Fuzzy-Muzzy Drain flies or Moth flies (PSYCHODIDAE)

 

Drain fly or Moth fly, Psychoda spp.

Drain flies or Moth flies are also called Sewage flies  

Details of the hairy wings of the drainfly
 

Microscopic details of the moth fly antenna

Drain fly larva on a slimy substrate

Drain fly larvae feeding on slimy organic muck on the toilet floor

Moth flies are also called by many names: Drain flies, Sewage flies, Filter flies and Psychodids. 

These common names are associated with the places and situations which represent their typical breeding and developmental sites. Mainly observed on toilets, in damp subfloors, in drainage, in greenhouses, sewage plants and other locations where moisture and the presence of decaying organic matter will support their feeding and breeding. These flies usually breed in the accumulation of slime around drain pipes, water closets, urinals, on undersurfaces of dishwashers and on sewage tanks.

These dark gray to blackish, delicate, small flies (adults 1.5-5mm long) are called moth flies due to their fuzzy, moth-like appearance, their bodies, wings and antennae are very hairy. The wings are broadly oval, pointed apically and are held roof-like over the body when it is at rest. Adults are typically live about 2 weeks.

Larvae are 4-10mm long, eyeless and legless. Body color pale with dark head, dorsal bands and breathing tube. Subcylindrical in shape, with head narrower than its body and the terminal segment forming a short hardened breathing tube. 

Female drain flies lay 10-100 eggs on organic muck accumulates. Both larvae and pupae have breathing tubes which allows them to breath in there gelatinous organic muck environment. The larvae feed on the algae, bacteria, fungi, microscopic organisms and sludge present on the organic muck. Larval period last for 8-24 days while pupal stage only 20-40 hours. Total development period (egg to adult) is 8-28 days depending on conditions. 

Drain flies are weak fliers, indoors they are usually seen crawling on walls and on other surfaces. When they do fly, they only cover short distances of a few feet and they move in a characteristic jerky pattern. It is important to note that due to their small adult size these insects are able to penetrate ordinary screens. Even though they are weak fliers, they can be carried by wind unto a facility. Furthermore, the presence of numerous adults indoors indicate the presence of an organic muck source nearby.  

Drain flies do not bite and even though they breed and feed on organic muck they do not transmit human diseases. However, in some case they are reported to cause bronchial asthma when the dust particles brought about by dead drain flies adults are inhaled.   

Integrated Pest Management (IPM) Tips for Drain flies 

1. Thorough inspection of breeding site. Check for slimy drains, sewer leaks, dirty garbage bins, bird baths, clogged roof gutters, clogged storm drains, air conditioners, moist compost, septic tanks, water closets, urinals, etc.

2. Elimination of the breeding and feeding sources of drain flies is key to control.

3. Pouring hot water on the drains can physically loosed and remove the gelatinous films..

4. Drains must be deep cleaned (mechanical removal of muck and slime accumulation with a brush and approved drain cleaning products).

5. If there are large number of adult drain flies, targeted indoor ULV, misting or aerosol application can be done. (Pesticide application must be conducted by properly trained and approved Pest Management Professionals (PMPs) ONLY!) 

6. Repeat: ELIMINATION of breeding sites is the key to long term control!   

I had a blast doing the microscopic analysis of these fuzzy-muzzy drain flies! The intricate detail of their hairy wings, body and antennae was truly awesome!

Awesome creatures! Awesome CREATOR!