The Brown China Mark (Elophila nymphaeata) is a species of moth of the family Crambidae. It is found in Europe. The moth is notable as its larva, like most members of the crambid subfamily Acentropinae, is aquatic and has tracheal gills. The wingspan is 16–20 mm. The moth flies from May to September depending on the location. The larvae feed on Potamogeton, Nymphaeaceae and Nuphar lutea.