Comparative toxicity of permethrin- and bifenthrin-treated cloth fabric for Anopheles farauti and Aedes aegypti.
In this laboratory study, we applied 3 formulations of permethrin (Peregin 500 EC, Dragnet 500 EC, and Dragnet 100 ME) and 2 of bifenthrin (Biflex 10 ME and Talstar 80 SC) to swatches of Australian military shirt fabric. The knockdown and mortality of Anopheles farauti and Aedes aegypti after exposure to treated fabrics were compared. The mortality of An. farauti exposed to permethrin-treated swatches for 3 min in World Health Organization test kits was 94.2-100% after initial treatment and fell to < 28% after 2 cold water washes. and knockdown was < 20% after 3 washes. The mortality of An. farauti exposed to bifenthrin-treated swatches was initially 100% and remained > 55% after 3 washes, whereas knockdown was < 25% after 2 washes. Mortality of Ae. aegypti exposed by tarsal contact to permethrin- and bifenthrin-treated fabrics was 84.8-100% prior to washing and fell to < 21% and < 40%, respectively, after 1 cold water wash. The ability of Ae. aegypti to obtain a blood meal through treated fabrics was variable, and a small percentage (0-6.1%) of mosquitoes obtained a blood meal through fabrics after initial treatment. The effect of cold water washing on the persistence of both chemicals in fabric by chemical assays showed that between 58% and 66% of both chemicals was lost from the test fabric after a single wash.
Frances
S P
SP
Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, Queensland 4052, Australia.
Watson
K
K
Constable
B G
BG
D000330:Aedes; D000818:Animals; D000852:Anopheles; D003020:Clothing; D003902:Detergents; D006801:Humans; D007303:Insect Vectors; D008889:Military Personnel; D009026:Mortality; D009032:Mosquito Control / Q000379:methods*; D026023:Permethrin / Q000008:administration & dosage / Q000633:toxicity*; D011722:Pyrethrins / Q000008:administration & dosage / Q000633:toxicity*; D015203:Reproducibility of Results; D013696:Temperature; D014867:Water
D003902:Detergents; D011722:Pyrethrins; D014867:Water; D026023:Permethrin; C099952:bifenthrin