Ingestion of attractive toxic sugar baits containing ivermectin before and after blood feeding affects the biology and reproduction of <scp> <i>Aedes aegypti</i> </scp> (Diptera: Culicidae)

The attractive toxic sugar bait (ATSB) is an alternative approach for mosquito control, combining an attractant, a phagostimulant (sugar) and an insecticide. In this study, we evaluated the effects of ATSBs containing ivermectin (IVM, 15 ppm) on the biology and reproduction of Aedes aegypti females under different conditions relative to blood feeding. The bait was prepared with guava juice, 70% brown sugar, water, food dye and IVM. Females aged 5-7 days from the LaBEIn colony were allocated to two treatment groups: bait before blood feeding (BB) and bait after blood feeding (AB). Each group consisted of 20 females, with three replicates, and the treatments were applied 48, 72, or 96 h BB or AB. Blood engorgement was reduced by approximately 80% in all BB treatments during the first gonotrophic cycle, while no effect was observed in AB females. Survival decreased by up to 90% in BB females at all time points, whereas AB females exhibited a 94% reduction only at 96 h. For reproductive traits, including oviposition rate, egg number and hatching, the strongest reductions occurred in BB females (up to 80%) and in AB females exposed 96 h AB, also during the first gonotrophic cycle. Overall, ATSB-IVM ingestion caused pronounced sublethal effects on Ae. aegypti, impairing blood feeding, survival, oviposition, fecundity and fertility, with greater impacts when ingestion occurred BB and during the first gonotrophic cycle. These results highlighted the potential of ATSB-IVM as a complementary strategy for vector control.