Moth fly - also called drain fly or sewer fly - Psychodidae

A moth fly I found in my house - I froze it and brought it out to photograph it.

A species I have never seen before - they were not in the Lower Mainland or in Alberta, but they seem to live out here in the Okanagan.  They are small, only a few millimeters across, and blackish. I only ever see them in the spring, and never more than one or two of them.  They are called drain flies or sewer flies because the larvae live inside the empty space of drains.  They are called moth flies because of the fuzzy moth-like wings they have.

They seem to peak in April, which was when I found this individual.  The adults lay their eggs in damp environments that have encrustations present.  This is where the word "drain" flies come in.  Think of a shower that hasn't been used in ages.  The drain will be empty, unused for a long period of time, with a P-trap (that S-shaped pipe under a drain) that is either empty or low.  The flies can sense its presence (be one with the Force, Luke) and travel into the drain and lay their eggs.

Moth flies - the ones here in Canada, anyway, are harmless.  In large numbers, they can be annoying.  The larvae can live in the matted mass of junk that gets trapped in every drain, things like hair, grease, and soap residue.  They feed on the bacteria and other microbes that live off the carnage inside your semi-clogged drains.  They need air to breathe, so, like mosquito larvae, they have small siphons off their abdomens that obtain oxygen in their wet environment.

If you have a problem with moth flies/drain flies, there is a video here you can watch.

Here is another image of the moth fly.

Thanks for reading.

Eric Svendsen     www.ericspix.com