BULLETIN of the ILLINOIS NATURAL HISTORY SURVEl HARLOW B. MILLS, Chief The Pseudoscorpion of Illinois C. CLAYTON HOFF ""''^^^m, ^/% Printed by Authority of the STATE OF ILLINOIS ADLAI E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION NOBLE J. PUFFER, Director STATE OF ILLINOIS Adlai E. Stevenson", Governor DEPARTMENT OF REGISTRATION AND EDUCATION Noble J. Puffer, Director NATURAL HISTORY SURVEY DIVISION Harlow B. Mills, Chief \'oliime 24 BULLETIN Article 4 The Pseudoscorpions of Illinois C. CLAYTON HOFF Printed by Authority of the State of Illinois URBAN A, ILLINOIS June 1949 STATE OF ILLINOIS Adlai E. Stevenson, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Noble J. Puffer, Director BOARD OF NATURAL RESOURCES AND CONSERVATION Noble J. Piffer, Chairman A. E. Emerson, Ph.D., Biology George D. Stodrard, Ph.D., Litt.D., L.H.D., L. H. Tiffany, Ph.D., Forestry LL.D., President of the University oj Illinois L R. HowsoN, B.S.C.E., C.E., Walter H. Newhouse, Ph.D., Geology Engineering Roger Adams, Ph.D., D.Sc, Chemistry NATURAL HISTORY SURVEY DIVISION Urbana, Illinois Scientific and Technical Staff Harlow B. Mills, Ph.D., Chief Bessie B. Henderson, M.S., Assistant to the Chief Section of Economic Entomology Section of Applied Botany and Plant Pa thology George C. Decker, Ph.D., Entomologist and Head Leo R. Tehon, Ph.D., Botanist and Head Cedric Carter, Ph.D., Plant Pathologist J. H. Bigger, M.S., Entomologist J. L. L. English, Ph.D., Entomologist J. L. FoRSBERG, M.S., Associate Plant Patholo gist C. J. Weinman, Ph.D., Entomologist S. C. Chandler, B.S., Associate Entomologist G. H. Boewe, M.S., Assistant Plant Pathologist Willis N. Bruce, M.A., Assistant Entomologist Robert A. Evers, M.S., Assistant Botanist John M. Wright, M.A., Assistant Entomologist Section of Game Research and Manage- H. B. Petty, M.A., Associate in Entomology Extension ment Ralph E Yeatter, Ph.D., Game Specialist Section of Faunistic Surveys and Insect Frank C. Bellrose, B.S., Associate Game Spe- Identification cialist Harold C. Hanson, M.S., Assistant Game Spe- H. H. Ross Ph.D., Systematic Entomologist cialist and Head James S. Jordan, M.F., Assistant Game Tech- Milton W. Sanderson, Ph.D., Associate Tax- nician onomist Lewis J. Stannard, Jr., M.S., Assistant Tax- Section of Publications and Public Rela- onomist tions Leonora K. Gloyd, M.S., Laboratory Assistant Tames S. .Avars, B.S., Technical Editor and Philip W. Smith, B.S., Laboratory Assistant Head Dorothy A. Moulton, Technical Assistant Blanche P. Young, B..A., Assistant Technical Section of Aquatic Biology Editor Charles L. Scott, B.S., Assistant Technical George W. Bennett, Ph.D., Aquatic Biologist Photographer '. and Head William C. Starrett, Ph.D., Associate Aquat- Technical Library ic Biologist Marguerite Simmons, M..^., M.S., Technical D. F. Hansen, Ph.D., Assistant Aquatic Bi- Librarian ologist R. Weldon Larimore, M.S., Research Assist- Cooperative Wildlife Research ant {Illinois Department of Conservation and U.S.: Daniel Avery, Field Assistant Fish and JJ'ildlife Service, Cooperating) Paul Moore, B.S., Project Leader Forestry J. Section of George C. Arthur, B.S., Project Leader Willet N. Wandell, M.F., Forester and Head Lysle R. Pietsch, M.F., Project Leader Lawson B. Culver, B.S., Associate in Forestry John C. Calhoun, B.S., Assistant Project Extension Leader Consultant in Herpetology: Hobart M. Smith, Ph.D., Assistant Professor of Zoology, University of Illinois. This paper is a contribution from the Section of Faunistic Surveys and Insect Identification. (68424—2M— 11-48) ,^.^^^2 FOREWORD During the latter part of 1946, all the vey of the pseudoscorpions. Dr. Hoff re- zoological collections of the Illinois Natural ported such unusual findings, and a fauna so History Survey were brought tojicther into much more extensive than had been ex- one section, formerly the Insect Survey Sec- pected, that we soon decided to make his tiiiii, which was then renamed the Section study the basis of a thoroughgoing faunistic of Faiinislic Surveys and Insect Identifica- report on the group for Illinois. tion. Previously, the Natural History Sur- This decision was strengthened by the vey had published a series of reports on the very apparent need for such a study of the insects of Illinois and, at the same time, had pseudoscorpions. Up to about 1930 the tax- developed the entomological collections. The onomy of this group in North America was double aim of the above reorganization in a preliminary and superficial stage. It was, first, to effect a well-balan.ed program was not until comprehensive analyses of the in the Survey's faunistic activities with the known world fauna were presented by J. C. hope that useful reports on the Illinois fauna Chamberlin and Max Beier in the 1930's would be made for groups other than insects that a groundwork was laid for modern and, second, to build up a comprehensive studies of the group. Since no detailed fau- reference collection of study material for nistic report has previously been prepared the identification of animal groups occurring for any region on the North American con- in the state. tinent, we hope that this Illinois report will A firm basis of expansion in several non- prove useful to many investigators. insect groups, such as the fish and mollusks. We are grateful indeed to Dr. Hoff for was provided several years ago by the ex- the identification of material and prepara- tensive Illinois collections of Stephen A. tion of the manuscript, and for contribut- Forbes. Robert E. Richardson, and Frank ing much of his own time to this project. C. Baker. Although in recent years certain Members of our staff in the Section of Fau- other groups, especially the arthropods and nistic Surveys and Insect Identification have reptiles, have been fairly well collected in contributed materially to the project. Sev- the state along with the insects, our collec- eral of them have assisted with the field pro- tions of many forms are at a beginning level. gram and with adaptation of the manuscript The general aim for all groups is now the to current Survey practices. Four total one that has been developed for the insects: views of pseudoscorpions were prepared to build up as extensive and inclusive a col- especially for this work by Dr. Carl O. lection of Illinois species as possible, and to Mohr, formerly Associate Entomologist and supplement this with representatives of other Artist. Mr. James W. Curfman assisted North American genera and species in each with the preparation, numbering, and letter- group. ing of the plates. Mr. Lewis J. Stannard, We feel fortunate in presenting this ac- Jr., Mrs. Leonora K. Gloyd, and Mrs. count of the pseudoscorpions of Illinois as Dorothy A. Moulton compiled the index and the first report of the expanded part of the assisted in assembling the Illinois records, program. In 194.? we began a co-operative preparing the bibliography, and checking and undertaking with Dr. C. Clayton Hof-f. then integrating the manuscript. at Quincy College, Quincy, Illinois, with the We have enjoyed throughout the help and view of investigating the pseudoscorpion co-operation of the Technical Editor, Mr. fauna of the state. At that time we were James S. Ayars, and Mrs. Drew S. Wetzel making extensive ground cover samples in and Mrs. Blanche P. Young of his staff. connection with certain insect projects, and Herbert H. Ross this activity dovetailed very well with a sur- Systematic Entomologist CONTENTS BIOLOGY 413 Feeding Habits.— Enemies.— Development. — Maturity ami Reproduction. HABITAT PREFERENCES 415 Deciduous Forests.—Rock Outcrops.—Saml Dunes.—Swamps and Bogs.-— Domestic Situations. iDISTRIBUTlON 416 ! Widely Distributed Species.— Southern Species.—Northern Species.—Other Species. 'collecting METHODS 418 PREPARATION OF MATERIAL 422 MORPHOLOGY 423 Body.—Appendages.—Genitalia. ACKNOWLEDGMENTS 427 'classification 427 Disposition of Material.—Systematic List. 1 Key to Suborders 428 f.mwilies Tridenchthoniidae 429 Chthoniidae 431 Ideoroncidae 444 Syarinidae 444 Neobisiidae 444 Menthidae 447 Olpiidae 447 Garypidae 447 Cheiridiidae 449 Sternophoridae 449 CHERNETmAE 449 Atemnidae 485 Cheliferidae 485 LITERATURE CITED 494 INDEX 497 of pseudoscorpion Ground cover or duff in woods such as these harbors a wide variety leaves should be brushed away and species. When a sample is to be collected, the dry top Samples from the lee ot a log the moist lower leaves and the top layer of soil scooped up. are often unusually productive. The Pseudoscorpions of Illinois C. CLAYTON HOFF* PSEUDOSCORPIONS are minute large series of many species and obtaining animals only a few millimeters long, for the first time what appears to be a fairly with the general appearance of di- accurate representation of the total fauna minutive scorpions except that they have no of Illinois. At the present time the list of tails. They belong to the large phylum of known Illinois species stands at 26. Un- joint-legged animals, the Arthropoda, and to doubtedly, other species will be found with the class Arachnida. which, in addition to additional collecting; the present study, the pseudoscorpions, embraces the spiders, based on over 5,000 specimens, represents mites, ticks, scorpions, and other related about .550 collections. groups. Pseudoscorpions are seclusive in The object of this report is twofold, first habit, occurring in soil cover and rotten logs, to present illustrated keys and descriptions under bark, and in similar places out of for the identification of species in this region, doors: one species is found in houses. In and, secondly, to summarize information their natural habitat, these little brown ani- regarding the distribution, biology, and habi- mals arc difficult to see. especially when they tat preferences of the species. As an aid in ilraw in their legs and "play possum." In use of the keys, a section has been included this position they look like little specks of on morphology, in which the structures now dirt.