[...] 'A very abundant species everywhere' in Robson's day [...] its range in northern Britain has a distinct easterly bias. In Durham the situation similar [to Northumberland], both in abundance and distribution. Although it was known to J. P. Robson in the part of Teesdale around Barnard Castle, and it does come to the Hamsterley Forest trap each year, it has never appeared in the Upper Teesdale trap at Langdon Beck. The moth flies from the first week in June commonly to late July and occasionally into August in coastal localities, but the flight period is markedly shorter inland.