Somatochlora Selys,1871(Corduliidae) - Emeralds

Somatochlora hineana(illus. by Susan Fawcett)

Notes -Michigan SpeciesList - Key -References
Back toCorduliidae - Back to Anisoptera - Back toHome Page
Page last updated: 07 July2005 (MFO) (Page still under construction!)

Notes on theMichigan Species of Somatochlora

Of the 26 species of Somatochlora found inNorth America, 12 species have been reliably recorded in Michigan(see maps below). Sometimes commonly encountered corduliids, theselarge larvae principally frequent streams but also are encountered inlakes as well as seeps and bogs, or springs and streams drainingthese systems. This species appears most common in the UP.

Several species listed in the key below haveonly rarely been encountered in our state. S. cingulata, S. linearis and S.tenebrosa are also known only from afew counties in the state, in the UP and LP, respectively.S. elongata, S. kennedyi, S. minor, S.walshi and S. williamsoni are found inwidely scattered localities in both the lower and upper peninsulas.S.forcipata, S.franklini and S. incurvata have beenfound only in the UP. The early record for S. tenebrosa (Kormondy 1958), which did not have any locality information, hasrecently been determined to be S.hineana, and new records for thisspecies have been found in calcareous fens in the Lower Peninsula.S. ensigera is also known from several records in northern Ohio andcentral Indiana, and thus may also be encountered in the southernpart of our state. The endangeredS. hineana(Hine's Emerald) - currently known only from northern Illinois andnorthern Wisconsin and northern Michigan (in the Great Lakes region,but populations are now known from Missouri). This species apparentlyfavors small seeps draining calcareous escarpments through thicklyvegetated wetlands. Several populations of S. incurvata have beenlocated in Jackson Co., Wisconsin, from which the larva has beenreared and whose description is soon forthcoming (Smith 1997). Additional populations Mackinac Co., Michigan, haverecently been discovered, and recent adult surveys have shown thespecies to be locally common (Steffins 1997; unpubl. MOSdata, 2005).).

Other links with information on the biology orecology of Somatochlora:

 

back totop
Michigan SpeciesList

Map 1Map 2Map 3
Map 4Map 5Map 6
Map 7Map 8Map 9
Map 10Map11Map 12

Somatochloracingulata (Selys,1871) - Lake Emerald - Map1
Somatochloraelongata (Scudder,1866) - Ski-tailed Emerald -Map 2
*
Somatochloraensigera Martin,1907 - Plains Emerald
Somatochloraforcipata (Scudder,1866) - Forcipate Emerald -Map 3
Somatochlorafranklini (Selys,1878) - Delicate Emerald -Map 4
Somatochlorahineana Williamson,1931 - Hine's Emerald -EndangeredSpecies -Map 5
Somatochloraincurvata Walker,1918 - Incurvate Emerald -Map 6
Somatochlorakennedyi Walker,1918 - Kennedy's Emerald -Map 7
Somatochloralinearis (Hagen,1861) - Mocha Emerald - Map8
Somatochloraminor Calvert in Harvey,1898 - Ocellated Emerald -Map 9
Somatochloratenebrosa (Say, 1839) - Clamp-tipped Emerald
Somatochlora walshi(Scudder, 1866) - Brush-tipped Emerald - Map 10
Somatochlorawilliamsoni Walker,1907 - Williamson's Emerald -Map 11
*Not yet foundin Michigan, but may be encountered in southern part of thestate

backto top
Key to Mature Larvae of Michigan Somatochlora
(Adapted from
Walker and Corbet(1975), Daigle(1991), and Cashatt et al. (inprep.))

Larvae undescribed (1997) -S.incurvata

1a.Dorsal hooks present (picture) - 2

1b. Dorsal hooks absent (picture) - 8


2a.(1a). Dorsalhooks 5 or 6-9 and are low knobs, blunt, the last one not extendingto middle of segment 10 (picture) - S. williamsoni - character table

2b. Dorsal hooks falciform, acute, the last one projectingbeyond the middle of segment 10 (picture) - 3
Back to previouscouplet (1)


3a.(2b).Epiproct of male longitudinally concave, anteapical tubercle slightlyelevated (picture) -4

3b. Epiproct of male nearly flat above, anteapical tuberclenot elevated (picture) - 5
Back to previouscouplet (2); Back to beginning ofkey
Note: For the six species that follow this couplet, for only maleshave reliable distinguishing characters been found.


4a.(3a).Middorsal hook on Ab3 vestigial, hook on Ab small but well-developed(picture); total length > 23 mm; hind femur length6.8-7.6 mm - S.hineana - charactertable
Note:Because this species is federally listed as ENDANGERED, collectionwithout permit issued by USFWS is illegal.

4b. No middorsal hook on Ab3, hook on Ab4 vestigial(picture); smaller than above, total length < 23mm; hind femur length shorter, ca. 6.0 mm - S. tenebrosa - character table
Back toprevious couplet (3);Back to beginning ofkey


5a.(3b). Dorsalhook on abdominal segment 4 not greaterthan 0.25x than that segment's mid-dorsal length (picture) -6

5b. Dorsal hook on abdominal segment 4 greater than 0.5xthan that segment's mid-dorsal length (picture) - 7
Back to previouscouplet (3); Back to beginning ofkey


6a.(5a). Lengthof lateral abdominal spines < 0.5x as basal width; epiproct notacuminate (picture); cerci equal in length to epiproct (picture); noseries of long prominent setae on posterior margins of abdominalsegment (picture) - S. linearis- charactertable

6b. Length of lateral abdominal spines = or > 0.5x asbasal width; epiproct acuminate with very slender tip (picture) -S.walshi-charactertable
Back to previouscouplet (4); Back to beginning ofkey


7a.(5b). Hindtibiae greater than 8.4 mm, hind femora greater than 7.4 mm -S.elongata -charactertable

7b. Hind tibiae less than 8.4 mm, hind femora less than 7.4mm; dorsal hooks present on segments 3-9; dorsal hook on Ab4 inlateral view about 0.75x length of hook on Ab5 (picture); well-developed dorsal hook on Ab3 -S.minor -charactertable
Back to previouscouplet (4); Back to beginning ofkey


8a.(1b). Labiumextending laterally over inner edge of eyes (picture); male cerciwith outer margin not regular arcuate, more or less sinuate; lateralspines, when present, on both abdominal segments 8 and 9 (picture);metafemur long, usually greater than 7.3 mm; abdomen with a medianseries of slightly elevated dorsal prominences (picture); epiproct of male with a distinct knob oneach side (picture) - S.cingulata - character table

8b. Labium not extending laterally over inner edge of eyes(picture); male cerci with outer margin regularly arcuate (picture);lateral spines, when present, confined to segment 9 (picture);metafemur greater than 7.3 mm; abdomen without median dorsalprominences (picture); epiproct of male without lateral knobs(picture) - 9
Back to beginningof key (1)


9a.(8b). Fringeof hair on hind margins of 6-9 forming two rows of dorsolateral tufts(picture); lateral spines absent from 9 or represented by very minutedenticles (picture); lateral setae 9 or 10 (picture) -S.forcipata- charactertable

9b. Fringe of hair on hind margins of 6-9 not forming tworows of dorsolateral tufts (picture); lateral spines normally presenton 9 (picture); palpal setae 7 or 8 (picture) - 10
Back to previouscouplet (7); Back to beginning ofkey


10a.(9b). Fringeof hair on middle of hind margin of 7 or 8 forming a thick, dorsaltuft (picture) -S.kennedyi- charactertable

10b. Fringe of hair on hind margin of 7 or 8 not forming athick median tuft (picture); body length 17mm, hind femur 5.25mm -S.franklini- charactertable
Back to previouscouplet (8); Back to beginning ofkey

backto top
CharacterTable for Mature SomatochloraLarvae of Michigan [under construction]

Species

length

setae

mental setae

no. of palpal crenations

max. no. of crenation setae

dorsal hooks

palpal

mental

outer

inner

0/+

Ab3

Ab4

cingulata key

26-28

5-7

10-13

4-5 longest

3-4 variable

7-8

1-3

0

0

0

elongata key

23-24.4

6-7

11-12

4-6 longest

6-8 shorter

9

5-6

+

0

+

forcipata key

19-20

9-10

12-15

4-6 longest

4-5 shorter

7-9

3-5

0

0

0

franklini key

17.5

7-8

13

4-6 longest

4-5 shorter

10

4

0

0

0

hineana key

23-25

7-10

11-16

9-10 longest

3-5 shorter

9

12

+

v

+

kennedyi key

21

9-10

12-13

4-6 longest

4-5 shorter

9-10

4

0

0

0

linearis key

22

6-7

11-12

5-6 longest

9-10

5-7

+

0

v

minor key

21-22.5

6-7

11-13

7-8 longest

5-6 shorter

9

5-6

+

+

+

tenebrosa key

20-22

8

11-12

5-6 longest

9-10

6-7

+

0

0/v

walshi key

20.5

7

9-10

7 longest

3 much shorter

9

4-5

+

0

v

williamsoni key

23-25

8

11-12

4-5 longest

9-10

6-7

+

0

0
+ = present; 0 = absent; v =vestigial
References

Cashatt, E. D. and T. E.Vogt (2001). "Description of the larva of Somatochlora hineana with akey to the larvae of the North American species of Somatochlora(Odonata: Corduliidae)." International Journal of Odonatology 4(2):93.

Daigle, J.J. 1991. A new key to the larvae of North American Somatochlora. Argia3(3):9-10.

Foster, S. E. and D. A. Soluk (2004)."Evaluating exuvia collection as a management tool for the federallyendangered Hine's emerald dragonfly, Somatochlora hineana Williamson (Odonata: Cordulidae)." BiologicalConservation 118(1): 15.

Hagen, H. A.1861. Synopsis of the Neuroptera of North America, with a list of theSouth American species. Smithsonian Miscellaneous Collections 4:1-347.

Harvey, F.L. 1898. A contribution to the Odonata of Maine, II. Entomological News 3:269-277.

Jones, C. D. (2001). "Somatochlora incurvata (incurvate emerald) new to AlgonquinProvincial Park, Ontario." Ontario Odonata 2(May 2001).

Jones, C. D. and P. S. Burke (2004)."Mocha emerald (Somatochloralinearis), new to Ontario andCanada." Ontario Odonata 5(Nov 2004).

Kormondy,E. J. 1958. A catalogue of the Odonata of Michigan. MiscellaneousPublications, Museum of Zoology, University of Michigan, No. 104.43pp.

O'Brien, M. (1997). "Somatochlora tenebrosa not in Michigan." Williamsonia1(4), November 1997: 3.

O'Brien, M. (2001). "Somatochlora tenebrosa at Ives Road Fen." Williamsonia5(4): 7.

O'Brien, M. F. (2001). "Hine'semerald dragonfly: a federally-endangered species Somatochlora hineana Williamson." Williamsonia5(2-3): 5.

Martin,René. 1907. Cordulines. Collections zoologiques du Baron Edm.de Selys Longchamps, Catolgue systématique et descriptif.Coll. Selys Longchamps 17:1-94, f 1-99, cpl 1-3.

Say, T. 1839.Descriptions of new North American neuropterous insects andobservations on some already described by (the late) Th. Say.Journal of the Academy ofNatural Science of Philadelphia 8:9-46.

Scudder,S. H. 1866. Notes on some Odonata from the White Mountains of NewHampshire. Proceedings of theBoston Society of Natural History 10:211-222.

Selys-Longschamps, E. de. 1871.Synopsis des Cordulines. Bulletin de l'Académie royale des Sciences deBelgique(2)31:238-316;519-565.

Selys-Longschamps, E. de. 1878.Secondes additions au synopsis des Cordulines. Bulletin de l'Académie royale desSciences de Belgique(2)45:183-222.

Smith, W. A.1997. Wisconsin Williamsonia andT & E status for corduliids and gomphids. Williamsonia 1(4):7

Soluk, D.A., B.J. Swisher, D.S.Zercher, J.D. Miller, and A.B. Hults. 1998. The ecology of Hine'semerald dragonfly (Somatochlora hineana): Monitoring populations and determining patterns ofhabitat use. Activity summary and report of findings (September1996-August 1997). IL Nat. History Survey, Champaign, IL. 111pp

Steffins,W. 1997. New Somatochloracounty records and notes for the UP. Williamsonia1(4):7.

Steffens, W. P. (1998). "Newdistribution records of Somatochlora hineana (Odonata: Corduliidae)."Great Lakes Entomologist 31(1): 25.

Vogt, T. E. and E. D. Cashatt (1994)."Distribution, habitat, and field biology of Somatochlora hineana(Odonata: Corduliidae)." Annals of the Entomological Society ofAmerica 87(5): 599.

Walker, E.M. 1907. A new Somatochlora with a note on the species known fromOntario. The CanadianEntomologist 39:69-74.

Walker, E.M. 1918. On the American representatives of Somatochlora arctica with description of two new species (Odonata).The CanadianEntomologist53:221-226.

Walker, E.M., and J. S. Corbet. 1975. The Odonata of Canada and Alaska, Vol. 3.University of Toronto Press: Toronto. xvi + 308.

Williamson, E. B. 1931. Anew North American Somatochlora(Odonata - Cordulinae). Occasional Papers of the Museum of Zoology, Universityof Michigan 225:1-8, 1pl.

backto top