Biochemical mechanisms of insecticide resistance in field population of Dengue vector Aedes aegypti (Diptera: Culicidae).

Insecticide resistance has been known to be prevalent in several insect species including mosquito. It has become a major problem in vector control programme due to pesticide resistance through detoxification enzymes. The present study investigated the toxicity of Ae. aegypti to organophosphates and pyrethroid insecticide and biochemical mechanisms involved in insecticide resistance in larval population. Larval bioassay revealed an LC50 value of 0.734 ppm for dichlorvos and 1.140 ppm for λ-cyhalothrin exposure. Biochemical assay revealed increased activity of AChE (0.3 µmole/mg protein) and GST in dichlorvos (1-1.5 µmole/mg protein) treatment and esterase activity in λ-cyhalothrin treated compared to control activity. These studies suggest that AChE and GST is associated with organophosphate and esterase associated with pyrethroid resistance in Ae. aegypti