What we can expect in fruit fly trends

If the Queensland Fruit Fly (QFF) prevalence pattern in the Goulburn Murray Valley (GMV) follows previous years, there will be an upsurge of captures during the third week of November. Fruit fly numbers will increase until the summer peak is reached, which is generally in late January/ early February. This peak time represents overlapping fruit fly generations and occurs while there is an abundance of fruit of many different types and species at this time of the year in urban areas.

Harvesting and pruning

Most fruit flies are currently in their immature stage in infested fruit, while some will be in the soil. You can reduce the potential number of flies prevalent in the summer when most fruit is being harvested in urban areas, by removing and destroying all fruits that are not wanted, or if they can be used green, or can ripen after harvest on the shelf, to harvest them early (before they can be infested). We know that one QFF female can produce as many as 400 female offspring in her lifetime. We also know that one large fruit, such as a QFF-infested grapefruit, can produce many more than 50 QFF. Even a few unmanaged fruit can start a huge population explosion at a later date when there are a lot more fruit around.

Fruit fly baits for the home garden

Now that most flies are immature it won’t be long before adults emerge from their pupae in the soil in a population explosion. This new generation will cause much damage in home gardens and their offspring will then move on from urban areas to rural locations causing damage there later in the season.

Home garden fruit fly control strategies

  • Remove – unwanted fruit and fruiting plants, before they fruit;
  • Monitor – fruit for signs of fruit fly activity and sting marks with traps;
  • Imports – reduce the amount of fruit you bring home from unmanaged production areas;
  • Clean – pick up fallen fruit and harvest unwanted fruit. Destroy it in plastic bags or by heating, freezing, etc;
  • Trim – keep fruit trees manageable by pruning. Make sure there are no unreachable fruit on the tree;
  • Cover – netting or paper covers on fruit, fruit trusses or netting whole plants will protect from fruit flies;
  • Treat – fruit fly baiting can be very effective in home gardens especially if neighbours work together.