Determination Of Insecticides' Lethal Concentrations And Metabolic Enzyme Levels In Triatoma Dimidiata

Objective. The feasibility of the use of WHO impregnated paper and biochemical assays to determine lethal concentrations (LC50 and LC99) and insecticide metabolic enzyme levels of Trictoma dimidiata. Materials and methods. LC50, and LC99 were calculated with WHO papers impregnated at different concentrations of malathion, propoxur and deltamethrin; the percentage of insensitive acetylcholinesterase (iAChE); and the levels of esterases, glutathione S-transferases, and monooxygenases in laboratory nymphs of the first stage (5 to 7 days), were undertaken using the WHO biochemical assays. Results. Respectively the LC50 and LC99 mu g/cm(2) obtained for malathion were 43.83 and 114.38, propoxur 4.71 and 19.29, and deltamethrin 5.80 and 40.46.A 30% of the population had an iAChE, and only a few individuals had high P-45(0) and beta-eterase levels.Conclusion. Impregnated papers and biochemical tests developed by WHO for other insects, proved to be feasible methods in monitoring insecticide resistance and metabolic enzymes involved in T. dimidiata.