A Survey of Fruit Flies (Diptera: Tephritidae: Dacinae) and their Opiine Parasitoids (Hymenoptera: Braconidae) in Palau

Surveys for fruit flies and their parasitoids, conducted by male lure trapping and host fruit sampling in 2001, 2013, and 2014, demonstrate that the agricultural pests Bactrocera dorsalis, B. frauenfeldi, and B. umbrosa and noneconomic B. calophylli (Diptera: Tephritidae: Dacinae) are present and widespread in Palau. The COI gene haplotype networks and aedeagus measurements of B. dorsalis, detected in Palau in 1996, suggest that it is most likely of Philippine origin. Bactrocera occipitalis, previously reported from Palau, was not collected during these surveys, and is probably absent. Fopius arisanus (Hymenoptera: Braconidae: Opiinae) was reared from fruit containing parasitized larval fruit flies. Parasitism was low (3.4-11.7%), compared to Hawaii or French Polynesia, where F. arisanus has lowered populations of B. dorsalis. Fruit production in the Republic of Palau is affected by native and invasive pest fruit flies (Diptera: Tephritidae: Dacinae). This Pacific Island nation comprises 343 islands (488 km2), located 900 km east of the Philippines. The largest island is 396 km2 Babeldaob, but most of the population is concentrated on Koror Island. Hardy and Adachi (1956) listed the species of Bactrocera on Palau as B. frauenfeldi (Schiner), a generalist pest of fruit, B. umbrosa (Fabricius), a pest of breadfruit and jackfruit, and B. calophylli (Perkins & May), a non-economic species breeding on Indian laurel (Calophyllum inophyllum L.). Limited trapping and host fruit surveying in 1988-90 confirmed the presence of the first two species (Allwood et al. 1999). The presence of a suspected new immigrant pest species, causing significant damage on starfruit (Averrhoa carambola L.), was confirmed in September 1996, and the fly was identified as Bactrocera dorsalis (Hendel) by R.A.I. Drew (Leblanc 1997). In response, methyl eugenolbaited detection traps were deployed in 1999–2000, and B. dorsalis was found to be widespread over all the main islands (Kayangel, Babeldaob, Koror, the Rock Islands, Peleliu, and Angaur). In technical feasibility and socioeconomic study reports (Allwood et al. 1999, McGregor 2000), it was concluded that B. dorsalis and B. umbrosa could be eradicated by using the male annihilation technique (MAT) and protein bait spraying at a P oceed ngs of the hawai an entomological society (2015) 47:55–66