Chitin synthesis inhibitor effect on Aedes aegypti populations susceptible and resistant to organophosphate temephos.
BACKGROUND
In Brazil, dengue vector control is hampered by the resistance of Aedes aegypti L. populations to organophosphates (OPs). Insect growth regulators (IGRs) are a promising alternative, as their mechanisms of action are different from those of conventional insecticides. The authors analysed the effect of the IGR triflumuron, a chitin synthesis inhibitor, on the Ae. aegypti insecticide-susceptible strain Rockefeller, as well as on field populations both susceptible (TemS) and resistant (TemR) to the OP temephos.


RESULTS
Triflumuron arrested development and inhibited adult emergence of the Rockefeller strain in a dose-dependent way (EI(50) and EI(90) of 0.8 and 1.8 microg L(-1) respectively). A direct relationship between triflumuron concentration and the precocity of its effects was evident. TemS and TemR temephos resistance ratios (RR(90)) were 4.5 and 13.8, triflumuron RR(90) being 1.0 and 1.3 respectively.


CONCLUSIONS
The IGR triflumuron exhibited a dose-dependent effect against the reference Ae. aegypti Rockefeller strain. It was also effective against two field populations, regardless of their OP resistance status. The present results are discussed in the context of utilization of chitin synthesis inhibitors as potential alternatives in the control of Ae. aegypti in Brazil.
Martins
Ademir Jesus
AJ
Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, Brazil.
Belinato
Thiago Affonso
TA
Lima
José Bento Pereira
JB
Valle
Denise
D
D000330:Aedes / Q000187:drug effects*; D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D002686:Chitin / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology; D011157:Population Dynamics; D000002:Temefos / Q000494:pharmacology*
D001549:Benzamides; D007306:Insecticides; D002686:Chitin; C023957:triflumuron; D000002:Temefos