There are 4 stages in the life cycle that you should be aware of.
Egg: 1 female can lay up to 100 eggs per day inside host fruits and vegetables.
Larva: after hatching, maggots begin eating fruit from within, causing it to rot and fall to the ground.
Pupa: it chews its way out of the host fruit and burrows into the soil where it forms a pupal case around itself and begins its transformation into adult form.
Adult: it emerges from the ground, begins feeding, then mating and searches for a suitable fruit to lay eggs in.
In the right conditions, the Queensland Fruit Fly can complete its lifecycle in around 30 days, potentially allowing for 9 generations per year.