While some horticultural pests can be seen and control measures put in place before damage becomes widespread, fruit flies can easily go unnoticed until after the damaging effects of larvae have already destroyed the fruit. The movement of fruit flies within townships also means that if you are in a fruit fly affected area it is important to apply preventative control measures, even if you didn’t observe any damage last year.
By understanding what can make fruit fly control more challenging than it is for some other pests, it is possible to take the right actions throughout the year to minimise the impact on your crop. Fruit fly control doesn’t need to be difficult, but it does take commitment.
Challenge one – knowing when fruit flies are active
Unlike pests that bite or chew plants, the presence of fruit flies is not always obvious. The first time you know of fruit flies are affecting your crop might be the time you cut open or harvest a piece of infested fruit by which time it is too late. Those developing larvae are also protected from predators and many chemicals that might be used.
Depending on where you live, fruit flies might be active throughout most of the year, or might only be active from late spring or early summer. However, regardless of the time of year, fruit flies will be looking for ripe or ripening fruit to lay their eggs in. You need to have control measures in place before fruit starts to ripen.
Therefore, it is important to get control measures in place early in the season. Control activities should commence five to six weeks before harvest and well before fruit starts to develop colour.
Challenge two – a wide host range
Fruit flies mostly affect fruit that is approaching maturity. Fruit that is starting to develop some colour or becoming soft is the most likely to be attacked. Adult fruit flies will be active in warmer weather as long as there is moisture available.
However, fruit flies will also attack a wide range of fruits and fruiting vegetables that might be ripening in your garden over a period of months. This means that a problem can develop in an early season crop such as summerfruit or tomatoes and then move onto other crops you might be growing.
Therefore, it is important to control fruit flies throughout the year and in all the crops you might grow. It is also important to consider other host fruits that might be grown in your area.
Challenge three – pest movement
Adult fruit flies are capable of flight and will move between properties and crops in search of food. Fruit flies will also disperse from refuges such as unmanaged or roadside trees, even if they have a good source of food. While fruit flies don’t necessarily move long distances, it means that an isolated fruit fly problem can spread and affect adjacent properties and become a community wide problem.
The most effective fruit fly control will be achieved when all landholders and members of the community are working together and not allowing fruit fly populations to build up. Controlling fruit flies or other pests across larger area and not just on a single property is known as “area-wide management”.
Therefore, the most effective fruit fly management will be an area-wide approach that covers multiple backyards or orchards. Partnering in fruit fly management with neighbours and adjoining properties will give the best result for everyone.