WSU CAHNRS and WSU Extension


Search by pest name

A  B  C  D  E  F  G  H  I  J  L  M  N  O  P  R  S  T  W  Y 

Pest NameDescription 
Moth flies (drain flies)Moth flies (drain flies)Moth flies (sometimes called drain flies) are small hairy moth-like dipterans (true flies) in the family Psychodidae. As a group, they don’t get much larger 5 mm (about 1/5 inch) long. The small larvae are aquatic and their legless bodies end with an obvious breathing tube. The adult flies have the habit of holding their wings roof-like over their bodies. In nature they are often found in shady places along streams with decaying waste material or around sap emanating from trees. When found in human habitats, they develop in decaying organic debris in sewage beds, compost, septic tanks, or filthy garbage containers. In homes they emerge from the drains of sinks, bathtubs, or shower stalls where bacteria, fungi, and sludge have accumulated. In nature they are considered beneficial recycling organisms. In human habitats, most species are merely a nuisance. Occasionally, when adult numbers become excessive, they have been implicated in cases of inhalant allergy.