Length 10 to 12 mm. The adults are rather plain, largely grey or brown with paler mottling. Full identification of the Hydropsyche species requires analysis of the genitalia. Where the subject of an image has not received genitalia examination, which is necessary to be certain of accuracy in this species, it is highlighted with a red box. For that reason it is only claimed as likely to be this species.

Hydropsyche instabilis.

Streams and Rivers.

June to September.

They are members of the net-spinning group, so called because the aquatic larvae spin cup-like nets to catch small organisms and debris to eat.

Common and widespread throughout Britain.

Common in Leicestershire and Rutland.