Stephens' Gem Megalographa biloba
Wingspan 38-44 mm.
A rare, presumed immigrant species to the British Isles, with only a handful of examples having turned up, mainly in south-west England or west Wales. The species is a native of North America, and there is evidence that at least some records have coincided with arrivals of American birds in Britain.
Although the early stages have not been recorded in the British Isles, the species is apparently sometimes a pest of cultivated lettuce in its native land.