Greek goldenring (Cordulegaster helladica)
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Insecta |
| Order | Odonata |
| Family | Cordulegastridae |
| Genus | Cordulegaster (1) |
| Size | Male length: 68 - 78 mm (2) Female length: 78-83 mm (2) Male length of abdomen: 50 - 60 mm (2) Female length of abdomen: 59 - 63 mm (2) Male hindwing: 41 - 46 mm (2) Female hindwing: 46 - 49 mm (2) |
The Greek goldenring is classified as Endangered (EN) on the IUCN Red List. Subspecies: Cordulegaster helladica buchholzi, C. h. helladica and C. h. kastalia (1).
Also referred to as spiketails and biddies, golden-ringed dragonflies (Cordulegastridae) are large black dragonflies with generally bright yellow rings more or less encircling their abdomen, depending on the species (2) (3). The Greek goldenring (Cordulegaster helladica) exhibits wide abdominal yellow rings, possesses conspicuous yellow markings on the thorax and the head and has large green eyes. Males and females are similar in appearance but females are distinctly larger. Separation from the Turkish C. insignis is mainly possible through the more squarish and flat back part of the occipital triangle (ovoid and swollen in insignis), its green eyes (generally bluish in insignis) and the tapering shape of the male inferior appendage (sides parallel in insignis) (2).
The Greek goldenring is endemic to southern Greece, including the Peloponnese Peninsula, prefectures of Attica and Phokis, south-eastern part of Fthiotida prefecture, and the islands of Evia, Andros, Tinos and Naxos (1).
Found along springs and spring-brooks (head-water systems), the Greek goldenring is perhaps even found at larger brooks (1).
Virtually nothing has been recorded of the Greek goldenring’s biology and behaviour, but this may be inferred from what is known about C. bidentata, which has a similar structural morphology and habitat. The eggs should hatch 2 to 11 weeks after egg deposition and the larval period should last two to six years, depending on the altitude. It should include around 15 stadia. After metamorphosis and emergence, adults, which are, like other Odonata species, generalised, opportunistic feeders, feed on flying insects. Males don't establish territories but patrol over long distances along river edges, searching for reproductive females, and standing quite often on herbs or branches exposed to the sun. Females are generally hidden and are much more scarcely observed than males. They lay by driving their eggs in the sandy sediments of rivers and brooks through a rhythmic vertical flight, distinctive of golden-ringed dragonflies (4).
Populations of the Greek goldenring appear to be severely fragmented, and some previously reported sites have recently been found dry and deserted as a result of water extraction for human use. Thus, the population is believed to be declining due to habitat destruction, caused at least in part by water harnessing by humans (1).
No conservation measures currently target the Greek goldenring, but there is a need for control of water use and forest preservation (1).
Authenticated (18/12/2006) by Jean-Pierre Boudot, CNRS, Université Henri Poincaré Nancy I, France.
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Larval: of the stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
- Metamorphosis: an abrupt physical change from the larval to the adult form.
- Prefecture: a district administered or governed by a prefect.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
- Territory: an area occupied and defended by an animal, a pair of animals or a colony.
- Thorax: part of the body located near the head in animals. In insects, the three segments between the head and the abdomen, each of which has a pair of legs.
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IUCN Red List (March, 2011)
http://www.iucnredlist.org - Dijkstra, K.D.B. and Lewington, R. (2006) Field Guide to the Dragonflies of Britain and Europe. British Wildlife Publishing, Gillingham.
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Dragonflies and Damselflies in Languedoc (September, 2006)
http://www.ghmahoney.org.uk/insects/dflyl_corga.htm - Grand, D. and Boudot, J.P. (2006) Les Libellules de France, Belgique et Luxembourg. Editions Parthénope, Mèze.