Somatochlora

Identification to species requires examination of male cerci or female subgenital plates, which are distinctively shaped in each species. The combination of metallic green body, brilliant green eyes, and yellow thoracic/abdominal markings separates Somatochlora from many other Corduliidae. The distinctive male abdominal shape (bulbous segments 1-2, constricted segment 3, club-shaped remainder) is diagnostic for the genus except in S. borisi. Some species require expert examination and are difficult to distinguish in the field.

Medium-sized dragonflies with dark bodies and metallic green lustre. Eyes are brilliant green. Many species have dull to bright yellow markings on the thorax and/or abdomen. Male abdomens distinctive: first two segments bulbous-shaped, third constricted, remainder club-shaped with straight ending. Female abdomens have straighter sides. Exception is S. borisi, which has Cordulia-like abdominal shape. Wings typically have two crossveins between hind wing base and triangle.

Larvae typically inhabit bogs, fens, and forest streams; some species occur in lakes. Not found in marshy ponds. Many species are restricted to very specific habitats and are rare and local. Habitat specificity is pronounced, with individual species often limited to particular wetland types or stream conditions.

Northern Hemisphere: Europe, Asia, and North America. Some species extend into arctic regions north of the treeline. Southern limits include Spain, Turkey, northern India, northern Vietnam, Taiwan, and the southern United States. In North America, most species occur in the boreal forest and/or Appalachian Mountains. Altitudinal range extends to at least 3,700 m in S. semicircularis. One species (S. sahlbergi) is circumboreal.

Adults feed in flight on small insects. Larvae are aquatic predators feeding on small invertebrates.

Incomplete metamorphosis: egg, nymph (naiad), adult. Eggs laid in water, aquatic vegetation, or submerged debris; in some species females use projecting subgenital plate as pseudo-ovipositor to insert eggs into substrate. Nymph stage lasts from several months to multiple years depending on species. Adults may occur at some distance from breeding habitat in mixed swarms.

Adults feed in flight and may form mixed swarms at some distance from breeding sites. Some species are strong fliers that patrol territories.

Aquatic and aerial predator as larvae and adults respectively. Some species are indicators of intact bog, fen, and forest stream ecosystems due to habitat specificity.

Subject of conservation concern for habitat-specialist species. S. filosa and S. linearis are subjects of distributional research in Canada. Some species serve as indicators of wetland ecosystem integrity.

• CorduliaS. borisi was formerly placed in Somatochlora but resembles Cordulia in abdominal shape; other Somatochlora species distinguished by distinctive male abdominal morphology
• Other Corduliidae generaSomatochlora distinguished by combination of metallic green lustre, brilliant green eyes, yellow markings, and male abdominal shape (bulbous-constricted-club pattern)

• dragonfly
• emerald
• boreal
• wetland
• stream
• bog
• fen

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• What the Fossil Record Tells Us About Insect Extinctions in Deep Time
• Beauties in the Bog - Buglife Blog - Buglife
• The ubiquitous tiger beetle | Beetles In The Bush
• Découverte de la cordulie tricoteuse (Somatochlora filosa) au Canada et reconsidération de la cordulie linéaire (Somatochlora linearis) au Québec, deux espèces rhéophiles de libellules