New Guinea fruit fly

Have you seen New Guinea fruit fly?

Be on the lookout for New Guinea fruit fly and report it to Biosecurity Queensland.

Early detection and reporting are the key elements in controlling New Guinea fruit fly.

Call Biosecurity Queensland on 13 25 23.

New Guinea fruit fly (Bactrocera trivialis) is a pest of horticultural crops that is found in Papua New Guinea and Indonesia.

It is important to let us know as soon as you suspect New Guinea fruit fly so that it can be eradicated before it becomes too widespread.

Other namesBactrocera trivialis (Drew)


  • About the same length as a common housefly but more slender.
  • Similar to a small wasp.
  • Grows to 7 mm in length.
  • Mainly black.

Similar species

The Queensland fruit fly is a similar size but is an overall reddish-brown colour. An expert eye is needed to identify New Guinea fruit fly under a microscope. Traps used to catch Queensland fruit fly can also catch exotic fruit flies, so it is important to check traps carefully.

Distribution New Guinea fruit fly is widespread in mainland Papua New Guinea. It is less common in the highlands. It is also present in Indonesia (West Papua, Sulawesi)
It has been detected several times in the islands of Torres Strait. It has not established a presence as any detection is immediately eradicated under the Long-Term Containment Strategy for Exotic Fruit Fly in Torres Strait.
  • New Guinea fruit flies are active throughout the year.
  • The adult female lays eggs under the skin of the fruit
  • The eggs hatch into larvae (maggots) which feed on the fruit.
  • Once larvae have finished feeding, they drop from the fruit and burrow into the soil to develop into pupae.
  • Pupate emerge as adult fruit flies.
  • This life cycle will typically take 3-5 weeks for completion in summer, and longer over winter.
Hosts New Guinea fruit fly is known to affect 11 host species in 9 genera and 8 families. It commonly affects lilly pilly, guavas and oranges and there are records of it breeding from chilli, mango, grapefruit, tropical almond, peach and Baccaurea species.

As with other fruit fly species, females 'sting' the fruit when they lay their eggs inside. Larvae tunnel into the fruit and considerable damage can occur inside the flesh before obvious signs can be seen on the fruit. The most obvious signs of infestation are:

  • small, discoloured patches on the skin, which develop from the stings
  • affected fruit will rot and often fall from the plant prematurely
  • larvae feeding on cucurbit flowers and stems.

New Guinea fruit fly could easily be brought into Australia by illegal imports of fruit. Costly quarantine restrictions and eradication measures would be required if it established in Queensland.

It would also have serious consequences for our horticultural industries. Some countries have trade restrictions on fruit that come from regions known to have New Guinea fruit fly. Growers would likely face difficulties exporting their produce.
Spread Like most tropical fruit fly species, New Guinea fruit fly multiplies rapidly and can spread over large distances. It is capable of establishing in tropical areas of Australia.
Risk period New Guinea fly occasionally moves into the Torres Strait with the monsoonal winds each wet season and is eradicated annually as part of a proactive containment strategy by the Queensland and Australian Governments.The greatest risk period for incursion from this pathway is over summer, although it could also be introduced through illegal imports of fruit.
Monitoring and action

Keep a look out and let us know if you notice unusual fruit flies or there are changes in the pattern of damage to crops.

Government monitoring

Queensland Government monitors a network of traps for New Guinea fruit fly in high-risk urban and remote centres in Queensland. Australian Government conducts surveillance on each inhabited island in Torres Strait. If it is detected in Queensland, we have well-planned eradication strategies in place.

As a result of the pest's heavy infestation habits, revised field control strategies may be needed should it become established in horticulture production regions.

More information

Exotic fruit fly surveillance program