Crambus lathoniellus is a very common species too. It is very variable and may be almost unmarked like the one in the top picture, or very well marked like the one in the bottom picture. The caterpillars live on or in various grasses, including breeded species. It is quite small, reaching a wingspan of no more than 22 mm. The adults are on the wing from May untill August. This species is abundant all over the British Isles, except for Orkney and Shetland where this is an uncommon species.
Even among scientists this was an awkward grassmoth to name, for in the past it was also known as Crambus pratorum, Crambus pratellus en Crambus nemorella.