Although a fairly common damselfly, I've only recently spotted one of these at Croome. There were two at the very southern end of the river - normally a very good place for dragonflies and damselflies. The colours are beautiful metallic blues and greens, making them quite distinctive from other damselflies. Another difference is the wings are often spread when resting, rather than the normal tight in line with the body. Emerald damselflies appear quite late in the summer.