Topical applications of pyrethroid and organophosphate mixtures revealed positive interactions against pyrethroid-resistant Anopheles gambiae.
The efficacy of a binary mixture of bifenthrin (pyrethroid) and chlorpyrifos-methyl (organophosphate) has been tested against susceptible and pyrethroid-resistant strains of Anopheles gambiae Giles, the major malaria vector in sub-Saharan Africa. Dose-mortality regression lines were determined for each insecticide alone and in mixtures by topical applications on adult female mosquitoes. A combination index (CI) was used to quantify the interactions occurring between the pyrethroid and organophosphate insecticides. The results revealed synergism at high doses against both susceptible (0.7 > CI > 0.3) and pyrethroid-resistant (0.9 > CI > 0.7) An. gambiae. These results suggest that insecticide mixtures may be an alternative strategy for vector control, especially in areas where mosquitoes are resistant to pyrethroids.
Bonnet
Julien
J
Laboratoire de Lutte contre les Insectes Nuisibles, 911 Avenue Agropolis, BP 64 501, 34 394 Montpellier, France.
Corbel
Vincent
V
Darriet
Frederic
F
Chandre
Fabrice
F
Hougard
Jean-Marc
JM
D000818:Animals; D000852:Anopheles; D004390:Chlorpyrifos / Q000031:analogs & derivatives*; D005260:Female; D007305:Insecticide Resistance; D007306:Insecticides; D009032:Mosquito Control; D011722:Pyrethrins
D007306:Insecticides; D011722:Pyrethrins; C099952:bifenthrin; D004390:Chlorpyrifos; C007031:chlorpyrifos-methyl