The control of phlebotomine sandflies (Diptera: Psychodidae), the vectors of
leishmaniasis, is directed mostly against adults as larvae develop in unknown or inaccessible habitats. In the current study we tested
geraniol, a natural plant-derived product, as a space repellent and the synthetic
pyrethroid prallethrin as a diffusible
insecticide.
Geraniol was dispersed in the air using diffusers with an electric fan and
prallethrin was evaporated using electrically heated evaporators. Both substances were tested in inhabited bedrooms and in tents.
Geraniol failed to effect significant reductions in the numbers of either Phlebotomus papatasi Scopoli in rooms or Phlebotomus sergenti Parrot in tents. In laboratory experiments,
geraniol proved ineffective in preventing sandflies from feeding. By contrast,
prallethrin was highly effective in reducing the number of sandflies in rooms as well as in tents. Exposure of sandflies to
prallethrin in laboratory experiments caused 97% mortality rates. Both
prallethrin and, to a lesser extent,
geraniol reduced the number of Culex mosquitoes captured in tents. Electric liquid-
vaporizers with 1.5%
prallethrin are highly effective in protecting people from sandfly
bites in confined spaces and may be useful in combating
cutaneous leishmaniasis.