Resistance of Aedes aegypti from the state of São Paulo, Brazil, to organophosphates insecticides.
Since the reintroduction of Aedes aegypti in the state of S o 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 (Mar lia 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.
Macoris
Maria de Lourdes G
Mde L
Núcleo de Pesquisa, Serviço Regional, Sucen, Marília, SP, Brasil. macoris@sucen.sp.gov.br
Andrighetti
Maria Teresa M
MT
Takaku
Luiz
L
Glasser
Carmen M
CM
Garbeloto
Vanessa C
VC
Bracco
José Eduardo
JE
D000330:Aedes / Q000187:drug effects* / Q000201:enzymology; D000818:Animals; D001681:Biological Assay; D001938:Brazil; D003715:Dengue / Q000517:prevention & control; D004950:Esterases / Q000378:metabolism; D005278:Fenitrothion / Q000494:pharmacology*; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000201:enzymology; D009032:Mosquito Control; D000002:Temefos / Q000494:pharmacology*
D007306:Insecticides; D004950:Esterases; D000002:Temefos; D005278:Fenitrothion