PACIFIC FRUIT FLY (Bactrocera xanthodes (Broun))

Female Pacific fruit fly     (Photo: S. Wilson)	Female fly laying eggs in fruit  (Photo: S. Wilson)

DISTRIBUTION: Fiji Islands, Tonga, Niue, Samoa, American Samoa, Southern group of Cook Islands (introduced in the early 1970's), Wallis and Futuna. Introduced on Nauru (first detected in 1992), but being eradicated by male annihilation. Detected in April 1998 on Raivavae (French Polynesia), but being eradicated by male annihilation. This species belongs to a complex of sibling species. The three other species in the complex, respectively present in New Caledonia (B. paraxanthodes Drew and Hancock), Vanuatu (undescribed new species) and Samoa (undescribed new species) do not attack edible fruits and are not attracted or are only weakly attracted to methyl eugenol.

 

New species near B. xanthodes from Vanuatu     (Photo: S. Wilson)

HOST PLANTS: It is known to attack 40 host plant species in 30 genera and 22 families. Published host plant records from surveys in Fiji, Tonga, Samoa and Cook Islands include: Detailed host list.

BIOLOGY: Adults mate at dusk. Females oviposit in ripening fruits as well as in fallen fruits. This species is common village/orchard and suburban environment, where breadfruit is common, and is absent from forest habitats. Laboratory colonies of this species, reared on papaya-based diet, are maintained in Fiji, Tonga, Samoa and Cook Islands. Heat tolerance studies have been completed in Fiji, Tonga and Cook Islands, and have been published.

ECONOMIC IMPORTANCE: Damage assessments have provided data on percent of ripe edible fruits infested by Pacific fruit fly. In Samoa, it infests 4-31% of the "Sunset" variety papayas and 19-37% of the local variety. In American Samoa, it attacks up to 62% of ripe breadfruits. In Nauru, it damaged 12% of ripe breadfruits before its eradication commenced. In Cook Islands, B. xanthodes and B. melanotus both infest papaya, and losses by both species are 12% during the summer and 1% during the winter.

MALE LURE: Methyl eugenol.

QUARANTINE SURVEILLANCE: Methyl eugenol trapping and regular host fruit surveys of high risk species, especially breadfruit and papaya.

OPTIONS FOR RESPONSE (If newly discovered in a country): Increased trapping, increased host fruit sampling, restriction of fruit movement, protein bait spraying, male annihilation.

CONTROL: Fruit bagging, protein bait spraying, destruction of fallen and overripe fruits, early harvest of mature green fruits.

REFERENCES:
Drew, R.A.I. 1989.The tropical fruit flies (Diptera: Tephritidae: Dacinae) of the Australasian and Oceanian regions. Memoirs of the Queensland Museum. Volume 26. 521 pp. (Description and illustration).  
Drew, R.A.I., Allwood, A.J., Tau, D. 1997. Bactrocera paraxanthodes Drew and Hancock - an example of how host records and attractant responses contribute to taxonomic research.  pp.131-133 in: Allwood, A.J., and Drew, R.A I., Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp. (Taxonomy of B. xanthodes species complex). 
Foliaki, S., Armstrong, J. 1997. Heat tolerances of immature stages of Bactrocera facialis and B. xanthodes (Diptera: Tephritidae).   pp.239-246 in: Allwood, A.J., and Drew, R.A I., Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp. (Heat tolerance in Tonga). 
Kassim, A., Allwood, A.J. 1994. Fruitflies and their control in Cook Islands. South Pacific Commission Pest Advisory Leaflet. 8pp. (Extension leaflet with good overview of B. xanthodes).  
Leweniqila, L., Heimoana, V., Purea, M., Munro, L., Allwood, A.J.,  Ralulu, L., Tora Vueti, E. 1997. Seasonal abundances of Bactrocera facialis (Coquillett), B. passiflorae (Froggatt), B. xanthodes (Broun) and B. melanotus (Coquillett) in orchard and forest habitats.  pp.121-124 in: Allwood, A.J., and Drew, R.A I., Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp. (Ecology, seasonal abundance). 
Purea, M., Putoa, R., Munro, E. 1997. Fruit fly fauna in the Cook Islands and French Polynesia.  pp.54-56 in: Allwood, A.J., and Drew, R.A I., Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp. (Seasonal abundance, hosts).  
Stechmann, D.H., Englberger, K., Langi, T.F. 1988. Estimation of mortality of Dacus xanthodes (Broun) maggots in fumigated and non-fumigated watermelons, a fruit fly (Dipt.: Tephritidae) of plant quarantine importance in the Pacific region.  Anzeiger für Schädlingskunde, Pflanzenschutz, Umweltschutz, 61: 125-129. (Fumigation treatment in Tonga).  
Tora Vueti, E., Hamacek, E.L., Kassim, A., Walker, G.P., Balawakula, A., Ralulu, L., Leweniqila, L., Kumar, D. 1997. Effectiveness of various larval diets for rearing Bactrocera passiflorae (Froggatt) and B. xanthodes (Broun) in the laboratory in Fiji.   pp.153-156 in: Allwood, A.J., and Drew, R.A I., Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp. (Rearing methods). 
Tora Vueti, E., Ralulu, L., Leweniqila, L., Balawakula, A., Frampton, C.M. 1997. Heat tolerances of immature stages of Bactrocera passiflorae (Froggatt) and B. xanthodes (Broun) in Fiji.  pp.234-238 in: Allwood, A.J., and Drew, R.A I., Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp. 
Tora Vueti, E., Ralulu, L., Walker, G.P., Allwood, A.J., Leweniqila, L., Balawakula, A. 1997. Host availability - Its impact on seasonal abundance of fruit flies.  pp.105-110 in: Allwood, A.J., and Drew, R.A I., Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp. (Ecology, seasonal abundance). 
Waddell, B., Clare, G.K., Petry, R.J., Maindonald, J.H., Purea, M., Wigmore, W., Joseph, P., Fullerton, R.A., Batchelor, T.A., Lay-Yee, M. 1997. Quarantine heat treatments for Bactrocera melanotus (Coquillett) and B. xanthodes (Broun) (Diptera: Tephritidae) in Waimanalo papaya in the Cook Islands.  pp.251-255 in: Allwood, A.J., and Drew, R.A I., Management of fruit flies in the Pacific. ACIAR Proceedings No 76. 267pp. (Ecology, seasonal abundance).

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