Dark Arches Apamea monoglypha
Wingspan 45-55 mm.
A common species throughout the British Isles, there are frequent melanic specimens, especially in the north.
Occurring in a variety of habitats, especially more grassy areas, it is on the wing from July to August, with a later second brood in the south.
It is readily attracted to light and one of the commoner species in the moth trap in late summer.
The larvae feed on the bases and stems of various grasses.