On Sep 13, 2006, wallaby1 from Lincoln United Kingdom (Zone 8a) wrote:
These curious creatures will dart about and eat insects. The male seems to like a slightly higher point to perch on, they will often perch on a tall stick.
There are four very similar Darters in the UK. This is the only one to have the distinctive orange-red veining in the wings, mostly on the leading edges and just below. The veining in the female is more yellow.
The tip on the wing, the pterostigma, in the male is a reddish brown, or pale red to yellow, the female yellow.
They have yellow stripes down the backs of the legs, the abdomen colour varies from olive green to yellow in the female, or green, or brown, or predominantly red in the male.
The male I viewed looked green with a red back, but they do look different when photographed. The female looked green with a brown back.
This is the only one of the four similar species (Common, Ruddy, Vagrant, Red-veined) to have a blue colour to the lower edges of the eyes when mature. In order to properly identify the female I eliminated others by using the above points plus other information available, the main deciding factor being the blue I could see on the edge of the eye above the wing. On enlarging to expanded pixels I could see the definite blue next to the green. It is not always possible to get very clear pictures of all the details.
The female can also be separated from the male by the ovipositor (egg laying organ), visible towards the end of the abdomen on the lower side.