Laboratory study on the effect of deltamethrin WG and WP formulations against Anopheles maculatus Theobald (Diptera:Culicidae) on rough and smooth surfaces of bamboo wall.

Adults of Anopheles maculatus were tested for their residual activity to wettable powders (WP) and water dispersible granule (WG) formulations of deltamethrin. The residual effectiveness and lifespan of deltamethrin WG and WP were also assessed against the mosquitoes using rough and smooth surfaces of bamboo. Tests were conducted once a month up to 14 months after spraying using WHO standard method for the bioassay of insecticidal deposits on wall surfaces. Mortality data revealed that both deltamethrin WG and WP were effective against An. maculatus up to 14 months post-spraying. Efficacy and residual activity of deltamethrin WG at 25mg/m2 had proved to be the longest on both rough and smooth surfaces of bamboo.