Susceptibility of Four Species of Diabrotica to Insecticides1

Abstract

Topical LD₅₀, values were determined for 15 insecticides to adult northern corn rootworm, Diabrotica longicornis (Say), southern corn rootworm D. undecimpunctata howardi Barber, western corn rootworm, D. virgifera LeConte, and striped cucumber beetle, Acalymma (=Diabrotica) vittata (F.). All species, collected in Illinois, showed substantial resistance to aldrin and heptachlor but resistance patterns to the carbamates and organophosphates were variable. The southern corn rootworm showed higher resistance to DDT, fensulfothion, fonofos, malathion, and diazinon compared to the other species, The striped cucumber beetle showed higher resistance to malathion than the other species.