Assessing radiation-induced enzyme activation in Aedes aegypti: Potential challenges for SIT-based vector management

This study characterizes the Aedes aegypti population from Fernando de Noronha Island, Pernambuco, Brazil, prior to implementing the Sterile Insect Technique (SIT). The main objective was to assess changes in glutathione S-transferase (GST) enzyme activity, previously linked to cypermethrin resistance in this population, in 2010. GST activity was measured in both male and female mosquitoes, masse produced in lab, after exposure to ionizing radiation. The populational evaluation after six years showed a complete susceptibility to cypermethrin, deltamethrin and lambda-cyhalothrin, although GST activity remained altered, increasing furthermore following irradiation (50 % higher in irradiated males and 31 % higher in irradiated females compared to non-irradiated controls). This stress response to gamma radiation suggesting implications for the effectiveness and viability of sterile males, particularly when SIT is combined with chemical insecticides. These findings enhance our understanding of radiation's impact on metabolic responses of the sterile males and provide valuable insights for refining integrated control strategies in vector management programs.