EFFECT OF INSECTICIDES ON SUSCEPTIBILITY AND ESTERASE ACTIVITY OF SPODOPTERA LITURA (NOCTUIDAE:LEPIDOPTERA)

Spodoptera litura is the major pest of economically important crops and many vegetables. ithas more than 120 host plant species and is the major pest of cauliflower, cotton, strawberry, tomato, apple and many other crops. many insecticides have been used for the management of s. litura but the continuous use of insecticide leads to the development of resistance against these insecticides. s. litura has developed resistance against the major insecticides including pyrethroids and carbamates. present study was conducted to determine the susceptibility and esterase activity of the 3^rd and 5^th instar larva of spodoptera litura against three insecticides. esterase is one of the enzymes which cause the detoxification of the insecticides leading to the resistance development. three different concentrations i.e. lc40, lc50 and lc60 of each insecticide were used. esterase activity against each insecticide was determined after 30 min, 2, 24 and 48 hrs. the results revealed that highest activity was found against fenvelrate and lowest activity was found against flubendamide in 3^rd and 5^th instar of s.litura. on the basis of toxicity and enzyme activity among all the tested insecticides, flubendamide found to be very effective against s.litura and can be used for the control of this pest.