Ophiogomphus Selys, 1854 - Snaketails

Notes -Michigan SpeciesList - Keys -References
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Page last updated: 25September 1998 (EB)

Notes on the Michigan larvae of Ophiogomphus

Six of the approximately 17 species ofOphiogomphus known from North America have been reliably recorded inMichigan (see below). O.rupinsulensis, probably our most commonophiogomphid, is widely distributed throughout the state.O. carolusand O. colubrinus are widely distributed in the UP and the northern LP.O. aspersus is known from three widely scattered records in the LPand one record from Gogebic County in the western UP. New larvalrecords exist for O.anomalus (Iron Co.) and O. howei (Escanba Co.) inthe UP (D. Cuthrell, Michigan Natural Features Inventory, pers.comm.). A species only recently described, O. susbehcha (Vogt and Smith1993), may be encountered in thewestern part of the UP and is included in the key below (T. Vogt,pers. comm.). Except for morphologically distinctive larvae ofO. anomalus and O.howei (see key below), reliablespecies-level identification usually works only for maturespecimens.

Larval Ophiogomphus are common inclean rivers and streams (rarely from wave-swept shores of lakes),particularly where water quality has not been degraded by changes toflow or by siltation from channelization or agricultural activities.Frequently found in sand and/or gravel substrates, larvae liesubmerged within the substrate or underneath rocks or boulders.Sometimes more than one species is found together in onemicrohabitat. Vogt and Smith1993 found larvae of O. howei andO. rupinsulensis together with a new described species,O. susbehcha, in a largeWisconsin river. Larvae of the three species were found in deep (1m),swiftly flowing water among sand and gravel substrate interspersedwith large boulders. I (EB) have found O. rupinsulensis insimilar habitat in the Pine River, Marquette Co. (26 June 1997), fromwhich a large number of larvae had just emerged to transform on thevertical surface of a bridge support. Walker (1958) remarks that O.aspersus and O. colubrinus preferclear, cold rapid streams with gravelly or sandy beds, whereasO. rupinsulensis appears more tolerant of warmer streams with somewhatmore silting. Kennedy and White(1979), who first described the larvalform of O. howei from specimens collected in Pennsylvania and Virginia,found individuals in sand and gravel substrate in clean, swiftlyflowing waters. Tennessen(1993) found larvae in medium to large(10-100m width) rivers with predominately gravel and sand substratesinterspersed with large rocks and boulders. He also noted the lack ofdisturbance due to forestry and agricultural habitats in sites thatO. howei were found. Based on these Wisconsin populations,emergence in Michigan probably occurs in very late May through June.Kennedy andWhite (1979) also describe thisspecies' emergence and nymphal diet: "The nymphs were observedclimbing out of the river and up vertical mud banks. Emergence eitheroccurred while clinging to the exposed mud bank or in the grassyvegetation on the top of the bank. Emergence occurred between earlymorning and early afternoon... Foregut contents of 5 O. howei mid-instarnymphs..revealed water mites...mayfly nymphs...and midge larvae. Twodistinct size classes...were collected from the New River suggestinga 2 year life cycle."

WWW-Links on the ecology or biology of larvalOphiogomphus:
Ophiogomphus of NE North America>>http://www.hsrl.rutgers.edu/NY.ophio.html
Consevationstatus and habitat info on O. howeiin Maine, USA>>http://wlm13.umenfa.maine.edu/randy/www/tande/group/PSTail.html
Briefhabitat notes from Ottawa, Ontario>> http://www.cyberus.ca/~jdsankey/odon2.html

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MichiganSpecies List of Ophiogomphus

Map 1Map2Map 3
Map4Map5Map 6
County distribution for the Michigan species of
Ophiogomphus
Click on map for a largerimage

Ophiogomphusanomalus Harvey, 1898 - Extra-striped Snaketail - Map 1
Ophiogomphus aspersus Morse,1895 - Brook snaketail - Map2
Ophiogomphus carolus
Needham, 1897 - Riffle snaketail - Map 3
Ophiogomphus colubrinus
Selys, 1854 - Boreal snaketail - Map 4
Ophiogomphus howei
Bromley, 1924 - Pygmy snaketail - Map 5
Ophiogomphus rupinsulensis
(Walsh,1862) - Rusty snaketail - Map 6
*
Ophiogomphus susbehcha Vogt and Smith,1993 - Susbehche snaketail

* not yet recorded in Michigan, but maybe encountered in the western half of the UP

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Key to Mature Larvae ofMichigan Ophiogomphus
(Modified from
Walker 1933, Walker 1958 and Carle 1992)

1a. Middorsal abdominalhooks vestigial or lacking on all segment (Figures 1a1, 1a2) -2

Fig.1a1 Fig. 1a2
Fig. 1a1:
O.howei exuvia (6x dorsalview), from New River, Grayson Co., WV, collected by J. H. Kennedy on07 May 1977. UMMZODO-0809.
Fig. 1a2: Ibid., (6x, lateral view).

1b. Middorsalabdominal hooks well-developed on some abdominal segments (Fig. 1b1)- 3

Fig. 1b1
Fig. 1b1: Ophiogomphusrupinsulensis larva (6x,lateral view), collected from Hearted River, Luce Co., MI, by theInstitute of Fisheries Research on 18 October 1950.UMMZODO-0870.


2a.(1b). Lateral spines present on Ab7 (Figure 2a1); baseof Ant4 broad, appearing to completely cap that of Ant3 (Figure 2a2);cerci about 0.5x the length of epiproct (Figure 2a3); large, maturespecimens 27-32 mm - O.susbehcha

Fig.2a1Fig. 2a2
Fig. 2a3
Fig. 2a1:
O.susbehcha exuvia (12.5x,lateral view), from St. Croix River, Burnett Co., WI, collected by T.E. Vogt on 30 May 1990.
Fig. 2a2: Ibid., (25x, dorsal view).
Fig. 2a3: Ibid., (12.5x, dorsal view).

2b. Lateralspines absent or vestigial on Ab7 (Figure 2b1); base of Ant4 narrow,much narrower than that of Ant3 (Figure 2b2); cerci > 0.7x lengthof epiproct (Figure 2b3); small, mature specimens 19-23 mm -O. howei

Fig.2b1 Fig. 2b2
Fig. 2b3
Fig. 2b1:
O.howei exuvia (12.5x, dorsalview), from New River, Grayson Co., WV, collected by J. H. Kennedy on07 May 1977. UMMZODO-0809.
Fig. 2b2: Ibid., (25x, dorsal view).
Fig. 2b3: Ibid., (25x, dorsal view).

Back to beginning ofkey


3a.(1b). Ant4 broadly capping distal end of Ant3, Ant3 notdistally narrowed (Figure 3a1) - O.anomalus

Fig.3a1
Fig. 3a1:
Ophiogomphusanomalus larva (25x, dorsalview), from Paint River, Iron Co., MI, collected by D. L. Cuthrelland D. A. Hyde (Michigan Natural Features Inventory) on 19 June 1996.UMMZODO-2029.

3b. Ant4minute, considerably narrower than Ant3, Ant3 distally narrowed(Figure 3b1) - 4

Fig. 3b1
Fig. 3b1:
O.carolus larva (25x, dorsalview), from Paint River, Iron Co., MI, collected by D. L. Cuthrelland D. A. Hyde (Michigan Natural Features Inventory) on 19 June 1996.UMMZODO-2032.
Back to beginning ofkey


Note: Ab10 is oftentelescoped within, and partially concealed by, Ab9. To accuratelymeasure the middorsal length of Ab10, it may be necessary to gentlyextend this portion of the abdomen out so that the anterior border ofAb10 is visible. This can be done by gently but firmly grasping withforceps both Ab9 and Ab10, and pulling these apart until the anteriorborder of Ab10 becomes visible. Often, particulate matter accumulatesalong the border, and this should be cleaned with a fine hairedbrush.

4a.(3b). Length of cerci2x the middorsal length of Ab10, their basal width not less than 0.5xthe length of their dorsal edge, and < 2.0x their middle width;cuticular granules coarse and deeply pigmented (Figure 4a1);middorsal hooks on Ab7-9 heavy, in lateral view rapidly acuminate(Figure 4a2) - 5

Fig.4a1Fig. 4a2
Fig. 4a1:
Ophiogomphuscarolus larva (12.5x, dorsalview), collected from Paint River, Iron Co., MI, by D. L. Cuthrelland D. A. Hyde (Michigan Natural Features Inventory) on 19 June 1996.UMMZODO-2032.
Fig. 4a2:
Ophiogomphusrupinsulensis larva (6x,lateral view), collected from Hearted River, Luce Co., MI, by theInstitute of Fisheries Research on 18 October 1950.UMMZODO-0870.

4b. Length ofcerci 2.5x the middorsal length of Ab10, their basal width < 0.5xthe length of their dorsal edge, and > 2.0x their middle width;cuticular granules fine and not much darker than surrounding area(Figure 4b1); middorsal hooks on Ab7-9 slenderer, in lateral viewmore gradually tapered (Figure 4b2) - 6

Fig. 4b1 Fig.4b2
Fig. 4b1: Ophiogomphuscolubrinus larva (12.5x,dorsal view), collected from Mio Pond, Osceola Co., MI, by C. L.Hubbs and T. H. Langlois on 26 July 1924. UMMZODO-2113.
Fig. 4b2: Ibid., (6x, lateral view).

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5a.(4a). In lateral view middorsal hooks on Ab7-9appressed, those on 8 and 9 low and nearly flat (Figure 5a1); Ant3spatulate, length about 2.0-2.5x that of width (Figure 5a2); cerciabout 0.61-0.71x that of epiproct; dorsal knob on Ab2 a rounded knob,somewhat backwards aslant (Figure 5a3) - O. carolus

Fig.5a1 Fig. 5a2
Fig. 5a3
Fig. 5a1:
Ophiogomphus caroluslarva (12.5x, lateral view),collected from Paint River, Iron Co., MI, by D. L. Cuthrell and D. A.Hyde (Michigan Natural Features Inventory) on 19 June 1996.UMMZODO-2032.
Fig. 5a2: Ibid., (25x, dorsal view).
Fig. 5a3: Ibid., (12.5x, lateral view).

5b. In lateralview middorsal hooks on Ab7-9 raised, convexly arched (Figure 5b1);Ant3 enlongate, length about 2.5-3.0x that of width (Figure 5b2);cerci about 0.70-0.75x that of epiproct; dorsal knob on Ab2 moreupright - O.rupinsulensis

Fig. 5b1 Fig. 5b2
Fig. 5b1:
Ophiogomphusrupinsulensis larva (12.5x,lateral view), collected from Hearted River, Luce Co., MI, by theInstitute of Fisheries Research on 18 October 1950. UMMZODO-0870.
Fig. 5b2: Ibid., (12.5x, dorsal view).

Back to previous couplet(3a); Back to beginning of key


6a.(4b). Distal lateral margin of prementum of labiumbarely divergent to parallel (Figure 6a1); dorsal hooks on Ant 8 and9 apically acutangulate or rectangulate in dorsal view (Figure 6a2);length of lateral spines on Ant8 and 9 equal (Figure6a3) - O. colubrinus

Fig. 6a1Fig. 6a2
Fig. 6a3
Fig. 6a1:
Ophiogomphuscolubrinus larva (12.5x,ventral view), collected from Mio Pond, Osceola Co., MI, by C. L.Hubbs and T. H. Langlois on 26 July 1924. UMMZODO-2113.
Fig. 6a2: Ibid., (12.5x, dorsal view).
Fig. 6a3: Ibid., (12.5x, dorsal view).

6b. Distallateral margin of prementum of labium slightly convergent (picture);dorsal hooks on Ab8 and 9 apically obtusangulate in dorsal view(picture); lateral spines on Ab9 smaller than those on Ab8 (picture)- O. aspersus
Back to previous couplet(3b); Back to beginning of key

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References

Bromley, S. W. 1924.A new Ophiogomphus (Aeschnidae: Odonata) from Massachusetts.Entomology News 35(10):343-344.

Carle, F. L. 1992.Ophiogomphus (Ophionurus) australisspec. nov. from the Gulf Coast ofLouisiana, with larval and adult keys to American Ophiogomphus (Anisoptera:Gomphidae). Odonatologica21(2):141-152.

Harvey, F. L. 1898.Contributions to the Odonata of Maine II. Entomological News9(3):59-64.

Kennedy, J.H., and H. B. White. 1979. Description of the nymph ofOphiogomphus howei (Odonata: Gomphidae). Proceedings of the Entomological Society ofWashington 81(1):64-69.

Morse, A. P. 1895. NewNorth American Odonata. Psyche 7:207-211.

Needham, J. G. 1897.Preliminary studies of N. American Gomphinae. The Canadian Entomologist29(7):164-168, (8):181-186.

Selys-Longchamps, M.E. de. 1854. Synopsis des Gomphines. Bulletin de l'Académie royale des Sciences deBelgique 21:23-114.

Tennessen, K. J.1993. New distribution records for Ophiogomphus howei(Odonata: Gomphidae). The Great LakesEntomologist 26(3)245-249.

Vogt, T. E. andW. A. Smith. 1993. Ophiogomphussusbehcha spec. nov. from North CentralUnited States (Anisoptera: Gomphidae). Odonatologica21(2):141-152.

Walker, E. M. 1933.The nymphs of the Canadian species of Ophiogomphus Odonata,Gomphidae. The CanadianEntomologist 65:217-229.

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

Walsh, B. D. 1862.List of the Pseudoneuroptera of Illinois contained in the cabinet ofthe writer, with descriptions of over forty new species, with noteson their structural affinities. Proceedings of the Academy of Natural SciencesPhiladelphia 14:361-402.

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