|Sears Wichmann, Sheila
Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2014
Publication Date: 3/1/2015
Publication URL: http://handle.nal.usda.gov/10113/61381
Citation: Roehrdanz, R.L., Sears Wichmann, S.G. 2015. 28S ribosomal RNA sequences separate five prominent Lygus (Hemiptera: Miridae) pest species into three species clusters. Annals of the Entomological Society of America. 108(2):211-214.
Interpretive Summary: The group of pest plant bugs (Lygus) that includes the tarnished plant bug, the western tarnished plant bug and several of its close relatives is a significant concern in a variety of agricultural settings. Detailed examination of specimens is required to identify the species and sometimes even that leaves uncertainty. Phylogenetic relationships within the group are not understood, leaving us to guess at which species might be capable of interbreeding and potentially altering their pest behavior. We compared a nuclear gene DNA sequence from samples of six species. The results indicate three clusters of two closely related species that loosely correlate with their geographic distribution. There is also the suggestion that two of the species may have undergone some hybridization.
Technical Abstract: A segment of the nuclear 28S rRNA gene was compared among six species of Lygus (L. hesperus, L. keltoni, L. borealis, L. elisus, L. lineolaris, L. vanduzeei). The DNA sequences separate into three main groups. The LL group contains L. lineolaris and L. vanduzeei. Group LBLE is comprised of L. elisus and most of the L. borealis. Group LH includes L. hesperus and most of L. keltoni. Some L. keltoni were part of the LBLE group and some L. borealis were part of the LH group. The 28S region does not contain sufficient genetic polymorphism to delineate species. The apparent polyphyly of L. borealis and L. keltoni could reflect historic interbreeding, recent development of a hybrid swarm, or highlight inadequacies of morphospecies identification.