Importance of crop hygiene and host management

Are fruit flies enjoying your backyard more than you?

Fruit trees and veggie patches have long been a staple of Aussie backyards, and recent events have seen a resurgence in their popularity as many of us take the opportunity to enjoy our gardens. Unfortunately, we’re not the only ones enjoying our backyard fruit trees and veggie patches.

Encouraged by favourable weather conditions, the past season saw a massive surge in the numbers of Queensland fruit fly (Qfly) across the eastern Australian states. As Australia’s top horticultural pest, Qfly costs millions of dollars to farmers through damaged crops, pest control expenses and lost market opportunities. But it’s not only farmers who are affected, in fact we all are, as fruit and veg are an everyday essential.

Recent research has identified that managing the sources of reinfestation from urban areas is vital to control Qfly. With a heritage from more tropical locations, Qfly likes to spend the winter in sheltered warmer areas. The locations around our homes and suburbs offer perfect conditions for Qfly to take refuge from the cold. Early action can help stop the overwintering Qfly move into surrounding areas as the weather warms up. During other parts of the year our backyards, unless taken care of with regular management practices, can provide a safe haven protecting Qfly from the control efforts of our neighbours and local farmers.

Another feature which makes our backyards and gardens such a great location for Qfly is the variety of different fruits and vegetable we grow. With over 200 different host species, Qfly are not picky eaters, a key characteristic which makes Qfly such a problematic pest. Qfly hosts include some of our most popular home-grown fruit and veg varieties such as citrus, tomatoes, capsicum and chillies, blueberries, strawberries, apples, stonefruit, and grapes to name a few. The wide variety of host plants help sustain Qfly populations throughout the year, and at key times, such as the start of spring, key hosts can enable Qfly to rapidly build up in number. In particular, early ripening fruits such as loquats or late season hosts such as some citrus varieties, are standout contributors.

A safe home and lots of food supports another aspect which makes Qfly such a great pest, namely that they can breed in large numbers. A single female fruit fly can lay hundreds of eggs in her short lifetime, and recent research has also shown that most of the eggs laid into a range of different fruits obtained from backyard trees in Sydney developed successfully into flies. This means that multiple generations can grow during a season and a single fly can lead to a population explosion.

We all have a part to play in controlling Qfly, but what can you do to help in your backyard?

One of the easiest things you can do is to keep your backyard free of host material and practice good hygiene. If you have fruit trees make sure you remove fallen fruit and do not leave ripe fruit on the tree. Removed fruit must be destroyed and the best way to do this is by using heat. An easy way to do this is to bag the fruit in a sealed plastic bag and leave it in the sun. Don’t be tempted to put the fruit in the bin or compost heap until you’ve done this as the larvae can still pupate and become adult flies.

If you are no longer using your fruit trees or have host trees as ornamentals remove them and consider replacing them with a nonhost tree. Many councils offer a service to do this especially in our horticultural production areas if you can’t do this yourself.

If you are actively using your fruit trees and veg patches there are ways to protect your crops by using insect netting along with Qfly baits and traps. Check your traps and inspect you fruit for the tell-tale sting signs which are where the Qfly has laid its eggs.

Qfly is a serious pest and controlling it is everyone’s responsibility. If everyone does their part, we can enjoy not only the benefits of our own labour in the garden but also benefit from the hard work of our Aussie farmers.

You can access a range of resources on how to manage Qfly on the Department of Agriculture website

/Public Release. This material comes from the originating organization/author(s)and may be of a point-in-time nature, edited for clarity, style and length. The views and opinions expressed are those of the author(s).View in full here.