Large Alder Sawfly

I was out surveying grasslands around Grafham Water when I came across this impressive hornet-mimic. At approximately 3cm long, it has quite a fearsome appearance, but is, in fact, totally harmless. The Large Alder Sawfly Cimbex connatus  was thought to be extinct in Britain until it was re-discovered in Wiltshire in the 1990's. It has since spread through southern England and up the east coast as far as Yorkshire, possibly favoured by the widespread planting of Italian and Grey Alder in amenity areas. Nevertheless, it remains relatively rare, and the adult is quite rarely seen. It was quite amenable to being photographed, and even let me pick it up. Eventually it flew away, its wings making a deep throaty buzz.