SURVIVAL RATES OF ANOPHELES-CULICIFACIES S L AND ANOPHELES-PULCHERRIMUS IN SPRAYED AND UNSPRAYED VILLAGES IN GHASSREGHAND DISTRICT, BALUCHISTAN, IRAN, 1991

Survival rates, expectation of life, and expectation of infective life of Anopheles culicifacies and Anopheles pulcherrimus were estimated i n sprayed and unsprayed villages in the highly malarious Ghassreghand District, Iran, during the 2 peak malaria transmission seasons in 1991 . The daily survival rate of An. culicifacies was estimated as 0.84 an d 0.78 during May and 0.89 and nil during September-October in the uns prayed and sprayed villages, respectively. For An. pulcherrimus the da ily survival rate was estimated as 0.80 and 0.78 in May and 0.83 and 0 .78 in September-October in the unsprayed and sprayed villages, respec tively. The impact of indoor residual spraying during the first peak o f transmission on An. culicifacies and An. pulcherrimus (expressed as the product of the degree of reduction of the expectation of infective life and the degree of reduction of expectation of life) was calculat ed as 3.5 and 1.5 times, respectively, that in the absence of control. The impact of indoor residual spraying on An. culicifacies during the second peak of transmission was almost complete, whereas that for An. pulcherrimus was 3.4 times than that in the absence of control.