Common in a wide range of marginal, aquatic habitats, including bogs, damp heathland and mosses, throughout the British Isles. Widespread and fairly common in Hampshire and on the Isle of Wight. Wingspan 10-15 mm. Generally considered to be day-flying, but often recorded over-night at light traps. The
Glyphipterix form a distinctive group, in which the forewing has a characteristic bulge in the costal half of the termen, and appears distinctly folded longitudinally, although
G. fuscoviridella is atypical.
G. thrasonella has a diagnostic elongate coppery black mark at tonus, which include three silver dots (MBGBI Vol 2). Larva believed to feed within stems of various species of Rush, although the exact foodplant is uncertain.