DEATH VALLEY JUNE BEETLE PROJECT 1995 for NATIONAL BIOLOGICAL SURVEY and DEATH VALLEY NATIONAL PARK by -------------------~~~-~~~~~~~DA~Ud~R.~R{J££"Rl"b=======-------------------------------------------------------- MIAMI UNIVERSITY OXFORD, OHIO TABLE OF CONTENTS SECTION PAGE ABSTRACT ......................................................................................................... 1 INTRODUCTION ................................................................................................ 1 METHODS sampling strategy .......................................................................................... 5 genetic analysis ............................................................................................. 7 RESULTS genetic data................................................................................................... 8 sampling results ............................................................................................ 9 DISCUSSION taxonomic status .......................................................................................... 13 aistii5ution................................................................. ; ................................ 1'5~=~------------------------- biology ....................................................................................... ;................ 17 sexual attraction ........................................................................................... 21 predators ...................................................................................................... 22 threats .......................................................................................................... 22 CONCLUSION ................................................................................................... 25 ACKNOWLEDGEMENTS ................... ~ ............................................................. 25 LITERATURE CITED .................................................................................... ·... 26 INDEX TO TABLES, FIGURES, AND APPENDICES TABLE # PAGE 1. Collection sites for june beetle survey ........................................................ 38 2. Enzyme and buffer systems used for electrophoretic analysis of Polyphylla ............................................................................................... 44 3. Allele frequencies for P. anteronivea ........................................................ .45 4. Allele frequencies for P. erratica ....................... ~ ....................................... 45 5. Genetic variability at 14 loci for all populations of P. anteronivea and P. erratica (standard errors in parentheses) ................ .46 6. Matrix of genetic similarity and/or distance coefficients between P. anteronivea and P. erratica ................................................................... 4 7 7. Matrix of genetic similarity and/or distance coefficients for selected Polyphylla taxa.......... ,' ................................................................... 48 8. Estimated acreage for Polyphylla erratica ................................................. .49 1. Location of Death Valley National Park....................................................... 8 2. June beetle census locations along the Amargosa River drainage and the Saline and Eureka Valleys in Death Valley National Park.............. 29 3. Polyphylla erratica survey sites along the Amargosa River drainage .......... 30 4. Polyphylla anteronivea survey sites in Saline and Eureka Valleys .............. 31 5. Polyphylla anteronivea male ........................................................................ 32 6. Polyphylla erratica male and female ........................................................... 33 7. Saline Valley Dunes. (A) north side of lake with mesquite covered dunes; (B) west side of lake with creosote and open sand ........................... 34 FIGURE # PAGE 8. Alkali flats with Distichlis saltgrass (A) Ash Meadows; (B) Saratoga Springs ...................................................................................... 35 9. Female Polyphylla erratica in her burrow about eight inches below the soil surface ................................................................................... 36 10. Polyphylla erratica impaled on mesquite thorn by loggerhead shrike at Saratoga Springs ....................................................................................... 37 APPENDIX A Hardy, A.R., and F.G. Andrews. 1978. Studies in the Coleoptera of western sand dunes. 1. Five new Polyphylla Harris. Pan.-Pac. Ent. 54:1-8. B Young, R.M. 1988. A monograph of the genus Polyphylla Harris in America north of Mexico (Coleoptera: Scarabaeidae: Melolonthinae). BulL of the Nebraska State Mus. 11: 1-115. 1995 DEATH VALLEY JUNE BEETLE REPORT David Russell Department of Zoology, Miami University, Oxford, OH 45056 ABSTRACT The beetle genus Polyphylla (Coleoptera: Scarabaeidae: Melolonthini) is a taxonomically difficult group. This genus has had over 73 names proposed for the 28 currently recognized species north of Mexico. Five of these species are currently listed as Category 2 organisms-­ candidates for federal listing as threatened or endangered but for which insufficient information is known. The purposes of this study were: 1) to ascertain the taxonomic status of the Category 2 species Polyphylla anteronivea and P. erratica using data from allozyme electrophoresis; 2) to survey Death Valley National Park and adjacent areas to determine the present distribution of both taxa; 3) to study present populations in light of potential threats to their existence. A total of 144 sites were surveyed over three collecting periods between April 28 and June 29, 1995. Fourteen loci from 11 enzyme systems were examined using starch gel electrophoresis. Analysis of 38 P. anteronivea and 44 P. erratica revealed significantly different =~~=a;Hel~f=re<tuenG-ies===-at leur 1@6i-~with~ce.~ante1=oni"llea possessing three--_-----_------------___ _ unique alleles. Genetic distance estimates (Nei unbiase9 minimum distance = 0.17; Modified Roger's distance = 0.42) were calculated between the two species. The biological and genetic results of this study indicate that P. anteronivea and P. erratica represent valid species. The distributional survey showed these beetles to be restricted in range, although common in appropriate habitats. Habitat alterations, primarily by water removal, represent the greatest potential threat to these species. INTRODUCTION The beetle genus Polyphylla (Coleoptera: Scarabaeidae: Melolonthini) is found discontinuously throughout the Northern Hemisphere. Of the 65 species known worldwide (Dalla Torre 1912, DeWailly 1948, 1993), 32 are found in the New World. Since the genus was first described by Harris (1841) over 73 names have been proposed for the 28 currently recognized species in America north of Mexico (Young, 1988). Numerous attempts have been made in the last 150 years to identify morphological characters that provide accurate species identifications. Indeed Polyphylla as a whole appears replete with apparent homoplasies and convergent evolution as its members have independently evolved similar characteristics to survive in extremely hostile environments. The present systematics of Polyphylla makes identification tentative at best. Fifteen of the 28 currently described species of Polyphylla north of Mexico are found in a single sand dune system or on a single mountain top (Young, 1988). Frequently, collection location is used to differentiate specimens because of a lack of substantial morphological characters. Five species of Polyphylla are currently Category 2 species-- candidates for federal listing as threatened or endangered but for____________________ _ which insufficient information is known to make a formal decision. The purpose of this study was threefold: 1) to ascertain the taxonomic status of the Category 2 species Polyphylla anteronivea and Polyphylla erratica using data from allozyme electrophoresis; 2) to survey Death Valley National Park and adjacent areas to determine the present distribution of both taxa; 3) to study the present populations in light of potential threats to their existence. The present distribution of both species was thought to be (Hardy and Andrews, 1978) primarily within the borders of· Death Valley National Park (Fig 1). Though described as separate species by Hardy and Andrews (1978) their current taxonomic status is in 2 question. As Young (1988) stated in his monograph "... there are certainly gradations between the two [Po anteronivea and P. erratica] which can only be clearly identified by the collecting locality". Upon extracting the aedeagi (not done by Hardy and Andrews (1978) at the time of the original description) Young (1988) found no significant differences and stated there "was insufficient data to decide whether these two names represent valid, somewhat cryptic species, or a single, perhaps clinal, taxon. This species [Po anteronivea] is very closely related to P. erratica, so closely III fact that I doubt that both names represent biological species." The Saline Valley Snow-front June Beetle (P. anteronivea) IS known only from the sand dune complex in the Saline Valley of Inyo Co., CA (Fig 2B). With the signing of the Desert Bill in early 1995, Saline Valley was incorporated into Death Valley National Park. Typical individuals are easily distinguished from closely related specIes (especially P. erratica) by the thick covering of white scales on