Demography of Habrobracon hebetor (Hym.: Braconidae) on Galleria mellonella (Lep.: Pyralidae) at different temperatures

Demographic parameters of Habrobracon hebetor Say (Hym.: Braconidae) reared on the last larval instars of Galleria mellonella (L.) were studied at 20, 25, 28, 30 and 35 ± 0.5°C, 60 ± 5% R.H. and 16L: 8D h conditions. The gross fecundity rate of the parasitoid was 43.17 eggs at 20°C that was approximately half of it at other temperatures. Net fecundity and net fertility rates increased as the temperature increased. Their lowest values were 8.49 and 8.405 at 20 ± 0.5°C and the highest values were 30.47, 30.47 eggs at 30°C, respectively. Their values decreased more than 30% and amounted to 21.49 and 20.63 eggs at 35, respectively. Reproductive value (Vx) was at maximum value at the early period of female reproduction and decreased as females aged. In other words, it was at peak, when females were 30, 18, 14, 14 and 11 day-old at above temperatures. The highest value of net reproductive rate (R0) was 17.06 at 30°C and the lowest (6.27) at 35°C. The intrinsic rate of increase (rm) had the highest value (0.17) at 30°C and the lowest (0.039) at 20°C. The highest value of finite rate of increase (λ) was 1.186 at 30°C and the lowest (1.04) at 20°C. In other words, the parasitoid population would increase 11.86% daily at 30°C. Mean generation time (T) was the longest (41.81 days) at 20°C and the shortest (14.93 days) at 35°C. The longest doubling time (DT) (17.82 days) was obtained at 20°C and the shortest (4.072) was at 30°C. These results showed that the temperature at 30°C would provide a more favorable condition for mass rearing of H. hebetor.