Morley's Final Catalogue: Extremely rare, and found only singly. Tuddenham (T. & J. Brown of Cambridge); Beccles (Crf) and Gorleston (Hist. Yarm., probably in error): ante 1890. One in Copdock Rectory avenue, c. 1895 (Hkg). One at Kessingland in June 1890 (Ctw). One found floating on Oulton Dyke about 1920 (D). One female bred 21 May 1927 from Belton larva (Ellis).
Recent status: Scarce, almost exclusively coastal.
Identification: Compare with similar White Ermine, examples of which can show remarkably few black spots on fore-wings. Water Ermine lacks the single black spot on hind-wing of White Ermine. Overall a longer, slimmer moth and cleaner looking than White Ermine.
Habitat: Wet meadows, marshes including and salt-marshes.
Recorded in 22 (38%) of 58 10k Squares.
First Recorded in 1890.
Last Recorded in 2019.