SOME BIOLOGICAL FACTORS AFFECTING THE PRODUCTION OF THE LARVAL PARASITOID BRACON BREVICORNIS WESM (HYM, BRACONIDAE)

The number of progeny of Bracon brevicornis was greatly affected by th e number of deposited eggs of Bracon females per host larva. The incre ase in the egg clutch size from 5 to 25 eggs/larva increases the proge ny 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 parasitizatio n which leads to optimal parasitism were studied. The most appropriate crowding level of B. brevicornis females to O. nubilalis full grown l arvae was studied. The sex ratio of produced parasitoid progeny was si gnificantly affected by changing the sex ratio of parent parasitoids, while there was no effect on the number of deposited eggs per host.