THE EFFECTS OF DIETARY YEAST ON THE CELLULAR IMMUNE-RESPONSE OF DROSOPHILA-MELANOGASTER AGAINST THE LARVAL PARASITOID, LEPTOPILINA-BOULARDI

The role of dietary yeast in Drosophila melanogaster cellular immunity was investigated. Host larvae deprived of yeast immediately after par asitization by the cynipid wasp Leptopilina boulardi encapsulated a si gnificantly lower percentage of the parasitoid's eggs than hosts trans ferred to a medium with yeast. When the transfers of hosts were made 2 4 hr after exposure to the parasite, diet had no effect on the immune response that had commenced prior to the transfers. This study demonst rates for the first time the effect of a specific dietary component on the immune responsiveness of Drosophila against a larval parasitoid.