RESIDUAL TOXICITIES OF 3 INSECTICIDES TO 4 SPECIES (COLEOPTERA, CARABIDAE) OF ARTHROPOD PREDATOR

In laboratory bioassays, four carabid species [Agonum dorsale (Pontopp idan), Bembidion lampros (Herbst), B. obtusum Serville, and Demetrias atricapillus (L.)] that are important predators of aphids in cereals i n the United Kingdom were exposed to deposits of deltamethrin, dimetho ate, or pirimicarb on glass for up to 72 h. We detected differences be tween compounds and species that are discussed in the context of expos ure of these predators to insecticides in the field. We also describe problems involved in obtaining comparative toxicity data when dilution s of field application rates for target species are used in bioassays with nontarget species. Such problems add another dimension to risk as sessment based on laboratory data.