|Monday, 14 January 2013 12:22|
French Polynesia's 3543 km² land mass is comprised of 35 islands and 83 atolls, divided into the northern Marquesas Islands (1049 km²), the central Tuamotu Islands (726 km²), the Western Society Islands (includes Tahiti) (1573 km²), the eastern Gambier Islands (45 km²) and the southern Austral Islands (147 km²). The largest, highest and most populated island is Tahiti (1045 km², 2241m).
Fruit flies in French Polynesia became a major focus of interest in July 1996, when Oriental fruit fly was discovered on Tahiti, following a training course on quarantine surveillance and emergency response planning conducted in May 1996 in Cairns, Australia. A large scale eradication program was conducted in 1997 by aerial drop of coconut husk pieces soaked in a mixture of methyl eugenol and Malathion combined with protein bait spraying in areas of high fruit fly density. Six campaigns, two months apart, were done in 1997. Fruit flies however survived in isolated pockets of breeding populations. From these, they multiplied and spreaded all over Tahiti and Moorea. Efforts to eradicate the species resumed in January, 1999. A new eradication technology, consisting of papier mâché blocks treated with Methyl eugenol and Fipronil, was introduced to French Polynesia to replace the Malathion-based blocks. The technology, referred to as "BactroMAT ME", has been developed by Aventis CropScience.
Mr. Djeen Cheou, Chef, Section Police Phytosanitaire, Service de l'Économie Rurale
For more information on the programme in French Polynesia, consult their WEB site: www.agriculture.gov.pf
FRUIT FLY SPECIES: There are seven species. Bactrocera kirki was first recorded in Tahiti in 1928 and is now widespread over most of French Polynesia (except the Marquesas and Rapa Island, in Austral Archipelago). Queensland fruit fly (Bactrocera tryoni) was discovered in Tahiti around 1970, probably brought from New Caledonia by travelers carrying infested fruits and covers the same geographic range as B. kirki. In July 1999, B. tryoni was trapped in the Marquesas on Nuku Hiva. Cue-lure trapping was intensified and protein bait spraying applied from August 1999 to February 2000. It was last trapped in April 2000. In November 1999, it was detected on Tahuata Island (Marquesas), and its eradication is still in process. It was trapped on Hiva Oa in May 2002, and is still being eradicated. Oriental fruit fly (Bactrocera dorsalis) was detected in Tahiti in July 1996. In an attempt to eradicate the species, coconut husk blocks soaked in a solution of methyl eugenol plus insecticide were distributed by ground teams and from the air in Tahiti and Moorea six times in 1997. Hot spots of breeding fly populations were not completely eradicated, and from these fly populations spread again all over the two islands. The eradication programme resumed in early 1999. In February 2000, it was detected on Hao, and promptly eradicated. The species is unfortunately spreading, and it was discovered on in May-June 2002 on Huahine, Raiatea and Tahaa. [For a complete report, consult Pest Alert No 27, available in English or in French (311 Kb pdf document). Pacific fruit fly (Bactrocera xanthodes) was detected on Raivavae in April 1998. It is presently being eradicated using cotton wicks dipped in methyl eugenol and Malathion and protein bait spraying. The same species was found on Rurutu Island in May 2000, and a similar eradication campaign was initiated in June 2000. More recently, it was discovered on Rimatara (June 2002).
There are three additional non-economic species. B. luteola (Malloch) is known from Bora Bora and Hao. It is not known to be attracted to male lures. B. atra (Malloch) is known only from Raivavae (Austral Islands) and is sampled with Cue-lure. B. perfusca (Aubertin), another species attracted to Cue-lure, has been recorded from Hiva-oa, Nuku Hiva and Ua Huka (Marquesas Islands), as well as Tahiti.
ECONOMIC IMPORTANCE OF FRUIT FLIES: No data are available on percent damage on specific hosts, but general host fruit surveys and observations have shown that Oriental fruit fly and Queensland fruit fly, and B. kirki to a lesser extent, are the major pest species in French Polynesia.
Surveys: 1. Established a network of permanent trapping sites on eight islands of French Polynesia with Cue-lure and methyl eugenol traps and, in some sites on Tahiti, with Medfly Trimedlure traps. 2. Collected and held in the laboratory for adult fly emergence samples of commercial/edible and wild/forest fruit samples. 3. Determined that there are seven species of fruit flies (Tephritidae: Dacinae) in French Polynesia, and compiled host ranges for most species. Used this data as the basis for negotiations on quarantine protocols for export of fruits and vegetables.
Pest status: 4. Confirmed that three species are of economic importance – B. tryoni, B. kirki and B. dorsalis.
Eradication: 5. Engaged in a major campaign for the eradication of Oriental fruit fly on Tahiti and Moorea by male annihilation and protein bait spraying. 6. Engaged in an eradication campaign against Pacific fruit fly (B. xanthodes) on Rurutu and Raivavae by male annihilation and protein bait spraying. 7. Engaged in eradication of Queensland fruit fly in the Marquesas. 8. Consultancy work carried out in May 2004 to assess and evaluate the past and present fruit fly eradication activities and to make recommendations for the future. 9. Since 2002 to 2004, a total of 523,127 Fopius arisanus had been imported from Hawaii. It has now been confirmed that Fopius arisanus has been recovered from 21 of the 21 communities on Tahiti island, and also from the four outer islands of Moorea, Huahine, Raiatea and Tahaa in the Society islands and one island, Rurutu in the Australes islands. Parasitization has also been proven to have averaged 50% and also the numbers of Oriental and Queensland fruit fly emerging from fruits have been reduced by as much as 75%.
Development of National expertise: 10. Published in the ACIAR Proceedings No. 76 of the Symposium on the Management of Fruit Flies in the Pacific, one scientific paper on fruit flies in French Polynesia and published a Pest Advisory Leaflet on Fruit Flies in French Polynesia. 11. Hosted a Regional Symposium on eradication of Oriental fruit fly from Tahiti and Moorea in Papeete on November 24-27, 1997. Representatives from fourteen Pacific Island countries and territories attended. 12. Provided training to farmers and exporters and government personnel of French Polynesia on the importance of fruit flies to production and national quarantine, identification, control methods, and quarantine treatments. 13. A two week attachment training for staff of the Plant Protection Service in Tahiti working on the fruit fly eradication program was conducted in Fiji Islands from 1-12 March 2004. The attachment training involved fruit fly rearing, fruit fly parasitoid rearing and surveillance procedures. The Plant Protection Officer and the technician who attended the training are currently involved in the establishment of fruit fly colonies for rearing of fruit fly parasitoids. This activity is part of the fruit fly eradication program in French Polynesia.
Emergency response planning: 14. 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 608 trapping sites with one methyl eugenol trap, and 291 sites with a Cue-lure trap, covering thirty-two islands (or groups of islands): Tahiti (184 ME, 21 Cue), Moorea (20 ME, 14 Cue), Leeward Group (153 ME), Tuamotu Group (84 ME), Gambier Islands (19 ME, 10 Cue), Marquesas (54 ME, 227 Cue) and Australes Islands (91 ME, 8 Cue). There are also 20 Trimedlure traps on Tahiti. Samples of guava, mango, soursop, tropical almond, Tahitian chestnut, tomato and cucumber are regularly collected for quarantine surveillance. There are fruit fly posters at the airport. There is a quarantine awareness program running on television, radio, and in newspapers.
Download Pest Alert No 16 on oriental fruit fly discovery in French Polynesia (Oct 1996) in English (38 Kb pdf document)