What's it look like?

These small stumpy fies are black and glossy in colour, but you're probably more likely to pick it up with the damage that occurs than see the flies. Damage will show up with yellow spots on the leaves and a generally weakened plant results if left untreated. You may also notice swollen reddish stems too. Stems become brittle and break easily.

What it attacks

The flies attack all varieties of beans except broad beans. so that's all bush and climbing beans! So beware, it attacks the leaves and stems of the plants.

What to do before it arrives

The flies are especially bad in warm humid weather durning mid to late summer, so if you get a crop growing as early as possible in spring then you'll have less problems. Try growing garlic around the plants to repel the flies.

What to do if you already have problems

Remove and destroy any infected leaves as soon as you notice them. DO NOT COMPOST! Encourage vigorous growth of untouched parts of the plant by applying compost around the soil and give plenty of water. Practice crop rotation to avoid future problems.

For further information:

ABC Online Forum
From: kimmys mum ®. 5/09/2003 7:23:56 PM. Subject: Bean fly. post id: 8491. Can anyone tell me of an environmentally friendly way of preventing bean fly. ... way to dispatch bean fly - it is like fruit fly so that ...
http://www2b.abc.net.au/gardening/newposts/8/topic8491.shtm