Laboratory evaluation of fipronil, a phenylpyrazole insecticide, against adult Anopheles (Diptera : Culicidae) and investigation of its possible cross-resistance with dieldrin in Anopheles stephensi
J. Kolaczinski et C. Curtis, Laboratory evaluation of fipronil, a phenylpyrazole insecticide, against adult Anopheles (Diptera : Culicidae) and investigation of its possible cross-resistance with dieldrin in Anopheles stephensi, PEST MAN SC, 57(1), 2001, pp. 41-45
Adult mosquitoes from two strains of Anopheles gambiae and from three strai
ns of Anopheles stephensi were exposed to 0.25% fipronil-treated papers in
WHO test kits or to 500 mg fipronil m(-2) impregnated mosquito netting in b
ioassay spheres. For comparison, tests were also carried out with the pyret
hroid permethrin, using the same methods and doses, and on papers treated w
ith 0.4 and 4% of the cyclodiene insecticide dieldrin. Compared with the sa
me doses of permethrin, fipronil showed less and delayed activity. Two of t
he An stephensi strains were resistant to fipronil and dieldrin. To investi
gate whether this was due to a resistance mechanism in the An stephensi str
ains acting against both insecticides, the most fipronil- and dieldrin-tole
rant strain was further selected in two separate lines with one of the inse
cticides, followed by tests with the insecticide that the line had not been
selected with. This indicated a concomitant rise of resistance to dieldrin
in the fipronil-selected line and vice vel sa. Repeated back-crossing of t
he two lines with a susceptible strain and re-selection with either dieldri
n or fipronil gave evidence for the involvement of a single resistance mech
anism to both insecticides. Permethrin resistance in both lines declined wi
th selection for dieldrin or fipronil and confirms the absence of cross-res
istance between fipronil and pyrethroids. (C) 2001 Society of Chemical Indu
stry.