Temperature Effect on the Growth and Development of Habrobracon hebetor Say (Hymenoptera: Braconidae) Reared on Ephestia elutella (Hübner) (Lepidoptera: Pyralidae) Larvae

Abstract

Augmentative release of parasitoids has been an important component of integrated insect management for stored product protection. Understanding the effect of different temperatures on the growth and development of parasitoids is in favor of mass rearing of parasitoids. Habrobracon hebetor Say (Hymenoptera: Braconidae) is a highly cosmopolitan, gregarious ecto-parasitoid of a variety of Lepidopterous larvae. Thus, the growth and development of H. hebetor reared on Ephestia elutella (Hübner) (Lepidoptera: Pyralidae) larvae were investigated at 15, 20, 25, 30, and 35 °C. Habrobracon hebetor could complete growth and development, and the developmental duration decreased with increasing temperature at 15, 20, 25, 30, and 35 °C. The development threshold temperatures of H. hebetor eggs, larvae, pupae, and egg-to-adult stages were 13.89, 6.39, 9.24, and 9.29 °C, and the effective accumulated temperatures were 23.33, 46.40, 142.68, and 240.31 °C·d, respectively. The total number of eggs laid by H. hebetor, the hatching rate of H. hebetor eggs, and the percentage of female offspring reached the maximum of 192.39, 83.89%, and 74.04% at 30 °C, respectively. There was no significant difference in pupal survival rate in the temperature range of 15 °C to 35 °C. At 30 °C, the pre-oviposition duration of H. hebetor was the shortest (0.87 d). Therefore, the optimal rearing temperature of H. hebetor was 30 °C. The present results are useful for the large-scale rearing of H. hebetor using E. elutella larvae as hosts and effectively implementing the biological control of stored-product insects.