Eradication of introduced Bactrocera species (Diptera: Tephritidae) in Nauru using male annihilation and protein bait application techniques.
Four introduced Bactrocera species were recorded in the Republic of Nauru in 1992. A programme to eradicate the four species was implemented between October 1998 and December 2000. The objectives were to eradicate the introduced pest fruit flies that were a threat to neighbouring Pacific Island countries and territories, to test the efficacy of fipronil as an alternative toxicant to malathion for the management of fruit flies, to train national plant protection and quarantine staff in fruit fly eradication and emergency response techniques, to establish and up-grade the quarantine services in Nauru, and to increase fruit availability for local consumption. A combination of male annihilation and protein bait application techniques was used for eradication. The male annihilation technique involved distributing fibreboard ('Canite') blocks impregnated with male fruit fly lure (methyl eugenol and/or cue-lure) and the insecticide fipronil in a loose grid, resulting in at least 300 blocks per km2 over Nauru. The blocking campaigns were repeated every eight weeks from late October 1998. The protein bait application technique involved spraying host fruit trees in hot spot areas with protein insect lure and fipronil gel on a weekly schedule. Three of the four species, namely oriental fruit fly (B. dorsalis), Pacific fruit fly (B. xanthodes), and melon fly (B. cucurbitae), were declared eradicated. Populations of mango flies (B. frauenfeldi) still persist. The Government drafted and promulgated a new Agricultural Quarantine Act and established an Agricultural Quarantine Service in Nauru. A major benefit of the eradication programme is that people in Nauru once again are able to eat mangoes and breadfruit after a decade of near-total losses due to introduced fruit flies.