen weighing 3.49 pounds was taken. The absence of pike in the col- lections below this station substantiates the statement of Coker (1930:214) that Keokuk, which is 69 miles below New Boston, “‘is evidently south of the common range of the true pike in the Mississippi River.” More than 91 per cent of the pike taken during the entire survey were caught at the four uppermost 1946 sam- pling stations. Commercial fishery statistics suggest that the pike has not been common in the Mis- souri section of the Mississippi River for at least a*half century. In 1894 pike repre- sented 0.01 per cent of the total Missouri commercial catch from the Mississippi, and no pike was reported for the year 1899, table 8. In the Illinois section of the Mis- sissippi, the pike was rather common in the commercial catch for 1894 and 1899. In the Iowa section, the catch of pike by commercial fishermen amounted to 25,- 042 pounds in 1899. Forbes & Richard- son (1920:209), writing nearly a_ half century ago, stated that the number of pike had greatly decreased in Illinois waters during the previous 25 years. The taking of pike is now restricted in the Caruthersville-Dubuque section of the river to sport fishing, and the species is too scarce in this section, other than in Iutinois Narurat History SurvEY BULLETIN Vol. 25, Aram the upper part, to be of much importance’ even as a sport fish. Perches PERCIDAE Three species of sport fishes belonging’ to the perch family have been reported to occur in the Mississippi River. The yel~+ low perch, Perca flavescens (Mitchill), according to Forbes & Richardson (1920:/ 227), is essentially a lake fish but occurs) also in running water, most abundantly in the larger rivers. Townsend te 684, 721) gave the 1899 commercial t of the yellow perch from the Mississippi ii) River by Illinois fishermen as 1,521 pounds and by Iowa fishermen as 9,665 pounds. He did not report a yield of perch for the! Missouri section of the river. Coker (1930:204) wrote several years later that the yellow perch was apparently not com-! mon in the vicinity of Keokuk, but sug- gested that it might become more abun- eerie in the impoundment at Keokuk since it is ‘“essentially a lake fish.” He reported that the expected increase had not occurmede up to 1926. In the Caruthersville-Dubuque survey: not a single specimen of yellow perch was: taken. This fish is usually not considered: “net shy’ and it appears that if the spe- cies occurred in numbers in the parts of the! river investigated at least a few specimens! would have been netted. Although the yel- low perch formerly occurred abundantly) enough in the Iowa section of the Mis- sissippi to be of some value commercially, | the draining of bottomland lakes and: backwaters in the valley may have had the effect of reducing the population. These’ former lakes probably abounded in aquatic vegetation and, according to Greene’ (1935: 162), one of the most potent eco- logical factors in the distribution of the! yellow perch is aquatic vegetation, a usa necessity for successful spawning. Larg perch populations frequently are associa with extensive sandy shoals, and silting of: such areas may limit the numbers of perch.) The pikeperches are of some importance: to the sport fishery of the Mississippi River, | and large catches of these fishes are not un-/ common from the upper part of the D-MR section of the river. Experienced anglers’ usually make their catches in the fall. In | September, 1951 FISHES OF THE Mississippi RIVER 315 Table 21.—Length-frequency distribution of the sauger and the yellow pikeperch in test-net collections from the Mississippi River between Caruthersville, Missouri, and Dubuque, Iowa, in 1944 and 1946. SAUGER | YELLow PIKEPERCH Toran Lencru 1x IncHES ine — MR-C | D-MR | D-MR | D-MR | D-MR Section Section | Section Section Section 1944 1944 1946 1944 1946 SS _ = 4 sin oe SSS — — 1 y Me coi ie ose sieye See bees 2 2 1 9 = Ls Sha a ee 5 1 9 | 5 Sa eee 9 10 13 — 1 Ts 5 NSE ae 4 I 17 = 1 ee 1 13 11 1 ae, 0 eee — 14 4 — 1 + eee renee — = a = MIRE oe oe ofa Secs cae ees oe = == = = 1 Ta eee ee — — — = ah 0) er — — — =a = 7 eee a = <= poe me) DPI atacc esac ee ees _ — = 1 2 sh T/ a — = aul 2 LF, GSS Sa a — = == DS Sue eGR eee — — == = 1 OS ie 21 46 68 2 17 oo od: ao ee ee P3i1 14.8 13ES 18.8 14.3 those sections of the Mississippi surveyed, two species of pikeperches were taken, namely, sauger (Stizostedion canadense) and yellow pikeperch, known also as wall- eye (S. vitreum vitreum). The sauger was much more abundant in the Caruthersville- Dubuque section of the river than the yel- low pikeperch. In the Caruthersville-War- saw section 6/7 specimens of sauger were taken as compared with only 2 specimens of yellow pikeperch. The yellow pikeperch did not occur in any of the collections from the MR-C section. In the Burlington- Dubuque section the sauger continued to be more abundant than the yellow pike- perch. From this section of the river 68 saugers and 17 yellow pikeperches were taken. According to Coker (1930:204), the sauger was evidently much more com- mon than the yellow pikeperch at Keokuk 20 or more years ago. On the basis of the ‘distribution and abundance of the pike- perches it appears that the sauger is much more tolerant of turbid waters than the yellow pikeperch. Table 21 indicates that the sauger is usually smaller than the yellow pikeperch. The largest yellow pikeperch taken during the survey was 24.9 inches in length and weighed 6.25 pounds. Black Basses and Other Sunfishes CENTRARCHIDAE The black crappie (Pomoxis nigro- maculatus) and the white crappie (Po- moxis annularis) were the most abundant sunfishes taken in the survey. Crappies were taken at all but three of the stations; however, they were much more common in the D-MR section than in the section be- low, Appendix B. In the MR-C section crappies accounted for only 5.1 per cent of the total number of all fishes caught in test nets, whereas in the lower D-MR section, that part surveyed in 1944, crap- pies represented 25.8 per cent of the total test-net catch. In the Burlington-Du- buque section, surveyed in 1946, crappies accounted for 33.0 per cent of all fishes in the test-net collections. The abundance of the crappies relative to the other species of sport fishes is expressed graphically in fig. 15. It may be seen from this graph that at the majority of the stations crappies were more abundant in the collections than all the other sport fishes combined. At the stations where other sport fishes predominated, there were only small total catches of sport fishes. Usually at such stations the sauger and white bass domi- 316 I_ttinors NaTuRAL History SurveEY BULLETIN nated the sport fish catch. In the MR-C collections the black crappie appeared to be slightly more abundant than the white. In the 1944 D-MR collections, the black crappie was almost twice as abundant as the white; however, the dominant black crappie populations were confined to the station just above the mouth of the Mis- souri River, the next station upstream, which is Grafton, and Cincinnati Land- ing. At the last of these stations only 7 crappies were taken, a number too small to be of any significance. At Grafton the black crappie was extremely abundant as compared with the white. At Winfield, the next station upstream from Grafton, the crappie population was predominantly white. This dominance of white crappies continued at the remaining upper river sta- tions in 1944 and 1946 with the exception of Cincinnati Landing. 100 80 60 : ; BLACK 40 CRAPPI 20 PER CENT OF SPORT FISHES {0} Fig. 15.—The relative abundance, as determined by test-netting, of the white crappie, black Vol. 25, Art. Hansen (1951:224), in his study of the) biology of the white crappie, observed that crappie samples taken in hoop nets did ni necessarily indicate the relative abundan of the two species. At Lake Chautauqua near Havana, Illinois, he found that dominance of black crappies or white cra pies shifted in an erratic manner from we to week. In view of Hansen’s study, actual status of the species of crappie that is dominant in the test nets of a given se tion of river becomes uncertain. Howeve the constant dominance of the black cra pie in catches during the three sampling pe- riods at Grafton tends to substantiate the) belief that it is more abundant there th the white. The dominance of the whi crappie in most of the upper river colle tions between Winfield and Dubug (1944 and 1946) indicates that this sp cies is probably more abundant than the eta tetetss SS SO 7% %y* Pate eMete% seats atatetatst KS LLL G LAL G ALLO OY. crappie, and other sport fishes at the various field stations on the Mississippi River betwee Caruthersville and Dubuque, 1944 and 1946. The percentages are based on the total number o sport fishes taken at each station. No sport fishes were taken at Cape Girardeau nor at Cl Cave. The number taken at Ste. Genevieve, two, was considered too small to be significant ¥ September, 1951 & 1944 and 1946. FISHES OF THE Mississipp1 River 317 Table 22.—Length-frequency distribution of the black crappie and the white crappie in test- collections from the Mississippi River between Caruthersville, Missouri, and Dubuque, Iowa, Brack Crapple Wuire Crappie OTAL LENGTH IN INCHES ; 4 MR-C D-MR D-MR 5 D-MR D-MR | MR-C i) Section Section Section Section Section | Section ts 1944 1944 1946 1944 | 1944 1946* a eae 2 = — — 56 = = 32 MEME Soi =. eee eee — 3 257 1 7 463 0 SE 1 21 149 — 40 394 MIE 5 oho wie ns ses 41 121 | 142 21 148 212 = EE eee er 48 291 | mays 37 191 239 MEME er es). cos ek es ee 18 369 | 194 34 219 392 os 1 11 418 288 17 147 446 re 4 145 128 4 100 358 Le _ 21 16 3 24 152 | Ie Sa _ 2 3 2 3 33 ME e SON ce lee — | 1 1 — —_ + ES re | —_— — 1 a — — al sumber................| 12: 1,392 1,452 119 | 879 2,725 Average leneth.............. TS: 8.4 Gale rt 7.9 8.0 725 Per cent 8 inches or more.... 26.8 68.7 AS 05" ees One 56.1 50.8 * D-MR 1946 data include 51 white crappies from a catch with a 1%-inch hoop net by J. S. Barnett, a commercial fisherman at Oquawka, Illinois. black in the D-MR section. Coker (1930: 202) found the white crappie was ap- parently about three times as abundant as the black at Keokuk. - The length-frequency distributions of the black crappies and white crappies taken in the test nets are presented in table 22. Slightly more than 50 per cent of the white crappies taken were 8 inches or more in length; with the exception of individuals taken in the 1944 D-MR section, a smaller proportion of the black crappies were of these lengths. Age and growth studies made from the scales of these fishes showed that the white crappies grew faster than the blacks, which probably accounts for the greater percentages of large white crap- Pies. It is difficult to determine the abundance of the largemouth black bass (Micropterus salmoides) from net and seine collections. As anyone who has attempted the netting of this bass realizes, it is not easily taken in numbers even where a large population may be present. Therefore, very little can be said regarding the status of the largemouth in the river. In the poisoning censuses of fish populations made in back- Waters adjoining the Mississippi at ‘Oquawka and Savanna, the largemouth population was rather low. Since these censuses pertain to only two localities, they do not necessarily indicate the over- all status of the bass population. The largemouth black bass formed only an in- significant part of the test-net collections in the MR-C section in 1944 and of those in the D-MR section in 1946. In the D-MR section in 1944 the largemouth amounted to 1.4 per cent of the total num- ber of fishes caught. Of these, 76.4 per cent were taken at Grafton. As was stated previously, some of the nets were set in bottomland lakes and sloughs of the Graf- ton area, long known as excellent for bass fishing. Anglers usually fish for bass in backwater lakes and sloughs of the Mis- sissippi rather than in the river proper. As shown in table 23, the average length of largemouth black bass taken in the test-net collections was more than 10 inches. In each year of the survey, two spotted black bass (Micropterus punctulatus) were taken in the collections. This species of bass is too scarce in the Caruthersville- Dubuque section of the river to be of any importance to the sport fishery. The 1944 specimens were taken at Caruthersville and the 1946 at Fulton, Illinois. No specimen of the smallmouth black bass (Micropterus dolomieu) was taken 318 in the test-net collections; however, one small specimen was taken with a minnow seine at Claryville, Missouri. The ab- sence of this species from the test-net col- lections indicates that it is probably scarce in the area investigated, and that the large- mouth is the only representative of the black basses that occurs in large enough numbers to be of any importance to the sport fishery. The green sunfish (Lepomis cyanellus) appeared to be quite scarce in the Mis- sissippi. In 1944, 18 fish of this species were taken in the test-net collections at Table 23.—Length-frequency distribution of the largemouth black bass in test-net col- lections from the Mississippi River between Caruthersville, Missouri, and Dubuque, Iowa, in 1944 and 1946. Tora. MR-C D-MR D-MR LENGTH Section | Section | SEcTION in IncHES 1944 1944 1946 6.8- 7.7 1 1 — 7.8- 8.7 1 2 1 8.8- 9.7 1 3 1 9.8-10.7 1 15 1 10.8-11.7 2 22 4 11.8-12.7 3 40 3 12.8-13.7 — 17 3 13.8-14.7 1 7 3 14.8-15.7 — 8 _ 15.8-16.7 — 6 — 16.8-17.7 — — 2 17.8-18.7 — 2) — Total number 10 123 18 Average length 10.9 12.4 12.6 Table 24.— Length-frequency distribution of the bluegill in test-net collections from the Mississippi River between Caruthersville, Mis- souri, and Dubuque, Iowa, in 1944 and 1946. TorTaL MR-C D-MR D-MR LENGTH Section | Secrion | Section in INCHES 1944 1944 1946 2.8- 3.7 — — 6 3.8- 4.7 6 11 60 4.8- 5.7 5 87 59 5.8- 6.7 20 231 75 6.8- 7.7 vi 204 5 7.8- 8.7 _— 23 33 8.8- 9.7 — oo — 9.8-10.7 1 —— a 10.8-11.7 — — — Total number 39 556 308 Average length Vo, ett 6.5 6.1 Ittinois NATuRAL History SurvEY BULLETIN Vol. 25, Areas Tiptonville and Crystal City, both MR-@ stations. Only 3 were taken in test nets in the D-MR section in 1946. Green sunfish were taken in minnow seine collections at Louisiana, New Boston, Sabula, and Mus- catine. ; saw. ‘This species seldom attains a lent of over + inches (Eddy & Surber 194 237) and it consequently has little value as a sport fish. according to Forbes & Richardson (1920: 242), is southern in distribution, “occur- ring in lowland streams and bayous of the lower Mississippi Valley, and in the soutt Atlantic region from Florida to Virginia In the Mississippi survey one specimen this species was taken in a minnow sei haul at Caruthersville and another in test-net collection at Cairo. This specie like the orangespotted, does not attai sufficient size to make it of much value | a sport fish. i: The bluegill (Lepomis macroaia is) was taken at the majority of the survey stations. This species was cola i tions of veri were ae at Graft and Dubuque. ; ae average size of the bluegills cathe Such a size is occ conside P by mieten anglers as fair for blucedl ’ Table 25.—Length-frequency distribution of the warmouth in test-net collections from Torau MR-C D-MR D-MR LENGTH Section | Section | SEcTIon tn INCHES 1944 1944 1946 3.8-4.7 1 = == 4.8-5.7 2 4 3 5.8-6.7 6 23 _— 6.8-7.7 5 25 3 7.8-8.7 1 — 4 Total number LS: 52 10 Average length 6.5 6.7 TEX September, 1951 average, 6-inch fish were about 3 years of age, indicating rather slow growth. The warmouth (Chaenobryttus coro- narius), according to Coker (1930:204), Was never very abundant in the Keokuk area of the Mississippi. This species was not taken abundantly anywhere during the Caruthersville-Dubuque survey. As in the case of the other sport fishes, the warmouth was taken more abundantly in the D-MR collections than in the collections farther south. It was taken less abundantly in the Burlington-Dubuque section than in the lower part of the D-MR section, that part surveyed in 1944. Age and growth studies of specimens taken from the Illinois-Missouri section of the Mississippi in 1944 tended to show that growth of the warmouth, table 25, was a little slower than that of the bluegill. Bluegills 3 years of age averaged 6.64 inches, whereas warmouths of this age averaged 6.16 inches. The warmouth is probably not abundant enough in the Caruthersville-Dubuque section of the river to be considered of much importance to the sport fishery. Sea Basses SERRANIDAE The white bass (Lepibema chrysops) and the yellow bass (Morone interrupta) are the only members of this large family, principally composed of marine fishes, oc- curring in the Caruthersville-Dubuque section of the Mississippi River. The white bass, according to Greene (1935: 160), is more northern in range than the yellow bass. In this survey both species were taken at the lowermost station, Caruthersville, and only the white bass in the Dubuque collections; however, one specimen of yellow bass was taken at Belle- vue, 17 miles below Dubuque, indicating that the species probably occurs at the geographic extremes of this survey. The test-net collections indicate that the white bass is more widely distributed than the yellow bass in that part of the river sur- veyed. The white bass was taken in greater numbers than the yellow bass in the MR- C section of the river; however, neither species was common there. In the D-MR section both species were much more FisHES OF THE Mississippi River 319 abundant than in the MR-C section, Ap- pendix B. The white bass accounted for 2.19 per cent of the total number of all fishes in the 1944 D-MR collections, the yellow bass for 0.05 per cent. In the total catch at the stations fished in 1946, the yellow bass was one and one-half times as abundant as the white bass. This re- versal in abundance was due to the large catch of yellow bass at New Boston, where 84.1 per cent of the 1946 catch of this fish was taken. One wing net (l-inch mesh) in a backwater area at New Boston pro- duced 198 yellow bass, amounting to 91.2 per cent of the 217 yellow bass caught at this station. Sex determinations made of these fish revealed that 96.5 per cent were ripe males. From this catch it appears that the males possibly are attracted dur- ing the spawning season by a few ripe females in the net. A more nearly accurate picture of abundance and distribution of white bass and yellow bass in the D-MR section can be obtained when the New Boston figures are omitted from the 1946 data for both species. When this is done the white bass appears to be three times as abundant as the yellow bass. The abundance of these fishes in the upper river has been discussed by several investigators. In 1888 near Quincy, Garman (1890: 137) found the white bass more abundant than the yellow bass, and, many years later at Keokuk, Coker (1930:207) found the white bass more common than the yellow bass. The former status of these fishes in Ill'nois is discussed by Forbes & Richard- son (1920:320). In discussing conditions of about 50 years ago these authors wrote the following regarding the white bass in the Mississippi: ‘It was formerly much more common than now. We are informed by Mr. H. L. Ashlock that a dozen years ago one could easily get a hundred pounds of it in an afternoon at Alton with a hun- dred-yard trammel-net, but that it has now almost disappeared.” At the same time these authors (1920:321) found the yel- low bass about twice as abundant as the white bass in II]linois. The average sizes of the white bass and the yellow bass in the test-net collec- tions differed only slightly, table 26. The white bass, however, attains greater sizes than the yellow bass. Both of these fishes 320 Table 26—Length-frequency distribution of the white bass and the yellow bass in test- I~ttinois NaturaAL History SurVEY BULLETIN Vol. 25, Art. collections from the Mississippi River between Caruthersville, Missouri, and Dubuque, Iowa, in 1944 and 1946. Wuire Bass YELLow Bass Torat Lencru In INCHES ef MR-C D-MR D-MR MR-C D-MR D-MR » Section Section Section Section Section Section 1944 1944 1946 1944 1944 1946 = SRS Wee hteraapae eee _— — ily — — 1% ESE ay Bod Dang en Sie cam — 10 23) — ss 34 SAB UG Dette & eye ci pee ean 2 17 9 — = 299 (WPM ee elas. Serer rene 6 30 13 1 — 18 4 Te O= LO de Ree ene aT et 5 25 27 1 1 1313 S28E OHCs ts Ret eae Meera cen ce 5 18 19 = is) 68 OBST OEE see Uw ean See ives _— 41 sey — a Ch WONG SU 7 oes. res vaestcies cee ae oie 1 24 22 — — 5a 1 Wet ol Wa Ben Nee tn ME 2 2) 10 — aa 1 SOAS For UU BR Ue ine ES A Saree 1 i 3 — = 7 JI Feed Safest ae mek a a Dean te 2 9 — = = _— LSE SSNS 2 zhane core, Seda ee _— 2 2 — = _— TS LBV Ge two So eee _— 1 — = — est Total. numberiac os che eee 24 193 162 2 4 258 Average length.............. 22) 9.4 8.4 7.8 9.0 8.4 | are considered as excellent sport fishes, and they often form an important part of the angler’s catch. PREDATORY FISHES In the present report the gars and the bowfin are grouped as predatory fishes. These fishes feed to a large extent upon other fishes and they have little commer- cial value. Many of the species designated in this report as commercial or sport fishes are also predatory in habits. The catfishes, black basses, and pikeperches are examples. Gars LEPISOSTEIDAE The shortnose gar (Lepisosteus plato- stomus)* occurred much more frequently in the test-net collections than did the other species of gars. This gar was abun- dant in the MR-C and D-MR sections of the river. The longnose gar (Lepisosteus osseus) also was common in both sections of the river; however, it occurred much less frequently in the test-net collections than the shortnose gar. Eighty-five specimens of the alligator *In this investigation the spotted gar, Lepisosteus pro- ductus Cope, if present, was not separated from the shortnose gar. gar (Lepisosteus spatula) were taken dury ing the survey. Of these, 84 were from MR-C section. The single specimen from the D-MR section was taken at Grafton, As shown in Appendix B, table 1, in the MR-C section the alligator gar was nette at only four stations. Eighty of the 84 specimens were taken at Cairo. Forbes & Richardson (1920:35) state that: “The home of the alligator-gar is in the streams of the Gulf of Mexico, from Mexico to Cuba. It ascends the Mississippi above St. Louis, and has occasionally been taken in the lower Illinois River.” The length-frequency distribution J the gars taken in the test-net collecmaay is given in table 27. The largest gar taken during the sur- vey was an alligator gar measuring 5 feet: 5 inches total length and weighing 54.81, pounds. ‘This specimen was taken in a 1-inch-mesh wing net at the Grand Tower. station. The alligator gar, according to! Dr. David Starr Jordan, reaches a length: of 20 feet (Forbes & Richardson 1920: 35). The average length of the alligator gar in the MR-C collections was 23.5 inches, an average less than that determined’ for the longnose gar. The shortnose gar, as shown in table 27, averaged much less in length than the other gars. & In some areas gars are sought by anglers merely for sport. The larger specimens, a ptember, 1951 cularly of alligator gars, provide a enge to an angler using only mod- tely heavy tackle. Bowfin AMIIDAE bowfin in the Midwest is con- by some anglers as an excellent fish. This fish will, on occasion, a spinner-bucktail combination or 4 1946. FIsHES OF THE Mississippt River 321 a plug. The vicious runs of the bowfin after striking an artificial lure are some- thing to be remembered, even by the ex- perienced angler. The value of the bowfin as a food fish seems to be a debatable sub- ject; however, the smoked flesh of a bow- fin is considered a delicacy by some. Fewer bowfins were taken in the col- lections from the MR-C section than in those from the D-MR section of the river. Catches of +1 bowfins at Winfield and 62 ‘Table 27.—Length-frequency distribution of the gars and the bowfin in test-net collections m the Mississippi River between Caruthersville, Missouri, and Dubuque, Iowa, in 1944 SHortNOSE GAR Loncnose Gar eee Bowrin Tora, LENGTH fas Incues MR-C D-MR|D-MR MR-C D-MR|D-MR MR-C/D-MR|MR-C|D-MR|D-MR ; Sec. | Sec. | Sec. | Sec. | Sec. | Sec. | Sec. | Sec. | Sec. | Sec. | Sec. 1944 | 1944 | 1946 | 1944 1944 | 1946 | 1944 | 1944 | 1944 | 1944 | 1946 = a = ae 1 re = = —_ = = = 1 — == — = — — — ae = ihe Ss a a Ee Re eral ieee Boss) 5 LE ESD pela | a ee ba A (a 53 8 a — = = _ 2 1 1 Pts. 2. AWeaelees oe | vi [yest (als Sa ae 3 1 108 87 9 on — = = — 3 + 3 51 | 102 6 2 2 a AS, ia 5 38 | 123 Fi Teale 16 Vy see 2 8 6 32 | 119 | 30 22190 1 a Ash mel Dan aed) WR. i 18) 109%] 32 2 8 3 Sie Sic atey a|nas2 eta... 37 | 91 | 45 2 7 1 7/— 2 5 1.38 Mase tysi 1 0.40) 0.07 oOo} — _ OV — — oq — = Oo — — S9}) Lite 1.19 19 6.98 1.19 3) 10.56 1.40 8} 12.08 1.30 3 2255 1.29 60} 35.02 4.65 268) 147.39) 15.84 62| 59.76) 10.21 1 1.66} 0.22 2} 58.86) 6.32 1 2.38 0.41 1 1.05 0.14 23} 53.49 Barb) 2 Tad 1.22 65| 48.29 6.41 301) 271.82) 29.21 68! 76.86) 13.13 Oo} — = 4 1.26) 0.14 2} SOS76l* 2Osl3 Oo — _— Qo} — —_ oq — _ oO — — 17| 12.88 1.38 4 1.64; 0.28 — == oOo} — _— Oo} — — 0} — _ Pees) > 5.53, 0) — — 21\ 14.14 1.52 6 2.40| 0.41 763.03, 100.00 294) 733.17, 100.00 741\| 930.67,| 100.00 357| 585.30) 100.00 336 Ittinors NaturaL History Survey BULLETIN Appendix B, Table Ste. GENEvievE, Mo. June 18-24, 1944 SpECIES u ms ec £ | 2g | 8? Mp EGE ee 5 25C) Oe, Z, Sa aS CommerciAL FIsHES Scaphirhynchus album*.... 2.0611 e cece ees Oo) — — Shovelnose sturgeon. ...........-+sss+--- Oo} — — Paddlefish’. 2 2). eee skies teresa Oo} — — American: ecelis ot iccs ss woe ne oe Oo} — — Bluessueker! Sane aie oe oe ee eee ae Oo — Biemotith buttal Osere sis sete eee ines Oo} — — Black: buflalovisot ences akin eee 1 5.94 0.56 Smallmouthibuttalate. ce emnc as enietetetertters 14, 29.98 2.81 Garpsucker ence c wee tiers rte ee 89} 148.91) 13.97 Cot TEGHOLSE Scie fo od Savage ser eae oO} 2 — == Ea A ine ee Tne sah ye 5 203 320| 616.7 57.87 Chainel Cathishise cacoh eck Sere 27| 49.96 4.69 Blucicathish e...-ece Meet apna ces 8 3.72) 0.35 Yellow bullheadiav.t 025: ch ence eee Oo} — = Brown) bullhead)a)) 5c. uss sti sean oo — — Blackibullhieadssaeisa- cc cece ea cle ie ene Oo; — — Flatheadreathishsa..05-0. etecsaryemei ree 28) 106.11 9.96 Breshwaterrum.jcs 5 osu via eee eee 45| 39.00 3.66 Subtotal: a Shes eke ere alee 532|1,000.32| 93.87 Sporr FIsHes Grass|pickerel\.s (4) 0c: cals se miele ae tee Ol = — Wellow:pikeperch*;< i. (wsa:ereseeey eee Oo — os SEIT eal Cala oitayree Micicech eR ied Miomtdeisy Pchy et 2) 1.66 0.16 Spotted blacks bassies11> iene acer Oe i — leareemouthiblackibass-.cenieeme ene Oo — — Greenjsunfish’: e255 os ce a ote Sect ee ae Oo} — — Bluegill: Pesce. ine ogo ete erie ees GQ) = —_— Warmotthivics.-te tsi so eee Oo} — — AB lteisc pic sates Sees tk Sere SOR Ree Oo} — 7 Wihite\crappler setae <-n eet eee eee Oo} — — Blackverappies igen 2 eee on eee eee Oi = White bass Wccc es case com leer a epee Oo; — = Wellow:bassicscein ic snackescs oot aoe oe Oo} — — SUDLOLGI NN Nee ptos sarse eden s Stas 2 1.66 0.16 Prepatory FisHes Mongnose pati. nels Seer ee eee |e LQRGS ee ale Shorthosei parks sdasce= Olean Nene eee 49} 42.03 3.94 Alligatonivars. 0595. coccinea ee ee Oo — —_— Bowlin setae ign east nea ee eee oj — — SULLDIAL De. cody one SA RT Oe ane 56) 61.68 5.78 ForaGeE FIsHes Mooneyeiand goldeye.. .'..2 oa. mae 2 ten) 0.11 Skipjack< is eaters teehee ree oOo = Gizzard shad), sin {ae cor eee 2 0.84 0.08 Golden'shiners;... kine cue tc Poe Oo} -- SUbtOiaL On abies ER ee 4 2.06 0.19 Lolli. Dasa we 594)1,065.72, 100.00 * None taken in test nets but one procured from angler at time of survey. + Carpiodes spp. Vol. 25, Art Crystat Crry, Mo. June 25-30, 1944 ns x a 4 | £3 bie E ce So 3 V6 Siow Zz =a aS ola = qs oF 6] pee pe S 7.95 1 0 ns = 0 as ae oem ie 21 14.52 1 41] 43.44) 5 a 4.20 0 210) 494.07) 62 6) °11562| aed 14, 13.48) 1 CO} far ne Ol = c= 3 1.53 0 38} 106.81 13 34 26.79 3 377| 724.41| 91 0 ay =a — =. Oh Ss 33 0 “ae = 1 0.77 0.10 1 0.32 0.04 4 0.73 0.09 (0) — = 10) = = 10|. 2.57] Sates 28 9.13 1.1 3). 1.59) eae — a 47)\ 15 1 ee 6 20.79 ue 20; 17.07] ata Oo == oe 0 = * — 26| 37.86 4 20/ 8.93) aia 9 3.00 0.38 0 — —= 29| 17.93) esa 479| 789.31| 100.00 tember, 1951 FisHEs OF THE Mississipp1 RIVER 337 tinued. Betow Movurts or Asove Mour# oF Steers Missourt River Missourt RIVER comb tat teas > Jury 10-15, 1944 Jury 10-15, 1944 aes eo) eo | B | Be | # a fm] 5 : ae u-=— Uo +4 = vu “yy ob e:|o2| = | 32 |c2| = | S2/c2| = | SE | oz 5 b 5 5 ot Ss a & Gy Pt Ba jes | 2 |Fe lds | 2 | Fe las | 2 | Ee | as , (0) = qe = 1 OS T2207 08 Oo} — —_— Oo — = q.— = oqo — _— oOo — — Oo — = qj — — Oo} — _ 1 0.85 0.11 3} 6.50) 0.81 i = _— 3 7.40) 0.87 oj — — Oo} — — Oo} — i Oo} — = Oo — — 3) 10.42 fe29, Oo} — _ 7| 19.58 2.30 13) DOs" 2u57 20s 7). 2251 oO — — Oo — — Olh.SUS55]) © 4.23 25) 79.38) 9.82 oq — _ 6} 2.19) 0.26 21) 13.29) 1.78 a §2.57| 6.50 Gt 2053210 3270 17) 16.35 1.92) 20! 12.44 1.67 = — (}) — q.6U— — qj — — . 183) 470.87} 58.25 54| 133.79 48.00 309) 372.35| 43.83 $1} 88.08) 11.81 4, 5.44) 0.67 1 2.40) 0.86 23) 28.75 SIS) 22) 4.09) 0.55 19] 12.85 1.59 6) 0-52)" 0219 14} Se23i— O62 8 5.96) 0.80 Oo — — QqQ — _ oj — — 1 0.50) 0.07 Oo — —— Oo — _ oOo} — — 2} 0.69} 0.09 oj — _ (0) _ oj — —_ 25; 14.49 1.94 25| 88.91) 11.00 27| 101.75) 36.50 44, 81.92) 9.64 (0) es — 41} 30.82) 3.81 25}, 14.23 Sk 227} 81.33) 9.58 Tahoe 58 235) 343) 778.03; 96.25 119| 263.01; 94.36 651| 615.22} 72.42 246) 208 .62| 27.97 Oo — = oj — _ ojo — 2 1.05 0.14 oOo — _— oO — _— oo — —_— oo — _— oj — _— (es —_ 1 1.04) 0.12 Oo — a Oo — _ oj — _ Oo} — _ Oo} — os oo — _ oqo — — 11} 16.66 1.96 30) 47.20) 6.33 0 ee _ ojo — _ oq = _— oj — _ 0} — => 41 0.64) 0.23 31 8.72 1.03 288] 65.79) (8.82 Oo — — jo. —_ oj = —_— 36} 10.81 1.45 Oo — — Oo — — oo = — Oo — — oOo — _ 3 1.01 0.36 4 1.14 0.13 74, 35.23 4.72 oo — —_— 4 1.87 0.67 303} 116.27) 13.69 331) 146.17} 19.60 oOo — _— Qo — _— 1 0.56 0.07 3 1.69 0.23 qo — _ Oo) - — — oe = 1 0.38) 0.05 ao — _ 11 3.52) 1.26 351) 144.39) 17.00 765| 308.32) 41.34 4, 9.64 LOS, Oo — — a dese), LOE87 5} 12.23 1.64 21} 20.72) 2.56 3 2.16) 0:99 100} 71.45 8.41 76} 90.09} 12.08 oOo — —_— oo — —_ oo — oo — — oOo — _ ot eS s6r e539 2} 3.94 0.46 8} 28.18 3.78 Pie 3030 3.75 5| 12.22) 4.38 109| 82.73\ 9.74 89) 130.50) 17.30 oqo — — Oo} — — 6; 3.70) 0.44 7 1.86} 0.25 Oo — _ 0 (ioe _— oF — _ Oo — _ [es oj — — 5). (3421-0740 134} 95.81} 12.85 (0) ed — O-— — Cl _ 2) 0:67 0.09 0) — Oo — = UN, 7. 18\) (Oc84 143| 98.34) 13.19 368 808 39, 100 00) 135) 278.75, 100.00, 1,122, 849.46) 100.00, 1,243\ 745.78) 100.00 338 Ittinois NaturaAL History SurveEY BULLETIN Vol. 25, Art. 5 j SPECIES ComMERrCIAL FISHES Scaphirhynchus album*®........+.0.- 05+ Shovelnose sturgeon. ..........+++-.-00- Paddlefish:.Sx that hace B elee loan e eases American: eels:...., Kaneohe aonsbona see eee Blué suckers3 8 -e. ee ee Biemiouth bultalowsne ee ee ee ene ee Black buffalas icc’ Ac kiko cee Smallmouth buffalo....................-. Garpsuckerstin vss. Atco) eo. c eet orane Northern redhorse.........-----0++--+-+- (Carp ete tasietrea ce mec ian eer ecto Ghannelicatfishiette. we waacek es ae Blueicathishy ees ose excuse eee Yellow bullheadte.¢ ent cee eee eee ee Brown: bullhead! a0... ce ie ctenkscrsiea eee Black'bullhead® ses esheets aera Blatheadicattishih ic... ss eenranne siete eee Ereshwaterdrimesssasee- tc eerie Subtotal Mee ae Ning aoe ieee Sport FisHEs Grassypickereli ervey chicactn eter Wellowapikeperch=..sesoer ate pte oes Satigersiee tice aero eea solar toute tate ese Spotted |blackibassa-. secu seen hae Largemouth black bass.................-. Green:sunifish!. 0) Se oes oe cr ce ema Whit icrappievssuc. 2.0 ecreeren Black crappie: sSc0-c a eee ee eee White bass’; Peo yin cae ee eee oka Mellow: Hasse casei one tadnitont seem ea Prepatory FisHEs Longnose'gars, piesa. ee ose ere ee Shortnoselgar: 7c ancaee = oO} — — Oo} — ~ 0.57 1} 0.22) 0.04 oOo; — — Oo} — — = Ale oes Ae lnk Oo} — —_ Bi 4698) eds =T i = oo — — 1 2.80) 0.80 2.03 Dh yon 2 ohne O99 Speen 6s64e 199 Sie 10225) 2 20a 1.01 3} 10.74) 2.01 1} 2.26] 0.68 2) 3.34) 0.96 ey 24) 28.26) 5.29 23) 15.81} 4.73 30} 21.42) 6.15 0.93 36| 34.29] 6.42 22| 18.36) 5.49 8) 7.64 2.19 = Dee LeSSin «(OL 35 Oo} — — Si 16702) Seles iB pv 55) 98.56) 18.45 33] 75.25) 22.50 45| 104.04) 29.88 3.16 34) 33.89) 6.35 18} 20.81] 6.22 13 |e 9sS9 2670 1.87 3} 2.48] 0.46 9} 1.64) 0.49 8} 3.62) 1.04 0.02 2}. 2:06 <0539 Oo} — _ Oo} — — — Oe — 0) = 0} — — 0.43 0} — — Oo. — — Oo} — — G75 15} 40.17) 7.52 19} 36.39} 10.88 33] 106.49} 30.58 5.62 34| 28.37| 5.31 98| 61.67| 18.44 S2}-232. 72 Ona 42.61 212) 291.55) 54.59 226| 238.83) 71.42 203| 312.74| 89.81 Oo} — _ (3) — oO} — — Oo} .— _ Deas O17 Oo} — — oO} — _ Oo} — — 2) 12.64)" 0.19 Oo} — _— Sir 2338) ea) OL Ten Os 59 ede e 0 —*) — o— | — = _ 0} — _ 0} 10.23} 1.18 Olea S993} le OS Oo} — — Oo. — — Oo} — — 0) = i — = oO}. — —_ 28! 5.76) 0.66 42) 9.40) 1.76 Oo} — — o| — — oO} — _ Oo — —_— oO} — — oOo} — = 0) — — 0 = = 0) = = (Miele == 254) 62.21; 7.18 236} 61.79) 11.57 19 FAO) 2721 1} 0.45} 0.13 Oe 202 521) 22.37. 77| 25.84 4.84 11] 3.80) 1.14 G)? = 2-01 BOSS 23| 16.50) 1.90 26| 12.89) 2.41 oO} — —_ 3]. 6.91), 1.98 1, 0.34 0.04 _ = 0; — — Oo} — —_ 389) 118.63) 13.69 386| 115.45) 21.61 33) 14.58) 4.36 17| 15.96} 4.58 18} 50.47} 5.83 4) 8.91 1.67 9| 28.65) 8.57 2) 3.34) 0.96 136, 121.50) 14.02 71} 60.04) 11.24 7) Me 1 La 6| 8.42) 2.42 Oo} — — Oo} — = Oe = On = 41| 128.05| 14.78 7| 25.42) 4.76 Ol, S240 theoe Oo} — - 195} 300.02| 34.63 82| 94.37) 17.67 33| 58.21) 17.41 8| 11.76} 3.38 Saee2eks 0:25: 10817) 0503 1} 0.55} 0.16 oO} — — Oo} = — oO} = — Oo; — — oe — = 142) 76.43) 8.82 67| 32.57| 6.10 44] 22.23] 6.65 i; 1/374 | eet eA Ps} Qo} — — oO — — Oo — _ a tS 147| 78.60) 9.07 68| 32.74, 6.13 45) 22.78) 6.81 18\ 7.78) 2235, 1,067| 866.44, 100.00 748) 534.11| 100.00 337| 334.40; 100.00 246 or 100 00 340 IttiNo1is NaturAL History SurvEY BULLETIN Vol. 25, Art. Appendix B, Table 1. Hannisat, Mo. Quincy, IL. Aua. 25-30, 1944 Sepr. 2-6, 1944 SPECIES Fe) L ps ex ei im S | 233) 82.) 2 ieee E me | Os g mE 5 PRK Nie 5 23 Z Sa as Z Sa CommercIAL FisHEs Scaphirhynchus album*.... 2.02.20... 0005 Oe Be oo — _— Shovelnose sturgeon................----- Oo} — — 3 4.78 0.4 Paddlefish:). 25) Sse vas, hao th eae Oo} — — 25) 104.70 8.6 American: éelis,.25 2 ail: soto oe ee ee 6) 14.26 3.18 2 3.725) 0.27 Blue sucker :.20305 7722s. Soh. Satanigeed See Oo} — — 0 _— Biemonth buffaloes. crete ae eee 2 6.85 1.53 6| 12.24 1.01 Black; buffalose. ae cae Be eee 2 3.25 0.72 2 3.72 0.31 Smallmouthibuffalos.3.ckea ene ee 6| 15.98 BUS, S12 GeeG: 2.18 Garpisuckerstis ste eea tee 30|— 125 152) 5.70 120} 105.46 8.75 cee redhorse: 2 eee a 1 127 0.28 tl 1.18 0.10 US oe ie SH away eae ea es ane 75| 178.52) 39.84 137) 345.79} 28.70 Chaise Catfish asa feo chee eer eee 18 9.73 22. ANG 126} 67.74 5.62 Blue catfhishs<.5 emiedest te: once 1 0.31 0.07 7 1.53 0.13 Yellow bullhead is... a ee Oo} — — 0| == Brownbullhead a: 2s tin canals eee oo — — 0 -— Blackibullbeads ss2s are ee a eee Oo} — — mA 1,97 0.16 Blathead’ cathishean 21-35 2.56 67 62.55 0.43 — _— 0 _ = 2 1.21 0.01 232 0.25 1 1.08 0.13 133 149.25 1.03 — — oj — — 18 2.30 0.02 2.21 0.42 oj — — 595 134.45 0.93 — a oOo) — — 67 19.71 0.14 _ — 0 — — 1 0.10 0.00 25.91 4.94 4 1.90 0.23 998 297.55 2.06 10.20 1.95 3 1.42 0.17 1,515 564.90 3.90 15.85 3.02 6 3.93 0.47 217 109.73 0.76 — — Oo — _ 6 1.88 0.01 55.49| 10.58 36| 29.68 3.56 3,623 1,350.11 9.34 14.27 D2 16) 18.70 2.24 194 403.33 2.79 57.39} 10.95 41; 39.94 4.78 1,411 Pes rh Wi, 9.03 — — (io — 85 249.29 Ras SS = OA = 110 324.66 2.24 71.66; 13.67 57| 58.64 7.02 1,800 2,284.45 15.78 1.93 0.37) 18 9.69 1.16 109 54.64 0.38 1.09 0.21 3 2a 0.25 15 Outs 0.06 30.12 Sauls 21; 10.28 ibe | 1,069 534.46 3.69 = — 0 _ — 2 0.67 0.00 33.14 6.33 42; 22.09 2.64 1,195 598.92 4.13 524.23) 100.00 592| 834.92) 100.00 15 513 14,470.76 100.00 Intinois Narurat History SurveEY BULLETIN Vol. 25, Art. § 06 Nestea 169 | a a ele al IT] ‘VISQIVANY WMO] “LUOdUIV VMO] ‘ANILVOSaAA] ‘TIT ‘NOLSOG MAN *¢ AVIN-PC Way ‘TTT ‘VAMVAOO VMO] ‘NOLONITUNG alae Z 19°19 \£L'929\00F |96°SZ \99' ZIF|Esé |b Io IEE ebs| FS6 | jeqoigns. 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C. 120 pp. War Department Corps of Engineers 1940. The middle and upper Mississippi River. Ohio River to Minneapolis. D Upper Mississippi Valley Division, St. Louis, Mo. United States Governt Office, Washington, D. C. 345 pp. 1946. Navigation locks and dams. Mississippi River. [United States] War Depa of Engineers. 8 pp. INDEX The following index covers Volume 25 of the Iniinors Narurat History Survey BuLLevin: Articles 1, 2, 3, 4, 5, and 6. d Indexing has been limited for the most part to the names of birds, fish, insects, mammals, and plants mentioned in the articles. In most cases, the singular form of the word has been used in the index, even though the plural form has been used in the text, as mouse for both mice and mouse. Abies balsamea, 39 Acer negundo, 38; see also Boxelder saccharinum, 38; see also Maple, silver Acipenser fuloescens, 288, 290; see also Sturgeon, lake transmontanus, 290 Acipenseridae, 288-90 Aedes, aegypti, 356 Agelaius phoeniceus phoeniceus, 62; see also Black- bird, red-wing Aix sponsa, 62; see also Duck, wood Alder, 87, 138 Algae, 55, 58, 230 Ameiuridae, 284, 303-11 Ameiurus melas, 218, 307; see also Bullhead, black melas melas, 283 natalis, 218, 310; see also Bullhead, yellow natalis natalis, 283 nebulosus, 283, 310; see also Bullhead, brown nebulosus marmoratus, 283 Amia calva, 282, 284; see also Bowfin Amiidae, 321-2 Amphiodon alosoides, 282, 284, 322; see also Gold- eye Anatoecus ferrugineus, 162-3 Anguilla bostoniensis, 282, 288; see also Eel, American Anguillidae, 291-2 Animal; see names of individual kinds and classes big game, 136 flesh-eating, 353 fur, 59, 103 game, 103, 374, 378 Anser canadensis, 80, 138; see also Canada goose Apichishkish, 203 Aplodinotus grunniens, 218, 283, 288; see also Drum, freshwater Ardea vat rag herodias, 62; see also Heron, great lue Arrowhead, 46, 218, 333; see a/so Duckpotato Arthropod, 354, 359, 361; see also names of indi- vidual kinds Ash, 39, 43, 49 black, 39 white, 38, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 57, 63, 64 Aspergillus, 162 fumigatus, 162 Aureomycin, 377 B B. c. leucopareia, 81; see also Branta B. tularense, 353; see also Bacterium tularense Bacillus tuberculosis, 1 Place names have not been indexed. Bacterium tularense, 356; see also B. tularense Baldcypress, 39; see also Cypress Balsam fir, 39 Barfish, 283 Bass bigmouth, 283 black, 283, 284, 312, 313, 315-9, 320 calico, 229, 283; see also Crappie, black Kentucky, 252, 283 largemouth [black], 218, 219, 222, 238, 252, 283, 309, 317, 318, 334-47 northern smallmouth black, 283 northern spotted black, 283 round, 283 sea, 319-20 silver, 283 smallmouth [black], 238, 252, 283, 317, 332 spotted black, 283, 309, 317, 334-47 strawberry, 283 striped, 283 warmouth, 283; see a/so Warmouth white, 283, 284, 287, 309, 315, 319, 320, 325, 334-47 yellow, 218, 219, 283, 309, 319, 320, 325, 334-47 Bdellonyssus bacoti, 356 Bean, 103; see a/so Soybean Beaver, 81, 138, 139, 198, 354 Bee, sweat, 361 Beetle, 274 Belly, flat, 283 Benzene hexachloride; see Hexachlorocyclohexane Betula nigra, 38; see also Birch, river Billberry, 105 Billfish, 282 Birch, river, 38, 39, 42, 44, 45, 46, 47, 48, 49, 51, 52, 63 Bird, 36, 61, 62, 74, 79, 128, 129, 149, 151, 353, 354, 356, 359, 361; see also names of in- dividual kinds and classes gallinaceous, 353 game, 372 passerine, 185 raptorial, 353 upland game, 359 Bittern, American, 61 Bivalve, 274 Blackbird, red-wing, 61, 62, 65 Blackgum, 39 Blackhorse, 282 Blind, duck, 48 Blueberry, 105 Bluefish, 282 Bluegill, 218, 222, 228, 230, 233, 238, 243, 283, 309, 312, 318, 319, 325, 334-47 Boater, coal, 283 Bob-white, 353; see a/so Quail Bonasa umbellus togata, 353 Bowfin, 282, 284, 321-2, 324, 334-47 Boxelder, 38, 39, 41, 42 [ 383 ] 384 Brant, 189 Branta, 81, 203-4; see also B. c. leucopareta and Goose canadensis, 80 canadensis canadensis, 203-4 , canadensis hutchinsi, 203; see also Goose, Rich- ardson’s canadensis interior, 75, 77, 79, 82, 83, 85, 196, 203-4 canadensis moffitti, 203-4 canadensis parvipes, 203 hutchinsii, 101, 136, 203-4 leucopareia leucopareia, 81, 203-4 leucopareia occidentalis, 203 minima, 128, 203 Bream, 283 American, 283 Buffalo, 219, 222, 295, 296, 324, 325; see also Buffalofish bigmouth, 282, 294, 297, 309, 325, 334-46 black, 282, 294, 296, 297, 309, 324, 334-46 blue, 282 brown, 282 bullhead, 282 bullmouth, 282 bullnose, 282 channel, 282 humpback, 282 liner, 282 mongrel, 282 quillback, 282 razorback, 282 redmouth, 282 roachback, 282 round, 282 roundhead, 282 sheepshead, 282 slough, 282 smallmouth, 282, 294, 296, 297, 298, 309, 324, 334-46 stubnose, 282 trumpet, 282 Buffalofish, 218, 267, 285, 286, 287, 288, 293-8, 311, 312; see also Buffalo Bug, bed, 356 Bugler, 282 Bullhead, 219, 283, 284, 285, 286, 287, 295, 303-11 black, 218, 283, 307-10, 324, 334-46 brown, 283, 309-11, 334-41 northern black, 283 northern yellow, 283 speckled, 283 yellow, 218, 283, 309-11, 334-46 Buforides virescens, 62; see "alsa Heron, green Buttonbush, 35, 38, 39, 41, 42, 43, 44, 45, 46, 47, 49, 52, 63, 64, 122 75, 77, 80, 81, 82, 196, G Cane, sugar, 123 Carex spp., 55; see also Sedge Caribou, 136, 138 Carnivore, 353 Carp, 218, 219, 222, 281, 283, 285, 288, 293, 294, 295, 298- 303 coldwater, 282 European, 283 German, 283 river, 282 Intinors NArurRAL History SurvEY BULLETIN Carp—continued silver, 219, 282 Carptodes; see also Carpsucker 4 carpio, 282, 292; see also Carpsucker, river a carpio carpio, 283 “4 cyprinus, 282 spp., 218, 292, 309, 334-47 velifer, 282 +3 Carpsucker, 218, 282, 292, 294, 295, 298, tite 324 325, 334-46 a northern, 383 river, 282, 292, 324 Carya illinoensis, 28; see also Pecan Casmerodius albus egretta, 62; see also Egret, American Cat, 353, 361 Cat [fish]; see a/so Catfish channel, 283 chucklehead, 283 Fulton, 283 Johnny, 283 Mississippi, 283 Morgan, 283 mud-, 283 shovelnose, 283 spoonbill, 283, 290 spotted, 283 yellow, 283 yellow-bellied, 283 Catfish, 267, 283, 284, 285, 286, 287, 288, 29. 303-11, 320, 323, 324, 325; see also {fish] blue, 283, 304, 305, 306, 307, 308, 309, 311, 334-41 t channel, 218, 219, 283, 285, 303, 305, 306, 30 308, 309, 324, 325, 334-46 flathead, 218, 219, 283, 304, 305, 306, 30 309, 324, 334-46 southern channel, 283 Catostomidae, 288, 292-8 Catostomus commersonnit, 218, 282; see also Su white commersonnit, 283 Cattail, 46, 47, 54, 59, 62, 64, 65, 218 Celtis laevigata, 38; see also Hackberry Centrarchid, 228, 255 Centrarcht ae. 315— 9 Centrarchus macroplerus, 283, 318; see also Flier. Centurus carolinus, 62; see also Woodpecker, eC bellied Cephalanthus occidentalis, 38; see also Butto: Ceophloeus pileatus abieticola, 62; see also \ pecker, pileated , Ceratophyllum demersum, 54; see also Coontaiiie ; Cercis canadensis, 38; see also Redbud Chaenobryllus coronarius, 218, 283, 319; see Warmouth ‘ Chaoborus, 274 Chara, 229, 230 Chen h. hy perborea, \01 Chicken, prairie, 361 a Chlordan, 2, 5, 6, 8, 19, 20, 23, 24, 26, 27, 28, 30, 31 Chloromycin, 377 Chrysops discalis, 356, 359 Cimex lectularis, 356 Cladonia, 95 Clam, 311 Cockspur, 54; see also Millet, wild Coffeetree, Kentucky, 38, 39, 42 s) 1949-1952 Colaptes auratus luteus, 62; see also Flicker linus virginianus, 353; see also Quail Condition coefficient of, 235, 236, 237, 239, 240, 241, 242, 261; see also K ndex of, 302, 303 tail, 54, 59, 64 thra, 274 Corn, 115, 116, 119, 120, 121, 127, 133, 159, 160, 161 field, 107, 122, 161, 326 us florida, 38; see also Dogwood Cotton, 123 field, 326 Cottontail, 356, 361, 366, 370, 371, 372, 374; see 4 also Rabbit Cottonwood, 36, 38, 39, 42, 44, 45, 46, 47, 49, 51, a 52, 53, 54, 55, 57, 59, 63, 64, 327, 329 Cowpea, 133, 160 Covote, 166, 353 Crappie, 283, 284, 312, 315, 324, 325 tblack, 211, 215, 216, 218, 219, 222, 223, 224, : 225, 226, 227, 229, 230, 234, 235, 238, a 252, 260, 261, 309, 315-7, 325, 334— 4 Coo ) white, 211-65, 283, 309, 315-7, 324, 325, 334- q 47 abnormalities, 234-5 color and structure, 234-5 excessive sliminess, 235 age and growth, 244-61 age determination, 244-7 annual growth period, 249-52 growth rates, 252-60 size and age distribution, 247-9 condition or plumpness, 235-44, 261 possible reasons for K loss, 243-4 seasonal changes in K values, 235-43 disease (lymphocystis), 234, 261 foods, 225 hoop-net sampling, 221-5 seasonal variations, 222 species variations, 222-5 migrations, 225 reaction to current, 225-6 reproduction, 226-34 reeding coloration, 226-7 changes in ovary size, 227-8 nesting habits, 228-30 sex ratios, 230-4 sexual maturity, 226 spawning season, 227 sport fishing, 219-21 Crataegus spp., 38; see also Hawthorn Crayfish, 62, 274 Croaker, 283 ‘Crowberry, 105 ‘Crustacean, 225 ‘Cutegrass, rice, 47, 54, 55, 57, 59, 62, 64, 333 Cycleptus elongatus, 282, 292; see also Sucker, blue me Cypress, 117, 118, 122, 157 Cyprinidae, 284, 298-303, 322; see also Carp and 4 Minnow Cyprinus carpio, 218, 283, 288; see also Carp D Deenate, 9, 10, 11, 12, 30, 31 INDEX 385 Dermacentor; see also Tick andersont, 354, 355, 359 variabilis, 354, 355, 359 Diamanus montanus, 356 Epes een aa 1; see also Didelphis virginiana virginiana, 60; see also Opos- sum Diospyros virginiana, 38; see also Persimmon Diver, 191; see a/so Loon Dog, 353, 361 bird, 133 husky, 139 Dogfish, 282 Dogwood, 39, 42 flowering, 38 Dorosoma cepedianum, 218, 225, 255, 282, 284, 322; see also Shad, gizzard Dragonfly, 274 Drum, 295 freshwater, 218, 219, 283, 285, 286, 287, 288, 309, 311-2, 324, 325, 334-46 Dryobates pubescens, 62; see also Woodpecker, downy villosus, 62; see also Woodpecker, hairy Duck, 62, 74, 81, 86, 126, 128, 135, 140, 143, 151, 156, 158, 162, 189, 191, 324; see also names of individual kinds, Blind, duck, and Hunting, duck black, 126 wood, 61, 62, 64 Dare 47, 54, 55, 59, 64; see also Arrow- eal Duckweed, 41, 55, 62, 64 E Eagle, 161 bald, 161 Echinochloa spp., 54; see also Millet, wild Echinostoma revolutum, 163 Eel, 285, 287 American, 282, 288, 291-2, 309, 325, 334-46 freshwater, 282, 323 Egret American, 61, 62 snowy, 62 Egretta thula thula, 62 Eider, 191 Elm, 35, 37, 39, 49, 59, 64, 122, 229 American, 38, 39, 42, 44, 45, 46, 47, 49, 50, 51, 52, 57, 63 slippery, 38, 42 Endamoeba histolytica, 1 Epetrum nigrum, 105 Esocidae, 314 Esox lucius, 218, 283, 284, 314; see also Pike vermiculatus, 283, 314; see also Pickerel, grass Esthiopterum crassicorne, 163 F Fever, deerfly, 352 Fiddler, 283 Fish, 33, 62, 211-65, 267-350; see also names of individual kinds and classes commercial, 267-350; see also Buffalo, Buffalo- fish, Bullhead, Carp, Carpsucker, Cat [fish], Catfish. Drum, Eel, Goldeye, 386 Fish—continued commercial—continued Mooneye, Paddlefish, Redhorse, Sucker, Sturgeon forage, 284, 312, 322-3, 334-47; see also Gold- eye, Minnow, Mooneye, Shad, Shiner, Skipjack fresh water, 269 game, 287, 313, 325; see a/so sport, below marine, 319 predator(y), 284, 299, 312, 320-2, 334-47; see also Bass, Bowfin, Catfish, Crappie, Gar, Pike, Pikeperch, Sauger sport, 267-347; see also Bass, Bluegill, Crappie, Flier, Perch, Pickerel, Pikeperch, Sauger, Walleye, Warmouth Fisher, 166 Flea, 354, 356 California ground squirrel, 356 rabbit, 354 rat, 356 Flicker, 61, 62 Flier, 283, 309, 318, 33441 Flooding of timber, 33-65 Fluke, 163 Fly biting, 361 deer, 356, 359, 361; see a/so Fever, deerfly house, 1-32 stable, 356 Flyway, 74, 76; see also Goose, Canada Atlantic, 74 Central, 74 Mississippi, 67-210 Pacific, 74 Forestiera acuminata, 38, 39; see also Waterprivet 497, 29, 30 Fox, 61, 64, 157, 161, 166 gray, 60 red, 60, 161, 166, 353 Fraxinus americana, 38; see also Ash, white nigra, 39; see also Ash, black Frog, 62 Furbearer, 359; see a/so Animal, fur G Gale, sweet, 138 Game, 129, 163, 185, 374, 376; see also Animal, Bird, Waterfowl, and names of individual kinds small, 136, 138, 377 Gar, 284, 320-1, 324 alligator, 282, 309, 320, 321, 324, 325, 334-41 billy, 282 duckbill, 282 longnose, 282, 309, 320, 321, 324, 334-47 Mississippi alligator, 282 northern longnose, 283 shortnose, 218, 282, 309, 320, 321, 324, 334-47 spotted, 320 Garpike, 282 Gaspergou, 283 Gleditsia aquatica, 38; see also Waterlocust Goarhead, 282 Goggle-eye, 283 Goldeye, 282, 284, 309, 322, 334-46 Gomphid, 274 Inuinoris NatrurAL History Survey BULLETIN Volume 25 Goose blue, 74, 104, 124, 136, 137, 140, 145, 146, 155, 191, 198; see also Wavy cackling, 128, 203 Canada, 67-210 annual bag, 135-52 Canada vs. United States kill, 149-52 on breeding grounds, 135-42 southern Canada and United States, 142-8 total annual bag, 148-9 classification of genus Branta, 203-4 crippling losses, 155-8 differential hunting losses, 152-5 eastern populations, 74-9 Hudson-James Bay populations, 74, 77-9 Eastern Prairie, 75, 76, 79, 88, 148, 196 Mississippi Valley, 75, 76, 79, 80, 84, 87, 88, 105, 106, 107, 113, 114, 141, 143, 144, 145, 148, 150, 180, 183, 189, 192, 193, 195, 196, 197, 198, 199 South Atlantic, 75, 76, 77, 91, 105, 106, 120, 196, 199 Southeast, 75, 76, 77, 78, 87, 89, 91, 105, 106, 110, 196, 199-202 North Atlantic population, 75, 77, 196 flyway concept, 74 goose behavior and hunting losses, 125-9 family grouping, 127-8 sociability, 128-9 wariness, innate and acquired, 126-7 history of goose hunting in Illinois, 129-34 Hudson-James Bay breeding range, 79-103 limits of range, 79-92 Mississippi Valley population, 82-7 other populations, 87-92 nest sites, 101-3 West Coast muskeg types, 92-6 West Coast production centers, 96-101 migration, 103-12 autumn migration routes, 103-9 spring migration routes, 109-10 time and rate of migrations, 110-2 mortality factors, 158-63 aspergillosis, 162 bound crop, 159-61 diseases, 161-2 lead poisoning, 158-9 parasites, 162-3 predators, 161 starvation, 159 tracheitis, 161-2 population survival, 172-88 longevity, 186-8 mortality, 172-86 calculated from band recoveries, 179- calculated from trap returns, 172-9 present situation, 195-6 productivity, 163-72 actual productivity, 166 breeding potential, 163-6 mating habits, 163 number of young, 165-6 reproductive maturity, 163-4 sex ratios, 164-5 data from Horseshoe Lake, 166-71 flock sizes, 171-2 theoretical vs. actual productivity, 171 1949-1952 Goose—continued Canada—continued Southeast population, 199-202 breeding range, 199 future status, 202 migration routes, 199 winter concentrations, 199-202 winter concentrations, 112-25 Arkansas, 122 coastal marshes, 124-5 Illinois, 116-20 Indiana, 121 Jack Miner Bird Sanctuary, 114-6 lower Mississippi River, 122-4 Michigan, 120-1 Ohio, 121 Wisconsin, 121 cape, 105 coast, 203 Eastern Canada, 203; see also Branta canadensis canadensis Fort George, 203 gray, 138, 203 grey, 139, 203 Great Basin Canada, 203; see also Branta can- adensis moffitti Hutchins’s, 203 interior Canada, 204; see also Branta canadensis interior and Todd’s Canada, below large swamp, 203 lesser Canada, 203; see also Branta leucopareia leucopareia lesser snow, 101 Richardson’s 101, 136, 203-4 snow, 74, 104, 124, 126, 136, 137, 140, 145, 146, 189, 191, 198; see also Wavy Todd’s Canada, 203; see also Branta canadensis interior and interior Canada, above tundra, 203-4 West Coast, 203 Western Canada, 203 white-fronted, 124, 155 Goujon, 283 Grass, 123, 194, 229 Jamaica saw, 124 Grassland, 121 Greaser, 283 Grindle, 282 Grouse, 138, 166, 361, 371 ruffed, 129, 353 sharp-tailed, 353 willow, 138 Gull, ring-billed, 166 Gum, see a/so Blackgum and Sweetgum tupelo, 117, 118; see a/so Tupelo, water Gymnocladus dioicus, 38; see also Coffeetree, Ken- tucky H Hackberry, 42, 44, 45, 46, 47, 49, 52, 63 sugar, 38, 39, 51 Hackleback, 282 white, 290 Haddock, 243 Haemaphysalis leporis-palustris, 354 » Hare, 351, 356, 366, 375 snowshoe, 138, 166, 353, 366, 370, 371, 375 varying, 370 INDEX 387 Hawthorn, 38, 39, 42, 44, 45, 46, 47, 48, 49, 52, 63 Hen moor, 191 sage, 353 Heptaklor, 29, 30 Heron, 62, 64 black-crowned night, 61 great blue, 61, 62 green, 61, 62 yellow-crowned night, 61 Herring, 323 blue, 282 river, 282 toothed, 282 Hexachlorocyclohexane, 2, 5, 6, 8, 19, 20, 21, 23, 25, 26, 28, 29, 30, 31 Hexagenia, 288 Hiodon tergisus, 282, 284, 322; see also Mooneye Hog, 353 ground, 353; see also Woodchuck Holly, 38, 39, 42, 44, 45, 46, 49, 52, 63 Hoosier, 283 Hornwort, 54; see a/so Coontail Horse, 131, 361 Hunting, duck, 61 Ictalurus Ffurcatus, 283, 304; see also Catfish, blue furcatus furcatus, 283 lacustris, 218, 283, 303; see also Catfish, chan- nel lacustris punctatus, 283 Ictiobus bubalus, 218, 282, 294; see also Buffalo, small- mouth niger, 218, 282, 294; see also Buffalo, black Tlex decidua, 38; see also Holly Insect, 356, 359; see also names of individual kinds and classes aquatic, 225, 274, 313 blood-sucking, 361 terrestrial, 225 Insecticides, residual, 1-32; see also names of in- dividual kinds Invertebrates, 225, 274 dJ Jack, 283 Jackpine, 86 Fussiaea sp., 218 K K (coefficient of condition), 235, 236, 237, 238, 239, 240, 241, 242, 243, 261; see also Con- dition Kaoosoupasawat nisku, 203 L Lagomorph, 351, 352 Lagomorpha, 351 Larch, 87; see a/so Larix laricina and Tamarack Larix laricina, 39; see also Larch and Tamarack Leech, 274 Leersia oryzoides, 54, 333; see also Cutgrass, rice 388 Legume, 122, 160; see also names of individual kinds Lemna, 55; see also Duckweed Lepibema chrysops, 283, 284, 319; see also Bass, white Lepisosteidae, 320-1 Lepisosteus osseus, 282, 320; see also Gar, longnose osseus oxyurus, 283 platostomus, 218, 282, 320; see also Gar, short- nose productus, 320 ; spatula, 282, 320; see also Gar, alligator spp., 284 Lepomis cyanellus, 218, 233, 283, 318; see a/so Sunfish, green gibbosus, 218 humilis, 283, 318 macrochirus, 218, 222, 233, 283, 312, 318; see also Bluegill macrochirus macrochirus, 283 megalotis peltastes, 233 microlophus, 233 Lepus; see also Rabbit, jack americanus, 370; see also Hare, snowshoe spp., 361 townsendii campanius, 351 Lespedeza, 122 Lichen, 93, 95 Lindane; see Hexachlorocyclohexane Lineside, 283 Liquidambar styraciflua, 39 Locust, honey, 39, 49 Loon, 191 Lotus, American, 333 Louse, 354, 356 chewing, 162 rabbit, 354 Lymphocystis, 211, 234, 261 Lynx, 166 M Magnolia, 39 Magnolia spp., 39 Maidencane, 124 Mallard, 126, 156, 191 Mallophaga, 162 Mammal, 36, 57, 64, 128, 129, 353, 354, 356, 359, 361; see also names of individual kinds Maple, 35, 37, 39, 47, 49, 50, 51, 52, 53, 57, 62, 64 silver, 37, 38, 39, 42, 44, 45, 46, 47, 48, 49-50, 51, 52, 55, 56, 59, 63, 64; see also soft, below soft, 37, 122; see also silver, above Mariscus ja(t)maicensis, 124 Marlate, 29, 30 Marmota monax monax, 61; see also Woodchuck and Hog, ground Marten, 166 Mayfly, 288, 311 Megastomatobus cyprinella, 218, 282, 294; see also Buffalo, bigmouth, and Buffalofish Melanerpes erythrocephalus, 62; see also Wood- pecker, red-headed Mephitis mephitis, 61; see also Skunk, striped Micropterus; see also Bass dolomieu, 283, 317; see also Bass, smallmouth [black] Intinois NaturaAL History Survey BULLETIN Volume Micropterus—continued dolomieu dolomieu, 283 punctulatus, 283, 317; see also Bass, spotted black ’ punctulatus punctulatus, 283 j salmoides, 218, 222, 283, 317; see also Bass, largemouth [black] 3 spp., 284 Microtus ochrogaster, 372 Millet, wild, 54, 64 Mink, 60, 64, 166 Minnow, 62, 219, 220, 274, 284, 313, 318, 322 Minytrema melanops, 218, 282; see also Sucker, spotted “a Mississippi River fishes, 267-350 Mite, 356 tropical rat, 356 Mollusk, 311 Mooneye, 282, 284, 309, 322, 334-47 - Morone interrupta, 218, 283, 319; see also Bass, yellow Morus rubra, 38; see also Mulberry, red Mosquito, 356 Moss, 85, 86, 87, 93, 96, 230; see also Sphagnum and Muskeg re Mouse, 353, 354, 356, 372 prairie meadow, 372 Moxostoma, 309, 340 anisurum, 282, 293; see also Redhorse, silver aureolum, 282, 293; see also Redhorse, northern spp., 218; see also Redhorse Mudfish, 282 Mulberry, red, 38, 39, 41, 42 Mule, 131 Mullet, 282 silver, 282 Musca domestica, 1, 30; see also Fly, house Musculium, 274 B Muskeg, 85, 86, 87, 88, 89, 92-6, 97, 99, 100, 102, 103, 107, 138, 166, 196, 197; see also Moss a Muskego nisku, 203 Muskrat, 57, 59, 60, 64, 138, 166, 353, 354, 361 Mussel, 59, 274, 323, 331, 332 Mustela vison, 60; see also Mink N Nelumbo lutea, 333 Neuroptera, 274 Newlight, 283 Northern, 283 Notemigonus crysoleucas, 218, 283, 322; see also Shiner, golden auratus, 283 Nyssa aquatica, 39 sylvatica, 39 O Oak, 51, 52 bur, 42, 44, 45, 49, 51, 52, 63 . pin, 35, 37, 38, 39, 42, 46, 47, 48, 49, 51, 52, 57, 3, 64 Oats, 122 “s Ondatra zibethicus zibethicus, 57; see also Muskrat 118, 29, 30 : Opossum, 60, 64, 361 Ornithobius goniopleurus, 163 : 1949-1952 Otter, 166 Owl, great horned, 166 P Paddlefish, 282, 285, 286, 287, 288, 290-1, 295, 309, 323, 325, 334-41; see "also Pele- fish and Spatula- fish Panicum hemitomon, 124 Parascaphirhynchus albus, 290 Parathion, 29, 30 Parsnip, water, 229 Partridge, 361 Hungarian, 185 Pasteurella tularensis, 352, 354, 356, 359 PD 544-C, 5, 11, 12, 13, 14, 15, 23, 26, 28, 30 Pecan, 38, 39, 42, 44, 45, 46, 47, 49, 50, 51, 52, 57, 63, 64 Pediocetes phasianellus, 353 Pele-fish, 290; see also Paddlefish Perca flavescens, 218, 314; see also Perch, yellow Perch, 283, 314 black, 283 grunting, 283 white, 283, 311 yellow, 218, 314, 325 Percidae, 314-5 Persimmon, 38, 39, 41, 42, 44, 45, 46, 47, 49, 51, 52,6 Pheasant, 188, 361 ring-necked, 172, 353 Picea spp., 39 Pickerel, 283, 314 grass, 283, 309, 314, 334-41 little, 283 mud, 283 Pig, guinea, 353, 356 Pike, 218, 284, 287, 309, 312, 314, 323, 324, 342-7 grass, 283 great northern, 283 northern, 283, 314 sand-, 283 Pikeperch, 314, 315, 320 yellow, 283, 284, 287, 309, 312, 315, 324, 325, 334-47 Pilodictis olivaris, 218, 283, 304; see also Catfish, flathead Pine, 127 Plant, 36, 54, 55, 59, 229, 261; see also names of in- dividual kinds and classes aquatic, 62, 218, 230, 261 herbaceous, 35 marsh, 46, 47 moist-soil, 47, 62 Platanus occidentalis, 38; see also Sycamore Plum, American, 38, 39, 42 Plunger, Des Moines, 282 Polygonum spp., 54, 56; see also Smartweed lapathifolium, 56 Polyodon spathula, 282, 288; see also Paddlefish Polyodontidae, 290-1 Pomolobus chrysochloris, 282, 323; see also Skipjack Pomoxis annularis, 211, 218, 283, 315; see a/so Crappie, white nigro-maculatus, 211, Crappie, black spp., 284 Pondweed, leafy, 54, 64 Poplar, 86 218, 283, 315; see also INDEX 389 Populus deltoides, 38; see also Cottonwood Potamogeton foliosus, 54; see also Pondweed, leafy Predator, 135, 155, 161, 166; see also Fish, pre- dator(y) Primrose, water, 218 Privet, 46, 49 Procyon lotor, 59-60; see also Raccoon Prosthogonimus sp., 163 Protonotaria citrea, 62 Prunus americana, 38; see also Plum, American Ptarmigan, 138, 166 Pumpkinseed, 218 Pyrenone, 29, 30 Q Quail, 133; see also Bob-white California, 185 Quercus macrocarpa, 38; see also Oak, bur palustris, 38; see also Oak, pin Quillback, 282 R Rabbit, 351-82 cottontail, 61, 64, 351, 352, 353, 357, 361, 366, 369, 370, 371, 372, 373, 374, 377, 378; see also Mearns cottontail and Oklahoma cottontail, de/ow domestic, 353, 375, 376 jack, 351, 353, 361 Mearns cottontail, 351, 352 Oklahoma cottontail, 351 swamp, 351 white-tailed jack, 351 wild, 356, 357 Raccoon, 59, 64, 157 Raspberries, dwarf, 105 Redbud, 39, 42 eastern, 38 Redhorse, 218, 219, 292-3, 309, 340 common, 282 northern, 282, 293, 309, 334-47 silver, 282, 293, 309, 342-7 Redstart, American, 62 Reefer, 282 Rhothane D-3, 2, 5, 6, 8, 19, 20, 23, 25, 26, 30, 31 Rice, 122, 124; see a/so Wildrice, southern Roach, 282 Roachback, 294 Rodent, 351, 352, 353, 354 Rooter, 282 Rotenone, 212, 257 Rubus arcticus, 105 Rush, bog, 229 Rye, 115, 133 S Sagittaria sp(p)., 46, 54, 218, 333; see also Duck- potato and Arrowhead Salix nigra, 38; see also Willow, black Salmon, jack, 283 Sardine, 243 Sauger, 283, 284, 309, 312, 315, 325, 334-47 eastern, 283 Scaphirhynchus album, 290, 309, 334-41 platorynchus, 282, 288; see also Sturgeon, shovel- nose 390 Ittinois NATURAL Sciaenidae, 311-2 Sciurus carolinensis, 61 niger rufiventer, 61 Sedge, 55, 59, 64, 93, 101, 102, 123, 194 Septophaga ruticilla, 62 Serranidae, 319-20 Shad gizzard, 218, 225, 235, 244, 255, 282, 284, 309, 322, 323, 324, 334-47 golden, 282 hickory, 282 white, 282 Sheep, 356 Sheepshead, 219, 283; see a/so Drum Shellcracker, western, 233 Shiner golden, 218, 283, 309, 322, 334-41 western golden, 283 Shovelnose, white, 290 Shrub, 35, 37, 41, 43, 49, 63, 64, 374; see also names of individual kinds Skipjack, 309, 323, 325, 334-41 Skunk, 353, 361 striped, 61, 64 Smallmouth, 283; see a/so Bass, smallmouth Smartweed, 47, 54, 56, 59, 62, 64, 229 Snail, 274, 311 Snake, bull, 353 Sovacide 544-C, 5 Soybean, 122, 132, 160, 161 Spatula-fish, 290; see a/so Paddlefish Sphagnum, 92, 96, 102; see also Moss Spirillum cholerae, 1 Spirodela, 55; see also Duckweed Spoony, 282 Spruce, 39, 79, 86, 87, 99, 101 black, 79, 86, 87, 92, 93, 95, 138 white, 79 Squirrel, 353, 359, 361 fox, 61 gray, 61 ground, 352 tree, 353 Starling, 63, 65 Stizostedion canadense, 283, 284, 315; see also Sauger canadense canadense, 283 vitreum vitreum, 283, 284, 315: see also Pikeperch, yellow, and Walleye Stomoxys calcitrans, 356 Streaker, 283 Streptomycin, 377 Sturgeon, 288-90, 295, 323 lake, 285, 288, 290 pallid, 290 sand, 282 shovelnose, 282, 285, 286, 287, 288, 289, 290 309, 325, 334-47 white, 290 Sturnus vulgaris vulgaris, 63; see also Starling Sucker, 219, 292-3 % blue, 282, 292, 293, 309, 323, 82557529) 3 G25 334-47 common, 282 fine-scaled, 282 gourdseed, 282 highfin, 282 Missouri, 282 spotted, 218, 282, 309, 342-7 5} History Survey BuLLETIN Sucker—continued striped, 282 white, 218, 282, 283, 309, 342-7 Sunfish, 219, 230, 283, 314, 315-9 green, 215-6, 218, 233, 283, 309, 318, 334-47 longear, 233 longfinned, 283 orangespotted, 283, 318 redear, 233 round, 283 Sweetgum, American, 39 Switchtail, 282 Sycamore, 37, 42 American, 38 Syloilagus acquaticus acquaticus, 351 Horidanus, 61; see also Rabbit, cottontail floridanus alacer, 351 Volume 25 ; wi 5 >, ~~ ~~ a Horidanus mearnsi, 351; see also Rabbit, Mearns — cottontail T Tamarack, 39, 86, 92, 93 Taxodium distichum, 39 Tern, arctic, 191 Tetrao Saliceti, 138 Thuja occidentalis, 39 Tick, 353, 354, 359, 361, 362, 366, 378 American dog, 354, 355 dog, 355 rabbit, 354, 369, 370, 377 Rocky Mountain wood, 354, 355 wood, 354, 356, 359 Timber, 85, 92 bottomland, 119 river-bottom, 33-65 Timothy, 115 Toxaphene, 2, 5, 6, 8, 19, 21, 23, 25, 26, 30, 31 Tree, 33, 65, 77, 79, 80, 86, 138, 374: see also names of individual kinds Trinoton querquedulae, 162 Trout cypress, 282 green, 283 Tularemia, 351-82 history, 352-3 in man, 356-66 distribution in Illinois, 361-6 distribution in United States, 356-61 Central region, 358-60, 370, 372, 379 Northern region, 358-60, 372, 379 Southern region, 358-60, 379 Western region, 358-61, 379 in wildlife, 353 rabbit hunter, effect on, 374-7 rabbit populations, 370-4 recommendations for avoiding, 377-9 - tick and insect vectors, 353-6 weather, influence of, 366-70 Tupelo, water, 39; see also Gum, tupelo Typha; see also Cattail latifolia, 46, 54 sp., 218 U Ulmus americana, 38; see also Elm, American fulva, 38; see also. Elm, slippery Urocyon cinereoargenteus cinereoargenteus, 60 z 1949-1952 Vaccinium sp., 105 uliginosum, 105 Vegetation, 327; see also names of individual kinds and classes aquatic, 63, 64, 314, 327 floating, 196 woody, 326 Velsicol AR-60, 12, 14, 17, 30 V4, 29, 30 Vulpes fuloa, 60, 353 Ww Walleye, 283, 312, 315, 325; see also Pikeperch, yellow Warbler, prothonotary, 62 Warmouth, 218, 283, 309, 318, 319, 334-47 Waterfowl, 62, 67, 74, 136, 138, 140, 149, 150, 155, 163, 166, 172, 182, 188, 189, 191, 192, 193, 201, 329; see also names of individual kinds and classes Waterlocust, 37, 38, 39, 42, 44, 45, 46, 47, 49, 50, 51, 52, 63, 64 Waterprivet, 35, 37, 38, 41, 42, 43, 44, 45, 46, 47, 49, 52, 63, 64 Wavy, 136, 140; see a/so Goose, blue and snow Wheat, 116, 119, 120, 122, 127, 133, 159 Wheatfield, 127 White-cedar, northern, 39 INDEX 391 Wildfowl, 151; see a/so Waterfowl and names of indiotdual kinds Wildrice, southern, 124 Willow, 36, 41, 43, 46, 47, 49, 51, 53, 55, 57, 59, 64, 87, 92, 122, 123, 138, 139, 159, 194, 326, 327, 329 black, 37, 38, 42, 43, 44, 45, 49, 52, 63, 64 Winnepego nisku, 203 Wolf, 166 Wolffia, 55; see also Duckweed Wolverine, 166 Woodchuck, 61, 64; see a/so Hog, ground Woodpecker, 61, 64, 65 downy, 61, 62 hairy, 61, 62 pileated, 61, 62 red-bellied, 61, 62 red-headed, 61, 62 Worm, 288 blood-, 274 flat-, 274 sludge, 274 tape, 376 Wren, house, 191 x Xenopsylla cheopis, 356 Z Zizaniopis miliacea, 124 Recent Publications — A—ILLINOIS NATURAL ‘HISTORY SURVEY BULLET Volume 22, Article 1—The Plant Bugs, or Miridae, of Illinois. B September, 1941. 234 pp., frontis. + 181 figs., bibliog., index. $1.2 Volume 22, Article 2 ‘—Studies of North American Plecoptera, with special r the fauna of Illinois. By T. H. Frison. September, 1942. 122 PP» rontis. bibliog., index. $1.00. ee 8: Volume 23, Article 1—The Caddis Flies, or Trichoptera, of Illinois. Ross. August, 1944. 326 pp., frontis. + 961 figs., bibliog., index. $1.50. Volume 23, Article 3 —Overfishing i in a Small Artificial Lake: Onized Lake Illinois. By George W. Bennett. May, 1945. 34 pp., frontis. + 15. figs., Volume 24, Article 1—The Mosquitoes of Lilinois (Diptera, Culicida H. Ross. August, 1947. 96 pp., frontis. + 184 figs., bibliog. 50 cents. Volume 24, Article 2—The Leafhoppers, or Cicadellidite: of Illin Balcluthinae). By D. M. DeLong. June, 1948. 280 Pp. frontis. bs index. $1.25. Volume 24, Article 3—The Bass-Bluegill Combination in a Small George W. Bennett. December, 1948. 36 pp., frontis. + 10 figs. 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Single copies of Ittinois NATURAL History Survey publications for which no price will be furnished free of charge to individuals until the supply becomes low, after nominal charge may be made. More than one copy of any free publication may be without cost by educational institutions and official organizations within the State prices to others on quantity orders of these publications will be quoted upon request. — Address orders and correspondence to the Chief Itutrnots NaturAL History SURVEY Natural Resources Building, Urbana, Illinois Payment preferably in the form of U.S. Post Office money order made out to State T Illinois, Springfield, Illinois, must accompany requests for publications on which a F BULLETIN | of the ILLINOIS NATURAL HISTORY SURVE HARLOW B. MILLS, Chief Tularemia, Weather, 2| and Rabbit Populations | RALPH E. YEATTER 5 | DAVID H. THOMPSON Printed by Authority of the STATE OF ILLINOIS ADLAI E. STEVENSON, Goversor DEPARTMENT OF REGISTRATION AND EDUCATION C. HOBART ENGLE, Director WAlenmeso. wv Oi i ie Sa ACh FIO LEE ENOTS AbLAl E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION C. Hopart ENGLE, Director NAD URAL HISTORY SURVEY DIVISION Hartow B. MI ts, Chief Volume 25 BU AenIN Article 6 a iularemia, Weather, and Rabbit Populations RAGIN Ee Ey oe ek AUI ER DPAWVen Ds Els EO MESON Printed by Authority of the State of Illinois URBANA, ILLINOIS June 1952 STATE OF ILLINOIS Apart E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION C. Hopart ENGLE, Director BOARD OF NATURAL RESOURCES AND CONSERVATION C. Hopart ENGLE, Chairman A. E. Emerson, Ph.D., Biology L. H. Tirrany, Ph.D., Forestry RocGer Apams, Ph.D., D.Sc., Chemistry WALTER H. NeEwnouse, Ph.D., Geology L. R. Howson, B.S.C.E., C.E., Engineering GeorGE D. Stopparp, Ph.D., Litt.D., L.H.D., LL.D., President of the University of Illinois DELyTE W. Morris, Ph.D., President of Southern Illinois University NATURAL HISTORY SURVEY DIVISION Urbana, Illinois SCIENTIFIC AND TECHNICAL STAFF HARLOW B. MILLS, Ph.D., Chief Bessig B. East, M.S., Assistant to the Chief Section of Economic Entomology GrorGE C. Decker, Ph.D., Entomologist and Head J. H. Biccer, M.S., Entomologist L. L. ENGiisH, Ph.D., Entomologist C. J. WEINMAN, Ph.D., Entomologist S. C. CHANDLER, B.S., Associate Entomologist Wits N. Bruce, M.A., Associate Entomologist Joun M. Wricut, M.A., Assistant Entomologist W. H. Lucxmann, M.S., Assistant Entomologist H. B. Perry, M.A., Extension Specialist in Entomology Pau Suranyl, Ph.D., Laboratory Assistant Massoup VARZANDEH, M.S., Research Assistant Norman C. Gannon, M.S., Special Research Assistant JEANE WARNER, Laboratory Assistant Sue E. Watkins, Technical Assistant Section of Faunistic Surveys and Insect Identification ROS, Ph.D., Systematic Entomologist and ea! Mitton W. SANDERSON, Ph.D., Associate Taxonomist Lewis J. STANNARD, JR., M.S., Assistant Taxonomist Leonora K. Groyp, M.S., Laboratory Assistant Puitie W. Situ, M.S., Laboratory Assistant WitiraM R. Ricuarps, B.S., Laboratory Assistant VerRA Twitty, B.S., Technical Assistant Section of Publications and Public Relations James S. Ayars, B.S., Technical Editor and Head BLANCHE P. Youn, B.A., Assistant Technical Editor WitiiaMm E. Crark, Assistant Technical Photographer James W. CurrMan, B.S., Technical Assistant Technical Library MARGUERITE Simmons, M.A., M.S., Technical Librarian RutH WarrRIck, B.S., Assistant Technical Librarian Section of Applied Botany and Plant Pathology Leo R. TEHON, Ph.D., Botanist and Head J. Cepric CarTER, Ph.D., Plant Pathologist J. L. Forsserc, M.S., Associate Plant Pathologist Ratpu W. AMEs, Ph.D., Associate Plant Pathologist PauL F. HorrMan, Jr., Ph.D., Associate Plant Pa- thologist G. H. Boewe, M.S., Assistant Plant Pathologist G. J. StEsseL, M.S., Assistant Plant Pathologist B. M. ZucKEeRMAN, M.S., Assistant Plant Pathologist Rosert A. Evers, M.S., Assistant Boltanist E. A. Curt, M.S., Special Research Assistant Rovenia F. Fitz-Geratp, B.A., Technical Assistant Section of Aquatic Biology GEORGE W. BENNETT, Ph.D., Aquatic Biologist and ea WILLIAM C. STARRETT, Ph.D., Associate Aquatic Biologist Donatp F. HANSEN, Ph.D., Assistant Aquatic Biologist R. W. Larimore, Ph.D., Assistant Aquatic Biologist Rosert D. Crompton, Field Assistant LEONARD DurHaM, M.S., Technical Assistanl* P. L. McNett, B.S., Technical Assistant* Section of Game Research and Management T. G. Scott, Ph.D., Game Specialist and Head Ravpu E. YEATTER, Ph.D., Game Specialist F. C. BELLRosE, B.S., Associate Game Specialist H. C. Hanson, M.S., Assistant Game Specialist J. S. Jorpan, M.F., Assistant Game Technician WILLIAM NuEss, Field Assistant LysLe R. Pietscu, M.F., Project Leadert Section of Forestry Wittet N. WANDELL, M.F., Forester and Head Lawson B. Cutver, B.S., Associate in Forestry Ex- tension Ross J. Mitter, M.S., Field Ecologist CHARLOTTE ASCHBACHER, B.A., Technical Assistant CONSULTANT IN HERPETOLOGY: Hosart M. SmitH, Ph.D., Associale Professor of Zoology, University of Illinois. CONSULTANT IN ParasitoLoGy: Norman D. Levine, Ph.D., Associate Professor of Veterinary Parasitology and of Veterinary Medicine, University of Illinois. *Employed by the Illinois Department of Conservation and assigned to the Natural History Survey for ad- ministrative and technical supervision. jEmployed by the Illinois Department of Conservation under terms of the Federal Aid in Wildlife Restoration Act and assigned to the Natural History Survey for administrative and technical supervision. This paper is a contribution from the Section of Game Research and Management. (48291—_4M—4-52) ake 2 FOREWORD T IS commonly assumed, by people who are not immediately associated with re- search, that endeavors in this field of ac- tivity can be completed in a short time and that findings of value will always accrue. This assumption is often, but not by any means always, valid. Further, short-term re- searches almost universally have their base in painstaking studies which have progressed over a long period, some time previous to the initiation of the short-term observations. Values which result from research studies are often so closely intertwined with time that these values do not become significant until observations have been continued over a long period. This is the case in the present important contribution, a study correlating game populations, weather, and human health, and utilizing observations covering about a quarter of a century. Dr. Thompson was zoologist for the IIli- nois Natural History Survey from 1923 to 1944 and, since that time, has been Senior Naturalist for the Forest Preserve District of Cook County, Illinois. Because of his earlier training in animal pathology and statistics, he became interested in tularemia soon after the first cases were reported in Illinois. In 1934 Dr. Yeatter, a specialist in research and management of upland game in the Middle West, joined our staff and teamed up with Dr. Thompson to work on the relation of human tularemia to rabbit hunting in Illinois. Dr. Yeatter has been principally responsible for completing the project during the past 10 years and for preparing this manuscript for publica- tion. These men noticed the relationship between mild autumn temperatures and the severe outbreaks of human tularemia which occurred in Illinois following the opening of the rabbit-hunting seasons in 1938 and 1939. Later they learned that Dr. Robert G. Green of Minnesota had already foreseen this re- lationship from a consideration of the life history of the ticks which transmit the in- fection from rabbit to rabbit and from a study of the course of the disease in the cottontail. The following study should be of interest to a great many people. Hartow B. Mitts, Chief Illinois Natural History Survey CONTENTS 0b. o Rive biG OBO CO DSAOI CIE eee Oe eeSee enc Renee tr 352 EIDE AREM UNS oe cl sifc eo Selatan cesses beaGiveweeceehe ares seeds 352 SOIREE IRN VP VEEIETD EXE FSIS Serer ove cS alto ae (Sree, aks OL olaheefas Fe) via eyotevars) ae os, ote sme eeafoierore 353 Tick PRNSEEBMESIS I CDM ROTOR Srey cya tone Vs mecls iets isis 4ayp avs wins auerarbvanale nye ced ag aware alate S158) oon eka Tet NARS = $425 orale Gee ae Eg einer nes 356 MR BEIB MANE INUGAREMIA soa. (< cis, «isis s cteccisin Siac co F'SSoies leisle sislayvie's ie vies Geieshiele ore 366 PE EneEORUEATIONS AND? DULAREMIA: <.osc.c ssc 5s 0 o6 nsis acclecv.ccie ewe ssa vaevee 370 MMUMARENIACAND) THE RABBIT) ELUNTER «05 +2500: sessile cose dee eedes vwasca scene an 374 PRECOMMENDATIONS. ....-.- 0-200. 0 eee eee eee eee eet eee ence e cen enees 377 SS MMARY NAS re cs cee forepeeies wins ) an st TULAREMIA Fig. 4.—Rocky Dermacentor andersoni bottom, female. Mountain wood _ tick, Stiles. Top, male; This tick is a source of tula- remia in humans and probably in domestic animals and wildlife. parts of the North American continent. It is found in western Bell (1945) reported that a natural barrier, apparently a bactericidal action of the ticks’ guts, keeps infection among dog ticks at a relatively low level. Green (1942) reported a maximum of only | infected to about 2,500 uninfected dog ticks in numerous tick samples collected in Minnesota. He noted that dog ticks in Minnesota go into a resting period in July and remain dormant until the follow- ing spring, and that they cause infection principally in May and June, just previous to becoming dormant. The Rocky Mountain wood tick is dis- tributed in southwestern Canada and in the western United States from the arid zone east of the Rocky Mountains west- ward to central Washington, central Ore- gon, and eastern California. Both im- mature and adult stages have been found 356 on a wide variety of mammals and birds (Cooley 1938). The adult stage has been reported as a source of human tula- remia in several western states. Wood ticks are believed to have caused a tula- remia outbreak among range sheep in Mon- tana (Philip, Jellison, & Wilkins 1935). Several kinds of insects are known to be carriers of tularemia. Prince & McMahon (1946) stated that the disease has been transmitted under experimental conditions by the bites of several insects, including deer flies, Chrysops discalis Williston, stable flies, Stomoxys calcitrans (Linnaeus), bed bugs, Cimex lectularis Linnaeus, and mosquitoes, dedes aegypti (Linnaeus). Lice and fleas, mentioned as vectors by Francis (1937), appear to be poten- tially important in the dissemination of tularemia in the northern states because they remain active in winter when most arthropod vectors are dormant. Ecke (1948) found that flea populations on Illinois cottontails were higher in winter than at other seasons. Evidence apparently is lacking, however, that either fleas or lice frequently transmit tularemia. Prince & McMahon (1946) reported that guinea pigs used in their transmission experiments remained negative for tularemia after exposure during 32 days to infected rat fleas, Xenopsylla cheopis (Rothschild), and California ground squirrel fleas, Diamanus montanus (Baker). They con- cluded that the two species of fleas tested do not play an important role in the spread of the disease. Green (1942) stated, “Fleas are found on rabbits in southern Minnesota during the winter; but, although these insects can transmit tula- remia, they appear to do so rarely.” Hopla (1951) found that tropical rat mites, Bdellonyssus bacoti (Hirst), re- tained tularemia organisms for consider- able periods after feeding on infected mice. Normal mice became infected when they crushed infected mites orally, but not when they were bitten by the mites. Tularemia in Man Francis (1937) stated that wild rabbits and hares are the source of more than 90 per cent of all human tularemia cases in the United States. Humans generally Ittinois NaturAL History SurvEY BULLETIN Vol. 25, Art. 6 become infected from contact of the bare hands with the flesh or blood of infected rabbits or from eating infected rabbit flesh that is insufficiently cooked. Usually in- fection from handling a diseased rabbit develops at the site of a scratch or puncture in the skin, but occasionally it develops in the eye as a result of contact with hands or of spattering of washings during clean- ing. There is considerable evidence that the disease organism also is able to pene- trate the unbroken human skin. Francis (1937) described a_ typical tularemia case as follows: “About 3 days after exposure to infection, illness begins with headache, chilliness, vomiting, aching pains all over the body, and fever. “The patient thinks that he has the ‘flu’ and goes to bed. ‘The sore on the hand devel- ops into an ulcer. The glands at the elbow or in the armpit become enlarged, tender, and painful, and later may develop into an abscess. There is sweating, loss of weight, and debility. Illness lasts about 3 weeks and is followed by a slow con- valescence covering a period of 2 or 3 months. Most patients recover without any bad after effects, but about 5 percent die, especially if the case is complicated by pneumonia.” Although there is no evi- dence of a natural immunity in man, persons who have recovered from the disease are permanently immune. In regard to the diagnosis of the disease, Francis (1937) wrote: “The history of tick-bite, fly-bite, or wild rabbit contact especially, or contact with other animals, when coupled with fever, an ulcer on the skin, and regional lymph-node enlarge- ment, should call attention to tularaemia. Diagnosis is made conclusive by obtaining agglutination of Bacterium tularense [Pasteurella tularensis] by the patient’s serum or by obtaining a culture of the organism from the patient’s ulcer or lymph nodes following guinea pig inoculation, or by obtaining a positive skin reaction using an antigen prepared by Foshay of Cincin- nati for intradermal injection.” As will be discussed later, treatment of tularemia in man has been facilitated in re- cent years by the use of antibiotics. Distribution in the United States. —It will be evident from fig. 5, showing the distribution of 23,921 cases of tulare- mia reported in the United States during ' 1 ; > F June, 1952 YEATTER & THOMPSON: TULAREMIA 357 ise R 2 f : y 4 Sane: Fa 1500 al pa 9g neasegt *4? 637 1484 1401 re BS 607 a 730 Fig. 5.—Total numbers of reported human tularemia cases in the various states during the period 1924-1949. Data from records of the United States Public Health Service. 787 the period 1924-1949, that the largest number of cases occurred in states lying in the central and south central portions of the eastern half of the country. Jellison & Parker (1945), who emphasize the importance of cottontail rabbits as a source of tularemia in humans, pointed out that Table 1—States that reported a total of 500 or more cases of tularemia, 1924-1949.* NuMBER OF STATE Cases PHOS ee igeecresl. Heke «ieee ase 3,051 BNE BeAISAS ope per yh sikte) coors e > as are clas o, 0 1,613 Ds al eae 12500 BPISCONED errs eerste ao.8 cia ose ae vs 1,484 UIRSTRIO Ge ean eee cis SEO ae OE IeeES 1,401 “UT eT Gla Pee ae eee eee 1,315 SURES Jee Gene Booenemencoer 1,310 RRRSTIESSCE a ote Alu ya < crcere e)ncei-des 1,100 JG Terie a? 28 Be eee ea ee 863 TEER Sep be Sosa ees 790 SOT SAT Rs Se apeeeoe ents PEP eens 787 (ABI | Aon NPS ee eee ener 698 SCRE ee a aie 637 1A TSSTSGT (2) 2 a ee ee 607 ' Thgl ee ee a, ee et Orem 597 OTTERS Ta AS Aer es, , 542 LGW gu oa EO RCnE ene 500 *Data from United States Public Health Service records except Illinois figure, which is from Illinois Department of Public Health and higher than figure from federal agency. cottontails and closely related forms are the only kinds of wild rabbits native to much of the region mentioned above. The states which, according to the records of the United States Public Health Service, reported 500 or more cases of tularemia in the period 1924-1949 are listed in table 1. Illinois, with more than 3,000 cases, reported the largest number, followed by Arkansas with 1,613 and Ohio with 1,500 cases. Although Illinois had the largest human population among the 17 states listed, more than one-half of all tularemia cases reported in Illinois in 1936-1949 were from counties in the southern third of the state, which had only about 12 per cent of the state’s population. Preliminary studies indicated that the human tularemia rate in Illinois and nearby states tended to fluctuate, but it was evident that the particular years in which increases, or decreases, occurred often were not the same in all parts of a geographic region. For example, in one year, 1938, there was a decline of about 50 per cent in the tularemia rate in the northern Great Lakes states, but at the same time there was a severalfold increase in Illinois and the regions adjoining it on the east and west. Later, in 1941, 358 Iruinois NarurAL History Survey BULLETIN Vol. 25, Art. 6 ———— 7 NORTHERN REGION \ ‘ 1 or ' ' art Fig. 6.—Four general regions of the United States which exhibit distinctive trends and seasonal distribution of human tularemia. when tularemia declined in Illinois, Indi- States may be divided conveniently into ana, and Iowa, there was a moderate in- four major regions, namely, Northern, crease in the states to the north. Central, Southern, and Western, fig. 6. With respect to human tularemia rates Trends in the annual tularemia rates dur- and seasonal distribution, the United ing the period 1935-1949 in these four 28 CENTRAL 24 e 20 CASES PER MILLION POPULATION NORTHERN Ae < 1936 1938 1940 1942 1944 1946 1948 Fig. 7—Trends in human tularemia rates during the period 1935-1949 in the four regions of the United States shown in fig 6. Data on which this graph is based are from records of the United States Public Health Service. June, 1952 PER CENT OF CASES IN EACH REGION BY QUARTERS NORTHERN CENTRAL YEATTER & THOMPSON: TULAREMIA MBM FigsT quarter SECOND QUARTER THIRD QUARTER FOURTH QUARTER GA WESTERN SOUTHERN Fig. 8.—Distribution of reported human tularemia cases by quarters of the year during the period 1939-1949 in the four regions of the United States shown in fig. 6. Data on whick this graph is based are from records of the United States Public Health Service. regions are shown in fig. 7. The seasonal distribution of tularemia in these regions is shown in table 2 and fig. 8. In the Northern and Central regions the majority of cases occur during late autumn and early winter. Rabbits, which are hunted at that time, cause most of the cases. As indicated by table 3, furbearers, squirrels, and upland game birds contribute a few cases. During other seasons, these regions show moderate numbers of cases that, presumably, result from bites of ticks or insects, from chance infections by a variety of mammals or birds, both wild and domestic, or from a small amount of year-round hunting. In the Southern Region, the human tularemia rate is fairly uniform through- out the year, indicating several sources of infection, the most important of which are rabbits, ticks, and insect vectors. Francis (1937) recorded 65 cases of tularemia in the southern states, chiefly from March through July, due to contact with dog ticks, Dermacentor variabilis. Pullen & Stuart (1945) reported that 176 (92.1 per cent) of 191 tularemia cases for which the apparent source was recorded in Loui- siana during a 1644-year period gave a history of contact with rabbits. In this region, year-round hunting probably plays an important part in transmission of tula: remia to human beings. The human tularemia rate in the Wes: ern Region is highest in summer. Because the principal insect and tick vectors in this region are most active from late spring to late summer, it appears that arthropods may play a relatively greater part in trans- mitting tularemia to humans there than in the Northern and Central regions. Wood ticks, Dermacentor andersoni, were reported by Francis (1937) to have caused more than 50 cases in Montana and sur- rounding states. According to the United States Public Health Service (Anonymous 1940), sheep handlers have occasionally be- come infected from contact with wood ticks or tick feces in the wool. Jellison (1950) listed, for the western states, 158 cases of tularemia probably caused by deer fly bites, and showed that the distribution of these cases corresponded roughly with the distribution of the deer fly species, Chrysops discalis Williston. Jellison et al (1950) reported contamination with Pas teurella tularensis organisms of certain natural waters in Montana and also a few cases of human tularemia caused by a contaminated domestic water supply. 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Nov. 10-Jan. 15 | Nov. 9 Nov. 19 Nov. 18 6.2 164 1941... Nov. 10-Jan. 15 | Nov.18 Dec. 5 Nov. 27 16.9 70 1942... Nov. 10-Jan. 15 | Oct. 23 Nov. 27 Nov. 14 1.6 40 1943... Nov. 11—Jan. 31 | Nov. 9 Nov. 24 Nov. 20 LS 24 1944... Nov. 11-Jan. 31 | Nov. 5 Dec. 6 Dec. 8 15.7 132 1945... Nov. 11—Jan. 31 | Nov. 9 Novy. 22 Nov. 29 g).) 60 1946... Nov. 11—Jan. 31 | Nov. 21 Dec. 5 Dec. 3 19.1 121 1947... Nov. 11-Jan. 31 | Nov. 12 Nov. 25 Nov. 29 11.6 35 1948... Noy. 11—Jan. 31 | Nov.12 Nov. 18 Dec. 8 de 41 1949. Novy. 11-Jan. 15 | Nov. 9 Dec. 3 Nov. 29 13.2 58 June, 1952 YEATTER & THOMPSON: TULAREMIA 3 loa Ke) 500 450 ~ TULAREMIA CASES eo oa DAYS BETWEEN OPENING OF SEASON AND AVERAGE DATE OF FIRST 10 FREEZING NIGHTS 2 30 o S 250 < 25 = © 200 20 < 20 > 3 100 10 50 ' 5 ' ‘ ‘ 4 1 AFTER ) OPENING OF SEASON () BEFORE v oa 1930 1932 1934 1936 1938 1940 1942 1944 1946 1948 Fig. 2+—The number of cases of human tularemia per year in Illinois and the average date | of the first 10 freezing nights in each autumn, 1929-1949. remia rates in each of the three zones in Ecke’s (1948) studies of ectoparasites each of those 5 years as they are related to on cottontails collected in central Illinois in the number of days between the opening — the autumn of 1947 indicate that migration date of the rabbit-hunting season and the of rabbit ticks to hibernating places was at mean date of the first 10 freezing nights. a peak in late October of that year and that This 5-year period includes 1938 and 1939, the great majority of these ticks had left when there was an epidemic of tularemia the rabbits to go into hibernation by the in Illinois, and 1936, 1937, and 1940, when time of opening of the hunting season in the tularemia rate was about average. A early November. Temperatures were summary is given in table 7. slightly above average in October and Table 7—Days from opening of rabbit-hunting season to average or mean date of first 10 freezing nights in autumn, number of hunting-zone-years represented, and tularemia rate in Tilinois, 1936-1940. Figures on weather and human tularemia rate were obtained by averaging data for each zone separately. Days From OPENING OF NuMBER OF Tucaremia Rare, Rassit-Huntinc Season To MEAN ZoNneE-Y EARS Cases per 100,000, Date or First 10 FreezING NIGHTS AVERAGED NoveMBER—FEBRUARY 30 to 39 days before.......... 1 14.1 20 to 29 days before..........- 1 14.2 10 to 19 days before............ cae 2 al Dntate Fidavs betores me wens Na she gis 0.20 ers Seen e 7 4.3 Mito S Mays) ARteb ac, castes ates = eee» 3 3 1.0 MB MrRsOl SD heirs vat eR tere ie bite