Black Tailed Skimmer (Orthetrum cancellatum)
Black Tailed Skimmers like large areas of open water with surrounding vegetation and occur round farm ponds and flooded gravel pits. They also like water gardens! They also occur in boggy areas where there is open water, they are not too bothered by the acidity of the water.
Flying from Late April right through until September the Black Tailed Skimmer is very much a dragonfly of the south of England and it is most common in 'Wessex' and that, of course, means Dorset.
Only the male is this bright blue, the female is green and brown and very similar to the Four Spotted Chaser so beware!