Common in dry pastures, sandhills, gardens and grassland throughout the British Isles, but absent from northern Scotland. Widespread and common in Hampshire and on the Isle of Wight. Wingspan 20-25 mm. The main confusion species is
A. inquinatella, but
A. geniculea has pair of chevrons across each forewing, while
A. inquinatella is variably streaked longitudinally. Larva feeds within stems of various grasses, living in a silken gallery.