Abstract
Methyl parathion (MP) (O,O-dimethyl O-p-nitrophenyl phosphorothioate) persistence in soil after 3 and 6 wk was increased 1.5- and 2-fold, respectively, in the presence of flucythrinate (FLU) {(RS)-.alpha.-cyano-3-phenoxybenzyl(S)-2-[4-(difluoromethoxy)phenyl]-3-methylbutyrate}. Permethrin (PERM) [3-phenoxybenzyl(1RS)-cis, trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] persistence after 6 wk was reduced 25-40% in the presence of MP. These types of insecticide-insecticide interactions demonstrate the need to consider more than degree of insect pest control when applying insecticide combinations. Changes in environmental behavior, e.g., soil persistence, must also be considered.