Naturalised in aquatic nurseries through accidental introduction in aquatic plants from the U.S.A. First recorded at Enfield, Middlesex from where it may have spread to other greenhouses, but probably not able to survive in the wild in Britain. Not recorded in Hampshire or on the Isle of Wight to date. Wingspan male 11-13 mm, female 13-17 mm. Larva feeds on water plants, living entirely underwater, causing sufficient damage to be a serious pest in some areas.