Queensland fruit fly numbers typically decline in the Goulburn Murray Valley as autumn sets in, however fruit fly activity will continue despite lower numbers being trapped. Continued activity is because temperatures will become too cold for trapping but will not be cold enough to stop mating, egg-laying and larval development, particularly through the first half of autumn. Now is the period when fruit fly build up before winter and if they survive the winter cold will start a new season of fruit damage next spring.

Garden hygiene and the removal of ripening or unwanted fruit is important. You will break the fruit fly cycle by successfully cleaning up your home garden and nearby untended land of potential fruit fly host material, as no fruit means no fruit fly.

Movement and activity

Even though numbers in urban areas may be down this does not mean that all fruit flies have left urban township areas. Many adults may have moved on, but they have left their offspring in urban areas in the form of eggs, larvae and pupae in and around late-infested fruit that hasn’t been picked up and destroyed. These will form adults towards the end of April when it’s too cold for fruit fly to be attracted to traps. If these adult flies are able to take refuge in warm spots on the urban landscape and survive the winter they will then infest fruit in the new season next spring. Removing these infestation sources before flies can find them will break the fruit fly cycle and reduce the number of adults surviving into next spring.

Stop the spread

Home gardeners and property owners in built up township areas should undertake essential fruit fly management strategies over the autumn months.

These include:

• The use of netting or bagging over autumn fruit
• Fruit or plant removal
• Fruit examination (for eggs and larvae)
• Notifying authorities of nearby untended/feral fruiting plants

Fruit fly activity

The below locations recorded trapping sites registering 12 or more Queensland fruit fly in total over recent weeks. These sites are of concern as they could become sites from which large numbers of fruit fly establish and spread. It is important that property owners in these areas take precautions to reduce the ability of fruit fly to infest fruit and to survive in them.

Ardmona Merrigum Shepparton East

Echuca Mooroopna Tatura

Euroa Orrvale Toolamba

Invergordon Rochester Undera

Kyabram Shepparton