Evaluation of the efficacy of pyrethroid pesticides against selected strains of Aedes mosquitoes using the who susceptibility test and by thermal fogging

Abstract

Tests on the efficacy of pyrethroid insecticides in fogging were conducted. These were done in two approaches: 1. A laboratory-based series of the WHO susceptibility tests on F1- generation female adult Aedes mosquitoes, and 2. A series of actual field thermal fogging using caged sentinel F1-generation Aedes mosquitoes. Based on the 98% WHO susceptibility test criterion, strains of Ae. Aegypti have shown to have incipient resistance to pyrethroids, making them less susceptible to laboratory and field tests. Ae. Albopictus was found susceptible to pyrethroids, but it requires further confirmatory tests based on field test results. The study recommends molecular tests on mechanisms involved, nationwide surveillance of susceptibility/resistance of dengue vector mosquitoes, and a review of the chemical control strategies used by authorities.