Preliminary Genetic Analysis of a Recently-Discovered Invasive True Bug (Hemiptera: Heteroptera: Plataspidae) and Its Bacterial Endosymbiont in Georgia, USA

Abstract

A true bug (Hemiptera: Heteroptera: Plataspidae), previously known only in the Old World from India and Pakistan to China, Korea, Japan and Malaysia to Australia, was discovered in mid-October 2009 in several northeastern counties in Georgia (USA). Specimens of the stinkbug were submitted by professional pest control operators and county agents following homeowner complaints of the large number of insects migrating from kudzu killed by recent frosts. The insect was identifi ed using morphological characters as the bean plataspid, Megacopta cribraria (F.) (Hemiptera: Plataspidae), by J.E. Eger, Jr. (Dow AgroSciences, Tampa, FL). The identifi cation was confi rmed by entomologists at North Dakota State University and the USDA-ARS Systematics Laboratory (Washington, DC). Genomic DNA was extracted using methods of Jenkins et al. (2009, Ann. Entomol. Soc. Am. 102: 380 395) from 3 specimens collected in northeast Georgia. The cytochrome oxidase subunit I (COI) gene fragment was then a mplified and sequenced according to Jenkins et al. (2009). The COI s equences from all 3 specimens were identical, indicating a single female line age. When these sequences were subjected to a GenBank Blast search (Altschul et al.1990. J. Mol. Evol. 215: 403 410), M. cribraria (GenBank # AY627332) was the closest match (11 base differences out of 789 total bases or 98.6% identity). A γ-Proteobacterium, Candidatus Ishikawaella capsulata (Hosokawa et al. 2006. PLOS Biol. 4: e337. DOI: 10.1371/journal.pbio.0040337), reportedly lives in the posterior midgut of plataspid stinkbugs and appears to be necessary for normal growth and development. It also has been implicated in increased fecundity (Fukatsu and H osokawa. 2002, Appl. Environ. Microbiol. 68: 389 396). The female bean plataspid,