Common Grass-veneer Agriphila tristella
There are many moths in this group, all rather similar and very hard to tell apart. To be sure about any identification you would have to catch one and spread its wings forcefully. And that is something we don't like to do. However judging from the white line, the animals in the pictures are Common Grass-veneers. Usually it is the white smear in the wing, running all the way to the end of the wing that gives this species away. However very dark animals, like the one in the bottom picture, lack the white smear and are very difficult to identify. The adults can be seen from June untill the beginning of October. Their wingspan is some 30 mm. An abundant species all over the British Isles in places covered with tall grasses, where the larvae live in. Agriphila tristella is a migrating species.
