The selection of insecticide resistance in
malaria vectors has the potential to compromise any
insecticide-based vector control programme. To ensure that the
insecticides used for indoor residual spraying and
insecticide-treated nets in Zambia remain effective and their choice is evidence based, insecticide resistance surveillance and monitoring are essential. This study assessed and compared the residual efficacy of
etofenprox (Vectron 20 WP), an
ether pyrethroid, at 0.1 g/m(2) with
pyrethroids:
bifenthrin (
Bistar 10 WP) and
lambda-cyhalothrin (Icon 10 CS) at 25 mg/m(2) for indoor residual spraying. We also assessed the resistance status of
etofenprox to local
malaria vectors, An. funestus s.s and An. gambiae s.s, using World Health Organization standard protocols. The residual efficacy of Vectron 20 WP on cement, rendered walls of houses lasted for four months with 100% mortality. By the eighth month, the killing effect had reduced to 73.8% compared to 63.3% for
bifenthrin and 77.0% for
lambda-cyhalothrin. Susceptibility tests using standard World Health Organization assays on An. gambiae s.s showed susceptibility to
etofenprox (0.1%) but some resistance was detected to Anopheles funestus s.s. The product is recommended as an ideal
insecticide for indoor residual spraying for
malaria control in Zambia as part of a resistance management programme in selected areas of the country.