Effect of variation in temperature on development of Plasmodium berghei (NK 65 strain) in Anopheles stephensi.

Effect of temperature on the sporogonic cycle of Plasmodium berghei (NK 65) has been studied in vector Anopheles stephensi. To determine the optimum temperature for development of parasite, fed mosquitoes were kept at 16 +/- 1 degree C, 19 +/- 1 degree C and 26 +/- 1 degree C temperature. The temperature 19 +/- 1 degree C was found to be optimum for normal development of parasite within the vector. Sporulated oocysts were observed on the 10th day post feed and salivary glands were loaded with thousands of sporozoites on day 14. Temperature 16 +/- 1 degree C, though did not exert any deleterious effect on the morphology of parasites it delayed the development of sporozoites in the oocysts by 5 days as compared to control group. In the case of long exposure to this temperature, the sporozoites obtained from salivary glands became non-infective. Temperature 26 +/- 1 degree C was responsible for deterioration of all the stages of sporogonic cycle and it also checked the formation of sporozoites in the oocysts.