Manu Sankar ¹ Divya Yadav ¹ Sarita Kumar ^1,2*

• ¹ Acharya Narendra Dev College, University of Delhi, New Delhi, National Capital Territory of Delhi, India
• ² University of Delhi, New Delhi, India

Aedes aegypti, the vector of multiple arboviral diseases, is of prime health concern worldwide. The surge in Aedes-borne diseases emphasizes the urgent need for efficient vector control measures. Synthetic pesticides used traditionally, however, present environmental concerns and issues like resistance development causing use of higher chemical doses. Hence, alternate interventions like use of insect growth regulators (Diflubenzuron,; DFB) show promise because of their unique mechanism of action and environmental safety. Nevertheless, potential of mosquitoes have potential to develop resistance against any chemical. Hence,it, the present study investigates the possible use of DFB in combination with verapamil (DFB-V; 1:10) as the possible mosquito intervention measure. The effects of both DFB and DFB-V was assessed on the larval development and, expression of detoxification enzymes, -non-specific esterases, glutathione S-transferase (GST), acetylcholinesterase (AChE) and monooxygenases,; in two Ae. aegypti strains; laboratory-reared (AND-Ae. aegypti) and wild-caught (GVD-Ae. aegypti) strains of Ae. aegypti. The effects was also investigated on the survival ofand non-target organisms. Results showed that DFB-V treatment of the Ae. aegypti fourth instars caused 1.16-1.37 fold higher adult emergence suppression than DFB reducing the IE 50 values. The DFB treatment, though increased β-esterases, AChE and monooxygenases, yet but reduced the GST and αesterases levels. The effects enhanced with the use of DFB-V causing a significant decrease in α-esterase (7.7-fold) and increase in monooxygenases (7.810.0-fold) (p < 0.05) in AND-Ae. aegypti than the wild-caught strain. The variation in enzyme levels in the two strains may be due to the stress of caused by diverse insecticides of different chemical nature used in the fields. The studies showed the probable role of GST and α-esterases in increasing the growth regulatory effects of DFB when synergized with verapamil assisting in eco-safe vector management. Further, the DFB-V did not result in any significant any negative effects on the non-target organsims -Gambusia affinis, Mesocyclops thermocyclopoides and Paramecium tetraurelia spp. ascertaining its safe usety. This is the first ever report unraveling the effects of DFB-verapamil combination on the defense mechanism of Ae. aegypti. Further studies may assist in the development of focused and eco-safe plans effectively managing Ae. aegypti populations effectively.