Polar-Smaragdlibelle (Somatochlora sahlbergi)
• English name: Treeline Emerald
• German name: Polar-Smaragdlibelle
• French name: N/A
• Dutch name: Toendraglanslibel
• Swedish name: Tundratrollslända
• Norwegian name: Nordlig metalløyenstikker
• Finnish name: Tundrakiiltokorento
• Danish name: Tundra-smaragdlibel
• Italian name: N/A
• Czech name: N/A
• Slovenian name: N/A
• Bulgarian name: N/A
Polar-Smaragdlibelle
(Somatochlora sahlbergi)
Map data based on J.-P. Boudot & V. J. Kalkman (eds.),
Atlas of the European Dragonflies and Damselflies
| General | • a very dark, metallic-green species of the far north | |
| Classification | • suborder: Anisoptera (dragonflies); family: Corduliidae | |
| Conservation status | • IUCN Red List Europe: Data Deficient | |
| Scientific name | • Somatochlora sahlbergi Trybom, 1889 | |
| Name genus | • Somatochlora: from Grk. σῶμα (stem: σωματ-) = body +; χλωρός = green | |
| Name species | • sahlbergi: after Johan Reinhold Sahlberg (1845-1920), Finnish entomologist | |
| Distribution | • click or tap the Map button above | |
| Habitat | • deep bog pools and lakes on the tundra | |
| Dimensions | • typical body length: 48-50 mm; hindwing: 30-33 mm | |
| Notes | ➤ smaller and noticeably darker than Somatochlora metallica | |
| • very similar to S. alpestris with which it co-occurs | ||
| • cordulids are 'fliers': they spend a lot of time on the wing and seldom hang up for a rest | ||
| • seems to be active only in sunny weather | ||
| Both sexes | Head | • the eyes are green (brown in immature animals) |
| Abdomen | • S3 bears a narrow white ring on either end; the lower ring may be (partly) obscured | |
| • S4-S10 are uniformly black (or very dark green) | ||
| Wings | ➤ there is a single cubito-anal crossvein in the forewing (as opposed to the, unusual, two crossveins in S. alpestris) | |
| • the pterostigma is relatively light-coloured | ||
| Male | Abdomen | ➤ the upper appendages are single-angled |
| Female | Abdomen | • there are no yellow spots on the abdomen |
| • compared to S. arctica the abdomen is short and thickset | ||
| ➤ the vulvar scale is elongate and tapered in shape | ||
| Photographs | • all of our photos below were made in northern Finland |
Somatochlora sahlbergi (left) and S. alpestris (right), forewing
In S. alpestris the forewing has two cubito-anal crossveins. In S. sahlbergi (and all other European species of the genus) it has one.
Somatochlora sahlbergi (left) and S. alpestris (right), appendages, male
In S. alpestris the appendages are double-angled. In S. sahlbergi they are single-angled.
Somatochlora sahlbergi (left) and S. alpestris (right), vulvar scale
Note: in S. alpestris the vulvar scale is triangular in shape. In S. sahlbergi it is elongated in shape.
