Gomphus complex - Clubtails
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Notes

Michigan List of Gomphus species

Keys

References

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Page last updated: 24 November1999


Notes onthe Michigan larvae of the Gomphus-complex

The Michigan species of this large group ofdragonflies usually are grouped into three distinctive subgenera:Gomphus, Gomphurus and Hylogomphus. Larvae occupya variety of habitats, burrowing into (usually soft) substrates oflakes, ponds, streams and rivers.

Earlier workers usually grouped species ofGomphus, Gomphurus and Hylogomphus as well asStylurusand Arigomphus into a taxonomic "basket" called Gomphus, although mostrecognized distinctive groups warranting full generic rank.Needhamand Westfall's (1955) organization ofthe North American species into five distinctive groupings providedsome clarity, but currently no monophyletic grouping has been agreedupon. Most authors have been satisfied with the generic elevation forbut two groups - Arigomphus and Stylurus(see each respective page for a brief discussion oftheir generic elevation). Shortly after Needham and Westfall's 1955book, Walker(1957) published an analysis of adultgenitalia in Gomphus. He concluded that only three subgenera formed naturalgroupings - Arigomphus, Gomphurus, and Stylurus, whereasHylogomphus formed a distinct group around the speciesGomphus brevis, and with the remaining species of Gomphus sensu lato lackingdistinct, monophyletic relationships.

More recent work by Louton (1982) and Carle (1982, 1986, and 1995) attempted to find more natural groupings withinGomphurusand Gomphus sensu lato groups. Stenogomphurus andGomphurus(Carle1982) arose from two distinctivespecies groups from within Gomphurus, andGomphusand Phanogomphus (Carle1986) substituted for Needham andWestfall's Hylogomphus and Gomphus sensulato, respectively. May and Carle(1996), who give a good summary of thedebate, also point that Hylogomphusmay not be considered a "good" taxonbecause Needham and Westfall did not designate a type-species.Indeed, Garrison(1991) considers this a synomyn ofGomphus. The "conservative" method is to recognizeArigomphusand Stylurus as valid genera, whereas Gomphus (orPhanogomphus), Gomphurus (orGomphurusand Stenogomphurus) andHylogomphus (or Gomphus if Phanogomphus is recognizedinstead of Gomphus sensulato) are delegated as subgenera ofGomphus.The issue will only be resolved with a comprehensive morphological,ecological, behavioral and molecular review of known species in Asia,Europe and North America.

Links on the biology and ecology of larvalGomphus:
Biologyand habitat info on Gomphusapomyius>>http://www.hsrl.rutgers.edu/apomyius.html
Briefhabitat notes (Cumberland/Cape May Co., NJ, USA) on G. exilis andG. apomyius>>http://www.hsrl.rutgers.edu/cumb.cape.txt
Briefhabitat notes from Ottawa, Ontario>>http://www.ncf.carleton.ca/~bf250/odonata.html
Notbiology, but if flyfishing's your bag... >>http://bcadventure.com/adventure/angling/flies/dragonfly/nymph.htm
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Michigan Species List of Gomphus

G. (Hylogomphus)adelphus (syn. brevis) Selys, 1854 - Moustached Clubtail
G.(Gomphus)exilis Selys, 1854 - Lancet Clubtail
G. (Gomphurus) fraternus (Say,1839) - Midland Clubtail
G. (Gomphus) graslinellusWalsh,1862 - Pronghorn Clubtail
G. (Gomphurus) lineatifrons (Calvert, 1921) - Splendid Clubtail
G. (Gomphus) lividus Selys, 1854 - Ashy Clubtail
G. (Gomphus) quadricolorWalsh,1863 - Rapids Clubtail
G. (Gomphus) spicatus Hagen in Selys, 1854 - Dusky Clubtail
G. (Gomphurus) vastus (Walsh,1862) - Cobra Clubtail
G. (Gomphurus) ventricosus (Walsh, 1863) - Skillet Clubtail
G. (Hylogomphus)viridifrons Hine, 1901 - Green-faced Clubtail

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Key to the Mature Larve of Michigan Gomphus
Adapted fromLouton (1982, 1983) and Walker(1958)

1a. Middorsal length ofAb9 equal to, or greater than, half its basal width (fig); length ofAb10 ca. 0.66x-0.75x its width (fig) - Gomphus, 2

1b. Middorsallength of Ab9 less than half its basal width (fig); length of Ab10< 0.50x its width (fig) - 6


2a(1a). Well developedlateral spines on Ab7-9, very minute if present on 6 (fig); novestigial dorsal hook on Ab9 (fig); principally lentic -G. (Gomphus) spicatus

2b. Welldeveloped lateral spines on Ab6-9 (fig); Ab9 with at least avestigial middorsal hook (fig); middorsal length of Ab9 usually lessthan its width (fig) - 2


3a.(1b). Middorsal length of Ab9 about equal (>0.93x) toits basal width (fig); middorsal hook only on Ab9 -G. (Gomphus)quadricolor

3b. Middorsallength of Ab9 less than 0.9x (<0.88x) its basal width (fig);middorsal hook at least on Ab8 and Ab9 - 3
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4a.(3b). End hook of palpal lobe not much longer than thetooth adjacent to it (fig); Ab9 markedly wide, its middorsal lengthabout 0.55x its basal width (fig); middorsal hooks on Ab2-9 (fig) -G. (Gomphus)graslinellus

4b. End hookof palpal lobe produced, markedly longer than the tooth adjacent toit (fig); Ab9 narrower than above, its middorsal length about 0.75x(0.68-0.88x) its basal width (fig); middorsal hooks absent from Ab2-3(fig) - 4
Back to previous couplet(2); Back to beginning of key; Back tobeginning of subgenus key


5a.(4b) Mature larva large, > 29 mm in total length;edge of median lobe of labium straight or only slightly convex (fig);with at least small middorsal hooks on Ab6-7 (fig); epiproct longer(>1.10x) than middorsal length of Ab10; Ab10 distinctly wider thanlong (fig); - G. (Gomphus)lividus

5b. Maturelarva smaller, <28 mm in total length; edge of median lobe oflabium convex (fig); middorsal hooks only on Ab8-9 (fig); epiproctshorter than middorsal length of Ab10; Ab10 longer than above, nearlysquare in outline (fig) - G.(Gomphus) exilis
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6a.(1b). Lateral spines of Ab9 apart from Ab10, about samelength as those on Ab8 (fig); abdomen not markedly dorsoventrallycompressed (fig) - Hylogomphus, 7

6b. Lateralspines of Ab9 close to Ab10, markedly longer than those on Ab8 (fig);abdomen appears dorsoventrally flattened (fig) - Gomphurus,8
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7a(6a). End hook of palpal lobe about 2.0x the length of theadjacent tooth (fig); small vestigal middorsal hook on Ab9 (fig) -G. (Hylogomphus)adelphus

7b. End hookof palpal lobe > 2.0x the length of the adjacent tooth (fig); nomiddorsal hook on Ab9 (fig) - G.(Hylogomphus) viridifrons
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8a(6b). Apical margin of median lobe of prementum deeplyconcave (fig) - G. (Gomphurus)lineatifrons

8b. Apicalmargin of median lobe of prementum straight or slightly convex (fig)- 9


9a.(8b). End hook of lateral lobe of labium stronglyincurved, extending far past apex of the truncate, 3 to 4 lateralteeth next to it (fig) - G.(Gomphurus) vastus

9b. End hookof lateral lobe of labium much less curved or straight, at bestbarely extending past the 6 lateral teeth next to it (fig) -10
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10a(9b). Length of prementum long, 1.32-1.35x long as wide(fig); Ant3 long, length about 2.6x that of Ant1-2 combined (fig);lateral spines of Ab6-7 strongly divergent - G. (Gomphurus) ventricosus

10b. Length ofprementum shorter, < 1.10x long as wide (fig); Ant3 shorter,length about 1.5x that of Ant1-2 combined (fig); lateral spines ofAb6-7 only slightly divergent (fig) - G. (Gomphurus) fraternus
Back to previouscouplet (9); Back to beginning ofkey
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References

Calvert, P. P. 1921. Gomphus dilatatus, vasus, and a newspecies, lineatifrons (Odonata). Transactions of the American EntomologicalSociety 47:221-232.

Carle, F. L. 1986. The classification, phylogeny, andbiogeography of the Gomphidae (Odonata: Anisoptera). I.Classification. Odonatologica15(3):275--326.

Garrison, R. W. 1991. A synonymic list of the New WorldOdonata. Argia 3(2):1-30.

Hine, J. S. 1901. A new species of Gomphus and its nearrelatives. OhioNaturalist 1(4):60-61.

Huggins, D. G. and G. L. Harp. 1985. The nymph ofGomphus (Gomphurus)ozarkensis Westfall (Odonata:Gomphidae). Journal of the KansasEntomological Society 58(4):656-661.

Louton, J. A. 1982. Lotic dragonfly (Anisoptera:Odonata) nymphs of the Southeastern United States: identification,distribution and historical biogeography. Unpublished Ph.D. thesis,The University of Tennessee, Knoxville. 357 pp.

Louton, J. A. 1983. The larva of Gomphurus ventricosus(Walsh), and comments on relationships within the genus (Anisoptera:Gomphidae). Odonatologica12(1):83-86.

May, M. L., and F. L. Carle. 1996. An annotated list ofthe Odonata of New Jersey, with an appendix on nomenclature in thegenus Gomphus. Bulletin of AmericanOdonatology 4(1):1-35.

Needham, J. G. and M. J. Westfall, Jr. 1955. A Manual ofthe Dragonflies of North America (Anisoptera). University ofCalifornia Press: Berkeley, California. xii + 615 pp.

Say, T. 1839. Descriptions of new North Americanneuropterous insects and observations on some already described by(the late) Th. Say. Journal of theAcademy of Natural Science of Philadelphia 8:9-46.

Selys-Longchamps, M. E. de. 1854. Synopsis desGomphines. Bulletin de l'Académieroyale des Sciences de Belgique21:23-114.

Walker, E. M. 1957. The affinities of the North Americanspecies of Gomphus as revealed by the genitalia (Odonata, Gomphidae).Contributions of the Royal Ontario Museum, Division of Zoology andPalaeontology, No. 46, 24 pp.

Walker, E. M. 1958. The Odonata of Canada and Alaska,Vol. 2. University of Toronto Press: Toronto. xii + 318.

Walsh, B. D. 1862. List of the Pseudoneuroptera ofIllinois contained in the cabinet of the writer, with descriptions ofover forty new species, with notes on their structural affinities.Proceedings of the Academy of NaturalSciences Philadelphia14:361-402.

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