Small Red-eyed Damselfly (Erythromma viridulum) is a recent colonist to the county following its spread westwards across England in recent decades, and it is now more common than our other Erythromma species, Red-eyed Damselfly (E. najas).

Current distribution in the county: what we know

Tara Okon found what were believed to be the county’s first Small Red-eyed Damselflies, at Uskmouth nature reserve, in 2017. Tara’s account of her find can be read here. Subsquently, it transpired that the species was also seen during ecological surveys at Newport Docks on 15 July 2015 by David Gibbs.

Since then, the population of this species has dramatically increased and it is now found so widely that it would be impractical to list all of its sites (and such a list would soon become out of date). The following is an attempt to describe the progress of its colonisation; the dates given are those when it was discovered at each site, but it could easily have been undetected at some of these sites before those dates: either because an Erythromma damselfly was assumed to be Red-eyed Damselfly, or simply due to lack of recording visits (Small Red-eyed Damselfly does not require large species-rich lakes, and there are several small ponds at which it has been found which probably only received their first dragonfly recording visits from 2020 onwards as part of fieldwork for the Monmouthshire atlas project).

Following the discovery at Uskmouth nature reserve, there were other 2017 records from Ynys y Fro reservoirs, two sites in eastern Newport (Lliswerry Pond and the Western Lakes at Glan Llyn), and a pond to the west of Mathern fishing ponds. The Ynys y Fro sightings were by Darryl Spittle, and the other new sites found by Keith Jones.

In 2018 it was discovered at two further sites, the Fourteen Locks canal basin on the western edge of Newport, and more surprisingly Dingestow Court Lake, in the northeast of the county near Monmouth.

2019 records came from Magor Marsh, two sites on the western side of Newport (the main lake at Tredegar House and a reen south of Duffryn) and a pond at Chepstow Garden Centre.

No new sites were reported in 2020 or 2021 (at least in part due to recorders confining themselves to their local areas following the COVID-19 outbreak). However, a significant increase in the number of sites occurred in 2022, with records from numerous sites in the south: Spytty Pond in eastern Newport, Cwm Hedd, a fishing lake to the west of Newport, Cwmbran boating lake, a pond near Llanbadoc, and on the Monmouthshire and Brecon canal south of Cwmbran. Also, A second site was found in the northeast of the county: a pond near the Monnow Bridge, Monmouth. Most significantly, it was found at two sites in the northwest uplands: the Punchbowl on the eastern side of the Blorenge mountain, and Dunlop Semtex Pond in Brynmawr.

Further expansion occurred in 2023, with records from further sections of the Monmouthshire and Brecon canal around Cwmbran, strong populations at Wentwood reservoir and ponds on the Celtic Manor estate in the Usk valley north of Newport, from Ponthir reservoir, Llantarnam Ponds and Blaen Bran reservoir near Cwmbran, Goldcliff (a surprisingly late first record given this well-watched site’s proximity to Uskmouth), and at yet another site in the north of the county, a pond in Llanover. Just one new location was discovered in 2024, on the Gwent Levels just north of Goldcliff.

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

There are almost certainly many more Small Red-eyed Damselfly sites awaiting discovery in the county. This species can colonise even quite modest-sized ponds, and there are many such ponds across the county which have not been visited to record dragonflies. Given the continuing expansion of its population, there is no reason why this damselfly should not be present in suitable habitat anywhere in Monmouthshire. The small number of sites where Small Red-eyed Damselfly was recorded in previous years but not from 2020 onwards could be revisited to establish if the species is still present.

Distribution elsewhere

In South Wales, Small Red-eyed Damselfly is now well-established in southern parts of all four coastal counties, west to Pembrokeshire, but it has yet to make it much further north than this, although it is present in England close to the Welsh border as far north as Cheshire, so colonisation of further areas can be expected. In England it has reached Cornwall in the southwest, and Preston and Newcastle-upon-Tyne in the north. Elsewhere in Europe, it is found from Iberia and Portugal east to southwest Russia, north to southern Scandinavia, and south to Italy and Greece; it is also found in parts of North Africa and Turkey.