For anglers, the March brown (Rhithrogena germanica) is one of the most
iconic mayfly species. However, it is under threat across Europe and it’s
thought that the UK may be a stronghold for this species. We need your
help to discover where the March brown is found in the UK. The
relatively large (13-15mm) adults typically emerge en-masse from rivers around lunch time in March and April. If you see a hatch of these
distinctive insects please use this form to report the hatch.