DURATION OF EGG LARVAL AND PUPAL STAGES OF CULEX PIPIENS FATIGANS IN RANGOON BURMA

Abstract

Laboratory experiments to determine the duration of the immature stages of Culex pipiens fatigans were carried out because such information is important from the point of view of control by larvicides. At a temperature of 28.1[degree] C[plus or minus]0.7[degree]C the mean incubation period is 27.11[plus or minus]0.57 hr. Females spend a longer time in the pupal stage than males (34.16[plus or minus]0.74 hr. and 32.95[plus or minus]0.75 hr., respectively, at 28.6[degree]C[plus or minus]0.8[degree]C; there is no 24-hr. pupating or emerging rhythm. The duration of larval life is longer for the female (135.3[plus or minus]4.4 hr.) than for the male (118.4[plus or minus]2.4 hr.). Larvae that take a long time to pupate also take a long time to emerge. Wighholding of food for a few hours from 1st stage larvae increases the duration of larval life but does not affect that of pupal life. These observations on the differences between the sexes in the duration of larval and pupal life are in agreement with observations made on Aedes aegypti in Uganda.