|Tuesday, 15 January 2013 10:10|
Nauru is a single island (21km², 65m) originally covered with rich phosphate deposits that have been almost entirely mined out. The only forest left is a narrow belt along the coast and a large inland forest belt around the Buada Lagoon. There are however about 1400 mango trees, planted during World War II, that are considered a communal property. Mangos have become inedible since the introduction of Oriental fruit fly.
The four fruit fly species that occurred until recently in Nauru have all been introduced from Micronesia, the South Pacific and probably Asia as well. An ambitious program aiming at eradicating the four species was initiated in October, 1998, consisting of treating fiberboard block with Cue-lure and/or methyl eugenol mixed with the insecticide Fipronil and nailing these blocks to trees all over the island, as well as applying protein bait sprays in zones of intense fruit fly breeding. Three of the four species (Oriental fruit fly, melon fly and Pacific fruit fly) have been eradicated. However, melon fly, and possibly also Pacific fruit fly were reintroduced, due to lack of active quarantine inspection service. Eradication activities have ceased in early 2002.
The eradication program was funded by the Project on Regional Management of Fruit Flies in the Pacific, with inputs from Crawford Fund for International Agriculture Research (Australia), and the Nauru Government. The private sector in Australia (Aventis CropScience and Bronson and Jacobs) provided Fipronil and methyl eugenol, respectively. It was executed by the Department of Industry and Economic Development. For more information, please contact:
Mr. Joseph Cain, Secretary, Department of Industry and Economic Development,
Fibreboard blocks nailed to tree trunk (Photo: A. Allwood)
FRUIT FLY SPECIES: Every fruit fly species on Nauru was introduced from other countries. Mango fly (Bactrocera frauenfeldi) introduced from neighboring Micronesian islands. Melon fly (B. cucurbitae) was detected on Nauru in 1982. During a survey in 1992, Oriental fruit fly (B. dorsalis) and Pacific fruit fly (B. xanthodes) were also trapped. Oriental fruit fly and melon fly have successfully been eradicated by male annihilation. The last flies were trapped in early 1999. The last Pacific fruit flies were trapped in February 2002. Mango fly eradication is not as easy. Three years of blocking and limited protein bait spraying were not sufficient to eradicate the species. Unfortunately, the eradication program has ceased and melon fly (and possibly Pacific fruit fly as well) was reintroduced, due to an inactive quarantine inspection service. For the full story consult Pest Alert No 26 (in pdf, 47 Kb). Informal reports received in May 2004 from Nauru have confirmed that Melon fly and Pacific fruit fly have re-occurred on Nauru.
ECONOMIC IMPORTANCE OF FRUIT FLIES: Before eradication campaign was initiated, mango fly and Oriental fruit fly were collectively responsible for 95% infestation on mangoes, 90% on guavas, and up to 10% on Soursop, while 12% of breadfruits were infested by Pacific fruit fly. Since the eradication program has started, levels of damage have dropped to less than 5% and Nauruans can eat mangoes again.
Surveys: 1. Established and maintained a general fruit fly laboratory, including facilities for holding fruit samples collected in the field. 2. Established 41 trapping sites on Nauru. Trap sites made up of one trap baited with methyl eugenol and one with Cue-lure. 3. Collected and held in the laboratory for adult fly emergence almost 3000 commercial/edible and wild/forest fruit samples. 4. Determined that there are four species of fruit flies (Tephritidae: Dacinae) in Nauru (Bactrocera xanthodes, B. dorsalis, B. frauenfeldi and B. cucurbitae and compiled host ranges for all species.
Pest status: 5. Determined, by host surveys, the level of damage caused by fruit flies to guava, mango, soursop and breadfruit.
Fruit fly eradication: 6. Conducted an eradication program against the four species using a combination of male annihilation and protein bait spraying. Two species, Oriental fruit fly and melon fly, have been declared eradicated. Nauruans can now eat fresh mango for the first time in about fifteen years. 7. Assisted with the transfer of technology on fruit fly surveys using trapping and host sampling and fruit fly eradication methods to other Pacific Island countries and territories (PICTs), by hosting hands-on attachment training for 45 plant protection, quarantine and research staff from 19 PICTs, and SPC. 8. The Quarantine service for the island has been re-established and surveillance continued as an early warning system but the eradication program has been put on hold.
Quarantine legislation: 9. Nauru Government, in 2004, promulgated the first Agriculture Quarantine Bill (Plant & Animal Quarantine Regulation 2004) to prevent introduction of fruit flies and other exotic pests into Nauru. 10. Refresher training for Nauru Quarantine officers by SPC LRD Biosecurity was held in May 2006 including the review of all their quarantine border operations.
Emergency response planning: 11. Increased preparedness to detect quickly an incursion of an exotic fruit fly species and formulated an Emergency Response Plan to eradicate any introduction of a new unwanted species.
STATUS OF QUARANTINE SURVEILLANCE (as of October 2007): There are 14 trapping sites with Cue-lure and Methyl Eugenol traps, 6 trapping sites with Trimedlure that were re-established in May 2006. All trapping data were compiled on Excel spreadsheets. A Quarantine Act was formulated and was adopted. SPC LRD Biosecurity also provided Nauru Quarantine with a manually operated incinerator, inspection kits for officers and an amnesty bin fto be used at the airport.
Mapping by N. Waqa
Allwood, A.J., Stephenson, B., Pitcher, A. 1999. 1998 Progress report. Fruit fly eradication programme in Nauru. RMFFP Publication. 33pp.
Allwood, A.J., Vargas, R., Leblanc, L. 2001. Assessment of the Fruit Fly Eradication Programme in the Republic of Nauru. PMP-FFM Report. 13pp.
Allwood, A.J., Vueti, E.T., Leblanc, L., Bull, R. 2001. Eradication of introduced Bactrocera species (Diptera: Tephritidae) in Nauru using Male annihilation Technique and Protein Bait Sprays. Paper presented at the Island Invasive conference in February 2001 in New Zealand. 14pp.
Kumar, H. 1992. Duty travel report for Nauru. 6pp.
Tora Vueti, E., Allwood, A.J., Leweniqila, L., Ralulu, L., Balawakula, A., Malau, A., Sales, F., Peleti, K. 1997. Fruit fly fauna in Fiji, Tuvalu, Wallis and Futuna, Tokelau and Nauru. pp. 60-63 in: Allwood, A.J., and Drew, R.A.I. 1997. Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp.
Various authors. 1998-2001. FFERAD Newsletter. A 1-2 page newsletter on the progress of Nauru eradication programme, published every two months.
Waterhouse, D.F. 1993. Pest fruit flies in the Oceanic Pacific. pp. 4-47 in: Biological control. Pacific Prospects. Supplement 2. ACIAR Monograph No 20. viiii+138pp.
Download Pest Alert No 26 on melon fly re-introduction in Nauru (March 2002), available in English (47 Kb pdf document)
Download Pest Advisory Leaflet on Mango Fly in English (344 Kb)
Download Pest Advisory Leaflet on Melon Fly in English (192 Kb)