Queensland fruit fly appearance and life cycle
Watch this video to learn about the life cycle of Queensland fruit fly (QFF), how it spreads, and how to monitor fruit and vegetables for signs of infestation and control numbers.
Adult QFF are about seven millimetres long and are reddish-brown in colour, with distinct yellow markings.
There are four stages in the life cycle of QFF:
- Maggot (larva)
- Adult fly.
Female QFF lay white, banana-shaped eggs inside host fruits and vegetables. Eggs are 1 mm long and are not likely to be seen by gardeners.
One QFF can lay up to 100 eggs a day.
2. Maggot (larva)
After 2–4 days, a small creamy yellow maggot hatches from each egg. Maggots use their cutting jaws to eat the fruit, growing up to 9 mm long.
Maggots tend to eat towards the centre of the fruit often causing the fruit to rot.
Infested fruit may appear in good condition from the outside, however maggots and damage will be visible if you cut the fruit open.
When the maggot has completed growing, it chews its way out of the fruit – which by then has usually fallen to the ground – and burrows into the soil.
Once in the soil, the maggot changes into an oval, brown, hard pupa.
Inside the pupal case, the adult QFF develops.
4. Adult fly
The adult QFF emerges from the ground. After feeding and mating, females search for suitable ripe fruit to lay their eggs inside, restarting the cycle.
Sometimes stings may be visible on the surface of the fruit sized like the top of a pin.
While QFF activity generally increases in spring as the weather gets warmer, it is not strictly tied to a particular season. If sufficiently warm weather persists into autumn or winter, fruit flies can continue through their life cycle providing that a suitable host fruit or fruiting vegetable is available.