Present Status of Oriental and Mediterranean Fruit Flies and Their Parasites at Three Locations on Oahu, Hawaii

To establish present status of the oriental fruit fly (OFF), Dacus dorsalis Hendel, and the Mediterranean fruit fly (MED). Ceratitis capitata (Wiedemann), and their parasitoids on Oahu, Hawaii, a study was carried out from August to December 1987, by collecting guava fruit and trapping adult males with lures at three locations; Mt. Tantalus, Lyon Arboretum and Waimanalo. Mean weights of individual guava fruit collected from Mt. Tantalus, Lyon Arboretum, and Waimanalo were found to be 74.0 g. 78.2 g. 9.7 g respectively. Only OFF emerged from 180 fruit which were held in the laboratory, although adult males of MED were trapped at Waimanalo. Populations of OFF were most abundant at the highest elevation, Mt. Tantalus, where the mean number of flies trapped with a methyl eugenol lure in 15 minutes was 55.5. Numbers trapped al the middle elevation, Lyon Arboretum, and lower elevation, Waimanalo, were 29.7, 29.0 respectively. The number of puparia per kg fruit sampled was highest (72.0) at the lowest elevation, Waimanalo. The numbers or puparia per kg fruit from the middle and highest elevations were 60.5, 48.4 respectively. Mean parasitism by the opiine wasp Biosteres arisanus (Sonan) was 48.8%. 37.7%. 29.6% respectively for Mt. Tantalus, Lyon Arboretum and Waimanalo.