Beautiful Demoiselle (Calopteryx virgo) is a fairly widespread damselfly on flowing waters in Monmouthshire; it prefers faster-flowing rivers than its relative Banded Demoiselle (C. splendens).

The oldest record in our data set is from Devauden, near Chepstow, on an unspecified date in 1961 (observer P. C. Webb).

Current distribution in the county: what we know

There are many post-2019 records from the lower stretches of the Rhymney and Ebbw rivers, rivers and streams around Newport and in Torfaen, and the River Usk, with records also from the Olway Brook and the Gavenny and Trothy rivers in the centre and north of the county. In the northwest uplands it has only been recorded recently at Blaenavon. There are a few records of presumed wandering individuals from the Gwent Levels.

Current distribution in the county: what we don’t know

There are many rivers and streams throughout the county which are suitable breeding habitat for Beautiful Demoiselle. As with many other species, the low level of recording in the north, centre and east of the county is likely to be the reason for the lack of recent records, rather than because the species is not present there. It can be expected on many stretches of the Monnow and Trothy and their tributaries, around the streams that flow into the Usk and the Wye, and on the upper stretches of any streams which run south towards the Gwent Levels. There are older records in many of these areas.

It is surprising that in the west, Beautiful Demoiselle has been recorded (not just recently, but also in previous decades) almost solely on the southern stretches of the such rivers as the Rhymney, Ebbw, Sirhowy and not further north. Further recording here will determine if there are overlooked populations or if it is genuinely absent here.

While Beautiful Demoiselle is found on the Usk, the lack of records from the Wye is not surprising given that this is a slow-flowing river by the time it reaches Monmouthshire.

Distribution elsewhere

Beautiful Demoiselle is a common and widespread damselfly throughout Wales. In England it is common and widespread in the southwest, parts of the southeast, the west Midlands and Cumbria, with small isolated populations elsewhere; in Scotland, there is a population centred on Argyll and the southwestern highlands. Elsewhere in Europe, it is found from Ireland and Portugal east to western Russia, north to northern areas of Sweden and Finland, and south to Italy and Greece, though it is missing from much of Spain; outside of Europe, there are also populations in Morocco and Turkey.