Over all length 33 - 35mm. The males are blue and black and are hard to separate from Common Blue Damselflies, Enallagma cyathigarum. The final two segments of the abdomen, 8 and 9, have black markings on them whereas they are solid blue in the Common Blue. The blue shoulder stripes are thinner than the black lines below them (thicker in Common Blue) and there is a short black stripe below that in the blue of the side of the thorax (Coenagrion spur).The females have a blue form and a green form, both with black markings. Generally the females have much more black on them than the males. The females have green shoulder stripes on the thorax (blue in Common Blue females).
Small sheltered pools with abundant floating plants are their preferred habitat.
Status and distribution
They like to bask on floating aquatic vegetation and prefer the two gravel pits on the reserve, where there is a small population. Nationally they are an abundant damselfly with a distribution that covers most of the British Isles, except the northern half of Scotland.
Best time to see
End of June to late August.