Effect of Host Species and Temperatures on Ovipositional Efficiency and Survival of the Ecto–parasitoid, Goniozus claripennis

Abstract

The objective of the present study was to determine the efficiency of the Ecto-parasitoid Goniozus claripennis (Förster) (Bethylidae: Hymenoptera) on two insect host species, Galleria mellonella (L.) and Ephestia kuehniella (Z.) at four constant temperatures 20, 25, 30, 35°C, 65% relative humidity and 16:8 hours (Light:Dark) photoperiod on the egg laying and survival of G. claripennis. Results obtained showed that the range of eggs laid by a female was 1-20 eggs/larva and 1-16 eggs/larva, on both hosts, respectively. The category 5-8 eggs/larvae was the most prevalent under all studied temperatures and hosts. This category showed a higher percentage of eggs laid compared to other categories reaching 62.46 and 56.27% at 35°C on both hosts, respectively. The proportion of categories containing more than 8 eggs were the lowest and reached 1.28% in 13-16 eggs/larva at 20°C and almost zero in categories 17-20 eggs/larva at 30°C on G. mellonella, while they reached 3.33% in categories 9-12 eggs/larva at 20°C on E. kuehniella. The results obtained also indicated that the highest survival rate of parasitoids was 92.5 and 87.85% at 30°C, in categories containing 1-4 eggs/larva on G. mellonella and E. kuehniella, respectively. A negative linear regression relationship was observed between the number of eggs laid/category and temperatures on the survival rate of the parasitoid.

Keywords:

Ovipositional efficiency, survival, temperature, Goniozus claripennis, Galleria mellonella, Ephestia kuehniella