Absence of insecticide resistance in Anopheles gambiae s.l. (Diptera: Culicidae) after four decades of residual house spraying in Gokwe District, Zimbabwe.

Field tests showed that Anopheles gambiae s.l. from 4 villages in Gokwe District, Midlands Province, Zimbabwe, were susceptible to 4% DDT, 0.025% deltamethrin, 0.025% alpha-cypermethrin, and 0.1% lambdacyhalothrin. In the laboratory, F1 progeny of field-caught females that were identified as Anopheles arabiensis Patton were completely susceptible to deltamethrin, alpha-cypermethrin, lambdacyhathrin, and DDT. The use of insecticides in Gokwe district has not yet induced detectable resistance in An gambiae s.l.