THE RESIDUAL EFFECTS OF ALPHACYPERMETHRIN AND PERMETHRIN AGAINST THE DENGUE VECTOR AEDES-ALBOPICTUS (SKUSE) IN WOODEN HUTS IN MALAYSIA

The pyrethroids alphacypermethrin and permethrin were compared for res idual activity against the dengue vector Aedes albopictus (Skuse) in w ooden huts in Kuala Lumpur. Two huts were individually sprayed inside with one of the pyrethroids and the third hut served as a control. At an applied concentration of 0.01 g a.i./m(2), both pyrethroids were eq ually effective in causing more than 80% mortality of Ae. albopictus o ne week after spraying. The Ae. albopictus exposed to a higher concent ration of 0.05 g a.i./m(2) on alphacypermethrin treated walls showed 1 00% mortality one week post-spraying that declined to 91.3% mortality eight weeks post-spraying. In contrast, the permethrin-treated walls c aused 87.5% mortality one week after spraying and 75% mortality eight weeks after spraying. Thus, alphacypermethrin showed a greater residua l efficacy than permethrin in controlling the dengue vector.