Temperature and relative humidity on the biology and parasitism of solenopsis mealybug parasitoid Aenasius bambawalei (Hymenoptera: Encrytidae)

Abstract

Laboratory studies were conducted to find out the optimum combination of temperature and relative humidity for the development, longevity and parasitism of the parasitoid Aenasius bambawalei Hayat on its host Phenacoccus solenopsis Tinsley. The % parasitization was observed to be maximum in the treatment at 25±2°C and 65±5% RH and it was the least at 20±2°C and 45±5% RH. Shorter developmental period of 10 days was observed with the combined effect of 30± 2°C and 45 ± 5% RH. Disregard of humidity regimes, developmental period at 20 ± 2°C, 25 ± 2°C and 30± 2°C was found to be significantly different. In case of adult emergence, interactive effect of combination of temperature and humidity led to the least value of 24.85% at 20 ± 2°C and 45 ± 5% RH and maximum of 72.85% at 20 ± 2°C and 65±5% RH. The female sex ratio of A. bambawalei was observed to be the lowest (0.59) at 30± 2°C and 45 ± 5% RH and the maximum (0.76) at 25 ± 2°C and 65±5% RH.