Cordulegaster boltonii
Cordulegaster boltonii (Donovan, 1807)
Local names: Common goldenring, Zweigestreifte Quelljungfer, Gewone bronlibel, Cordulégastre annelé, Kungstrollslända
Species Information
Description
Black and yellow in colour, with green eyes. Frons is yellow, with a small black bar. Similar to C. bidentata but slightly larger, more yellow in appearance and it has different shapes of yellow markings on S1 and the sides of the thorax. Occipital triangle is yellow, not black as on C. bidentata. The anal loop of the hind wing consists of 5 cells, not 3. It is also very similar to C. trinacriae but the males can be distinguished by different shape of the anal appendages. C. boltonii and C*. trinacriae* occurences only overlap in a small area in Italy.
Size
Habitat
Cordulegaster boltonii favours woodlands, but also occurs along streams in open moorland and heath. The species is found in swift clear running waters including mountain torrents, runnels at headwaters, sand or sand-gravel streams, streams and small rivers. In small headwater streams and runnels it sometimes co-occurs with C. bidentata. In contrast with the latter, the larvae are able to cope with strong currents fairly well, enabling this species to colonise both upper and lower sections of rivers.
Distribution
Almost endemic to Europe with the only populations outside in the north of Morocco and Algeria. In Europe the core of the range of Cordulegaster boltonii extends from western Europe to western and southern Poland, the southern part of Fennoscandia and the Baltic states. To the east it is scattered and apparently rare from the Ukraine and Belarus all the way to the Urals in Russia. Many old records now is believed to instead be from the closely related C. heros (only made into a species of its own in 1979). To the west is found only a few times on Ireland but more common in Scotland, England and Wales.
Flight Period
May to September
Behavior
Males patrol relentlessly along suitable streams, chasing away any other competitors. Females oviposit in sandy or gravel bottoms of streams by, while still in flight, pushing their rear ends into the substrate over and over again.
Conservation Status
Similar Species
Cordulegaster bidentata, Cordulegaster heros, Cordulegaster trinacriae
External Links
Genus: Cordulegaster
Identification
Large dragonflies, easily recognised by their size (70-100mm), their black and yellow body patterns and their eyes just barely touching. Males have an anal triangle in the hindwing and auricles on the sides of S2. Females have a unique vulvar scale that serves as their ovipositor, this is projecting well beyond the tip of the abdomen. Eggs are oviposited into the bottom substrate of smaller running waters, like springs and brooks. Often Cordulegaster are the only species present in these waters.
Separation from other genera
Aeshnids are often large and have a similar appearance and wing venation, but the eyes are touching over a larger distance. Many gomphids are also black and yellow, but they are smaller and their eyes are widely separated. The very local Macromia splendens, from southern France and Iberia, and Anax immaculifrons, from Cyprus and southern Turkey, are similar in appearance. They differ in various markings and reproduce in larger waters.
Separation of the species
The Cordulegaster genus consists of two species-groups; group boltonii or group bidentata. Each is a complex of similar species, and the two groups distributions hardly overlap. If two Cordulegaster species co-occur, they belong to different groups. In areas where both C. boltonii and C. bidentata occur (western and central Europe), C. boltonii usually prefers larger brooks than C. bidentata. This results in C. boltonii being more often found in lowlands, whereas the C. bidentata is more common in lower mountain ranges. This partial segregation of the two species-groups is less clear in the East, in the Balkans and Turkey.
| Boltonii group | Bidentata group | |
|---|---|---|
| Yellow marking on side of S1 | Along lower hind margin, normally shaped as revered 'C'. | Oblique spot near middle of segment occasionally descends towards lower hind margin. |
| Yellow markings between two broad lateral thorax stripes. | Normally a well developed stripe, this complete or divided into 2-3 spots. | Normally restricted to a short streak just below wings, but this may extend downwards in very yellow individuals. |
| Upper appendages (viewed from above) | Diverging, with curved outer borders and close (almost touching) at the base. | Parallel, with straight outer borders and separated at base. |
| Cells in hindwing anal triangle | 5, rarely 3-8 | 3, rarely 2-5 |
| Boltonii group | Geographic range |
|---|---|
| C. princeps | Moroccan high and middle Atlas |
| C. trinacriae | Southwest Italy and Sicily |
| C. picta | North and west Turkey, islands in north and east Aegean Sea, Southeast Balkans |
| C. heros | West and south Balkans |
| C. Boltonii | The rest of Europe or northwest Africa |
| Bidentata group | Geographic range |
|---|---|
| C. helladica | South Greece, including Peloponnesse, Euboea and the Cyclades |
| C. insignis | Turkey, islands in north and east Aegean Sea, including Ikaria. Southeast Balkans |
| C. bidentata | Other parts of Europe |
Identification on the basis of the markings on the various body parts is problematic, it is still unclear which characters are reliable. Also, individual variation within populations occurs in a number of characters, like the size and extension of the black markings on the frons and other parts of the head, the shape and size of the yellow marking on the thorax between the two large lateral bands, the shape and size of the yellow marking on S1 and the presence of apical spots on S2-8. These characteristics are therefore not usable for identification purposes, unless otherwise stated in the species descriptions. In members of the Cordulegaster boltonii group, and especially in C. heros and C. pieta, a small spot may be present near the upper lateral corner of the antehumeral stripe. It may vary in size.
Females are generally larger than males, and has larger abdominal markings. Within various species, there are several subspecies recognised, with narrow or wide geographical zones in which intermediate specimens occur. Some subspecies have been described on the basis of such intermediate specimens, resulting in taxonomical confusion. Others were described on material of unknown or doubtful origin, complicating the determination of the exact distribution of the subspecies.
Behaviour
All species breed in permanent springs or smaller streams. Larvae development takes three to seven years. Males patrol over the water surface, often in a slow pace, searching for a female. When patrolling they are not easily disturbed, and can be well observed. If you stand motionless astride a small brook, a male may even fly through your legs! Females visit the water only for copulation and oviposition. The way she oviposits is highly characteristic, hovering over shallow water in a vertical position, repeatedly pushing the ovipositor into the substrate. An ovipositing female may do this more than 500 times, remaining at a particular site for 15 minutes, and therefore can be easily observed. Females tend to avoid males during oviposition, and may hide from them under overhanging vegetation.
Family: Cordulegastridae
The Cordulegastridae are a family of Odonata from the suborder Anisoptera. They are commonly known as spiketails. They have large, brown or black bodies with yellow markings, and narrow unpatterned wings. Their bright eyes touch at a single point, and they can be found along small, clear, woodland streams, patrolling slowly 30 to 70 cm above the water. When disturbed, however, they can fly very rapidly. They usually hunt high in forest vegetation, and prefer to capture prey resting on leaves or branches (known as gleaning).
The Cordulegastridae usually lay their eggs in the sand in shallow water, the female hovering just above the water with her body in a vertical position, and making repeated dips into the water with her abdomen.
The family is distributed worldwide with five different genera:
- Anotogaster Selys, 1854
- Cordulegaster Leach, 1815
- Chlorogomphus Selys, 1854
- Neallogaster Cowley, 1934
- Sonjagaster Lohmann, 1992
The name Cordulegastridae comes from the Greek kordylinus, club-shaped and gaster, belly. The common name spiketails refers to the females' prominent ovipositors.