Evaluation of the efficacy of deltamethrin using contact bioassays in a malaria vector control programme in Mpumalanga Province, South Africa

Field assessment of the residual effect of deltamethrin (20 mg/m(2)) agains t Anopheles arabiensis (Diptera: Culicidae) mosquitoes was performed during evaluation of the malaria vector control programme in Mpumalanga Province, South Africa. Ten treated sleeping rooms, five of which were mud- and five cement-walled, were used in bioassays with laboratory-reared An. arabiensi s. The bioassays were run for seven consecutive months after treatment. Sev en months after treatment deltamethrin-treated surfaces were still complete ly effective against the susceptible strain of An, arabiensis, with a 24-ho ur holding mortality of 100%.