Genetic relationship among Diabrotica species (Coleoptera : Chrysomelidae)based on rDNA and mtDNA sequences

Corn rootworms of the genus Diabrotica (Coleoptera: Chrysomelidae) are the most serious pest of corn in midwestern United States. Despite their econom ic importance, phylogenetic relationships within the genus remain unclear. Phylogenetic analysis of five Diabrotica species and subspecies was underta ken using DNA sequences of the nuclear rDNA first internal transcribed spac er region (ITS1) and a portion of the mtDNA cytochrome oxidase I and II gen es (COI/COII). Parsimony and maximum likelihood analysis indicated that sou thern corn rootworm is sister to banded cucumber beetle, whereas, northern corn rootworm forms a distinct clade with western and Mexican corn rootworm . ITS1 and COI/COII were found to be useful markers for determining phyloge netic relationships among diabroticites.