Latin American Poster Session
Adult Control
The national program for the control and elimination of Chagas disease in Mexico recommends the residual spraying of insecticides. In addition to traditional indoor spraying, the program has introduced targeted outdoor residual of spraying of structures and objects that are potential refuges for T. dimidita in the peridomicile. However, the residual effect of different currently available insecticide molecules and formulations against Triatoma dimidiata is insufficient. Here we report the residual efficacy of different insecticide formulations applied on wood and nude concrete block, which are the most common types of materials used to build structures found in the peridomicile of premises in rural areas of Mexico. Field doses of commercial residual formulations of deltamethrin (0.025 g/m2), bendiocarb (0.4 g/m2) and pirimiphos-methyl (1 g/m2) were applied to wood and nude concrete block substrates. Cone bioassays were done (24hrs up to 6-months) exposing nymphs of T. dimidiata for 72hrs to substrates and recording the mortality at 1-3-5 days post-exposure. All the formulations showed high efficacies on all substrates at 24hrs after treatment. After 30 days, mortality rates on wood ranged from 87% (deltamethrin) to 100% (bendiocarb and pirimiphos-methyl), and from < 48% (deltamethrin and bendiocarb) to 87% (pirimiphos-methyl) on nude concrete block. After 60 days, bendiocarb and pirimiphos-methyl showed a good performance (100%) on wood, while deltamethrin performance decreased on all substrates (32-55%). Only pirimiphos-methyl continue performing good ( >90% mortality) on nude concrete. After 6 months the performance on wood with bendiocarb and pirimiphos-methyl remained good (96%-100%) and intermediate (»50%) with deltamethrin. For nude concrete block, only the performance of pirimiphos-methyl was still good ( >90%).