Cuticular Penetration and Metabolism of Phenthoate in the Resistant and Susceptible Diamondback Moth, Plutella xylostella L.

Abstract

The study on the cuticular penetration of [methoxy-14C] phenthoate in the diamondback moth showed lower rates of cuticular penetration, lower amounts of radioactivity in the insect body and higher excretion rates of phenthoate in the phenthoate-resistant strains (OSS-R and OKR-R) than in the susceptible strains (OSS and OKR). An in vivo metabolism study using [methoxy-14C] phenthoate revealed no apparent difference between resistant and susceptible strains in overall rates of metabolism of [methoxy-14C]phenthoate. The 14C02 produced by treated insects was too small in amounts to be considered as a major product of phenthoate metabolism. Such results of the study indicated that reduced cuticular penetration of phenthoate is one of the important resistance mechanisms in the diamondback moth, Plutella xylostella L&. © 1987, Pesticide Science Society of Japan. All rights reserved.