Onion Maggot Resistance to Insecticides12

Abstract

Tests were done on adults of Hylemya antique (Meigen) to determine the susceptibility of 3 field strains relative to susceptible and cyclodiene-resistant laboratory strains to representative organochlorine, organophosphorus, and carbamate insecticides. Cultures were established from larvae collected at Gun Marsh (1965 and 1972) and Grant, Mich., and Holland Marsh, Ontario (1972). All 3 strains showed intermediate levels of resistance to aldrin, low but significant levels of resistance to DDT (× 1.7–× 2.4), several organophosphorus (OP) insecticidcs including parathion, ethion, VC-13 (0-2,4-dichlorophenyl O, O-diethyl phosphorothioate), fensulfothion, fonofos, chlorfenvinphos, diazinon, malathion, and naled (× 1.4–× 6.5) and a 3-, to 6-fold level of resistance to the carbamate, carbofuran. The Gun Marsh strain was more resistant to OP insecticides in 1972 than in 1965. In 1972, the Grant strain was generally the most resistant of the 3 strains to OP insecticides.