Somatochlora Temporal range: Oligocene - Present[1]
Female Somatochlora flavomaculata
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Odonata
Infraorder:	Anisoptera
Family:	Corduliidae
Subfamily:	Corduliinae
Genus:	Somatochlora Selys, 1871

Teneral Somatochlora metallica female

Somatochlora, or the striped emeralds,^[2] is a genus of dragonflies in the family Corduliidae with 42 described species found across the Northern Hemisphere.^[3]

Taxonomy

The name Somatochlora is derived from the Greek soma (body) and khloros (green).^[4] The species Corduliochlora borisi was formerly treated as a member of Somatochlora.^[3]

Description

Newly emerged male S. albicincta on its exuvia

Members of this genus are medium-sized dragonflies with dark bodies and a metallic green lustre. The eyes are brilliant green, and many species have dull to bright yellow markings on the thorax and/or abdomen. The abdomens of males are distinctive, with the first two segments bulbous-shaped, the third constricted, and the rest of the abdomen club-shaped with a straight ending. Females have abdomens with straighter sides.^[2] Identifying these dragonflies to species can be difficult.^[4] The cerci of males, on the tip of the abdomen, are distinctively shaped in each species, as are the subgenital plates on female abdomens. In some species, the subgenital plate is large and projecting, and is used as a "pseudo-ovipositor" for inserting eggs into a substrate.^[2]

Distribution

Illustration showing male cerci of several species of Somatochlora

Somatochlora species are found across the Northern Hemisphere in Europe, Asia, and North America, with some species extending into arctic regions north of the treeline.^[5] Some species extend south to Spain,^[6] Turkey,^[7] northern India,^[8] northern Vietnam,^[8] Taiwan^[9] and the Southern United States.^[10] At least one species, S. semicircularis, may be found at altitudes up to 3,700 m (12,100 ft).^[11] In North America, most species live in the boreal forest and/or the Appalachian Mountains.^[4]

Life history

Mating pair of Somatochlora flavomaculata

Somatochlora larvae typically live in bogs, fens, and/or forest streams, with some species found in lakes. They do not occur in marshy ponds.^[2] Many species are limited to very specific habitats and are rare and local. Adults feed in flight and may occur at some distance from their breeding habitat in mixed swarms.^[2]

Species

Larvae of several Somatochlora species

Somatochlora is the most diverse group within the Corduliidae.^[2] Of the 42 described species listed below, 25 are North American, 16 are Eurasian, and one is circumboreal (S. sahlbergi). Two additional fossil species have been assigned to this genus: S. brisaci, based on a wing from the Upper Miocene in France, and S. oregonica, based on two wings from the Oligocene in Oregon.^[1][12]

Image	Species[3]	Common Name(s)[13][14][15]	Distribution
	Somatochlora albicincta (Burmeister, 1839)	ringed emerald	Canada, northern United States[10]
	Somatochlora alpestris (Selys, 1840)	alpine emerald	Europe and Asia[16][9]
	Somatochlora arctica (Zetterstedt, 1840)	northern emerald	Europe and Asia[16][9]
	Somatochlora brevicincta Robert, 1954	Quebec emerald	Canada, northern United States[10]
	Somatochlora calverti Williamson & Gloyd, 1933	Calvert's emerald	southeastern United States[10]
	Somatochlora cingulata (Selys, 1871)	lake emerald	Canada, northern United States[10]
	Somatochlora clavata Oguma, 1922		Japan and Korea[17]
	Somatochlora daviesi Lieftinck, 1977		Bhutan, Nepal, and India[8][18][19]
	Somatochlora dido Needham, 1930		China and Vietnam[8]
	Somatochlora elongata (Scudder, 1866)	ski-tipped emerald, ski-tailed emerald	northeastern North America[10]
	Somatochlora ensigera Martin, 1907	plains emerald	central North America[10]
	Somatochlora exuberata Bartenev, 1910	Japan and eastern Russia[17]
	Somatochlora filosa (Hagen, 1861)	fine-lined emerald	southeastern United States[10]
	Somatochlora flavomaculata (Vander Linden, 1825)	yellow-spotted emerald	Europe[17]
	Somatochlora forcipata (Scudder, 1866)	forcipate emerald	Canada, northern United States[10]
	Somatochlora franklini (Selys, 1878)	delicate emerald	Canada, northern United States[10]
	Somatochlora georgiana Walker, 1925	coppery emerald	eastern United States[10]
	Somatochlora graeseri Selys, 1887		east Asia[17]
	Somatochlora hineana Williamson, 1931	Hine's emerald	Ontario and midwest United States[10]
	Somatochlora hudsonica (Hagen in Selys, 1871)	Hudsonian emerald	western and central Canada, northwestern United States[10]
	Somatochlora incurvata Walker, 1918	incurvate emerald	northeastern North America[10]
	Somatochlora kennedyi Walker, 1918	Kennedy's emerald	Canada, northeastern United States[10]
	Somatochlora linearis (Hagen, 1861)	mocha emerald	eastern North America[10]
	Somatochlora lingyinensis Zhou & Wa, 1979		Zhejiang[9]
	Somatochlora margarita Donnelly, 1962	Texas emerald	Texas and Louisiana[10]
	Somatochlora meridionalis Nielsen, 1935	Balkan emerald	southeastern Europe[20]
	Somatochlora metallica (Vander Linden, 1825)	brilliant emerald	Europe[8]
	Somatochlora minor Calvert, 1898	ocellated emerald	Canada, northern United States[10]
	Somatochlora ozarkensis Bird, 1933	Ozark emerald	Arkansas, Kansas, Missouri and Oklahoma[10]
	Somatochlora provocans Calvert, 1903	treetop emerald	southeastern United States[10]
	Somatochlora sahlbergi Trybom, 1889	treeline emerald	northwestern Canada, Alaska, northern Russia, Scandinavia[10][8]
	Somatochlora semicircularis (Selys, 1871)	mountain emerald	western North America[10]
	Somatochlora septentrionalis (Hagen, 1861)	muskeg emerald	Canada[10]
	Somatochlora shanxiensis Zhu & Zhang, 1999		Hubei, Shanxi[9]
	Somatochlora shennong Zhang, Vogt & Cai, 2014		Guangxi, Hubei[9]
	Somatochlora taiwana Inoue & Yokota 2001		Taiwan[9]
	Somatochlora tenebrosa (Say, 1840)	clamp-tipped emerald	eastern North America[10]
	Somatochlora uchidai Förster, 1909		Japan, China and Russia[21]
	Somatochlora viridiaenea (Uhler, 1858)		Japan, eastern Russia[17]
	Somatochlora walshii (Scudder, 1866)	brush-tipped emerald	Canada, northern United States[10]
	Somatochlora whitehousei Walker, 1925	Whitehouse's emerald	Canada, northwestern United States[10]
	Somatochlora williamsoni Walker, 1907	Williamson's emerald	eastern North America[10]

References