Last week (30-11-2009) I was in the NP and I came up on tree after tree beech, birch, oak and pine and found hundreds of dead and moribund Winter Moths - Operophtera brumata.They were on the lower part of the trunks, round the base on the ground below the trees. I was unsure if the adverse weather we had had caused this phenomenon. I asked on the Back Garden Moths forum was told that there was a chance that they had all emerged about the same time and may have just reached the end of their natural lives. This could perhaps have been hastened by the prolonged heavy rain followed by a large drop in temperature. The Moths must have fallen off the tree trunks where they would have been looking for females to mate with. I was hoping I would be able to return and find some of the wingless females as I had never seen them before, but was told this was unlikely as during the day they hide at the base of trees, but as the males were dying off, the females had probably laid their eggs and died too.
Today I was out and I came across more of the same scenario and I didnít find a female just thousands more dead moths. Very sad!
One thing I did notice when there were so many moths together was the variations in their sizes, a good 4mm in wing span in some cases Ė which is a lot in moth size!
(Image 2 is a live Winter moth)