Molecular diagnostics of three Diabrotica (Coleoptera: Chrysomelidae) pest species

A 257 bp region of the mitochondrial ND4 gene was analyzed for genetic variation in three species of corn rootworm, southern corn rootworm (Diabrotica undecimpunctata howardi Barber, SCR), northern corn rootworm (D. barberi Smith and Lawrence, NCR), and western corn rootworm (D. virgifera virgifera LeConte, WCR). Nucleotide sequencing revealed 26 polymorphic sites. Genetic distances averaged 8% for all pair-wise comparisons among the three species. Restriction maps were constructed from sequence data and compared to potential species specific restriction sites. Polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) revealed three restriction enzymes (Alu I, Apo I and Sau 3A) which produced diagnostic patterns for both adults and larvae. Only NCR showed intraspecific polymorphism.