Identifying Queensland fruit fly
Queensland fruit fly is typically about 7mm long and reddish-brown in colour, with distinct yellow markings along its body.Â
Queensland fruit fly wings are transparent with brown veins, which sets them apart from other similar fruit fly species.Â
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The female fly will have an ovipositor (stinger) which is how it injects its eggs through fruit skins.
About Queensland fruit fly
Queensland fruit fly (Bactrocera tryoni) is Australia's most destructive horticultural pest. Native to the subtropical regions of coastal Queensland and northern New South Wales, this small fly belongs to the insect family Tephritidae within the order Diptera.
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Adults are active and feed during the day, but mate at night. Females lay their fertilised eggs beneath the skin of ripening fruit, where the larvae hatch and feed on the fruit's flesh.
This feeding causes fruit to rot, spoil and often fall from the tree before it can be harvested.
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The economic impact on Australian agriculture is significant. Queensland fruit fly causes an estimated $28.5 million in crop losses every year, making it the country's most costly insect pest and one of the most important threats to the Australia's horticultural sector.
Understanding the
life cycle
Laying the eggs
Female fruit flies use a sharp, retractable, needle-like organ called an ovipositor to pierce the skin of ripening or decaying fruit. They deposit their eggs – which are tiny, white, and banana-shaped – just beneath the surface. A single female can lay up to 100 eggs per day.
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Larvae
In just 24 to 48 hours, the eggs hatch into tiny larvae (maggots) that begin eating the fruit from the inside out.
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The fruit will eventually fall to the ground after ripening and rotting. The fully matured larvae leave the fallen fruit and burrow into the soil to pupate. The maggot becomes inactive and changes into an oval, brown, hard pupa.
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Adult
The fly hatches and emerges from the ground. After feeding and mating, females search for suitable fruit to lay their eggs inside, restarting the cycle.
Use traps to monitor and kill flies
Traps are a simple and effective way to monitor Queensland fruit fly activity and help reduce adult fly numbers. If Queensland fruit fly are present in your garden, choose a bait trap that attracts both male and female flies. The traps use a protein-based lure to draw flies inside, where they are killed by an insecticide mixed with the protein lure.
Home gardeners utilise netting
Insect netting is the best way to prevent female Queensland fruit fly laying eggs inside your fruit and vegetables. These products can be purchased from nurseries, and home garden suppliers as well as online retailers.
Destroy dropped and unwanted fruit
Keep your garden free of unwanted, fallen and rotting fruit to eliminate potential breeding sites. Harvest fruit and vegetables as soon as they ripen, or pick them early if they will continue to ripen after harvesting. Dispose of infested or unwanted produce by microwaving or boiling to kill any maggots, or seal in a plastic bag and freeze for at least two days until frozen solid or sit in the sun to passively kill with heat before disposal.
Stay on top of pruning
Queensland fruit fly are attracted to ripening fruit, so harvesting your produce as quickly and efficiently as possible is one of the best ways to reduce the risk of infestation. Regularly prune your home garden fruit trees to make fruit easier to reach and harvest. Well-pruned trees also improve the effectiveness of protective netting and baiting programs.
Commercial growers utilise bait spray
Bait sprays are an effective way to attract and kill adult Queensland fruit flies before they can lay eggs. These products combine a food-based attractant with an insecticide, enticing hungry flies to feed on the bait and die before they infest your fruit.
​Protect your produce
Remove neglected host trees
Unwanted or neglected fruit trees can become year-round breeding sites for Queensland fruit fly, putting nearby gardens, orchards and vineyards at risk. Removing these trees and replacing them with non-host plants helps eliminate valuable breeding habitat, reducing the likelihood of fruit fly infestations. Report neglected host trees growing on public land to the relevant land manager, such as your local council.
