Comparison of Insecticide Resistance and Its Enzyme Mechanisms among <i>Aedes aegypti</i> Collected with Three Methods in a Dengue-Endemic City in Southern Mexico

Abstract

Background: Despite the physical and chemical effort to control Aedes aegypti, the arboviruses transmission in the south of Mexico remains latent.Trying to improve the methods of entomological surveillance routinely used, whether the estimation of resistance to insecticides used for its control, as well as their enzyme mechanisms, were influenced by the phase in which the mosquitoes were collected through three different collection methods was investigated. Materials and Methods: Mosquito collections from the "5 de Febrero" neighborhood in Tapachula, Mexico were obtained by ovitraps, larvitraps, and a CDC backpack aspirator. Insecticide resistance of F 1 females was determined by WHO diagnostic doses and resistance ratios (RR 50 ), furthermore, levels of insecticide metabolism enzymes were determined by biochemical assays. Results: Overall, in mosquitoes collected by ovitraps, larvitraps, and CDC backpack aspirator respectively, the low mortalities obtained with the discriminant dose to Malathion (27.57%, 26.97%, and 26.91%), and to Bendiocarb (50.5%, 45.36%, and 54.97%) suggest resistance. However, LC 50 for Malathion (0.922, 0.934, and 0.915) and for Bendiocarb (0.112, 0.109, and 0.107); and the low resistance ratios (RR 50 ) for Malathion (3.34, 3.29, and 3.27) and for Bendiocarb (2.15, 2.1, and 2.06) does not suggest resistance. Although a slight numerical variation is observed between the three LC 50 *Co-author Americo D. Rodriguez passed away on November 2020.