none Ostrinia nubilalis; HYMENOPTERAN-PARASITES; Bracon brevicornis; Parasitoid progeny production, influencing factors Bracon brevicornis; MATING-; REPRODUCTIVE-PRODUCTIVITY; Progeny production; EGG-NUMBER; Clutch size effect on progeny production; LEPIDOPTERAN-HOSTS; Ostrinia nubilalis; Parasitoid progeny production, influencing factors; POPULATION-DENSITY; Crowding effect on progeny production; POPULATION-SEX-RATIO; Progeny production relationships, lepidopteran host The number of progeny of Bracon brevicornis was greatly affected by the number of deposited eggs of Bracon females per host larva. The increase in the egg clutch size from 5 to 25 eggs/larva increases the progeny production. On the other hand, the increase in the egg clutch size of the parasitoid decreases the body size of produced female progeny. The ratios of parasitoid females-host larvae and time of parasitization which leads to optimal parasitism were studied. The most appropriate crowding level of B. brevicornis females to O. nubilalis full grown larvae was studied. The sex ratio of produced parasitoid progeny was significantly affected by changing the sex ratio of parent parasitoids, while there was no effect on the number of deposited eggs per host.