Seasonal dynamics of egg-laying and adult emergence of Kalaazar vector P. argentipes in Bihar, India

The dynamics of egg laying, larval hatching, pupation, adult emergence and sex ratio were studied in laboratory condition of natural population collected from an endemic pocket of visceral leishmaniasis in Bihar (India). The mean number of eggs laid/female was highest during summer season (49.7eggs/female), followed by winter (43.3 egg/female) and rainy (23.3). The larval hatching rate was highest in the winter (87%) and lowest in the summer (74%). Maximum sterility was also observed during summer. Pupation rate is highest in winter and lowest in summer Season. Similarly the adult emergence rate was highest in winter and lowest in rainy Season. The secondary sex ratio, i.e., no. of female/100 males was highest in rainy (157) & lowest in winter (103). The probable effect of genetic and epigenetic factors, on the seasonal variations in these parameters have been suggested. A comparison of the present data with these from other parts of the world hints that the present population of P. argentipes is comparatively more dangerous and dreadful.