RESISTANCE SHOWN BY A PARATHION-RESISTANT ONION MAGGOT (DIPTERA: ANTHOMYIIDAE) STRAIN TO SOME OTHER INSECTICIDES

Abstract

AbstractParathion-resistant (R) (× 24) onion maggot (OM), Delia antiqua (Mėigen) (Diptera: Anthomyiidae), adults showed 15-, 9.3-, and 7.7-fold levels of cross-resistance to direct contact applications of chlorpyrifos, naled and chlorfenvinphos, respectively, when compared at the LD50 with an insecticide-susceptible OM strain. R OM also showed 3.4-, 2.9-, 1.6-, and 1.3-fold levels of resistance to deltamethrin, permethrin, cypermethrin, and fenvalerate, respectively. The low-level resistance to the pyrethroids was probably conferred from DDT, to which the R OM strain had a 4.7-fold resistance level. Nevertheless, deltamethrin, cypermethrin, fenvalerate, and permethrin were 137, 58, 28, and 17 ×, respectively, more toxic to the R OM strain than was parathion.