Dry Cucurbitacin-containing Baits for Controlling Diabroticite Beetles (Coleoptera: Chrysomelidae)

Abstract

Dry ground baits impregnated with insecticide and containing cucurbitacins as arrestants and feeding stimulants are effective in controlling adult western corn rootworms, Diabrotica virgifera virgifera LeConte, and southern corn rootworms, Diabrotica undecimpunctata Howardi Barber. Bait effectiveness was proportional to the concentration of cucurbitacins, but differences between different bitter cucurbit sources were negligible. Carbamate insecticides, particularly methomyl, were generally judged superior for bait efficacy compared with organophosphorus and pyrethroid insecticides. Addition of eugenol to the dried cucurbitacin bait increased response of D. u. howardi adults to the bait by ca. 4-fold, but had no effect on response of D. v. virgifera. Initial studies suggest that substantial reductions in adult corn rootworm populations may be obtained with broadcast applications of baits containing ca. 0.1% cucurbitacins and 0.1% insecticide applied at 11–33 kg/ha in corn or cucurbits.