Department of Entomology, Post Graduate Institute, Mahatma Phule Krishi Vidyapeeth, Rahuri - 413 722, Maharashtra, India.
*Part of PhD thesis submitted by the first author to the Mahathma Phule Krishi Vidyapeeth, Rahuri - 413 722, Maharashtra, India.
The investigations on to the induction and activity of carboxylesterases (CE) in Helicoverpa armigera (Hubner) populations collected from different locations differing in pesticide usage were undertaken at the Department of Agricultural Entomology, M.P.K.V., Rahuri during 2002–04. The results clearly revealed that enzyme activity was lowest in case of H. armigera collected from low pesticide usage area and vice versa. As regard to the insecticides, all the five populations exhibited least or negligible induction of CE for endosulfan and slightly increased induction of CE for quinalphos over control as evident from enzyme activity. Maximum induction of CE was recorded in insect population exposed to synthetic pyrethroids viz., cypermethrin and fenvalerate. The level of resistance in H. armigera to quinalphos, fenvalerate and cypermethrin were associated with high level of CE induction.
Insecticides, metabolic resistance, carboxylesterases, Helicoverpa armigera
