Activity of insecticide detoxification enzymes in Pectinophora gossypiella (Saunders): Implications for insect pest management in cotton crops

Abstract

The pink bollworm Pectinophora gossypiella is one of the most important endocarpic pests in cotton. In the management of this pest, the  intensive use of synthetic insecticides has led to the reduction of its sensitivity to certain active ingredients. It is in this perspective  that the study was conducted to determine the enzymes involved in the metabolism of insecticides in P. gossypiella. Insects were  collected in five localities (Bouaké, Bouaflé, Vavoua, Sésuéla and Kounahiri) with high pest pressure in the southern cotton zone. The  collected insects were ground for the determination of enzymes involved in insecticide metabolism. The analyses showed a significant  increase in glutathione-δ-transferase activity in populations of Bouaké compared to the other localities. However, individuals from  Séguéla expressed more esterase (alpha and beta) and oxidase activities. Alpha and beta esterase activities were also more expressed in  Bouaflé individuals. The high enzymatic activity of esterases and oxidases in individuals from Séguéla and Bouaflé reflects a low  sensitivity to insecticides in which esterases and oxidases are involved in the metabolism. On the other hand, in Bouaké, only glutathione- δtransferases are involved in the detoxification of insecticides.