Oak Processionary Moth Caterpillar

These moths are a recent introduction to this country, but have taken a hold in the park where as many of the caterpillars as possible are removed each year. Last year about 8000 nests were removed. Apart from the damage to trees their hairs can cause a nasty painful rash. I know from past experience, but I still go looking for them. So far this year I have found several nests and a few processions. The image shows a small procession, they can be several hundred in size. I photographed a procession the other day which was about a metre in length.