Comparative studies on the influence of relative humidity and temperature on life table parameters of two populations of Cotesia flavipes (Hymenoptera: Braconidae)

Abstract

Cotesia flavipes Cameron (Hymenoptera: Braconidae) is a gregarious larval koinobiont parasitoid of gramineous stemborers from the Indo-Australian region. More recently, it has been introduced into several countries in East and southern Africa for regulation of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae). Establishment has varied from country to country and within country, suggesting that abiotic factors, such as temperature and relative humidity, may influence parasitoid performance. In this work, the effect of temperature and relative humidity on life table parameters of two populations of C. flavipes were measured. The results indicated that the factors and their interactions significantly affected the population growth of C. flavipes. The intrinsic rate of increase of the North Pakistan population of Cotesia flavipes was higher than that of the Indian population at all humidities at 28°C, but there were no differences at other temperatures or humidities.