The behaviour of Anopheles minimus Theobald (Diptera: Culicidae) subjected to differing levels of DDT selection pressure in northern thailand

Abstract

Anopheles minimus Theobald was studied in four villages that had experienced differing levels of DDT application during malaria control operations in the foothills of northern Thailand. During times of high population level, the behaviour of the mosquito was assessed with respect to man-biting indoors and outdoors and feeding from domestic bovids. Its responses in villages recently treated with DDT differed from those in villages that had not been treated for several years, so that the insecticide had little direct lethal effect. Furthermore, the influence of the insecticide on the behaviour of the insect was considerably longer than is the lethal effect of the chemical. There was a suggestion that the taxon A. minimus may include two or more morphologically-cryptic species.