The parasitoid, Bracon hebetor Say (Hymenoptera: Braconidae) is a gregarious larval ectoparasitoid of several lepidopteran species. The reproductive biology of B. hebetor was studied on the larvae of its host, the sesame capsule borer Antigastra catalaunalis (Duponchel) (Lepidoptera: Pyralidae) under laboratory condition. The obtained results revealed that the total preimaginal period of B. hebetor on A. catalaunalis was significantly affected by ambient temperature being shortest at 35^oC (6.9 days) and longest (12.5 days) at 25ºC. Mating status had a significant effect on the ovipositional periods, fecundity and longevity being 154.9 and 105.8 eggs /female in mated and virgin females, respectively. Oviposition pattern for mated females showed a gradual increase then declined as females aged with only one maximum peak 12 days post emergence with greatest mean daily fecundity of 21.4 eggs/female/day. The supplemental food had a significant effect on adults of B. hebetor.  Females of B. hebetor fed with pure honey together with the host larvae of A. catalaunalis parasitized a higher number of host (23.3 larvae) and laid a higher number of eggs per female (154.9 eggs). The numbers of paralyzed and parasitized hosts, number of daily laid eggs/host instar, longevity and percentages of emerged wasps were significantly affected by host instars. B. hebetor paralyzed all larval instars of A. catalaunalis but parasitized only third, fourth and fifth instar larvae. The fifth larval instar of A. catalaunalis was the most suitable instar for B. hebetor larval development than earlier instars as indicated by the highest total lifetime fecundity/female of 154.9 eggs and the highest percentage of emerged wasps of 93.5%.