Common fruit fly

(Drosophila melanogaster)

Adult: 2–4 mm
Larva: 3 mm

Identification marks

The common fruit fly belongs to the family of Drosophilidae. Drosophilidae flies are small, reddish brown or black and brown flies, which often have red eyes. Common species include the vinegar fly and the fruit fly. The larva is light in colour and resembles a worm.

Occurrence

Adult fruit flies are mostly seen indoors during the late summer and autumn. The larvae feed on various rotten vegetable-based waste, in particular, rotten fruit.

 

banaanikarpanen_luomus

They also eat beer or wine left at the bottom of glasses, ketchup, sweet jams, rotten potatoes, cucumber, kitchen waste and vinegar.

The populations in homes may have spread from store-bought fruits that have had eggs, which the human eye cannot see. During the summer, the adult flies can fly in through the windows or larvae can be brought in with slightly rotten berries and fruits.

The fruit flies reproduce quickly. The female may lay up to 400 eggs into food stuffs. The larvae grow up within a few days and encapsulate. A generation from an egg to an adult develops in around 10 to 14 days.

Damage

The fruit fly larvae ruin the food they have contaminated. The flies also spread yeast and bacteria on to food ingredients.

Prevention and extermination

Take care that no fruits are forgotten about in cupboards or on tables. Store all food stuffs in sealed containers and empty the bio waste bin regularly.

You can trap the flying adult flies into a container, which has some water and vinegar on the bottom with a drop of dishwashing liquid that helps to remove the surface tension.