none Aspects of plant foraging behavior were examined for Diaeretiella rapae (Hymenoptera: Aphidiidae), a parasitoid wasp that attacks aphids primarily on cruciferous plants. Arrival rates of naturally occurring D. rapae in artificial patches of 5, 10, 20, and 40 potted collard plants were measured in a field experiment. There was no patch-size effect (plants in larger patches were not more likely to be found), and plants with aphids were not more likely to be found than aphid-free plants. Furthermore, there was no dosage response to water bowl traps baited with chemical plant attractant placed in the same field. Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Host parasite relationships Diaeretiella rapae (Braconidae); Hemipteran hosts; Brevicoryne brassicae; Host seeking behaviour, effects of host food plant patch size; Host seeking; Hemipteran host food plant patch size relationships Brevicoryne brassicae (Aphidoidea); Hymenopteran parasites; Diaeretiella rapae; Host seeking behaviour; Plant hosts; Brassica oleraceae (collards); Patch size, effects on hymenopteran parasite host seeking behaviour; Host seeking; Hymenopteran parasite, effects of plant host patch size