AN ABSTRACT OF THE THESIS OF MICHAEL DAVID SCHWARTZ for the degree of MASTER OF SCIENCE in ENTOMOLOGY presented on Title: A REVISION OF THE BLACK GRASS BUG GENUS IRBISIA REUTER (HETEROPTERA:MIRIDAE) Redacted for privacy Abstract approved: John D. Lattin The black grass bug genus Irbisia Reuter was revised. Over 18,000 specimens were examined and information concerning the biology, host plant and distributional relationships of the species was compiled. In addition to external characters, the male claspers and vesica, and the female dorsal libiate plate of the bursa copulatrix and sclero- tized rings were used to distinguish the species. Sixty-nine charac- ters selected from male and female genitalia, and external morphology were cladistically analyzed. Thirty-two characters are intra- correlated, defining four species groups. Twenty-three species are recognized in the genus. Two keys to the species are presented. One new species, Irbisia knighti is described. The following synonymies are proposed: I. brachycera (Uhler) = I. gorgoniensis Bliven, I. paeta Van Duzee, I. tejonica Bliven, I. vestifera Bliven; I. californica Van Duzee = I. eurekae Bliven, I. paenulata Bliven; I. elongata Knight = I. retrusa Bliven; I. setosa Van Duzee = I. ustricula Bliven; I. solani (Heidemann) = I. lacertosa Bliven. Irbisia species diversity is greatest in the Coastal, Peninsular, Sierra and Transverse Ranges of California and decreases northward, northeastward and eastward. Major centers of endemism are located in California and the Rocky Mountains northwest of the Wyoming Basin; a minor center is located in the Siskiyou Mountains of southwestern Oregon. Faunal similarity analysis suggests that the present Irbisia fauna is derived from two source areas - one Californian, and one in the Rocky Mountains. The present distribution of I. sericans (StS1) may be derived from Beringian refugia. The distribution of the Irbisia species appears to be delineated by climatic conditions; late winter and early spring precipitation is required for growth of their cool season grass hosts. Over twenty native and introduced species of grasses are utilized by larval and adult stages of Irbisia in Oregon. Larval feeding was observed on four species of nongrass monocots, and species of Lupinus and Lathyrus (Fabaceae). There appears to be no grass host specificity among the Irbisia species. However, all the grass species utilized are in the subfamily Pooideae; genera from the Avenae, Poeae and Triticeae predominate. The Irbisia species are the earliest mirid to consume the grass resource, completing their life cycle before grass seed is mature. Many Irbisia species, upon maturity, leave grasses and congregate on conspicuous nearby shrubs and trees. Their dispersal is correlated with the blossoming of these plants; adult feeding on pollen, nectar or honeydew is suspected. A Revision of the Black Grass Bug Genus Irbisia Reuter (Heteroptera:Miridae) by Michael David Schwartz A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Commencement June 1981 APPROVED: Redacted for privacy Professor of Entqthogy in charge of major Redacted for privacy Head of Department of Entomology /2/ Redacted for privacy Dean of Gradu te School Date thesis is presented March 18, 1981 Typed by Elyse T. Larsen forMICHAEL DAVID SCHWARTZ ACKNOWLEDGEMENTS Many people have assisted during all phases of this study and without their contributions much of the research could not have been completed. Financial support was provided by a research assistantship through the Oregon State University Systematic Entomology Laboratory with funds made available by the Science Technical Advisory Fund. The Oregon State University Computer Center granted financial support for computer services for unsponsored research. Type specimens were borrowed from the California Academy of Sciences, San Francisco, (CAS), Dr. Paul H. Arnaud, Jr. and Cornell University, Ithaca, New York, (CU), Dr. Laverne L. Pechuman. The syntypes of Irbisia brachycera (Uhler) and I. pacifica (Uhler) were compared with topotypic specimens through the effort of Dr. John D. Lattin, Oregon State University, Corvallis.The holotype of I. cuneomaculata Blatchley was examined by Mr. Arwin V. Provonsha, Purdue University, West Lafayette, Indiana. In addition to the above, the following institutions or private collections and curators or individuals kindly loaned specimens: Alaska Agricultural Experiment Station, Palmer, (AKAS), Mr. David P. Bleicher; American Museum of Natural History, New York, (AMNH), Dr. Randall T. Schuh; Arizona State University, Tempe, (ASU), Dr. Frank F. Hasbrouck; Boise State University, Idaho, (BSU), Dr. Charles W. Baker; Brigham Young University, Provo, Utah, (BYU), Dr. Stephen L. Wood; California State Department of Food and Agriculture, Sacramento, (F&A), Dr. Alan R. Hardy; Canadian National Collection, Ottawa, (CNC), Dr. Leonard A. Kelton; Humboldt State University, Arcata, California, (HSU), Dr. Richard L. Hurley; Illinois Natural History Survey, Urbana, (INHS), Dr. Donald W. Webb; James Entomological Collection, Pullman, Washington, (WSU), Dr. William J. Turner; Los Angeles County Museum of Natural History, California, (LACM), Dr. Charles L. Hogue; Montana State University, Bozeman, (MSU), Ms. Sharon D. Rose; North Dakota State University, Fargo, (NDS), Dr. Edward U. Balsbaugh Jr.; Northern Arizona University, Flagstaff, (NAU), Dr. Clarence D. Johnson; Oregon State Department of Agriculture, Salem, (OSDA), Mr. Kenneth Goeden and Mr. Richard L. Westcott; Oregon State University, Corvallis, (OSU), Dr. John D. Lattin, Dr. Paul W. Oman, Dr. Loren K. Russell, Mr. Gary M. Stonedahl, Mr. Gary M. Cooper, Mr. Kenneth J. West; Pacific Union College, Angwin, California, (PUC), Dr. Lloyd E. Eighme; Polhemus Collection, Englewood, Colorado, (JTP), Dr. John T. Polhemus; San Diego Natural History Museum, California, (SDNH), Mr. David K. Faulkner; Santa Barbara Museum of Natural History, California, (SBNM), Dr. Scott E. Miller; Schuh Collection, Klamath Falls, Oregon, (JS), Mr. Joe Schuh; Snow Entomological Museum, Lawrence, Kansas, (KU), Dr. Peter D. Ashlock and Dr. George W. Byers; South Dakota State University, Brookings, (SDS), Dr. Burrus McDaniel; Southern Oregon College, Ashland, (SOS), Dr. Marvin D. Coffey; Texas A & M University, College Station, (TA&M and SHF), Dr. Joseph C. Schaffner; United States National Museum, Washington, D.C., (USNM), Dr. Richard C. Froeschner and Mr. Thomas J. Henry; University of Alberta, Edmonton, Canada, (UALB), Dr. George E. Ball; University of Arizona, Tucson, (UAZ), Dr. Floyd G. Werner; University of British Columbia, Vancouver, Canada, (UBC), Dr. Geoffrey G.E. Scudder; University of California, Berkeley, (UCB), Dr. Jerry A. Powell; University of California, Davis, (UCD), Dr. Robert 0. Schuster; University of California, Riverside, (UCR), Mr. Saul I. Frommer and Dr. John D. Pinto; University of Idaho, Moscow, (UID), Dr. William F. Barr; University of Nebraska, Lincoln, (UN), Dr. Brett C. Ratcliffe; University of Wyoming, Laramie, (UWY), Dr. Robert J. Lavigne; Utah State University, Logan, (USU), Dr. Wilford J. Hanson; Western Washington State College, Bellingham, (WWS), Dr. Gerald F. Kraft. Plant identifications were provided by Mrs. LaRae D. Johnston and Dr. Kenton L. Chambers, Herbarium, Oregon State University; Ms. Pamela Ann Camp, Bureau of Land Management, Spokane, Washington, and Dr A.H. Winward, United States Forest Service, Ogden, Utah. Dr. J.M. Ferris, Purdue University, West Lafayette, Indiana, provided a CDC 6500 version of the Wagner 78 maximum parsimony program of Dr. J.S. Farris, State University of New York, Stonybrook. Ms. Bonnie B. Hall, Scientific Illustrator, Oregon State University, Systematic Entomology Laboratory, Corvallis, illustrated the body of three species in dorsal view. I would like to express my sincere thanks to the members of my thesis committee, Dr. Kenton L. Chambers, Dr. John H. Lyford, Jr. and Dr. Paul W. Oman.Dr. John D. Lattin, my major professor, suggested this project, allowed me to make use of his own preliminary notes on the genus, aided in all facets of the research, and provided unerring guidance for its duration. I wish to especially thank these individuals: Dr. Vincent de Paul Razafimahatratra for teaching me the intricate and tedious technique of mirid genitalic dissection; Dr. Loren K. Russell for assist- ing me in collecting specimens on several field trips in California and Oregon; Dr. Paul W. Oman for providing me with numerous specimens from central Washington; Dr. George F. Knowlton for bringing to my attention the unpublished research of Mr. Earl J. Taylor, Yuma, Arizona; Mr. Taylor for allowing me to incorporate his data; Mr. Jeff B. Knight, University of Nevada, Reno, for graciously allowing me to incorporate his unpublished data on the biology of Irbisia species; Mr. Gary M. Cooper and Mr. Gary M. Stonedahl for their advice and sincere encouragement during this study; Ms. Elyse Larsen for the outstanding preparation of the manuscript; and the members of the household of Shady Manor for their moral support and understanding throughout my graduate studies. With great pleasure, I dedicate this thesis to my father, Henry R. Schwartz; I am sorry we cannot share this moment. TABLE OF CONTENTS Page INTRODUCTION 1 LITERATURE REVIEW 3 MATERIALS AND METHODS 6 BIOLOGY BIOGEOGRAPHY AND SUGGESTED PHYLOGENY 16 METHOD OF CLASSIFICATION 28 DISCUSSION OF TAXONOMIC CHARACTERS 30 DISCUSSION