In a visceral leishmaniasis endemic locality of northeast of Brasil where
all settlements were treated with cypermethrin, a follow-up of Lutzomyia
longipalpis populations was carried out by regular collections. The
residual effect of the insecticide was studied using biological assays on
three different types of walls.
The results showed that the insecticides had an effect on intradomiciliar
Lu. longipalpis populations limited to two months, and had no
significant effect on peridomiciliar vector populations. The mortality
rates of the tested sandflies were variable according to the type of wall.
The decreasing of the insecticide effect was marked since the 3rd month,
and mortality rates were identical whatever the type of wall since the 4th
month. Unsufficient residual effect was detected after the 4th month.
