New Guinea fruit fly

Alert

Have you seen New Guinea fruit fly?

Be on the lookout and report signs to Biosecurity Queensland on 13 25 23 or contact the Exotic Plant Pest Hotline on 1800 084 881.

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

New Guinea fruit fly is a pest of horticultural crops and found in Papua New Guinea and Indonesia.

Contact us immediately if you suspect New Guinea fruit fly so that it can be eradicated before it becomes widespread.

Cause

New Guinea fruit fly is a small fly known as Bactrocera trivialis (Drew).

Other names

  • Dacus trivialis Drew

Description

Adults

  • About the same length as a common housefly but more slender like a small wasp.
  • Approximately 7mm in length.
  • Mainly black with clear wings.

Larvae

  • Maggots are typically white.
  • Maggots similar to other fruit flies
  • About 7.5–9.5mm long.

Pupae

  • Like other fruit flies, varies in colour from white to yellow-brown.
  • Roughly cylindrical
  • The larvae change into adult flies within the pupa.

Plant stage and plant parts affected

  • Ripening fruit are affected.
  • Fruit of host plants including mango, peach, citrus, guava, chilli and lilly pilly.

Plant damage

As with other fruit fly species, females 'sting' the fruit when they lay their eggs inside. Larvae hatch from eggs and tunnel into the fruit, and considerable damage can occur inside the fruit before obvious signs can be seen on the outside of the fruit.

Fruit decaying bacteria are also deposited within the fruit during the egg laying process. These bacteria also contribute to fruit damage.

The most obvious signs of infestation are:

  • small discoloured or water-soaked patches on the fruit skin, which develop from the stings
  • affected fruit rotting and often falling from the plant prematurely.

May be confused with

The Queensland fruit fly is a similar size and colour to New Guinea fruit fly. An expert 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

Widespread on the island of New Guinea including Papua New Guinea and West Papua (Indonesia). It is less common in the highlands.

Hosts

New Guinea fruit fly is known to infest 17 host plant species in 10 families including mango, peach, citrus, guava, chilli and lilly pilly.

Impacts

Costly quarantine restrictions and eradication measures will be needed if New Guinea fruit fly were to arrive and establish in Australia. It would have serious consequences for our horticultural industries as many countries have trade restrictions on produce from regions known to have New Guinea fruit fly. Growers would likely face difficulties exporting their produce.

Home growers with backyard mango, peach, citrus, guava, chilli and lilly pilly plants would also be affected.

Monitoring and action

If you have fruit and vegetables that have had no problems with fruit fly in the past but are now infested with maggots, then it is possible that you have an exotic fruit fly species on your property.

Keep a look out and contact Biosecurity Queensland on 13 25 23 if you notice unusual fruit flies or there are changes in the pattern of fruit fly damage to your crops.

Control

The nationally cost shared Exotic Fruit Flies in Torres Strait Eradication Program undertakes surveillance for eradication for New Guinea fruit flies and other exotic fruit fly species that may be seasonally dispersed from Papua New Guinea to the Torres Strait Islands with the summer monsoon season.

The program includes:

  • trapping and identifying fruit flies for early detection
  • using pheromone-based insecticide baits (blocks) to attract and kill male fruit flies
  • using protein-based insecticide bait (spray) to kill adult female flies
  • movement restrictions to prevent pest introduction and spread by movement of infested fruit and vegetables.

Legal requirements

New Guinea fruit fly is a prohibited plant pest under the Biosecurity Act 2014. Report suspected New Guinea fruit fly to Biosecurity Queensland immediately on 13 25 23 or contact the Exotic Plant Pest Hotline on 1800 084 881.

If you think you have found New Guinea fruit fly, you must take all reasonable and practical steps under your control to minimise any associated risks. This is called a general biosecurity obligation (GBO).

New Guinea fruit fly is also a declared far northern pest. The far northern biosecurity zones (PDF, 333KB) have been established to prevent the spread of far northern pests.

Regulations are in place to restrict the movement of fruit and vegetables, plants and other plant material, soil and equipment (collectively called far northern pest carriers) which may harbour pests and diseases. You must apply for a biosecurity instrument permit to move any of these items out of the far northern biosecurity zones.

It is illegal to move a far northern pest such as New Guinea fruit fly or far northern pest carriers without a biosecurity instrument permit:

  • from far northern biosecurity zone 1 to a place outside of that zone
  • from far northern biosecurity zone 2 to a place outside that zone unless it is into far northern biosecurity zone 1.

You must observe movement restrictions if you are travelling to or around the Cape York Peninsula, or you live there.

For more information about biosecurity instrument permits, contact the Customer Service Centre on 13 25 23 (from interstate use (07) 3404 6999) or email qld.plantquarantine@daf.qld.gov.au.

Biosecurity Queensland inspectors at the Cape York Biosecurity Centre at Coen check vehicles moving south from Cape York Peninsula to ensure that pests or pest carriers are not moved from the zone.

Your cooperation in complying with these restrictions will help protect Queensland from exotic fruit fly outbreaks.

Further information