Host mortality and progeny production by the ectoparasitoid, Habrobracon hebetor Say (Hymenoptera: Braconidae) on diapausing and nondiapausing larvae of Plodia interpunctella Hübner (Lepidoptera: Pyralidae) were investigated in response to peanut depths and free space at standard environmental conditions. The free space was created by having four different quantities of peanuts in glass containers of fixed volume or same quantity of peanut in containers of different sizes. Host mortality caused by the parasitoids was significantly higher for diapausing larvae compared with nondiapausing larvae at corresponding peanut depth. Differences in peanut depth affected mortality of nondiapausing larvae exposed to parasitoids but diapausing larvae experienced the same level of mortality. Regardless of container sizes, host mortality was higher than 90.0% for both types of larvae. When equivalent peanut depths were compared, more F₁ parasitoids were produced on diapausing larvae than on nondiapausing larvae. Reduced peanut depth affected the sex ratio of parasitoid progeny reared on nondiapausing larvae but not those reared on diapausing larvae. Parasitoid progeny resulting from reduced peanut depth was male-biased and this was more evident with parasitoids that emerged from diapausing host larvae than nondiapausing larvae. Progeny production by H. hebetor was not influenced by container size. This study underscores the fact that host mortality caused by H. hebetor at different peanut depths was significantly different for nondiapausing host larvae, but was not so for diapausing larvae. The container sizes did not affect the performance of H. hebetor in killing P. interpunctella. The entire study emphasizes the potential of diapausing larvae for the rearing of H. hebetor.