Calopteryx virgo (Linnaeus, 1758)

Common name: Beautiful Demoiselle

Preferred environment: upland and lowland unpolluted lotic sites especially with wooded banks and of moderate flow with sandy and gravely beds.

Flight period: May to beginning of September; in northern Europe, including Ireland, June to early August.

Adult habitat and habits: males hold territories along riverbank defending perch on tree or riverside plant

Oviposition site and behaviour:females oviposit alone with male guarding, into stems of aquatic plants including aquatic Ranunculus spp., Sparganium, and aquatic Veronica spp.

Larval habitat and habits: larvae found amongst submerged plants and roots. Hibernate in gravel bed.

Emergence behaviour: emerges at night on low vegetation often some distance away from habitat.

Range: Europe, western Asia and northwest Africa. In Ireland mainly confined to the south and east of a line from Limerick to Dublin and also Connemara.

Determination of adults: species is keyed in Maibach (1987). Mature adults of both sexes are illustrated in colour in Askew (1988) and Brooks (1997).

Determination of larvae: keys to mature larvae in Askew (1988) and Brooks (1997). Photograph of mature larva in Brooks (1997)