Other Common Names
drain flies
sewage flies
filth flies
[all the above names refer to moth flies only - subfamily Psychodinae]
Numbers
90 species in the US and Canada
(1)
113 species in 21 genera in North America listed at
nearctica.com
Two main subfamilies: Psychodinae (moth flies) and Phlebotominae (sand flies); three other subfamilies of lesser importance
Size
adult body length 1.5-4 mm
(1)
larva 3-10 mm
Identification
Adult: resembles a tiny moth; body hairy, variably yellow through gray to black; wings held roof-like over body (moth flies; subfamily Psychodinae) or together above body (sand flies; subfamily Phlebotominae) when at rest; wing veins numerous, hairy, parallel, with no cross-veins in outer two-thirds of wing; antennae long, containing 12-16 segments, each segment bulbous with ring of long hairs (
plumose).
Larva: eyeless and legless; head darker and narrower than body; each segment with one or more dark rectangular bands dorsally; terminal segment narrows, forming dark-colored breathing tube
Pupa: resembles minute grain of brown rice
Egg: minute, brown to cream-colored
Range
many areas of the world; more common and diverse in tropical regions
Habitat
Moth flies (Psychodinae): adults often found around sewage installations, in public washrooms, and bathrooms in homes, and are attracted to light; larvae live in organic sludge that forms on inner surfaces of drains and sewage pipes; pupae occur on the surface of the organic film that the larvae have been living in
Sand flies (Phlebotominae): adults occur in a wide range of habitats but often near water in dry semi-arid areas in the Old World, and in tropical forests and savannas in the New World; larvae inhabit areas containing high levels of organic matter such as in animal burrows, termite hills, tree holes, and leaf litter
Season
spring through fall; all year in tropical and subtropical areas
Food
Moth flies (Psychodinae): larvae feed on algae, fungi and bacteria in sewage and organic sludge; adults feed in polluted water and on flower nectar
Sand flies (Phlebotominae): adult females in three genera suck blood from humans or reptiles in subtropical and tropical regions; larvae feed on dead organic matter in habitats mentioned above
Life Cycle
Moth flies (Psychodinae): in the home, females lay irregular masses of 30-200 eggs in the organic gelatinous film lining drains, particularly in bathtubs and showers; eggs hatch 32-48 hours after being laid, when ambient temperatures are 70ºF (about 20ºC), and larvae pupate 9-15 days later; pupa stage lasts 20-40 hours; development time from egg to adult is 7-28 days, depending on temperature and food availability; adults live for about two weeks
Remarks
Larvae of moth flies play an important role in purifying sewage in industrial sewage treatment plants.
Moth flies are very weak fliers, covering only a few feet at a time in short erratic flights. Outside, they can be blown considerable distances by the wind.
Sand flies are best known as vectors of trypanosome species in the genus Leishmania, causing diseases collectively known as leishmaniasis.
Internet References
classification and brief overview (Biodiversity Explorer, Iziko Museums of Cape Town, South Africa)
detailed overview giving description, biology, control methods (Gale Ridge, Connecticut Agricultural Experiment Station)
