Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2002
Publication Date: 7/10/2003
Citation: ROEHRDANZ, R.L. A MULTIPLEX POLYMERASE CHAIN REACTION METHOD FOR DIFFERENTIATING WESTERN AND NORTHERN CORN ROOTWORM LARVAE (COLEOPTERA: CHRYSOMELIDAE).. JOURNAL OF ECONOMIC ENTOMOLOGY. 96(3):669-672, 2003. Interpretive Summary: In some portions of the corn belt, the western corn rootworm and the northern corn rootworm both reach population levels that constitute a threat to agriculture. Because the larvae are visually identical it has not been possible to determine how they may interact with each other and whether there are significant differences in their feeding behavior. Differences between the two species in DNA sequence of part of the mitochondrial genome has been exploited to design polymerase chain reaction (PCR) primers that can be used for species identification. A common primer at one end of the region is used in conjunction with two other primers, one of which recognizes only northern corn rootworms and the second recognizes only western corn rootworms. When a PCR reaction is performed with DNA from a single insect, only one of the two species-specific primers is able to make a PCR product. Because the two possible PCR products differ in size by about 200 base pairs, it is easy to determine which primer has been successful and thus which species was present in the reaction. The primers were initially tested using DNA from adults of known species and are being employed to catagorize larvae collected from fields where both species are present.
Technical Abstract: Western and northern corn rootworms (Coleoptera, Diabrotica) are sympatric species and serious pests of maize cultivation in North America. Comparison of nucleotide sequence of mitochondrial cytochrome oxidase I and II was used to design PCR primers that discriminate immature stages of the two species based on differences in amplicon size. This facilitates investigations of larval interaction and competition between the species.