Evaluation of the pyrrole insecticide chlorfenapyr against pyrethroid resistant and susceptible Anopheles funestus (Diptera: Culicidae).
OBJECTIVE
To evaluate the pyrrole insecticide chlorfenapyr, which has a novel non-neurotoxic mode of action and is a promising alternative to conventional adulticides, against Anopheles funestus.


METHODS
The toxicity of a range of concentrations of chlorfenapyr against pyrethroid resistant and susceptible laboratory reared southern African An. funestus was assessed using standard WHO protocols and analysed using probit analysis.


RESULTS
The pyrethroid resistant strain showed consistently higher LD50 and LD95 values compared to the susceptible strain, but these differences were not statistically significant and the magnitude was twofold at most. The LD50 values recorded for An. funestus are approximately three-fold higher than those reported elsewhere for other species of anopheline.


CONCLUSIONS
Monooxygenase based pyrethroid resistance in An. funestus does not influence the toxic effect of chlorfenapyr. It is unlikely that such a small decrease in susceptibility of An. funestus to chlorfenapyr relative to other anophelines would have any operational implications. Chlorfenapyr is an important addition to insecticides available for malaria vector control, and could be used as a resistance management tool to either circumvent or slow the development of resistance.
Oliver
S V
SV
Vector Control Reference Unit, National Institute for Communicable Diseases, Sandringham, South Africa.
Kaiser
M L
ML
Wood
O R
OR
Coetzee
M
M
Rowland
M
M
Brooke
B D
BD
D000818:Animals; D000852:Anopheles; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D007303:Insect Vectors; D007305:Insecticide Resistance; D007306:Insecticides / Q000008:administration & dosage; D007928:Lethal Dose 50; D011722:Pyrethrins / Q000008:administration & dosage; D016019:Survival Analysis
D007306:Insecticides; D011722:Pyrethrins; C436643:chlorfenapyr