Life Table Analysis of Culex pipiens Under Simulated Weather Conditions In Egypt.

Abstract

The effect of fluctuating ambient air and water temperatures and relative humidity (RH) on the population parameters of Culex pipiens was studied using life table data during the winter-spring and summer-autumn seasons in Giza Province, Egypt. In winter-spring (20.46 ± 1.8°C and 51.68 ± 3.63% RH), the preadult survival rate for Cx. pipiens was 80.65%, which was higher than the 50.00% observed in the summer-autumn (30.19 ± 0.67°C and 52.68 ± 8.04% RH). During the winter-spring period, the developmental time of egg, larvae, and pupae of Cx. pipiens was 3.52, 12.69, and 5.92 days, respectively. There was a significantly shorter developmental period for summer-autumn (1.0, 8.59, and 2.04 days, respectively). Both female and male adults survived longer during winter-spring (61.83 days for female and 42.62 days for male adults) than during summer-autumn (24.38 days for female and 20.83 days for male adults). The fecundity (F) of female Cx. pipiens (524.7 eggs/female) and the net reproductive rate (R0) (245.4 offspring) were significantly higher during winter-spring seasons than in the summer-autumn (163.3 eggs/female and 38.10 offspring). Despite the higher F and R0 values in winter-spring, the intrinsic rate of increase (rm = 0.1181/day) and the finite rate of increase (λ = 1.1253/day) of the Cx. pipiens population were significantly lower compared to summer-autumn (rm = 0.1648/day; λ = 1.1792/day). Consequently, the mean generation time during winter-spring was significantly longer (46.6 days) than during summer-autumn (22.09 days). The data suggest that Cx. pipiens is an r-strategist.