Assessment of Lambda-cyhalothrin Toxicity on the Developmental and Reproductive Fitness of Dengue Vector, Aedes albopictus (Skuse) and the Associated Changes in the Activity of Insecticide Detoxifying Enzymes

Introduction: The emergence of resistance development in mosquitoes is a huge challenge for successful vector control programmes. Insecticides used in vector control mainly target the eradication of the vector population but often neglect their residual and long-time effect on the surviving population. Methods: In this study, Aedes albopictus were selected with sublethal doses of lambda-cyhalothrin and its effects on their life parameters and major detoxifying enzymes were analysed. Results: In the twelfth generation of the resistant population, there was a 101-fold increase in resistance ratio values of LC50. In addition, larval development time prolonged for 2 days and hatchability and fecundity were reduced by 52% and 93%, respectively when compared to the control group. Moreover, longevity was shortened by 9.43 days in females and 2.18 days in males. Significant changes in the activity of major detoxifying enzymes were observed where monooxygenase level was highest which indicates its role in lambda-cyhalothrin degradation leading to resistance, followed by both β-esterase and GST. Conclusion: The findings of the current study can be helpful in integrated mosquito management (IMM), where based on their life history traits, the vulnerable stage of vectors can be targeted for effective resistance management.