Water Ermine Spilosoma urticae
(Esper, 1789)Wingspan 38-46 mm.
A scarce and local species, occurring mainly in the south-east of England and occupying damp fenland localities.
There are similar forms of the White Ermine which have very few black spots, but the present species never shows a black discal spot on the hindwing.
It flies in June and July and will visit the light-trap. The larvae feed on a number of marshland plants such as water dock (Rumex hydrolapathum) and water mint (Mentha aquatica).