Cordulegaster bidentata
• English name: Sombre Goldenring
• German name: Gestreifte Quelljungfer
• French name: Cordulégastre bidenté
• Dutch name: Zuidelijke bronlibel
• Swedish name: N/A
• Norwegian name: N/A
• Finnish name: N/A
• Danish name: N/A
• Italian name: Guardaruscello collinare
• Czech name: páskovec dvojzubý
• Slovenian name: Povirni studenčar
• Bulgarian name: Двузъбесто воденичарче
Cordulegaster bidentata
Map data based on J.-P. Boudot & V. J. Kalkman (eds.),
Atlas of the European Dragonflies and Damselflies
| General | ➤ a very large black-and-yellow species with a patchy distribution in central and south-eastern Europe | |
| Classification | • suborder: Anisoptera (dragonflies); family: Cordulegastridae | |
| Conservation status | • IUCN Red List Europe: Near Threatened, Endemic | |
| Scientific name | • Cordulegaster bidentata Selys, 1843 | |
| Distribution | • click or tap the Map button above | |
| Habitat | • small shaded streams but also moss-covered dripping rocks | |
| Dimensions | • typical body length: 69-78 mm; hindwing: 45-50 mm | |
| Notes | ➤ for an overview of the differences between the species in the boltonii and the bidentata groups, tap or click here | |
| • the female lays her eggs by thrusting her abdomen repeatedly into wet mud, moss, etc. | ||
| • two species of the bidentata group very rarely co-occur at the same site; therefore if two Cordulegaster species co-occur, they very probably belong to different groups | ||
| Both sexes | Head | • the eyes are green (brown in immature animals) |
| • the occipital triangle is black | ||
| Thorax | • the thorax is black with three yellow bands, of which the middle one is heavily reduced and may even be absent | |
| Male | Abdomen | • each upper appendage bears two teeth on the underside (rather than one, as in the species of the boltonii group) |
| Photographs | • all of our photos below were made in the south of Italy and in Austria |
LineDrawing: the male's abdomen in dorsal view, and the male's head, thorax and abdomen in lateral view.
The boltonii group (left) and the bidentata group (right)
The former comprises C. boltonii, trinacriae, heros and picta.
The latter comprises C. bidentata, insignis and helladica.
In the boltonii group, note:
1. thorax: the middle band is (relatively) well developed,
2. upper appendages: close at base, then diverging, curved
(as opposed to separated at the base, then straight),
3. S1: the yellow spot sits at the bottom edge
(as opposed to the upper segment portion), and
4. anal triangle: typically five (as opposed to three) cells.
