Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2000
Publication Date: 9/1/2000
Citation: Szalanski, A.L., Roehrdanz, R.L., Taylor, D.B. 2000. Genetic relationship among Diabrotica species (Coleoptera: Chrysomelidae) based on rDNA and mtDNA sequences. Florida Entomologist 83(3):262-267. Interpretive Summary: Corn rootworms are a complex of species in the genus Diabrotica and are the most serious pest of corn in midwestern United States. In the United States, 20 to 25 million acres of corn are treated annually with soil insecticides to protect crops from corn rootworm larval feeding damage. In the southern part of the United States, Diabrotica species also pose a threat to cucurbits, peanuts, and sweet potatoes. The economically significant members of the genus include western corn rootworm, Mexican corn rootworm, northern corn rootworm, banded cucumber beetle, and southern corn rootworm. We have used DNA-based technology to examine the phylogenetic relationships of these pest species. In the process we have also discovered some DNA markers that can be used for molecular taxonomy and the identification of immature insects.
Technical Abstract: Corn rootworms of the genus Diabrotica (Coleoptera: Chrysomelidae) are the most serious pest of corn in midwestern United States. Despite their economic importance, phylogenetic relationships within the genus remain unclear. Phylogenetic analysis of five Diabrotica species and subspecies was undertaken using DNA sequences of the nuclear rDNA first internal transcribed spacer region (ITS1) and a portion of the mtDNA cytochrome oxidase I and II genes (COI/COII). Parsimony and neighbor-joining cladograms indicated that southern 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 phylogenetic relationships among diabroticites.