[Larval susceptibility of Aedes aegypti and Culex quinquefasciatus populations to chemical insecticides].
OBJECTIVE
To evaluate the susceptibility to chemical insecticides of Culex quinquefasciatus and Aedes aegypt larvae from areas subjected to control treatments or not.


METHODS
Bioassays for diagnostic concentration and multiple concentration were performed for organophosphate and pyrethroid insecticides according to World Health Organization parameters. The susceptibility was assessed for mosquito larvae collected from an area not subjected to chemical control (Campinas, State of S o Paulo, SP) and from other areas (Campo Grande, Mato Grosso do Sul, MS, and Cuiabá, Mato Grosso, MT), in Brazil, subjected to such treatments.


RESULTS
Tests for Culex quinquefasciatus larvae from Campinas, SP, allowed suspicion of resistance to cypermethrin and gave evidence of resistance to cyfluthrin. Larvae of this species collected in Campo Grande, MS, and Campinas, SP, presented resistance to temephos. For the colony from the latter locality, the following resistance rates were established: RR50=6.36 and RR95=4.94, in relation to a standard susceptible strain. Moreover, tests for Aedes aegypti showed similar susceptibility to temephos for a field population from Cuiabá, MT, and a laboratory population.


CONCLUSIONS
The results indicate resistance of Culex quinquefasciatus to organophosphate and pyrethroid insecticides and make evident the need for evaluation and monitoring of the efficiency of insecticides to be used in mosquito control programs.
Campos
Jairo
J
Departamento de Zoologia do Instituto de Biologia da Universidade Estadual de Campinas, Campinas, SP, Brasil.
Andrade
Carlos F S
CF
D000330:Aedes; D000818:Animals; D003465:Culex; D006801:Humans; D007305:Insecticide Resistance; D007306:Insecticides; D007814:Larva; D009032:Mosquito Control; D009943:Organophosphorus Compounds; D011722:Pyrethrins
D007306:Insecticides; D009943:Organophosphorus Compounds; D011722:Pyrethrins