Effects of three temperature regimes on rearing and biological activities of Bracon hebetor (Say) (Hymenoptera: Braconidae)

The body color of Bracon hebetor adults was either black, yellow with black spots, or completely yellow when development from egg to adult took place at 15–18°C, 25 or 35°C, respectively, and the wasps were reared on Ephestia cautella larvae. The longest adult life-span of both sexes occurred when adults reared and emerged at 25°C were held at 15–18°C. Female adults of all colors lived longer than males, especially at 25 and 35°C. The lowest parasitizing efficiency was at 35°C, whereas the highest number of eggs per female occurred at 25°C irrespective of the body color. In general, the parasitoid wasps have somewhat tolerated the three temperature levels and continued to reproduce in spite of their distinct variations in body color. Such variations might be of importance as a mechanism of survival for B. hebetor in date stores during the cold season as well as in the green date palm and cotton fields during warm seasons in Iraq.