Beautiful Demoiselle

• The male performs a courtship dance before the female, opening and closing his wings and showing her the spot in the stream where she will be able to lay her eggs.
• Like the rest of the dragonflies and damselflies, the male can use his copulatory organ to remove the sperm of previous males before mating.
• Its presence indicates good-quality water with bankside vegetation: it disappears from channelised or unshaded stretches.
• The male's wings are an intense metallic blue, almost black against the light, and he flies with a slow, undulating wingbeat more reminiscent of a butterfly's than of a damselfly's.
• Its courtship is a spectacle: the male defends a patch of aquatic vegetation suitable for egg-laying and, when a female arrives, performs a display flight before her, opening and closing his wings and showing her the site. She chooses as much for the territory as for him.
• The female lays her eggs by piercing the stems of aquatic plants underwater, and she can submerge completely for more than half an hour, carrying air clinging to her body.
• It is very sensitive to pollution and to the channelling of watercourses, and its presence indicates a river in good condition.
• It is told apart from its relative Calopteryx splendens because that species has only a blue band on the wing rather than the whole wing coloured.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Clean, shaded streams and rivers with moderate current

Size at birth

Spindle-shaped egg 1.2 mm long by 0.2 wide, bright yellow when laid and brown as it matures; the final-instar larva weighs about 4 mg

Sexual maturity

Emergence takes place from late May to late August and lasts about two hours; the maturation that follows depends on the weather

Gestation / incubation

The eggs hatch after about two weeks; the larva develops over two years through 10-12 instars among submerged vegetation and detritus, and overwinters buried in sand, silt or gravel

Litter / clutch size

Up to 250-300 spindle-shaped eggs inserted into the tissues of emergent or floating plants (endophytic laying), in a process that can take half an hour

Sources consulted: https://es.wikipedia.org/wiki/Calopteryx_virgo; Ficha de especie de Calopteryx virgo; ficha de especie (Wikipedia); iNaturalist; Ficha de especie de Calopteryx virgo (Nature Journeys); catalogo de odonatos; iNaturalist, ficha Calopteryx virgo

Best time: May to August, over shaded streams of clean water