Fruit fly
Fruit fly is responsible for more cursing gardeners than most other pests. Fruit fly females lay eggs under the skin of ripening fruit. Larvae burrow into the fruit and munch their way to maturity, destroying the fruit in the process. Prevent fruit fly by encouraging vigorous growth with good feeding, pruning, regular watering and mulching. Practise good sanitation by removing any fallen fruit regularly. If left, ripe fruit attracts fruit flies and makes it easy for larvae to tunnel into the ground to pupate. Companion planting of basil, chives, garlic, nasturtiums and tansy under trees will help confuse them. Use traps to attract and kill them (see how to make one on the right).

Pumpkin fly
Pumpkin fly can cause havoc on squash harvests. Just when you think that butternut is getting ripe, you see a little hole in it. Or that lovely zucchini - bent in the middle, because it has been stung by a pumpkin fly. And if the squash is not harvested and eaten straight away, the fruit eventually becomes infested with maggots and is inedible. 

Pumpkin flies are similar to fruit flies. The flies lay eggs in the fruit, which in turn develop into maggots that munch their way to maturity, destroying the squash.

Once they leave the squash or the fruit, they fall to the ground.

They have a very distinctive habit of ‘springing’ themselves along the ground to move to another area where they burrow under the soil to pupate.





Control of Fruit and Pumpkin fly

Good sanitation is the first step of control. Clear away all fallen fruit and remove any early  unpollinated fruit.

 These develop as normal at first, but then turn yellow, shrivel up, and eventually die off.

Use a fruit fly trap (see below) and spray young fruit with Bioneem. The incidence of stings can be severe in mid summer if the pumpkin fly populations are not controlled early. Start a regular spray programme with Bioneem every seven days when the plant starts flowering. If a serious problem develops, combine Pyrol and Bioneem at 5 ml each per litre of water and spray during the late afternoon when the pollinators are resting.

 Making a fly trap

1. Cut the top cone section off a two-litre plastic bottle (remove the lid first). Place the bait (molasses, rotten banana etc) in the bottom of the bottle. Turn the cone upside down and place it inside the base of the bottle, and use metal clips to secure it. (The tops of these can be used to hang it in place.)



2. Place strips of masking  tape up the sides of the bottle. (This gives insects a ‘ladder’ to grip onto when climbing up the sides.)  For larger insects, leave as is. For smaller insects such as pumpkin fly, cover the top with plastic and secure it with an elastic band.

3. Make holes in the plastic that allow tiny insects in. Hang them among the squash plants. Check  every second week. If you don’t like the look of plastic bottles, decorate them with twine and beads.