Identification
This is a large damselfly with a total length of up to 48 millimetres (1.9 in) and a hindwing length of up to 36 millimetres (1.4 in).
The male has translucent wings which each have a broad, dark iridescent blue-black spot (or band) across the outer part. On immature dragonflies the spot is dark brown. The body can be a metallic blue or blue-ish green.
The dark wing patch of the male starts at the nodus (the slight dip midway down the upper edge of the wing) but can reach up to the wing-tip in southern races. In the very similar species C. virgo (Beautiful Demoiselle), the dark starts before the nodus.
The female has translucent, pale green iridescent wings with a white patch near the tip (a pseudopterostigma), and a metallic green body.
Read more about this topic: Banded Demoiselle