Fighting fruit fly

Recognising fruit fly

The Queensland fruit fly is wasp-like, about 7 mm long and reddish brown with distinct yellow oval markings.

Female flies lay eggs in maturing and ripe fruit, with the larvae burrowing inside the fruit and destroying it. Larvae in fallen stung fruit burrow into the ground and emerge as adult fruit flies.

There can be five or more generations of fruit fly in a single growing season.

Baiting in the Bega Valley

In previous years Bega Valley Seed Savers provided Queensland fruit fly baiting for Bega and surrounds. The program ceased in 2017.

The program used organically certified Eco-naturalure, which can be purchased online from Bugs for Bugs. There are several other products available, or see fruit fly trap recipes. Contact your local nursery for further advice.

Using Eco-naturalure baits

Eco-naturalure combines food-based attractants and a bacteria-derived insecticide called spinosad. It works by attracting only fruit flies to eat it, and they die after ingesting the spinosad.

The bait can be applied directly to vegetation, or to durable card (e.g. Corflute offcuts). Cards need to be hung in a shady location, preferably in a tree canopy or in a bush. The baits do not need to be hung in a fruit tree or on other fruiting plants (e.g. tomatoes). Covering the baits with an upside down plastic container helps to protect them from rain, sun and wind (if the bait dries out it will not attract the flies).

Keys to successful baiting

Baiting is most successful when neighbouring gardens are involved.

Baits must be replaced each week, from September to April.

Baiting must be supported by good hygiene practices, such as picking all fruit as it ripens and cleaning up all fallen fruit, including at the end of season.

More information

Prevent fruit fly is an excellent website, with management options for home gardeners.

More simple things you can do to manage fruit fly

Remove any fruit trees you know you can't manage and replace them with non-fruiting varieties.
Keep your trees well pruned. Smaller trees are easier to manage.
Keep the ground under your fruit trees mown so that it's easier to pick up windfalls later in the season.
Allow chickens and other livestock to forage under your trees to clean up fallen fruit; although you may still need to pick up and dispose of uneaten fruit.
Dispose of rotten and infected fruit by solarising in a well sealed plastic bag - expose to the sun for at least three days, or seven days if temperatures are below 30°C; for several weeks before composting. Alternatively small quantities may be boiled, microwaved or frozen to kill insect eggs and larvae before disposal.
Do not put fruit or fruit scraps into uncovered compost bins or worm farms. Fruit flies will breed in these locations as happily as under trees.
Pick all the fruit, including quinces, by 30 April at the latest to prevent the fruit fly overwintering.
Consider using exclusion bags or netting to keep fruit from being stung by fruit fly.

Help your neighbours

For various reasons people may need help to manage or remove their fruit trees. It can be difficult to accept help or to tactfully offer help, but the rewards of freshly grown, fly-free fruit can be worth the effort.

Trees on public land are the responsibility of Bega Valley Shire Council. Ring their call centre on 02 6499 2222 to report problem trees on roadside vergers or other public land.