A Guide to the Adult Damselflies & Dragonflies of the Ottawa District

Key to Species

Most of this key is reduced from published works that include many more species than occur in the Ottawa District, primarily from E.M.Walker, 'The Odonata of Canada and Alaska'. I also consulted in detail J.G.Needham & M.J.Westfall, 'A Manual of the Dragonflies of North America'; A.Robert, 'Les libellules du Québec'; and R.Hutchinson & A.Larochelle, 'Manuel d'identification des Libellules du Québec'.

In the reduction, I favoured terms that are visible on a living insect. Each term of the key was verified using all applicable specimens in the Canadian National Collection of Insects (Ontario & Quebec, excluding the far north). The field-mark oriented sections marked by § symbols are my own, are based solely upon living insects within the Ottawa District, and appear only in cases where I am certain that they are significantly more reliable in the field here than the specimen-based key. I welcome suggestions for additional field marks.

1fore and hind wings similar; eyes separated by more than their own widthZygoptera 2
hind wing broader than forewingAnisoptera 11
2Zygoptera: damselfiles
wings not stalked at base, many crossveins before nodusCalopteryx 3
wings stalked at base, two crossveins before nodus2a
2awings held spread open when resting; vein M3 rises from M1-2 closer to arculus than to nodusLestes 4
wings held together above back when resting; M3 rises behind nodusCoenagrionidae 5
3Calopteryx: unstalked broad wings held together above back when resting
§ male: wing all clear, female: wing diffuse colour to beyond nodus, end clear; 3Jun-2SepC.aequabile
§ male: wing all dark, female: wing all smoky with white spot at stigma; 27May-10SepC.maculata
4Lestes male
lower appendages much less than half the length of upper; thorax dark metallic green, wings yellowish 27May-28JunLestes eurinus
lower appendages half or a bit less the length of upper; thorax nearly black 9Aug-13OctL.congener
lower appendages longer than upper, ends curved in; metallic green 30May-8AugL.inaequalis
lower appendages S-curved with divergent ends; blue eyes yellow lower lip black thorax 8Jun-9SepL.unguiculatus
upper appendages meeting at acute angle; dark metallic green 16Jun-27AugL.vigilax
abdomen very long and slender; hairy green lower lip, 15Jun- 10SepL.rectangularis
thorax metallic green above yellow sides; stout, 30May-25AugL.dryas
segment 2 3/5 as long as 3, rear tooth of upper appendages blunt, much smaller than front one; blackish, greenish face 6Jun- 21SepL.forcipatus
segment 2 1/2 as long as 3, rear tooth of upper appendages acute, as large as front one; blackish, greenish face 2Jul-21SepL.disjunctus
4a Lestes: female
ovipositor 1/2 or less as long as segment 7
ovipositor as long as segment 7
wing yellowishL.eurinus
thorax dark brown, narrow pale yellow stripeL.congener
dark areas of abdomen bronzy colourL.disjunctus
these areas greenishL.unguiculatus
4bgrey humeral stripe more than 1/2 as wide as dark brown stripe above; fewer than 14 postnodal crossveinsL.rectangularis
reddish-brown humeral stripe 1/3 or more thickness of metallic stripe aboveL.vigilax
this stripe yellowish, less than 1/4 thickness of stripe aboveL.inaequalis
4cthorax metallic green, stripe clear yellowL.dryas
thorax dull bronze-brown, stripe pale yellowL.forcipatus
leg hairs twice as long as the space between themArgia 6
leg hairs only a bit longer than the space between them5a
5a two spots on top back of head next to eye
no such spots
5bM2 arises near the 4th crossvein after the nodus in forewing, between 2nd & 3rd vein in hindwingIschnura 7
M2 arises near the 5th crossvein after the nodus in forewing, near the 4th vein in hindwing5c
5cmale: lower appendages with notch when viewed from side, female: segment 8 without spine on bottomCoenagrion 8
male: lower appendages triangular when viewed from side, female: segment 8 with spine on bottom rearEnallagma 9
5dbody only red and black; small 1Jun-8AugAmphiagrion saucium
body blue & black with bright sulphur yellow stripe on thorax rear; 7Jun-4AugChromagrion conditum
§ thorax metallic green top blue bottom, abdomen blue (male) blue-green (female) with black areas all the way to segment 10; 1Jun-28AugNehalinnia irene
§ as N.irene but no black on segments 9 or 10; 30May-12AugN.gracilis
6Argia: argos = bright (coloured)
upper parts of segments 3-6 black-brown; 7Jun-12SepArgia moesta
violet-blue; 19Jun-19AugA.fumipennis
7Ischnura: ischnos = thin, oura = tail
two narrow long shoulder stripes; 5May-15OctIschnura verticalis
two exclamation marks on shoulder; 4Jun-9SepI.posita
8Coenagrion: agrios = field
two long shoulder stripes; 12Jun-29JulCoenagrion resolutum
two wide exclamation marks on shoulder; (Muskoka 3Jun-25Jul)C.interrogatum
9Enallagma male: enallex = crosswise (striped)
black of segments 3-4 less than 2/3 length of segment; pale blue9a
this black more than 4/5 length of segment9c
9aupper appendages longer than lower, a pale bump on upper end9b
upper appendages clearly split in two; 30May-24Aug Enallagma ebrium
upper appendages short and rounded; 16May-24JulE.boreale
upper appendages slender with points curved up; 30May-21AugE.hageni
upper appendages with prominent tooth/ridge; 29May-27JunE.cyathigerum
9bupper appendages symmetrical viewed from side; 18May-20SepE.carunculatum
upper appendages asymmetrical; 6Jun-12SepE.civile
9cupper appendages tapered to slender upturned points; 15Jun-3SepE.geminatum
upper appendages split in profile9d
9dupper branch of upper appendages shorter than lower branch; 7Jun-19SepE.exsulans
both these branches about equal; 9Jun-14AugE.antennatum
9eupper appendages' height greater than 1/2 their length; 18Jun-29AugE.vesperum
otherwise; 3Jun-9SepE.signatum
10Enallagma female (these are reliably separable only by microscopic examination of thorax plate)
segment 8 with pair of large blue spotsE.geminatum
segments 8-10 entirely black aboveE.hageni or E.ebrium
segments 7,8,9 with similar markingE.civile or E.carunculatum
segment 8 entirely black, 9 or 10 not; eye spots elongated to or almost to occiput10b
segment 8 black only on rear half or all pale10a
10afine line between spots of segment 8E.boreale
these spots separated by a line at front, a wider gap at rear, side spots reach top of segment 10E.cyathigerum
10bblack humeral stripe twice or more width of pale stripe above10c
black stripe about same width or narrower10d
10cblack stripe divided by pale lineE.exsulans
not so dividedE.antennatum
10dpale stripe with gap in middle; M2 begins between crossveins 4- 5E.vesperum
no such gap; M2 begins between crossveins 5-6E.signatum
eyes separated by about half their widthGomphidae 17
eyes touching on top of head or separated by only a tiny fraction of their width11a
11atriangles about equally distant from arculus in both wings, both oriented lengthwise on wingAeshnoidea 12
triangle at least twice as far from arculus in forewing as in hindwing, forewing triangle oriented across wing, hindwing lengthwiseLibelluloidea 22
eyes barely touch at top or slightly separatedCordulegaster 21
eyes meet in seam at least height of occiputAeshnidae 13
medial space with more than 1 crossvein; 2 rounded pale spots on thorax sides, yellow stigmaBoyeria 14
with one crossvein or none13a
13asectors of arculus arising from its upper end, thorax uniform green; 21Apr-15OctAnax junius
sectors of arculus arising near its middle, thorax brown13b
13bRs vein not forked; 3 or more cubito-anal cross veins, blue body with bright yellow strips on thorax sides 8Jun-17Jul Basiaeschna janata
stalk of Rs vein with symmetrical fork13c
stalk of Rs vein up-arched and fork askew forwardAeshna 15
13cradial planate subtends 1 row of cells; very prominent blue frons, face yellowish margined with brown 20Jun-16Jul Nasiaeschna pentacantha
subtends more than 1 row at least basal half; largest Odonata here, brown & green, 7Jun-9SepEpiaeschna heros
14Boyeria: fly until well after dusk
wing base completely clear; side spots of thorax grey-bluish, segments 9 & 10 similar in colour, body grey-brown 27Jun- 7OctBoyeria grafiana
wings with brown spots at base (usually small); 2 clear yellowish thorax side spots, segment 10 more yellow than 9, body brown, 5Jul-22SepB.vinosa
15 Aeshna, male:
anal triangle with 3 cells; 2 yellow to green stripes on thorax
with 2 cells
15arear of head marked with yellow or brown, row of pale spots each side of segments 4-6; some green on segments 5-10, 12Jun-21Oct Aeshna umbrosa
rear of head black, no such spots; 19Jul-11OctA.constricta
15b central thorax stripe 1 mm or less wide and bent in sharp Z; eye seam little if any longer than occiput, greenish face, T-spot with crescent base (Tremblant 21Jun-14Sep)
central stripe not bent sharply, more than 1 mm wide; eye seam at least 2x length of occiput
15ccentral and lower thorax stripes interrupted, reduced to two elongate spots or absent; yellow head, dark body 2Jul-1Oct A.interrupta
these stripes wider, generally full length15d
15dface with fine but clear black-grey stripe on face suture15e
stripe not clear, more like a shadow than a marking; upper side of upper appendages hairy15f
15elarge pale spots between green side stripes of thorax, sometimes confluent with central stripe; 5 paranal cells, slender 19Jul-12Sep A.clepsydra
spotted with blue; 4-5 paranal cells 19Jun-15SepA.eremita
central thorax stripe clearly concave on front edge; 3-4 paranal cells 12Jul-10SepA.subarctica
central thorax stripe convex on leading edge (may be only slightly); 3-4 paranal cells 14Jul-31AugA.juncea
15fsegment 10 all black; large thorax stripes 27Jul-22Sep A.tuberculifera
pale spots on dorsum of segment 1015g
15gcentral thorax stripe mostly or all blue; 21Jun-27SepA.canadensis
this stripe all green; 14Jul-11AugA.verticalis
central thorax stripe 1 mm or less wide and bent in sharp Z; eye seam little if any longer than occiput, greenish face, T-spot with crescent baseA.sitchensis
central stripe not bent sharply, more than 1 mm wide; eye seam at least 2x length of occiput 16a
16apalp of ovipositor (see 4a) as long as segment 1016b
palp much shorter than segment 1016c
16bfront edge of central thorax stripe nearly straight; thin pencil of hairs at end of vulvaA.tuberculifera
this edge distinctly sinuate; no such pencil of hairsA.constricta
16cface with black line on face suture16d
any such line indistinct16f
16dcentral and rear thorax stripes interrupted, reduced to two elongate spots or absentA.interrupta
these stripes well developed16e
16efront thorax suture with large triangular pale spot belowA.clepsydra
4-5 paranal cells; spotted with green 19Jun-15SepA.eremita
central thorax stripe concave on front edge; 3-4 paranal cells A.subarctica
central thorax stripe convex on leading edge; 3-4 paranal cells A.juncea
16fcentral thorax stripe straight, margined with blackishA.umbrosa
central stripe distinctly sinuate16g
16gcentral thorax stripe mostly or all blueA.canadensis
this stripe all greenA.verticalis
triangles with a cross vein, each with a supplementary longitudinal vein springing from its outer edge; very large, small head, black and greenish yellow, eats other dragonflies 21Jun-21AugHagenius brevistylus
triangles clear, no such vein, rarely 65 mm long17a
17amale: hind wings with anal loop, usually 3 cells, lower appendage ends separated slightly, female: vulva nearly as long as the rear of segment 9Ophiogomphus 18
male: without anal loop, lower appendage ends widely separated, generally divergent, female: vulva usually less than half as long as the rear of segment 917b
17bsmall, 25-40 mm long, stigma less than 4x as long as wide and more than 2x as wide as the space behind its middle; greenish with lots of black 21Jun-14Aug Stylogomphus albistylus
42-65 mm long, stigma rarely less than 4x as long as wide, less than 2x as wide as this space17c
17clong hind legs reaching the base of segment 3 with 4-7 long spines below; dark brown, distinctive pale green markings on thorax 5Jun-31AugDromogomphus spinosus
hind legs not reaching beyond the middle of segment 2, only short spinesGomphus 20
18 Ophiogomphus: male
face striped across with black
face uniformly pale
18aupper appendages (top view) bowed, separated by a U-shaped space, ends blunt, lower appendages nearly as long as upper; greenish with black- brown markings 20Jun-5SepOphiogomphus colubrinus
upper appendages triangular with straight edges, separated by a V-shaped space, ends pointed, lower appendages shorter than upper; greenish with clear black markings 20Jun-2Aug O.anomalus
18bblack legs18c
legs with extensor surfaces yellow; greenish with brown markings 20Jun-28AugO.rupinsulensis
18clower appendages much shorter than upper and not projecting out to sides beyond them; greenish, brown markings on thorax 15Jun-11AugO.aspersus
lower appendages little if any shorter than upper and projecting sideways beyond them; yellowish green with brown markings 4Jun-7JulO.mainensis
face striped across with black19a
face uniformly pale19b
19athorax without a dark central stripe; occiput without spines but with a definite fringe of hairs, horns behind occiput stout O.colubrinus
thorax with dark central stripe; occiput with a pair of black spines, hair not in fringe, horns behind occiput very smallO.anomalus
19bhorns behind occiput stout and conspicuousO.rupinsulensis
horns absent or small19c
19csegments 8-9 without yellow spots; with a pair of high contiguous occipital spinesO.mainensis
segments 8 and 9 each with a yellow spot; occipital spines if present small and well separatedO.aspersus
face entirely yellow-green or olive20a
face partly or entirely dark20g
20alegs yellow on outside20b
legs entirely black or brown20c
20bmale: upper appendages without spine under, female: occiput with slightly convex margin fringed sparsely with hair, vulva less than 1/6th as long as segment 9 with lobes widely separated; dull brown and green 14Jun-10JulGomphus lividus
male: upper appendages with obtuse protrusion under, female: occiput slightly bilobed; dull yellow with pale brown thorax stripes 8Jun-12AugG.exilis
male: upper appendages with spine under, female: occiput with a central prominence and slight emargination on each side; dull greenish brown 24May-14JulG.spicatus
20cocciput half height of eye, shape as G.lividus, fringed with long black hair, male: upper appendages' ends convergent, slender and not meeting in middle, female: vulva about 1/3 as long as segment 9, triangular with a short narrow cleft, no horns on vertex; greenish with black markings 1Jun-17AugArigomphus furcifer
occiput height of eye, notched in middle, no hair protruding, male: these ends meeting in middle, female: vulva as G.furcifer; yellowish green with brown and black markings 6Jun-27JulA.cornutus
male: upper and lower appendages' ends parallel, directed rearward, female: vulva less than 1/4 as long as segment 9, angle between the lobes obtuse20d
20dsegments 7-9 only slightly enlarged, the greatest width less than twice the least width, 8 and 9 with scarcely any rim, edge of 8 straight in profile, 10 half as long as 920e
segments 7-9 greatly enlarged, the greatest width more than twice the least width, 8 and 9 with wide rim, edge of 8 convex in profile, 10 1/3 as long as 9 or less20f
20emale: front hamules almost as long as rear, ending in a long slender hook, female: vulva less than 1/2 as long as segment 9, about as wide as long, not tapering to end; clear brown green and yellow 4Jun-30JulGomphus descriptus
male: front hamules much shorter than rear, rounded at end, female: vulva more than 1/2 as long as segment 9, much narrower than long, tapering to end; brown green and yellow, very hairy 26May-22JulG.borealis
20ffront diameter of segments 8 and 9 about equal, 8 with a single triangular yellow spot on top, occiput of female with a small central hump; pale, hairy, wasp waist 1Jun-23JulG.fraternus
diameter of segment 8 much greater than 9, 8 with two spots on top, occiput of female without hump; green with bright brown markings, abdomen blackish, wasp waist 15Jun-14JulG.ventricosus
20gupper pale thorax stripes flowing together with collar stripe20h
these stripes isolated20i
20hsegments 7-9 as wide as thorax, 8 & 9 with wide curved side rims, 8 more curved than 9, 10 about a third as long as 9; thorax greenish yellow with bright brown markings, abdomen blackish with yellow at front and back 1May-31Jul G.vastus
segments 7-9 much narrower than thorax, rim of 9 more curved than 8, 10 more than half as long as 9; yellowish green with strong black markings 7Jun-21JulG.adelphus
20iabdomen not more than 1/7th longer than hind wing, male: rear hamules leaning somewhat backward20j
abdomen 1/5 to 1/3 longer than hind wing, male: rear hamules leaning somewhat forward20k
20jsmall, 32 mm abdomen 28 mm hindwing, pale yellow upper thorax stripes near middle line only slightly divergent; darkish, late JuneStylurus amnicola
large and robust, 40 mm abdomen 34 mm hindwing, these stripes not near middle line and very divergent; blackish with yellow bands on abdomen 25Jun-9SepS.scudderi
20ksegments 8 & 9 about equal in length, male: rear hamules tilted only slightly forward, front edges nearly straight; waspwaist, black and greenish yellow 7Jul-12OctS.notatus
segment 9 about 1/4 longer than 8, male: rear hamules tilted far forward, front edges concave; wings shorter than abdomen, black green and yellow 30Jun-16SepS.spiniceps
single row of yellow abdominal spots on top; July Cordulegaster obliqua
paired abdominal spots large, triangular and widely separated and eyes separated by a small space on males, usually on females; female ovipositor barely longer than segments 9+10, 28May-14JulC.diastatops
paired spots small, narrowly separated or confluent, rounded behind on males usually on females, eyes meet at point; female ovipositor 2x length of segments 9+10, 29May-14JulC.maculata
hind wing triangle about half as far from arculus as in forewing, anal loop about as long as wide, its included cells not in 2 long rows, undeveloped radial and medial planates Macromiidae 23
hind wing triangle at or very close to arculus, anal loop somewhat foot shaped, divided lengthwise by a midrib into 2 rows of cells22a
22aforewing triangle 1½ times as high as wide, anal loop with little if any development of toe, males: well developed anal triangleCorduliidae 29
forewing tringle 2x as high as wide, anal loop with well developed toe (except Nannothemis rear wing), male: no anal triangleLibellulidae 24
occiput and vertex pale; nodus of forewing about equally distant from stigma and wing base 23May-30Jul Didymops transversa
occiput and vertex black; nodus of forewing clearly closer to stigma than to wing base 15Jun-28AugMacromia illinoiensis
forewing triangle with front side broken making a quadrangle of it; anal loop of hind wing open rearward, smallest dragonfly here (wing 20 mm) 20Jun-9Aug
Nannothemis bella
triple-length vacant space under stigma; (Lanark 11Jun-30Sep) Pachydiplax longipennis
vein M2 distinctly waved24a
vein M2 smoothly curved24b
24awings with several bridge crossveinsLibellula 26
single bridge crossvein, large brown spot on rear base of hind wing; 13Jul-10SepPantala hymenea
single bridge crossvein, no such spot; 11Jun-27AugP.flavescens
24bbrilliant three-colour wings: clear, yellow, brownCelithemis 25
wings almost clear24c
24cvein Cu1 in hind wing arising from hind end of triangle Sympetrum 28
arising from outer side, sometimes only by vein width24d
24dforewing triangle inner side less than twice as long as front side, stigma short and thick, face bone white (if not check Sympetrum 28)Leucorrhinia 27
inner side more than twice as long as front, stigma about 3 times as long as wide, face greenish with brown hairs; radial planate subtends 1 row of cells (if 2 rows, it's Pantala flavescens 24a), mostly greenish to grey-blue, brown spots in segments 3-9 19Jun-5SepErythemis simplicicollis
25Celithemis: brilliant yellow and brown spots covering half or more of wings
§ 4 spots per wing, end one beyond stigma; 18Jun-23AugC.elisa
§ 5 spots per wing, end one inside stigma 15Jun-16Aug C.eponina
26Libellula: stout body shorter than wing span, medium size, hunch-backed appearance both at rest and in flight
§ wing clear (may be smoky at tip); forewing triangle 3-celled, eye seam longer than occiput, longer and slimmer than L.julia; 21Jun-14AugL.incesta
§ wings clear except for small dark basal spots; forewing triangle 2-celled, eye seam shorter than occiput; 7Jun-30Jul
[I am not certain that the wing basal spot can be used to separate julia from incesta - a few females in the national collection have basal spots, eye seam shorter than occiput, but 3-celled triangles.]
§ basal third of both wings covered full width by blackish band, tips clear; 26Jun-30AugL.luctuosa
§ nodus wing band at rear wider than 1/5 hindwing length, no spot at stigma, 28May-25Augmale L.lydia
§ large clear separate basal, nodal and wing-end spots, forewing basal colour does not extend into topmost cell of triangle, femalefemale L.lydia
§ as female L.lydia, but forewing basal colour extends into topmost cell of triangle making a notch in its rear; normally longer wingspan than lydia, males have prunescent spots on wings with age; 1Jun-28SepL.pulchella
§ hind wing with triangular yellow to brown spot at base with white crossveins and dark rear border, small clear brown spot at nodus; usually yellow costal streak, sometimes swarms 7May-28AugL.quadrimaculata
27Leucorrhinia: white face on black head; small, not stout, wings mostly clear
§ all blackish except for prunescence; trigonal interspace of forewing with two rows of cells inner third (other L. have 3 rows); 30May-21AugL.frigida
§ 'blood'-red flush on thorax (only when alive) especially around wing roots, usually on sides of segments 1-2 as well, otherwise black abdomen; prunescence can form a row of spots on top of abdomen of pattern similar to the yellow spots of L.hudsonica; 31May-19Aug
[Many publications use a 2-cell width of the radial planate to key this species. It is inapplicable here; several local populations have 1-cell planates.]
§ with line of broad oval yellow spots on top of segments 1-6 (reddish on some males), usually yellow is visible at the bottom of segments 1-2 even through prunescence; a bit stouter than other L., thorax may show a bit of red; 9Jun-30AugL.hudsonica
§ clear yellow or reddish spot on top of segment 7 much larger and brighter than anything on other segments; 19May-26AugL.intacta
§ white ring, or at least a lot of white, at junction of thorax and abdomen; a bit larger than other L., thorax with no red, the white can be largely obscured by prunescence; 1Jun-10AugL.proxima
§ segments 1-3 with line of narrow linear yellow streaks on top (may be faint); check of appendage shapes required to be sure (Renfrew 20Jun-7Aug)L.patricia
28Sympetrum: hybridise often, so expect intermediate forms
male: upper abdominal appendages with prominent tooth on bottom; female: subgenital plate deeply cleft28a
male: these appendages only finely toothed; female: plate with tiny tooth or none28c
28a wing veins reddish, overall brownish red; male: hamuli forked for about 1/4 visible length, rear branch 4 times as stout as inner, face cherry red with clear black line bottom quarter of lower lip; 21Jun-18SepSympetrum internum
wing veins not reddish, little or no black on lower lip or lower edge of black indistinct28b
28b reddish throughout, pale stripes on thorax; male: hamuli forked for about 1/3 visible length, rear branch barely twice as stout as inner, female: subgenital plate tips upturned against rear of segment 9, face yellowish red 13Jun-24Sep S.rubicundulum
abdomen with black side triangles, usually linked into a line with triangle-jagged top; initially yellow-brown turning red with age, male: hamuli forked for less than 1/4 its visible length, rear branch 2-3 times as stout as inner, frons white upper lip yellow-white, female: face greenish white 20Jun- 29OctS.obtrusum
28cwings tinged with dark yellow over basal half, larger area and darker on hindwings; brown, small pale yellow spots behind head 1Jul-1OctS.semicinctum
wings clear, yellow only on costal strip or at extreme base28d
28dlegs black; only Sympetrum with no red anywhere on male, only black and yellow 3Jul-26SepS.danae
legs more or less yellow18e
28elegs entirely yellow; yellow when young all red when mature, slender, thin legs 24Jul-3NovS.vicinum
legs striped with black on sides; brownish red, wings with yellow veins at tips 14Jul-14SepS.costiferum
M4 and Cu1 in forewing parallel to divergent29a
these veins convergent at wing margin29b
29aforewing triangle 3 cells, wings >30 mm; brownish, no visible spots or stripes, flies only briefly after dusk 7Jun-30JulNeurocordulia yamaskanensis
triangles and subtriangles each of a single cell, tiny (24 mm); black with reddish lower lip and pale yellow spot on thorax 19May-11JuneWilliamsonia fletcheri
29bwings with blotchy smoky brown spots at base, nodus and end; hindwing triangle 2-celled, large, brown hairy thorax 7Jun- 20AugEpicordulia (Epitheca) princeps
no such spots29c
29chindwings with opaque brown spots at base; brownish, face yellowish 25May-7JulHelocordulia uhleri

hind wing with 2 cubito-anal crossveins
with 1 such crossvein
Somatochlora 31
29dblack abdomen 2x(male) to 3x(female) as wide at end as at waist; male with white abdominal ring segment 2 and sometimes 3, green eyes; female yellow-brown segments 1 and 2, brown eyes; 18May-21JulDorocordulia libera
metallic green with green eyes, abdomen only twice as wide at widest point as at narrowest 24May-8AugCordulia shurtleffi
brownEpitheca 30
30 Epitheca (Tetragoneuria):
T-spot on frons clearly defined; male: upper appendages each with small sharp spine projecting downward at about 2/5th of its length 8May-10Jul
T-spot indistinct or incomplete (usually base only)
30amale: upper appendages with outer tip bent downward, with a bump on upper side where slope begins, no crossbar on frons T-spot, female: vulva ends cylindrical extending to margin of segment 9; stocky 6May-18JulE.canis
large triangular basal spot rear wings only, row of yellow spots each side of abdomen; male: without such a bump, female: ends conical extending well beyond margin of segment 9; hairy thorax 5Jun-18JulE.cynosura
31 Somatochlora:
upper lip yellowish, often with black band across front border, face below suture mostly yellow; brilliant bronze and green thorax, male: scythe-shaped appendages 1Jul-9Sep
Somatochlora tenebrosa
upper lip black, if partly yellow with no such black band31a
31amiddle segments with clear rings of white about 1/10th their length; one pale stripe/spot on side of metallic green thorax31b
no such white rings31c
31bthorax stripe barely distinguishable; male: lower appendage squared off, nearly parallel to its widely forking tip, female: appendages viewed from side straightish below, much more convex on upper margin (Tremblant 24Jun-4Sep)S.cingulata
yellow elongate spot each side of thorax; male: lower appendage elongate-triangular, strongly tapering to single upturned tip, female: appendages about equally convex on upper and lower margins, 26Jun-1SepS.albicincta
31ctwo side stripes on thorax31d
only one such stripe; face blackish green with 3 yellow spots, thorax metallic green with brown-violet markings 23May- 29AugS.franklini
31deach thorax stripe represented by round spot; face blackish blue 6Jun-30AugS.minor
these spots elongated31e
31efirst thorax stripe narrower and much longer than 2nd; face brownish yellow with black markings on frons, lower lip black 18Jun-1SepS.walshi
this stripe shorter, about 1/2 thorax height, usually narrower than 2nd31f
31fboth thorax stripes bright yellow and sharply defined31g
these stripes dull yellow and ill-defined31h
31gmiddle segments with pale spots at front bases; brown with metallic sheen 27May-27AugS.forcipata
these segments with no pale spots; yellowish face, barely visible yellow bars on metallic green thorax with light brown hairs (Tremblant 8Jun-30Aug)S.elongata
31hmale: upper appendages very hairy, tips recurved, female: subgenital plate triangular in profile, taper pointed and erect; dark with patches of dark yellow, hairy thorax (Tremblant 21Jun-15Sep)S.williamsoni
male: upper appendages not hairy, not recurved at tips, lower curved upwards, female: subgenital plate broadly triangular, not erect; blackish face with some pale yellow, hairy thorax 5Jun-11JulS.kennedyi
male: upper appendages not hairy, not recurved at tips, lower not curved upwards, female: subgenital plate cylindrical; segment 2 with single small pale spot each side, little thorax hair (19Jul-30Aug)S.incurvata

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