STATE OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION DIVISION OF THE NATURAL HISTORY SURVEY THEODORE H. PRISON. Chiij Vol. XX BULLETIN Article IV The Stoneflies^ or Plecoptera, of Illinois THKODORE H. FRISON PRINTED BY AUTHORITY OP THE STATE OF ILLINOIS URBANA, ILLINOIS JANUARY 1935 STATE OF ILLINOIS Honorable Henry Horner, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Honorable John J. Hallihan, Dirertor BOARD OF NATURAL RESOURCES AND CONSERVATION - ! Honorable John J. Hallihan, Chairman William Trelease, D. Sc, LL. D., Biology William A. Noyes, Ph. D., LL. D., Chemistry Henry C. Cowles, Ph. D., D. Sc, Forestry Chem. D., D. Sc, John W. Alvord, C. E., Engineering Edson C. Bastxn, Ph. D., Geology Arthur Cutts Willard, D. Eng., LL. D., President of the University of Illinois NATURAL HISTORY SURVEY DIVISION URBANA, ILLINOIS Scientific and Technical Staff Theodore H. Prison, Ph. D., Chief SECTION OF economic ENTOMOLOGY SECTION OF INSECT SURVEY W. P. Flint, B. S., Chief Entomologist H. H. Ross, Ph. D., Systematic En- C. C. CoMPTON, M. S., Associate En- tomologist tomologist Carl O. Mohr, Ph. D., Associate En- M. D. Farrar, Ph. D., Research E.n- tomologist, Artist tomologist L. H. TowNSEND, M. S., Assistant En- tomologist S. C. Chandler, B. S., Sontheni Field Entomologist J. H. Bigger, B. S., Central Field SECTION OF APPLIED BOTANY AND Entomologist PLANT PATHOLOGY L. H. Shropshire, M. S., Northern L. Ph. D., Botanist Field Entomologist R. Tehon, C. Carter, Ph. D., Assistant Bota- E. R. McGovran, Ph. D., Research J. nist Fellow in Entomology G. H. BoEWE, M. S., Field Botanist W. E. McCauley, B. S., Assistant Entomologist SECTION OF GAME RESEARCH AND SECTION OF AQUATIC BIOLOGY MANAGEMENT David H. Thompson, Ph. D., Zoolo- R. E. Yeatter, Ph. D., Game Special- gist ist F. D. Hunt, Field Naturalist D. F. Hansen, A. M., Assistant Zoolo- SECTION OF FORESTRY gist D. J. O'Donnell, M. S., Assistant L. E. Sawyer, B. S. F., Extension Zoologist Forester PUBLICATIONS Carroll Chouinard, M. A., Editor This paper ia a contribution from the Section of Insect Survey. ; FOREWORD This report grows out of studies begun in the fall of 1926 when the writer was first impressed with the abundance and variety of the fall and winter stoneHy population in Illinois. Field observations coupled with the rearing and collection of stoneflies were focused from 1926 to 1929 chiefl_\ on our fall and winter fauna, resulting in the publication by myself in 1929 of a detailed report concerning the "Fall and Winter Stoneflies, or Plecoptera, of Illinois." After the appearance of this paper atten- tion was directed mainly to the species constituting our spring and summer stonefly fauna and a minimum of effort and time has since been spent in study of the fall and winter species. The present paper, then, is a summary of our stonefly studies which have been more or less continuous since 1926. For com- pleteness this report has not been limited to the spring and sum- mer f(jrms but includes an entire survey of the plecopteran fauna of Illinois, which makes it possible to present a classification un- restricted by the seasonal idiosyncrasies of species, genera or families. It oilers, too, an opportunity to add further data con- cerning some of the fall and winter species not available at the time of the 1929 paper, and perhaps most important, it enables the presentation of a balanced and comparati\e picture of the stoneflies of this state. The writer has been greatl\- aided during the course of the study by various individuals and by the literature recording the observations and studies of other workers with this group of aquatic insects. I am indebted to Professors P. W. Claassen and J. G. Needham of Cornell university for the privilege of studying the extensive Plecoptera material in the collection of that institu- tion, and for the donation of specimens and inany other courtesies for the loan or donation of material, to Dr. Nathan Banks of the Museum of Comparative Zoology, Cambridge, Mass., Professor Ferris Neave of the University of Manitoba, Winnepeg. Pro- Dr. fessor Chauncey Juda\ , University of Wisconsin, Madison, iii D. 1. Rasmussen, U. S. Forest Service, Ogden, Utah, Professor H. E. Jaques, Iowa VVesleyan college, Alt. Pleasant, Iowa, and to Dr. R. D. Bird of the Dominion entomological laboratory, Treesbank, Man. Mr. W. J. Spencer, superintendent of the Sears hydroelectric station at Rock Island, 111., has greatly facilitated our studies by first indicating to us the accumulation of insect material on bar racks of hydroelectric stations and by allowing us to establish a rearing station on the property under his charge. A second rearing station was maintained for several years on the property of the Charleston water company, Charleston, 111., adjacent to the Embarrass river, and I am indebted to them for this privilege. Within the Survey I am indebted to Mr. Carroll Chouinard, editor, for taking care of the many details connected with the publication of this paper, to Dr. H. H. Ross, systematic ento- mologist, for aid with collection and rearing of material and with the final preparation of this article, and I am especially indebted to Dr. C. O. Mohr, associate entomologist, for his assistance in the collection and rearing of material and most of all for preparation of the many drawings. Urbana June 1, 1934 T. H. F. IV —- CONTKNTS PAGE Foreword {{{ Status of the Group 281 First studies by Walsh.—-List now nearly static— New classification pro- posed.-—Sex and stage associations. Stonefly Structure 285 Adults.—Nymphs. Biology of the Order 288 Distribution.—^Habitat preferences.—Seasonal ailjustments. — Habits of adults. —Habits of nymphs.— Enemies. Collecting, Rearing and Preservinc; Stoneflies M).^ Collecting adults.— Collecting nymjihs.— Rearing methods, [^reservation of material. Catalog of Species, including classification, dkscripiion, habits and records of ILLINOIS STONEFLIES 307 Classification. —More homogeneous grouping. —Basis of present division. New classification of the Plecoptera of North America.— List of species of the Plecoptera of Illinois.— Plates I-XIV illustrating keys.— Key to families of the Plecoptera of North America.—Pteronarcidae.—Taeniopterygidae.— Nemouridae. —Leuctritlae. —Capniidae. — Perlidae. —Perlodidae.—-Chloro- perlidae. Bibliography 461 Index 468 and Salt Fork river in park at Homer, Illinois. Submerged rocks, leaves of debris in the shallows of such a habitat often furnish the collector with nymphs Neophasganophora capitata, Acroneuria evolnta, Neoperla clymene and Perlesta placida. J ILLINOIS NATURAL HISTORY SURVEY BULLETIN VOLUME XX ARTICLE IV The Stoneflies, or Plecoptera, of Illinois IHKOnORF. H. KRISON STATUS OF THE GROUP THE STOXKFi.y FAUNA of Illinois has never attracted more than slight attention from entomologists. This has been partiallj^ due to an insistance upon pinning the adults after the manner em- ployed for preserving beetles, butterflies and most other insects— a method which inevitably results in shriveled specimens, to impede recognition of structural characters needed in making identifications and to render them so unattractive that the average entomologist is not interested. Two more conditions foster this neglect of the order: the adults are rarely seen in numbers by those not especially searching for them, and frequently adults and nymphs are not readily and accurately associated except by rearing. First studies by Walsh.— The one Illinois entomologist who was an outstanding exception to the general attitude was Benjamin Dann Walsh. His major publishings date from 1868, when as first state entomologist he issued the "First Annual Report on the Noxious Insects of the State of Illinois." His paper concerning certain neuropteroid insects in Illinois (1862)^ contained records and descriptions of stoneflies collected by himself mostly in the vicinity of Rock Island, and as Needham and Claas- sen (1925) state, "he collected so assiduously that the vicinity of Rock Island, III. has remained until recently one of the best worked fields in America for the neuropteroid groups." In the present paper the records and descriptions of Walsh are recognized or placed in synonymy upon the basis of a few specimens named by him and now in the Survey collec- tion or studied by the author, also upon the placements given them by ' Soo liihliosrauhv. p. -iiil. [281 282 ILLINOIS NATURAL HISTORY SURVEY BULLETIN XXMV Needham and Claassen (1925) as a result of their study of types in the Museum of Comparative Zoology, Cambridge, Mass., and upon our studies of the stonefly fauna now existing at Rock Island and in Illinois in general, which give strong circumstantial evidence concerning the species occurring there in former years. I have placed in synonymy or recognized with much confidence all of the species of Walsh with one exception, Chloroperlo nana, and this I believe may eventually be proved to be the same as Isoperlo minuta Banks. A revised tabulation of the species recorded by Walsh from the vicinity of Rock Island in 1862 gives us a present list of 15 species. In the tabulation of species by states as given by Needham and Claassen (1925), Illinois is credited with 14 species, but since two species of Pteronarcys are listed whereas all our evidence indicates but one, this list of 1925 includes only 13 species. If all the Walsh records had been placed by Needham and Claassen their list would have given 17 species for this state. Our studies to date give us a total of 36 species of stone- flies for Illinois plus at least two and possibly a third species as yet known only as nymphs and not placeable to species at present time—a list more than double those of Walsh or Needham and Claassen. The status of two Acroneuria nymphs and another nymph which I am tentatively placing as Neophasganophora need to be definitely estab- lished. Two of these, one Acroneuria and the Neophasganophora, are certainly species which are additions to our list.