Small Red-eyed Damselfly – Erythromma viridulum

European common name: Small Redeye

The Small Red-eyed Damselfly – Erythromma viridulum, is a more recent visitor to the region, but now well established. One of two very similar red-eyed damselfly species, positive identification needs care.


CoenagrionidaeBlue or red Damselflies

The male’s distinctive red eyes, and dark abdomen with its prominent blue ‘tail-light’, make it easy to separate from all other damselflies except the Red-eyed Damselfly – Erythromma najas, which is noticeably larger – the Small Red-eyed Damselfly is the region’s smallest.

In the male, segments 9 and 10 are entirely blue, forming the prominent ‘tail-light’. The blue colouring extends to the sides of segment 8, in a wedge shape. Segments 2 and 3 also have blue sides, with black on the dorsal surface. Seen from above, males feature a black ‘X marking on segment 10. Overall, there are more blue areas on the Small Red-eyed that in the Large Red-eyed.

The female has a black abdomen without a tail-light and has duller yellow greenish eyes. There is a thin yellow shoulder stripe on the sides of the thorax.

The most similar species is the Red-eyed Damselfly – Erythromma najas, and the differences are summarised below:

FeatureRed-Eyed Damselfly –
Erythromma najas
Small Red-Eyed Damselfly –
Erythromma viridulum
AbdomenFeatures a grey pruinescenceGlossy black, no pruinescence
Segments1, 9 & 10 blue, the rest are black2, 3 & 8 also (mostly) blue. 10 features a black ‘X’ marking seen from above
WingsWings extend to S8Wings extend to S7
LegsAll blackBlack with subtle blue stripe
EyesBlood redPaler red, tomato-like
Flight periodMay – SeptemberJuly – September

For other blue damselflies in the region, the obvious distinction is the red eyes of the male, and the generally dark abdomen in both the male and the female. Other things to look out for are noted below.

  • White-legged Damselfly – Platycnemis pennipes
    Noticeably larger, paler colouring, white legs, black is less extensive on dorsal segments. Four obvious shoulder stripes compared to two inconspicuous stripes of the Small Red-eyed.
  • Azure Damselfly – Coenagrion puella
    Obvious ‘U’ shaped marking on segment 2 and blue eyes in the male.Blue (or green in some females) colouring on abdomen more extensive. Narrow shoulder stripe on the male.
  • Common Blue Damselfly – Enallagma cyathigerum
    ‘Mushroom’ or ‘lollipop’ shaped marking on segment 2 of the male and blue eyes rather than red (male). Blue (or green in some females) colouring on abdomen much more extensive. Broader shoulder stripe.
  • Blue-tailed Damselfly – Ischnura elegans
    Tail-light doesn't extend to the tip; only segment 8 coloured blue (other colours in some female colour forms). The male has narrow, complete, shoulder stripes.

Like the similar Red-eyed Damselfly – Erythromma najas, favours still waters, large ponds, lakes, gravel pits and slow rivers, especially where there is floating vegetation – they are often seen on water lilies or floating mats of algae.

A more recent addition to Bedfordshire’s checklist, the Small Red-eyed damselfly is extending its range within the county’s borders (and indeed the rest of the UK). First discovered at the Finger Lakes at Priory CP, it has since dispersed and has been reported at many other sites including Felmersham NR, Wrest Park, Willington, and Sundon Chalk Quarry.

Visible between early July and early September, peaking in August. This is later than the Red-eyed Damselfly – Erythromma najas, which can be a useful aid in separating the two Red-eyed species.

Small Red-eyed Damselfly - Erythromma viridulum Male, The Grange Estate Willington.
Male Small Red-eyed Damselfly – Erythromma viridulum
Small Red-eyed Damselfly - Erythromma viridulum Female, Kempston.
Female Small Red-eyed Damselfly – Erythromma viridulum

External links for Small Red-eyed Damselfly – Erythromma viridulum:
British Dragonfly Society | Wikipedia