Susceptibility to insecticides and enzymatic mechanisms of resistance of Aedes aegypti (L.) in Puerto Rico

Background: Aedes aegypti (L.) plays an important role in the transmission of viral diseases such as dengue. In recent years in America have increased cases of this in almost all countries, including Puerto Rico, however, most vector control programs are limited by the development of resistance to insecticides Methods: Susceptibility tests were performed in 7 locations from Puerto Rico, temephos and Spinosad larvae (WHO, 1981) and permethrin in adults, with impregnated bottle (Brogdon, 1998) and determination of alpha and beta esterases, glutathione-s-transferases, oxidases and acetyl-cholinesterase. The susceptible Rockefeller strain was used for larvae. Results: The LC50 (mg / µL) for temephos was between 0.035 and 0.116 and about Rockefeller (LC50 0.009 mg / µL), were susceptible. To Spinosad LC50 (mg / µL), ranged from 0.14 to 0.16 and about Rockefeller (LC50 0.028 mg / µL) were tolerant. To permethrin LC50 (mg / µL) was between 13.58 and 39.46, while CK50 (mg / µL) of 19.53 to 50.86. The larvae had the alpha and altered glutathione-s-transferase and adults the alpha and beta-esterases. Discussion: Continued use of insecticides can cause resistance, however, larval populations were susceptible. Conclusions: Despite observed altered enzymes, enzyme mechanism tested insecticide resistance is not manifest. Perspectives: At present, the levels of susceptibility of this insect in Puerto Rico are not known, so its determination, help establish sustained control programs.