General
Adult fly 6mm-7mm. Wing span 15mm-17mm in length. The colouration is predominantly dark brown with a light striped appearance. Wings are strongly veined with brown shaded areas in the membranous zones with a dark patch on the leading edge of the wing. 

Significance
Eggs are laid in wet areas rich in organic matter e.g. sewerage works. Adult flies constitute a nuisance in domestic premises where they are often found on the windows.

Control
Single specimens no treatment. Swarms of adults use a space spray insecticide.
Consult specialist for further advice.