The dark basal patch and the comparatively well-developed median fascia distinguish this species from B. lancealana.
Marshes, bogs, banks of streams and canals and margins of lakes and ponds.
Recorded in 26 (9.6%) of the 270 2km squares of Huntingdonshire.
Last recorded in September 2018
Recorded date range (Adult): 20 May to 25 September