(Psychodidae)
Biology:
The butterfly mosquitoes, also known as moth flies, sewage flies, abort flies, gully flies or heart flies, are on average 1.5 to 5 mm long. The body and wings are characterized by dense hairs. The mosquitoes are usually dark-colored and have a more or less heart-shaped body outline that resembles tiny butterflies when at rest. Butterfly mosquitoes are not good fliers. They are found in damp rooms such as toilets, often on walls in the immediate vicinity of drainage openings. The eggs are usually laid and the larvae develop in damp places that are heavily contaminated with organic material (e.g. toilets, sewage pipes, manure, compost). For example, the gelatinous “biofilm” of impurities in sink traps or drainpipes that are not flushed regularly provides them with an ideal feeding ground.
Damage:
In general, these animals are considered pests and do not normally pose a problem. Only mass reproduction can become a hygiene problem under certain circumstances¸ especially if the animals occur in rooms where food is produced or stored. The large number of animals is often an indication of hidden moisture damage or hidden leaks in the sewage system.
