Since the reintroduction of Aedes aegypti in the state of São Paulo, in the middle of the 1980-decade, organophosphate insecticides are being used to control the dengue vector. In 1996, an annual program for monitoring the susceptibility of Ae. aegypti to the insecticides was implemented. Some of the results of this monitoring program are presented. Ae. aegypti populations from ten localities have been submitted to bioassays with the diagnostic dose of temephos and fenitrothion. Only two (Marília and Presidente Prudente) remain susceptible to both insecticides and one (Santos) exhibits true resistance. Ae. aegypti from the remaining localities showed an incipient altered susceptibility. Resistance ratios varied from 1.2 to 2.9 for temephos and from 1.5 to 3.2 to fenitrothion, indicating moderate levels of resistance. Biochemical assays did not detect alterations in the enzyme acetilcholinesterase, but indicated that resistance is associated with esterases.

Foi detectada, por meio de bioensaios, alteração dos níveis de suscetibilidade do Aedes aegypti a organofosforados em municípios do Estado de São Paulo

Baseline data on susceptibility of Aedes aegypti to organophosphates detected alterations in cities of the state of S. Paulo, Brazil

Baseline data on susceptibility of Aedes aegypti to organophosphates detected alterations in cities of the state of S. Paulo, Brazil

Foi detectada, por meio de bioensaios, alteração dos níveis de suscetibilidade do Aedes aegypti a organofosforados em municípios do Estado de São Paulo