Information for gardeners

Remove unwanted fruit and vegetables

Pick and use fruit or vegetables as they ripen, and don't leave them on the plant for fruit flies to attack. Collect and destroy any rotting or unwanted host produce, whether it is on the ground or on the plant, to reduce the risk of fruit fly maggots developing.

Do not put untreated produce in your compost or worm farm as this will aid the Queensland fruit fly life cycle. Also, do not dispose untreated produce directly into your rubbish or green bin, as it may cause a new infestation in another area.

Microwave unwanted fruit or vegetables to kill any maggots. Alternatively, place produce in a plastic bag, seal the bag and either leave it in the sun for 5-7 days or place it in a freezer for two days. The bagged, treated fruit or vegetables can then be discarded in your rubbish bin.

Bagged, unwanted oranges exposed to the sun.

Prune and remove unwanted host plants, and replace with alternative plants

Host fruits on fruit trees often ripen at the same time, producing loads of fruit that must be harvested quickly. If you wish to keep these fruit trees, prune them to a manageable size so you can reach the produce easily. Also reduce the size of the tree so it does not produce more fruit than you need.

Remove any unwanted or neglected host trees on your property and replace them with non-host alternative plants such as local wattles or grevilleas. This will reduce the risk of Queensland fruit fly attacking your produce and also remove potential breeding sites in your area.

Harvest produce early

If possible, plant early-maturing host fruit and vegetables and/or harvest the produce early if it will continue to ripen after it is picked. Harvesting prior to ripening removes fruit from trees before female Queensland fruit flies can lay their eggs. Planting fruits that are harvested in late Spring and early Summer also removes host material before Queensland fruit flies have had time to build up their populations to damaging numbers.

Exclusion

Use physical barriers to stop female Queensland fruit flies laying eggs in your produce.

Tree nets

Cover fruit trees with very fine UV stable mesh netting over a frame, using PVC tubes and stakes as a frame. Alternatively, use an outdoor gazebo with zippers as it is easier to inspect trees and harvest fruit when it ripens. Depending on the produce, you may need to install nets when fruit begins to develop so insects can pollinate flowers early in the season. All nets should be secured around the trunk base or to the ground to protect your crop.

If you have had a fruit fly infestation previously, fruit fly pupae may be in the ground under your fruit trees. In this situation, secure the bottom of the net to the trunk base to stop any adult fruit flies emerging from the ground to inside the net. If they are inside the net, Queensland fruit flies can infest your crop.

Bags and sleeves

When fruit begins to develop, place bags and sleeves over the fruit you wish to keep. Remove any flowers or developing fruit from the plant that are not covered by the barrier. Secure bags and sleeves to the plant with tie wire, clothes pegs or string.

Nets, bags and sleeves can be purchased from nurseries and home garden retailers.

Baiting

Baits are an insecticide that is mixed with a Queensland fruit fly food attractant. They are usually spot-sprayed onto the trunk and branches of host plants, which the pests feed on while they are in the tree canopy. These treatments are often used to reduce Queensland fruit fly numbers in an area. Baits can be purchased from nurseries and home garden retailers.

Insecticide spraying

Insecticides which are usually applied to leaves and developing fruit can kill adult Queensland fruit fly on contact or destroy eggs and larvae in fruit, depending on the insecticide. They can be purchased at nurseries and home garden retailers.

As insecticide sprays can be harmful if used incorrectly, always read the label and follow the instructions. Also, make sure that the withholding period has passed before picking treated produce and always wash treated fruit or vegetables before eating them.

Please note that insecticide sprays can kill beneficial insects in the garden and repeated use can cause insecticide resistance.

For more information about fruit fly management, visit the Prevent Fruit Fly website.