BLISTER BEETLES (COLEOPTERA: MELOIDAE) OF WISCONSIN: DISTRIBUTION AND ECOLOGY By Daniel A. Marschalek A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Entomology) at the UNIVERSITY OF WISCONSIN-MADISON 2013 Date of final oral examination: 12/7/12 The dissertation is approved by the following members of the Final Oral Committee: Daniel K. Young, Professor, Entomology Daniel L. Mahr, Professor Emeritus, Entomology Claudio Gratton, Associate Professor, Entomology Eileen M. Cullen, Associate Professor, Entomology Don M. Waller, Professor, Botany Mark E. Berres, Assistant Professor, Animal Sciences i BLISTER BEETLES (COLEOPTERA: MELOIDAE) OF WISCONSIN: DISTRIBUTION AND ECOLOGY Daniel A. Marschalek Under the supervision of Professor Daniel K. Young At the University of Wisconsin-Madison Meloids are commonly referred to as “blister beetles” due to the toxin (cantharidin) they possess which can cause blistering of human skin. Several meloid species have long histories of negatively impacting agriculture resulting from large foraging aggregations and negatively impacting livestock health. Even with these important and interesting aspects, little is known about these beetles in their natural habitats. There are recent faunistic surveys of selected insect taxa in Wisconsin but a formal investigation of Meloidae is lacking. The blister beetle fauna of several states has been published, but this survey represents the first in the Midwestern United States. This study provides a comprehensive list of all meloid species documented from Wisconsin, as well as taxonomic keys and summaries for each species (species pages) which includes taxonomy, description, and natural history. During this survey, 28 species in seven genera were documented in Wisconsin, with 10 species considered new state records. Initial efforts identified Gnathium minimum (Say) with a limited distribution in Wisconsin which represents a peripheral or even disjunct population for the species. For these reasons I chose to further investigate the ecology of G. minimum. A marking study of G. minimum at Spring Green Prairie State Natural Area resulted in recapturing 54 of the 104 marked adults from 24 July to 16 August 2008. The maximum daily count was 34 while the maximum daily Jolly-Seber population size estimate was 59 individuals. ii Most individuals remained within 12 m of their original capture location, but 601 m was the maximum movement detected. I also conducted a G. minimum population genetics study to compare the genetic variation and magnitude of genetic differentiation of the Wisconsin peripheral population compared to the core population. The percent of polymorphic loci was 52.3 and 52.9, and expected heterozygosity 0.1815 and 0.1883 for the Kansas/Colorado and New Mexico/Texas regions, respectively. Specimens from Wisconsin had a lower percent of polymorphic loci (36.8) and expected heterozygosity (0.1438). FST values, isolation-by-distance patterns, and GENELAND genetic clusters provide evidence that dispersal among sampling locations is greater in the core population and that local populations in Wisconsin are more isolated. iii Acknowledgements This research would not have been possible without the assistance I received from numerous individuals. I am truly appreciative for their cooperation during this project. This research involved two very different topics with their own set of specialized techniques. I am greatly appreciative to Dan Young and Mark Berres for dedicating so much of their time with me so that I could learn and apply these techniques. They both provided a great deal of instruction and guidance throughout the Ph.D. program. The other committee members, Dan Mahr, Claudio Gratton, Eileen Cullen, and Don Waller, also provided valuable guidance when developing the scope of this research. I am also very grateful to John Pinto and Jeff Huether for graciously offering advice and information concerning blister beetles. Their expertise of meloids was especially valuable during the development of this project, but also throughout the later steps of this research. Much of this research was dependant on access to previously collected material. For this reason I wish to thank the following people for loaning specimens: Charles Bomar (University of Wisconsin-Stout), Susan Borkin (Milwaukee Public Museum), Mike Bourquin (Retzer Nature Center), Mike Draney (University of Wisconsin-Green Bay), Gene Drecktrah (University of Wisconsin-Oshkosh), Eric Heeg (The Coleopterists Society, Youth Incentive Award Project), Rich Henderson (Wisconsin Department of Natural Resources), Jamee Hubbard (University of Wisconsin-Stevens Point), Steve Krauth (University of Wisconsin-Madison), Phil Pellitteri (University of Wisconsin-Madison), Scott Sauer (Wisconsin Department of Natural Resources), Kurt Schmude (University of Wisconsin-Superior), Paul Skelley (Florida State University), Margaret Thayer (Field Museum of Natural History), and Jay Watson (Wisconsin Department of Natural Resources). I would also like to thank Kansas Deparment of Wildlife and Parks, The iv Nature Conservancy (Nick Miller and Steve Ritcher), Wisconsin Department of Natural Resources (Thomas Meyer), and University of Wisconsin-Madison Arboretum (Brad Herrick) for their assistance in obtaining collecting permits. Specifically related to the population genetics study, I would like to thank Whitney Cranshaw, Boris Kondratieff, and Darren Pollock for providing specimens. These additional specimens provided for a wider geographic perspective without requiring a substantial investiment of time and money on my part. While insect identification was the main focus of this research, plant identification was also an important aspect. Jeb Barzen and Andrew Williams provided assistance with identification of several plant species so that I could expand the list of known food plants for blister beetles. The University of Wisconsin-Madison library staff also deserves mention due to the countless articles and books I have requested over the years. Working so closely with everyone associated with the Young and Berres labs has been a great experience. This includes, but not limited to: Rachel Arango, Craig Brabant, Andrew Cassini, John Dorshorst, Jeff Gruber, Kari Gullickson, Matt Hayes, Nate Hoftiezer, Julia Janicki, Kyle Johnson, Becky Kirby, Nadine Kriska, Jesse Mayry, Hoa Nguyen, and Michele Price. Our daily discussions not only provided important advice but also provided invaluable support and encouragement. I look forward to future collaborations on the professional level as well as continuing our friendships. Finally, I would like to thank my family and friends for their support throughout my time working on this degree. They provided important reasons to step away from work and enjoy the other aspects of life. v Table of Contents Abstract………………………………………………………………………………………….... i Acknowledgements…………………………………………………..…………………………. iii Table of Contents…………………………………………………………….…………….…….. v Chapter 1: A Survey of the Blister Beetles of Wisconsin (Coleoptera: Meloidae)……….……... 1 Abstract……………………………………………………………………………………..……. 2 Introduction………………………………………………………………………………………. 3 Methods……………………………………………………………………………………...….. 10 Results .......................................................................................................................................... 13 Key to the Wisconsin Genera of Adult Meloidae…………………………….………………… 13 Genus Epicauta Dejean................................................................................................................. 15 Key to the Wisconsin Species of Adult Epicauta......................................................................... 16 Epicauta fabricii (LeConte).............................................................................................. 20 Epicauta flavocinerea (Blatchley).................................................................................... 24 Epicauta murina (LeConte) ............................................................................................. 25 Epicauta cinerea (Forster) ............................................................................................... 27 Epicauta flobcina Pinto .................................................................................................... 30 Epicauta funebris Horn .................................................................................................... 32 Epicauta obesa (Chevrolat) ............................................................................................. 34 Epicauta pensylvanica (Degeer) ...................................................................................... 36 Epicauta atrata (Fabricius) .............................................................................................. 40 Epicauta sericans LeConte .............................................................................................. 43 Epicauta occidentalis Werner .......................................................................................... 46 vi Epicauta vittata (Fabricius) ............................................................................................. 48 Genus Lytta Fabricius ................................................................................................................. 52 Key to the Wisconsin Species of Adult Lytta............................................................................... 53 Lytta sayi LeConte ..........................................................................................................