HOST PLANT EFFECTS ON INSECTICIDE RESISTANCE IN CORN ROOTWORMS

摘要

A highly aldrin resistant population of western corn rootworm (Diabrotica virgifera virgifera LeConte, WCR) has recently invaded the northeastern United States, and is supplanting the northern corn rootworm (D. barberi Smith and Lawrence, NCR) as a major corn pest. Although central Pennsylvania populations of WCR are highly resistant (2070 μg/g insect) to the cyclodiene aldrin, sympatric NCR populations are essentially non-resistant (8 μg/g insect) based on 24 hour topical mortality determinations with adults. Also, both rootworm species have mild resistance (5 X) to the carbamate carbofuran, but no resistances to the organophosphates terbufos and isofenphos were detected. The mechanism for the remarkable difference in aldrin susceptibility between WCR and NCR is unclear, since both species exhibit similar biologies, and aldrin has long been suspended for use in the United States and is no longer a selecting factor. We report here the possible role of xenobiotic metabolizing enzymes in explaining the susceptibility differences, particularly in relationship to alternative host plant feeding.