Nauru is a single
island (21km˛, 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 programme 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
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:
Cain, Secretary, Department of Industry and
(674) 444-3181 FAX: (674) 444-3791
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 programme 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
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
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 programme has started, levels of
damage have dropped to less than 5% and Nauruans can eat mangoes again.
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
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
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.
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.
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:
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.
(Photo and mapping by N
A.J., Stephenson, B., Pitcher, A. 1999. 1998
Progress report. Fruit fly eradication programme in Nauru.
RMFFP Publication. 33pp.
A.J., Vargas, R., Leblanc, L. 2001. Assessment of the Fruit Fly Eradication
Programme in the Republic of Nauru. PMP-FFM Report. 13pp.
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.
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 05
on fruit fly survey results in Nauru
(Jan 1993), available in
English (35 Kb pdf document)
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
English (344 Kb)
Download Pest Advisory Leaflet on Melon Fly in
English (192 Kb)