Robson had relatively few records, but noted that as it was generally distributed, it would 'probably be found in all woods where Birch abounds'. This is still probably a fairly accurate comment [...] In Durham the central Wear valley area produces the most records: Chester-le-Street, Durham and the surrounding areas all have it wherever birch grows, and it is at several sites in the Derwent valley. Higher in the Wear valley it is found in the Hamsterley Forest trap, at Knitsley Fell, and in many of the woods along the Browney. Strangely, it has never been recorded in Teesdale, though TCD is sure it must be there.