RESUMO
The effects of two insecticides on Anopheles albimanus populations were investigated by spraying two blocks of 10 houses each in a village of the state of Chiapas, México, in August 1984. One block was sprayed with bendiocarb at a dosage of 0.4 g of active ingredient per square meter (ai/m2) and the other was sprayed with deltamethrin at a dosage of 0.025 g ai/m2. The interior walls, approximately two-thirds of the roof surfaces (including the exterior eaves), and the undersurfaces of all furniture were sprayed. The effects of the insecticides on mosquito behavior were measured every two weeks during the 17 weeks following the sprayings by capturing mosquitos that entered the open doors os the houses, attracted to human bait inside. In order to evaluate mosquito movement patterns, the houses were also surrounded with curtain-traps. Captured specimens were individually marked, released in treated houses, and recaptured to define behavior patterns and gauge mortality. In addition, wall surface bioassays were carried out to determine residual insecticide activity. Results indicate that both insecticides produced initially an irritant or repellent effect that prevented lethal intoxication levels. Mosquitoes entering houses before feeding tended to avoid treated surfaces, as shown by low mortality rates