Opiine Parasitoids (Hymenoptera: Braconidae) of Oriental Fruit Fly (Diptera: Tephritidae) on Kauai Island, Hawaii: Islandwide Relative Abundance and Parasitism Rates in Wild and Orchard Guava Habitats

Abstract

During a 2-yr survey of Kauai Island, four species of opiine parasitoids were recovered from host fruits infested with Bactrocera dorsalis (Hendel) [= Dacus dorsalis Hendel]; Biosteres arisanus (Sonan), Diachasmimorpha longicaudata (Ashmead), Psyttalia incisi (Silvestri), and Biosteres vandenboschi (Fullaway). These species constituted 87.5, 9, 2.4, and 1.1% of the total parasitoids recovered in 1988, and 95.1, 0.9, 4, and 0.04% of the total parasitoids recovered in 1989, respectively. Total islandwide opiine parasitism rates on the basis of live parasitoids recovered from oriental fruit fly pupae were 41.4% in 1988 and 53% in 1989. Wild common guava, Psidium guajava L., and strawberry guava, Psidium cattleianum Sabine, were the most prevalent hosts infested with oriental fruit fly encountered during our roadside survey. Population studies in a large commercial common guava orchard indicated that oriental fruit fly infestation of fruits was correlated with infestation of wild common guava fruits in surrounding wild habitats. Positive correlations between numbers of B. arisanus , the dominant parasitoid, and numbers of oriental fruit fly indicated a density-dependent relationship. Overall, percentage parasitism of B. arisanus was significantly higher in wild habitats than in orchard habitats. Relative abundance of D. longicaudata, P. incisi , and B. vandenboschi were significantly higher in orchard habitats than in wild habitats.