CALIFORNIA EMERALDS aka Corduliidae

CALIFORNIA EMERALDS aka Corduliidae

Emerald (and other) checklists originally provided by Ron Lyons
with COMMON (English) NAMES OF DRAGONFLIES
as originally adopted by the Dragonfly Society of the Americas
(Argia, vol.8, no.2, 1 August 1996)
with all current revisions.
Information for this site has been collected and edited by Kathy Biggs who assumes full responsibility.

New links &/or information was added to this site in 2008
CA Distribution Maps are based on information originally collected by Dennis Paulson and updated by confirmed sightings.
If you find a species in a new county please contact Kathy Biggs &/or Tim Manolis.

The species of Emeralds indicated below have been found in California.
References to images/drawings/scans are as follows:
CA Dragonflies = Common Dragonflies of California, A Beginner's Pocket Guide by Kathy Biggs 2000
CA Dragons&Damsels = Dragonflies and Damselflies of California by Tim Manolis. UCPress. April 2003
SW Dragonflies = Common Dragonflies the Southwest, A Beginner's Pocket Guide by Kathy Biggs 2004
CA&SW Dragonflies = Dragonflies of California and Common Dragonflies the Southwest,
A Beginner's Pocket Guide (with dust jacket) by Kathy Biggs 2006
CA Insects = California Insects by Jerry Powell and Charles Hogue
Dragonflies N.A. = Dragonflies of North America by James G. Needham, Minter J. Westfall, Jr., Michael L. May 2000
LA Insects = Insects of the Los Angeles Basin by Charles Hogue
Dragonflies through Binoculars = Dragonflies through Binoculars, A Field Guide to Dragonflies of North America by Sidney W. Dunkle 2000
Dragonflies of Washington = Dragonflies of Washington by Dennis Paulson, Seattle Audubon Society 1999
Stokes Guide = Beginner's Guide to Dragonflies by Blair Nikula, Jackie Sones. A Stokes Guide. May 2002
Audubon Guide = Audubon Society Field Guide to North American Insects and Spiders
* = photograph/scanning(s) available to see at this Internet website

Scientific Name
Common Name
archaic names
local photos/scans
distribution map

Remarks/Description
Habitat/Flight Dates
Picture in book
*Photo/scan at website

FAMILY Corduliidae
Emeralds
aka Green-eyed Skimmers
3 CA genera; 5 species
sizes: medium - large with length of 42 - 52 mm
males: often dark abdomens with brilliant metallic tones on thorax;
some, however, have abdomens that are patterned;
all have emerald green eyes and abdomens that are expanded at the midpoint ('spindle-shaped')
females: like the males except their bodies are more stout with a more even shape
nymph: hairy, dark colored
habitats:wooded ponds and streams in the mountains
behaviors: they emerge in mass; perch by hanging;
strong, fast and erratic flyers;
sometimes fly for only short periods during day

Scanned images by Kathy Biggs
CA Dragonflies p. 38
CA Dragons&Damsels p. 124, 125
Dragonflies through Binoculars p. 135
Dragonflies N.A. p. 494-499
*Emeralds of the Southwest
*Key to larva in Michigan, UMMZ

GENUS: Cordulia
The American Emeralds
1 CA species
male: metallic green thorax, dark abdomen with forked appendages
behavior: strong flier
habitat: found in the Mountains

Scan by Kathy Biggs
CA Dragons&Damsels p. 125
Dragonflies N.A. p. 500
*American Emerald at Southwest Dragonflies Website
*Key to larva in Michigan, UMMZ

Cordulia shurtleffi
American Emerald
photo male
photo male
photo male
photo young male
photo young male
photo female
photo female
photo female
photo female
photo female
photo female
photo young female
photo female emerging
scan male side
scan male top
scans male
scan male top
scan male side
scans teneral males
scans young female
scan young female
distribution map
size:medium, length 42 - 48 mm, wingspan 60 - 65 mm
male: mature has emerald green eyes; immature's are brown;
thorax dark with green metallic tones; shows no yellow;
abdomen 'spindle-shaped' - has enlarged area at mid-length;
single thin white ring at beginning of the dark abdomen;
top appendages forked
female:s imilar to male but body broader; less curvaceous
nymph: fairly hairy, robust with distinct brown lateral thoracic stripe and lack of mid-dorsal abdominal hooks
similar species: Mountain Emerald has appendages forming a semi-circle (similar to the shape of the pinchers on earwigs);
Ringed Emerald has a white ring at each segment
habitat: wooded ponds, bogs, slow waters;
Walker and Corbet (1975) indicate that they prefer sphagnum bogs/ponds; larvae are able to tolerate poorly oxygenated, stagnant waters
behavior: mass emergence
flight period: May - September
distribution: mostly in northern mountains

CA Dragonflies p. 38, 40
CA Dragons&Damsels p. 125-126; pl. 25
CA&SW Dragonflies p. 56
Dragonflies of Washington p. 20
Dragonflies through Binoculars p. 136; pl. 22
Dragonflies N.A. p. 501
*Photo by Joshua Rose his Dragonfly Pics site
*Photos by Ray Bruun at his Dragonfly & Damselfly Photography Pages
*Photos by Ray Bruun at his Dragonfly & Damselfly Photography Pages
*Photos by Doug Aguillard at his Dragonfly Website
*Photos by Tom Murray at Dragonfly Photos Website
*American Emeralds at Southwest Dragonflies Website
*Scan by Dennis Paulson at Washington Odonata Photo Gallery"
*Scans of nymph by Dennis Paulson at University of Puget Sound's "Odonata Larva"
*Photograph by Blair Nikula
at Dragonflies of Massachusetts
*Photo by Mark O'Brien at THE MICHIGAN Photo Archive

GENUS: Epitheca
aka GENUS: Tetragoneuria
The Baskettails
2 CA species
male: non-metallic colors; brown and yellow patterned
hairy thoraxes
nymph: smooth, hairless, depressed abdomen
habitat: found at lower elevations than other Emeralds
behavior: often fly at waist height along trails and paths in sunlit areas

Scan by Kathy Biggs
CA Dragons&Damsels p. 124
Dragonflies through Binoculars p. 141
Dragonflies N.A. p. 573-580 (as Tetragoneuria)
*Baskettails of the Southwest
*Key to larva in Michigan, UMMZ
*Information at Notes on the Michigan Species of Epitheca

Epitheca canis
Beaverpond Baskettail
Genus Tetragoneuria
archaic 'common' name: Dog's Head
photo male
photo male
photo male
photo male
photo male
odd photo males
photo immature male
photo immature male
photo immature male
photo immature male
photo immature male
photo female
photo female
photo female
photo female
scans male 2001
scans male
scans female
distribution map
size: medium, length 42 - 53 mm, wingspan 62 - 64 mm
male: teal green eyes contrast with dull brown and yellow patterned body; immatures have duller (brown) eye color;
face from above pale; forehead lacks T-spot; thorax brown with pale hairs;
dark abdomen is flattened and enlarged mid-length with a row of yellowish spots along sides;
clear wings; top appendages bent down at tips
female: like male, body broader; wings can show diffuse brownish wash
similar species: much rarer Spiny Baskettail has straight appendages
habitat: all slow waters, usually at lower elevations than other emeralds
behavior: often flies a beat up and down dirt pathways at ~human waist height;
males defend a territory by flying a beat of ~30 ft at lake edge near suitable habitat for the female to deposit her eggs:
females lay strings of eggs which they attach to emergent/floating vegetation
flight period: March - July; mostly a spring species
distribution: central and northern California

CA Dragonflies p. 39
CA Dragons&Damsels p. 128-129; pl. 26
Dragonflies through Binoculars p. 147-text; pl.23 picture
CA&SW Dragonflies p. 55
Dragonflies N.A. p. 580 (as Tetragoneuria)
Audubon Guide: plate 372 unidentified
*Photos by Chris Heaivilin at his CA Compendium Odonata
*Photos by Doug Aguillard at Dragonflies of San Diego & Imperial Counties
*Photos and scans at Dragonflies of the Southwest
*Photo by Steve Valley at Oregon Odonata Photo Gallery
*Photo of egg mass by Steve Valley at his Dragonfly Gallery 1
*Scan by Dennis Paulson at Washington Odonata Photo Gallery
*Photo by Dave Westover at Digital Dragonflies, taken in Wisconsin
*Photograph by Blair Nikula at Dragonflies of Massachusetts

Epitheca spinigera
Spiny Baskettail
aka Genus Tetragoneuria
photo male
photo female
scan male
scan female
distribution map

description: very similar to Beaverpond Baskettail (see above);
T-spot on frons clearly defined;
face from above dark;
top appendages straight, not bent down- this differentiates them from Beaverpond Baskettail;
nymph/exuvia have distinctive long spines on seg. 9 that extend beyond the abdomen tip - can be used as voucher for distribution
similar species: Beaverpond Baskettail's upper appendages bend down at tip
habitat: slow waters of wooded marshes/lakes/ponds/streams/rivers
flight period: June - July
distribution: rare; in Sierras

CA Dragons&Damsels p. 129-130; pl. 26
Dragonflies of Washington p.20
Dragonflies through Binoculars p. 145-text
Dragonflies N.A. p. 586 (as Tetragoneuria)
*Photos by Chris Heaivilin at his Compendium Odonata website
*Photo by Steve Valley at his Dragonfly Gallery 1
*Photos and scans at Dragonflies of the Southwest
*Scan of male by Dennis Paulson at Washington Odonata Photo Gallery
*Scan of female by Dennis Paulson at Washington Odonata Photo Gallery
*Photos by Curtis Williams at Digital Dragonflies taken in Wisconsin
*Photo by Dave Westover at Digital Dragonflies, taken in Wisconsin
*Photo of nymph at Baskettails of Michigan
*Photograph by Blair Nikula at Dragonflies of Massachusetts

GENUS: Somatochlora
The Striped Emeralds
2 CA species
males: metallic green
behavior: sometimes fly high (30 - 40')
habitat: mountain species

Scan by Kathy Biggs
CA Dragons&Damsels p. 125
Dragonflies through Binoculars p. 148
Dragonflies N.A. p. 531-544
*Striped Emeralds of the Southwest

Somatochlora albicincta
Ringed Emerald
photo teneral male
male in flight
photo female
scans male
scan male top
scan male side
scan male side
scan male top
scans teneral males
scan female
scan exuvia
distribution map
size: medium, length 45 - 52 mm;
hind wing 27 - 33 mm
male: green eyes & metallic green thorax;
dark body has very fine incomplete white rings marking each section;
pale elongate spot side of thorax;
'spidle-shaped' abdomen - enlarged area mid-length;
upper appendages have thin upward pointing 'hook' at tip
female: quite similar
similar species: American Emerald had white ring only at beginning of abdomen;
Mt. Emereald has no rings on abdomen
habitat: still waters; northern species
flight period: June - August
distribution: only found at a few high places in CA

CA Dragons&Damsels p. 127; pl. 25
Dragonflies of Washington p.20
Dragonflies through Binoculars p. 150-text; pl.23 picture
Dragonflies N.A. p. 544
*Photos and scans at Dragonflies of the Southwest
*Photo by Dennis Deck at Dragonflies and Damselflies of Oregon and Washington
*Scan by Dennis Paulson
at Washington Odonata Photo Gallery

Somatochlora semicircularis
Mountain Emerald
photo male
photo male
photo male
photo male in flight
photo female
scan male, top view
scan male, side view
scan male, top view
scan male, side view
scan female, side view
scan female, top view
scan female, side view
scans male
scans female
distribution map
size: medium, length 47 - 52 mm, wingspan 60 - 66 mm
male: emerald green eyes; dark metallic green thorax with yellow marking on side;
two pale spots each side of first abdominal segment; one incomplete ring;
'spidle-shaped' abdomen - enlarged area mid-length;
appendages point inwards, forming a semi-circle
female - similar to male; shows 2 yellow spots atop segs. 1 & 2;
wings have a slight golden tint, esp. at base
similar species - American Emerald's appendages slightly splayed, not semi-circular in shape;
Ringed Emerald has rings each segment
habitat - ponds, sedge meadows with small streams
flight period - June - August
distribution - mostly in northern mountains

CA Dragonflies p. 41
CA Dragons&Damsels p. 126-127; pl. 25
CA&SW Dragonflies p. 57
Dragonflies of Washington p.20
Dragonflies through Binoculars p. 150-text; pl.26 picture
Dragonflies N.A. p. 566
*Photo at Stirling's Dragonfly Photos
*Photos and scans at Dragonflies of the Southwest
*Photo by Steve Valley at Oregon Odonata Photo Gallery
*Scans by Dennis Paulson at Washington Odonata Photo Gallery

DRAGONFLIES of California and
Common DRAGONFLIES of the Southwest
A Beginner's Pocket Guide

by Kathy Biggs
(includes damselflies)

A coloring book -
Dragonflies of North America
A Color and Learn Book
with Activities
May 2007 Click here for more information

by Kathy Biggs and Tim Manolis
For children, grandchildren & your inner child!

Click here to return to CALIFORNIA DRAGONFLY FAMILIES

*Scientific Name* Common Name archaic names local photos/scans distribution map	Remarks/Description Habitat/Flight Dates	Picture in book *Photo/scan at website

FAMILY Corduliidae Emeralds	aka Green-eyed Skimmers 3 CA genera; 5 species sizes: medium - large with length of 42 - 52 mm males: often dark abdomens with brilliant metallic tones on thorax; some, however, have abdomens that are patterned; all have emerald green eyes and abdomens that are expanded at the midpoint ('spindle-shaped') females: like the males except their bodies are more stout with a more even shape nymph: hairy, dark colored habitats:wooded ponds and streams in the mountains behaviors: they emerge in mass; perch by hanging; strong, fast and erratic flyers; sometimes fly for only short periods during day	Scanned images by Kathy Biggs CA Dragonflies p. 38 CA Dragons&Damsels p. 124, 125 Dragonflies through Binoculars p. 135 Dragonflies N.A. p. 494-499 Emeralds of the Southwest Key to larva in Michigan, UMMZ

GENUS: Cordulia The American Emeralds	1 CA species male: metallic green thorax, dark abdomen with forked appendages behavior: strong flier habitat: found in the Mountains	Scan by Kathy Biggs CA Dragons&Damsels p. 125 Dragonflies N.A. p. 500 American Emerald at Southwest Dragonflies Website Key to larva in Michigan, UMMZ

*Cordulia shurtleffi* American Emerald photo male photo male photo male photo young male photo young male photo female photo female photo female photo female photo female photo female photo young female photo female emerging scan male side scan male top scans male scan male top scan male side scans teneral males scans young female scan young female distribution map	size:medium, length 42 - 48 mm, wingspan 60 - 65 mm male: mature has emerald green eyes; immature's are brown; thorax dark with green metallic tones; shows no yellow; abdomen 'spindle-shaped' - has enlarged area at mid-length; single thin white ring at beginning of the dark abdomen; top appendages forked female:s imilar to male but body broader; less curvaceous nymph: fairly hairy, robust with distinct brown lateral thoracic stripe and lack of mid-dorsal abdominal hooks similar species: Mountain Emerald has appendages forming a semi-circle (similar to the shape of the pinchers on earwigs); Ringed Emerald has a white ring at each segment habitat: wooded ponds, bogs, slow waters; Walker and Corbet (1975) indicate that they prefer sphagnum bogs/ponds; larvae are able to tolerate poorly oxygenated, stagnant waters behavior: mass emergence flight period: May - September distribution: mostly in northern mountains	CA Dragonflies p. 38, 40 CA Dragons&Damsels p. 125-126; pl. 25 CA&SW Dragonflies p. 56 Dragonflies of Washington p. 20 Dragonflies through Binoculars p. 136; pl. 22 Dragonflies N.A. p. 501 Photo by Joshua Rose his Dragonfly Pics site Photos by Ray Bruun at his Dragonfly & Damselfly Photography Pages Photos by Ray Bruun at his Dragonfly & Damselfly Photography Pages Photos by Doug Aguillard at his Dragonfly Website Photos by Tom Murray at Dragonfly Photos Website American Emeralds at Southwest Dragonflies Website Scan by Dennis Paulson at Washington Odonata Photo Gallery" Scans of nymph by Dennis Paulson at University of Puget Sound's "Odonata Larva" Photograph by Blair Nikula at Dragonflies of Massachusetts Photo by Mark O'Brien at THE MICHIGAN Photo Archive

GENUS: Epitheca aka GENUS: Tetragoneuria The Baskettails	2 CA species male: non-metallic colors; brown and yellow patterned hairy thoraxes nymph: smooth, hairless, depressed abdomen habitat: found at lower elevations than other Emeralds behavior: often fly at waist height along trails and paths in sunlit areas	Scan by Kathy Biggs CA Dragons&Damsels p. 124 Dragonflies through Binoculars p. 141 Dragonflies N.A. p. 573-580 (as Tetragoneuria) Baskettails of the Southwest Key to larva in Michigan, UMMZ *Information at Notes on the Michigan Species of Epitheca

*Epitheca canis* Beaverpond Baskettail Genus Tetragoneuria archaic 'common' name: Dog's Head photo male photo male photo male photo male photo male odd photo males photo immature male photo immature male photo immature male photo immature male photo immature male photo female photo female photo female photo female scans male 2001 scans male scans female distribution map	size: medium, length 42 - 53 mm, wingspan 62 - 64 mm male: teal green eyes contrast with dull brown and yellow patterned body; immatures have duller (brown) eye color; face from above pale; forehead lacks T-spot; thorax brown with pale hairs; dark abdomen is flattened and enlarged mid-length with a row of yellowish spots along sides; clear wings; top appendages bent down at tips female: like male, body broader; wings can show diffuse brownish wash similar species: much rarer Spiny Baskettail has straight appendages habitat: all slow waters, usually at lower elevations than other emeralds behavior: often flies a beat up and down dirt pathways at ~human waist height; males defend a territory by flying a beat of ~30 ft at lake edge near suitable habitat for the female to deposit her eggs: females lay strings of eggs which they attach to emergent/floating vegetation flight period: March - July; mostly a spring species distribution: central and northern California	CA Dragonflies p. 39 CA Dragons&Damsels p. 128-129; pl. 26 Dragonflies through Binoculars p. 147-text; pl.23 picture CA&SW Dragonflies p. 55 Dragonflies N.A. p. 580 (as Tetragoneuria) Audubon Guide: plate 372 unidentified Photos by Chris Heaivilin at his CA Compendium Odonata Photos by Doug Aguillard at Dragonflies of San Diego & Imperial Counties Photos and scans at Dragonflies of the Southwest Photo by Steve Valley at Oregon Odonata Photo Gallery Photo of egg mass by Steve Valley at his Dragonfly Gallery 1 Scan by Dennis Paulson at Washington Odonata Photo Gallery Photo by Dave Westover at Digital Dragonflies, taken in Wisconsin Photograph by Blair Nikula at Dragonflies of Massachusetts
*Epitheca spinigera* Spiny Baskettail aka Genus Tetragoneuria photo male photo female scan male scan female distribution map	description: very similar to Beaverpond Baskettail (see above); T-spot on frons clearly defined; face from above dark; top appendages straight, not bent down- this differentiates them from Beaverpond Baskettail; nymph/exuvia have distinctive long spines on seg. 9 that extend beyond the abdomen tip - can be used as voucher for distribution similar species: Beaverpond Baskettail's upper appendages bend down at tip habitat: slow waters of wooded marshes/lakes/ponds/streams/rivers flight period: June - July distribution: rare; in Sierras	CA Dragons&Damsels p. 129-130; pl. 26 Dragonflies of Washington p.20 Dragonflies through Binoculars p. 145-text Dragonflies N.A. p. 586 (as Tetragoneuria) Photos by Chris Heaivilin at his Compendium Odonata website Photo by Steve Valley at his Dragonfly Gallery 1 Photos and scans at Dragonflies of the Southwest Scan of male by Dennis Paulson at Washington Odonata Photo Gallery Scan of female by Dennis Paulson at Washington Odonata Photo Gallery Photos by Curtis Williams at Digital Dragonflies taken in Wisconsin Photo by Dave Westover at Digital Dragonflies, taken in Wisconsin Photo of nymph at Baskettails of Michigan *Photograph by Blair Nikula at Dragonflies of Massachusetts

GENUS: Somatochlora The Striped Emeralds	2 CA species males: metallic green behavior: sometimes fly high (30 - 40') habitat: mountain species	Scan by Kathy Biggs CA Dragons&Damsels p. 125 Dragonflies through Binoculars p. 148 Dragonflies N.A. p. 531-544 *Striped Emeralds of the Southwest

*Somatochlora albicincta* Ringed Emerald photo teneral male male in flight photo female scans male scan male top scan male side scan male side scan male top scans teneral males scan female scan exuvia distribution map	size: medium, length 45 - 52 mm; hind wing 27 - 33 mm male: green eyes & metallic green thorax; dark body has very fine incomplete white rings marking each section; pale elongate spot side of thorax; 'spidle-shaped' abdomen - enlarged area mid-length; upper appendages have thin upward pointing 'hook' at tip female: quite similar similar species: American Emerald had white ring only at beginning of abdomen; Mt. Emereald has no rings on abdomen habitat: still waters; northern species flight period: June - August distribution: only found at a few high places in CA	CA Dragons&Damsels p. 127; pl. 25 Dragonflies of Washington p.20 Dragonflies through Binoculars p. 150-text; pl.23 picture Dragonflies N.A. p. 544 Photos and scans at Dragonflies of the Southwest Photo by Dennis Deck at Dragonflies and Damselflies of Oregon and Washington *Scan by Dennis Paulson at Washington Odonata Photo Gallery
*Somatochlora semicircularis* Mountain Emerald photo male photo male photo male photo male in flight photo female scan male, top view scan male, side view scan male, top view scan male, side view scan female, side view scan female, top view scan female, side view scans male scans female distribution map	size: medium, length 47 - 52 mm, wingspan 60 - 66 mm male: emerald green eyes; dark metallic green thorax with yellow marking on side; two pale spots each side of first abdominal segment; one incomplete ring; 'spidle-shaped' abdomen - enlarged area mid-length; appendages point inwards, forming a semi-circle female - similar to male; shows 2 yellow spots atop segs. 1 & 2; wings have a slight golden tint, esp. at base similar species - American Emerald's appendages slightly splayed, not semi-circular in shape; Ringed Emerald has rings each segment habitat - ponds, sedge meadows with small streams flight period - June - August distribution - mostly in northern mountains	CA Dragonflies p. 41 CA Dragons&Damsels p. 126-127; pl. 25 CA&SW Dragonflies p. 57 Dragonflies of Washington p.20 Dragonflies through Binoculars p. 150-text; pl.26 picture Dragonflies N.A. p. 566 Photo at Stirling's Dragonfly Photos Photos and scans at Dragonflies of the Southwest Photo by Steve Valley at Oregon Odonata Photo Gallery Scans by Dennis Paulson at Washington Odonata Photo Gallery