The Beautiful Demoiselle is strictly a river insect, and it breeds mainly in moderate to fast-flowing reaches of rivers and streams. Unlike the somewhat similar Banded Demoiselle, Calopteryx splendens, the Beautiful Demoiselle does not breed in small stillwaters such as garden ponds and canals.
In the summer sunshine these delightful insects with their iridescent bodies and elegant wings flit among waterside plants and occasionally foray well away from their natal watercourses.
In most fast-flowing rivers there is limited opportunity to use a damselnymph imitation, as the natural nymphs are slow moving creatures.
Places where a damselnymph can be effective include gravel-bottomed chalkstreams and spate rivers wherever limited in-stream weed growth allows for nymph fishing close to the riverbed. This is not an easy matter, but an artificial Damselnymph cast upstream and twiched across the river as its drifts on the current can be an effective tactic when trout are not rising to other surface-borne food.
To imitate these sizeable morsels, try a large Green Nymph (tied on a size 6 or 8 long-shank hook) twitched gently as the current carries it downstream near the riverbed and as close as you can to any beds of streamer weed such as starwort (Callitriche species) or water crowfoot (Ranunculus species). Takes can be savage in fast water, so be prepared!
Trout get to eat many more of the immature nymphs than they ever do of the adult damselflies, and so an imitation of the winged adult is unnecessary
In southern Britain the Beautiful Demoiselle is a fairlty common damselfly, but it is found mainly in southern England and in Wales, and in parts of southern and central Ireland. Further north it becomes increasingly scarce and localised.
There are about forty species of dragonflies and damselflies in the British Isles, although some are now quite rare and are hardly ever seen.
Left: this female Beautiful Demoiselle Calopteryx virgo was photographed in southern England by Simon Harding.