The braconid Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) is a major solitary, larval endoparasitoid of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). The impact of dietary protein was investigated in the laboratory by comparing performance of C. plutellae on honey, which is commonly used to rear the parasitoid, to that on a novel diet made of honey and pr...