Somatochlora meridionalis
Somatochlora meridionalis Nielsen, 1935
Local names: Balkan emerald, Balkan-Smaragdlibelle, Zuidelijke glanslibel, Cordulie méridionale
Species Information
Description
Very similar to Somatochlora metallica, with the same metallic green shine, and which it replaces in south-eastern Europe. In practice it can be identified by the presence of one or rarely two yellow spots at the sides of the thorax. The pterostigma is usually darker than on other emeralds, black rather than brown (however black pterostigmas occur on some S. metallica). The yellow spots on S2 and S3 are larger, but this character is variable and should not be used without other characteristics in identifying.
Size
Habitat
Somatochlora meridionalis is found at largely or completely shaded streams and small rivers, and is mainly confined to running waters, although there are reports of reproduction in standing waters in Italy. Most breeding habitats are small to large streams or small rivers with clear water and generally sparse vegetation. The species is also found at runnels and small irrigation canals in agricultural landscapes in northern Italy. It can be common in intermittently flowing streams that become fragmented into residual, largely disconnected pools during summer, where the larvae are able to survive the dry season. Adults are mostly seen along shaded stretches of watercourses and the presence of shade on most of the water surface is an important habitat characteristic. S. meridionalis is mainly a lowland species most common below 500 m. It can, however, occur at higher elevations and was, for example, found between 1 200 m and 1 600 m in the Rhodope Mountains in Bulgaria.
Distribution
Somatochlora meridionalis ranges from south-east France to western Turkey. The species is nearly endemic to Europe, with only a handfull of populations known from the western half of Turkey. High densities of populations are being found in Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Bulgaria and the European part of Turkey. The species has a more scattered occurrence in Albania, Macedonia, Serbia, Romania and Greece (including Crete). Further north it is known from mostly isolated populations in Austria and the Czech Republic. The situation in Hungary is unclear as most national Somatochlora records are based on larvae that were not identified to species. Confirmed Somatochlora meridionalis adults have been found in western Hungary, but these records were either unpublished or published under S. metallica. A review of records of S. metallica and S. meridionalis in central Europe is essential to properly understand their respective distributions in this area. It is unclear how far east the species can be found and future work might show the species to be present in Moldova and southwest Ukraine. In the western Mediterranean, disjunct populations of S. meridionalis are known from central Italy, Corsica and from an area running from north-west Italy to south-east France.
Flight Period
June to August
Behavior
Males patrol long stretches of streams, following precisely its course at low height, often in deep shade, avoiding sunny spots and clearings. The fast flight is interspersed by hovering stops. May also be active in overcast weather.
Conservation Status
Similar Species
Somatochlora *metallica
External Links
Genus: Somatochlora
Somatochlora, or the striped emeralds, is a genus of dragonflies in the family Corduliidae with 48 described species found across the Northern Hemisphere. This is a large genus, especially in North America from where the not so apt name 'striped emeralds' originates, and the only corduliid genus with more than a single species in Europe.
Identification Diagnosis
Somatochlora are medium-sized dragonflies, with largely dark bodies that have a metallic green lustre. Eyes are reddish brown at emergence, but becomes brilliant green. Frons are dark metallic green with yellow spots on both sides.
Abdomens of males generally have a diagnostic shape (exept S. borisi who more resemble a *Cordulia). S1-S2 is bulbous, S3 is waisted, S4-S10 gradually widens up to about halfway, around S6-S7, and then gradually narrowes. They are not clubbed near the end. The abdomen is dark green to almost black, with minor yellowish markings on the sides. Male appendages are rather long, often with upcurled tips and several irregular ventral teeth. Lower appendage is triangular, with a narrow, upcurved tip. Female appendages are very long. Their vulvar scale is large, visible when viewed from the side, often shaped like a spout or trough, and distinctly projecting in most species.
Separation from other genera
Both Cordulia and Oxygastra have a uniformly dark frons, the male of these genera has a conspicuously clubbed abdomen, with S7 and/or S8 widest, and a deeply notched lower appendage. Their females have inconspicuous vulvar scales. Moreover, Cordulia has only one cross-vein between the hindwing triangle and base (not two) and Oxygastra has deep yellow streaks down the middle of the abdomen.
Separation of the species
The seven species found in Europe may be most easily determined in the hand by the shape of the anal appendages in males and by the vulvar scale in females. The patterns of yellow spots on the face, thorax and abdomen are also distinctive features.
Behaviour
Male patrols are swift and often stealthy or erratic. Females are especially shy, but may be detected by the rustling of wings while ovipositing alone under the cover of dense vegetation. Both sexes rarely perch near the waterside, but rather up in trees.
Family: Corduliidae
The Corduliidae, also knowns as the emeralds, emerald dragonflies or green-eyed skimmers, is a family of dragonflies. These dragonflies are usually black or dark brown with areas of metallic green or yellow, and most of them have large, emerald-green eyes. The larvae are black, hairy-looking, and usually semiaquatic. They are not uncommon and are found nearly worldwide. The Treeline Emerald (Somatochlora sahlbergi) belongs to this family and is not (yet) rare but considered extremely hard to see as an adult. It is one of the species most endangered by the global warming.