RESIDUES OF FOUR SYNTHETIC PYRETHROIDS AND AZINPHOS-METHYL ON APPLE FOLIAGE AND THEIR TOXICITY TO AMBLYSEIUS FALLACIS (ACARI: PHYTOSEIIDAE)

Abstract
Residue analysis of apple foliage obtained from an orchard treated with the insecticides cypermethrin, fenvalerate, deltamethrin, permethrin, and azinphos-methyl revealed detectable residues on the leaves 8–9 weeks after the last treatment. Laboratory studies of foliage showed that of the synthetic pyrethroids, permethrin was initially as toxic as the other synthetic pyrethroids; however, its toxicity decreased considerably by the 5th and 6th week post-treatment. Azinphos-methyl was the least persistent and toxic insecticide evaluated. Unless new pest-management strategies are developed, the use of synthetic pyrethroids post-bloom in an integrated-pest-management program would not be desirable where Amblyseius fallacis (Garman) is the principal predator of phytophagous mites.