I had a walk along the field boundary of the nearby SWT Lound Lakes Reserve for about an hour after dusk this evening. Armed with a torch I checked the trunks for Winter Moth. The boundary trees are mostly mature sycamore with a few mature oaks and birch interspersed. The moths were very active although I didn’t notice any flying in the chilly wind blowing across the field. I counted 270 in the hour with about 100 of these being females in cop. They seemed to favour the sycamores with some of the oaks also holding fair numbers. I did not see any on the birches. Many of the females had climbed the wooden fence boundary posts under the trees and some were even on the barbed wire. The cool wind did not seem to deter their activities. The only other moth seen was a Mottled Umber.
Brian
As a follow up, I had another walk round the same trees this evening (6 days later). The torch revealed that the male Winter Moths were still present in good numbers but there was no sign of any females on the sycamores & oaks. The birches on the other hand, on which there were no moths 6 days ago now held good numbers of males plus a fair number of paired up females. Does this indicate that the larva mature at a slightly slower rate when feeding on birch?