Effect of Dienochlor on Oogenesis of the Mexican Bean Beetle (Coleoptera: Coccinellidae)

Abstract

Oviposition by the Mexican bean beetle, Epilachna varivestis Mulsant, was reduced by about 32% on pinto beans and nearly stopped on soybeans by treatment of the leaves with dienochlor at the manufacturer’s recommended rate for the control of mites. Dissection of the affected beetles showed that this was caused by interference with oogenesis. Survival of larvae and adults was normal on treated pinto beans but low on treated soybeans. In contrast, fecundity and survival of adult Colorado potato beetle, Leptinotarsa decemlineata (Say), females on potatoes were not affected by the miticide, even at four times the recommended rate of usage. The results are consistent with a mode of action involving, in part, interference with nutrient use.