Response of Anopheles farauti to permethrin-treated net and cloth fabrics in the laboratory.

The median effective dose of permethrin for knockdown and mortality of Anopheles farauti s. s. exposed to 2 net and 2 cloth fabrics was estimated. There were no significant differences in the knockdown or mortality of An. farauti or Aedes aegypti following 15-180-sec exposure to permethrin-treated bed nets and polyester/cotton fabric. Despite the presence of permethrin (0.007-0.068 mg/cm2) in bed net material, 18.2-50% of An. farauti adults successfully obtained a blood meal through the nets, and although all of them were knocked down after 60 min, up to 77.8% recovered within 24 h and 57.1-100% of the survivors were bloodfed. The results indicate that this important vector of malaria can obtain a blood meal through treated bed net material and emphasizes the importance of avoiding contact with the net while sleeping.