La resistencia del aedes aegypti a ciertos insecticidas de hidrocarburos clorados y de fosfato orgánico en Puerto Rico

Abstract

A laboratory colony of Aëdes aegypti established from specimens collected at Isla Verde near San Juan, Puerto Rico, was found to be highly resistant to certain chlorinated hydrocarbons and moderately resistant to some organophosphorus insecticides. In the first group of experiments ten parts permillion of DDT and of lindane and 7.5 p.p.m. of dieldrin were required to obtain 100 per cent mortality of the larvae after 24 hours exposure to the insecticides. In another group of experiments, after a number of months of colonization, 10 p.p.m. of these three insecticides did not result in 100 per cent mortality, and resistance to dieldrin became very great, for at 10 p.p.m. this insecticide gave 66 per cent dead and 80 per cent dead plus moribund. Chlordane at 10 p.p.m. gave only 14.5 per cent kill. Malathion, dipterex and diazinon produced 100 per cent mortality at 2.5 p.p.m. Bayer 21/199 was the most effective giving 96.5 per cent mortality at 0.5 p.p.m. and 100 per cent mortality at 1.0 p.p.m. The high resistance to DDT and dieldrin was confirmed by tests with adult females which indicated a range of mortality for DDT (4.0 per cent) of 11 to 63 per cent and for dieldrin (1.6 per cent) of 0 to 22 per cent. This appears to be the first report of high resistance to both DDT and dieldrin in a strain of Aëdes aegypti(AU)