Sewage / Drain Flies

INTRODUCTION
These flies get the common name of moth fly from their fuzzy appearance, their bodies and wings being very hairy. The drain/filter/sewage fly common names are from places or situations which represent typical breeding and developmental sites. Although usually thought of as nuisance pests, there have been cases where inhalation of their body parts caused bronchial asthma. Moth flies are found throughout the United States and most of the world.

RECOGNITION
Adults about 1/16-1/4" (1.55 mm) long, delicate and fuzzy. Color pale yellowish to brownish gray to blackish, depending on the species. Antennae 12- to 16- segmented, each segment bulbous and with a whorl of long setae (hairs). Wings broadly oval, pointed apically, veins and margins hairy, and held rooflike over body at rest. Non-biting. In addition, ocelli absent and cross veins restricted to basal 3rd of wing. Mature larvae about 1/8-3/8" (4-10 mm) long, eyeless and legless. Subcylindrical in form, with head narrower than body and terminal rear (apical) segment narrow, forming a short hardened (sclerotized) breathing tube. All or some body segments with narrow, transverse, sclerotized, strap-like bands (usually 2 or 3) on their dorsum. Color pale with head, dorsal bands, and apical breathing tube dark.