(Ragonot, 1883)[Synonyms: Piercea alismana]
Wingspan c. 12mm.
This species is distributed over southern parts of England, ranging northwards to Lancashire, and occupies riverine and other watery habitats.
The larvae feed on water-plantain (Alisma plantago-aquatica), where they feed internally in the flower stems, consuming the pith.
Adult moths are on the wing between June and August, and fly at sunset, but also come later to light.