Selective Toxicity of Three Synthetic Pyrethroids to Eight Coccinellids A Eulophid Parasitoid, and Two Pest Chrysomelids

Abstract

The toxicities of 3 synthetic pyrethroids (permethrin, cypermethrin, and fenvalerate) were determined for 8 species of predaceous coccinellids, 2 pest chrysomelids (northern corn rootworm and cereal leaf beetle) and a hymenopteran parasitoid of the cereal leaf beetle as topical LD 50 's or contact LC 50 's. All species were collected from corn or oat fields. Two of the pyrethroids, permethrin and fenvalerate, demonstrated selectivity in favor of most of the coccinellid species, whtle cypermethrin was more active against the ladybird beetles than the pest chrysomelids. All 3 pyrethroids were considerably more toxic to the parasitoid than to its chrysomelid host.