Six of the approximately 17 species of Ophiogomphus known from North America have been reliably recorded in Michigan (see below). O. rupinsulensis, probably our most common ophiogomphid, is widely distributed throughout the state. O. carolus and O. colubrinus are widely distributed in the UP and the northern LP. O. aspersus is known from three widely scattered records in the LP and one record from Gogebic County in the western UP. New larval records exist for O. anomalus (Iron Co.) and O. howei (Escanba Co.) in the UP (D. Cuthrell, Michigan Natural Features Inventory, pers. comm.). A species only recently described, O. susbehcha (Vogt and Smith 1993), may be encountered in the western part of the UP and is included in the key below (T. Vogt, pers. comm.). Except for morphologically distinctive larvae of O. anomalus and O. howei (see key below), reliable species-level identification usually works only for mature specimens.
A new key to the Ophiogomphus of the Western Great Lakes appeared in 2016, with the paper by Smith and Tennessen should be useful for identifying the larvae of what has sometimes been called "Awfulgomphus."
Larval Ophiogomphus are common in clean rivers and streams (rarely from wave-swept shores of lakes), particularly where water quality has not been degraded by changes to flow or by siltation from channelization or agricultural activities. Frequently found in sand and/or gravel substrates, larvae lie submerged within the substrate or underneath rocks or boulders. Sometimes more than one species is found together in one microhabitat. Vogt and Smith 1993 found larvae of O. howei and O. rupinsulensis together with a new described species,O. susbehcha, in a large Wisconsin river. Larvae of the three species were found in deep (1m), swiftly flowing water among sand and gravel substrate interspersed with large boulders. I (EB) have found O. rupinsulensis in similar habitat in the Pine River, Marquette Co. (26 June 1997), from which a large number of larvae had just emerged to transform on the vertical surface of a bridge support. Walker (1958) remarks that O. aspersus and O. colubrinus prefer clear, cold rapid streams with gravelly or sandy beds, whereas O. rupinsulensis appears more tolerant of warmer streams with somewhat more silting. Kennedy and White (1979), who first described the larval form of O. howei from specimens collected in Pennsylvania and Virginia, found individuals in sand and gravel substrate in clean, swiftly flowing waters. Tennessen (1993) found larvae in medium to large (10-100m width) rivers with predominately gravel and sand substrates interspersed with large rocks and boulders. He also noted the lack of disturbance due to forestry and agricultural habitats in sites that O. howei were found. Based on these Wisconsin populations, emergence in Michigan probably occurs in very late May through June. Kennedy and White (1979) also describe this species' emergence and nymphal diet: "The nymphs were observed climbing out of the river and up vertical mud banks. Emergence either occurred while clinging to the exposed mud bank or in the grassy vegetation on the top of the bank. Emergence occurred between early morning and early afternoon... Foregut contents of 5 O. howei mid-instar nymphs..revealed water mites...mayfly nymphs...and midge larvae. Two distinct size classes...were collected from the New River suggesting a 2 year life cycle."
WWW-Links on the ecology or biology of larval
Ophiogomphus of NE North America >>http://www.hsrl.rutgers.edu/NY.ophio.html
Consevation status and habitat info on O. howei in Maine, USA >>http://wlm13.umenfa.maine.edu/randy/www/tande/group/PSTail.html
Brief habitat notes from Ottawa, Ontario >> http://www.cyberus.ca/~jdsankey/odon2.html
1a. Middorsal abdominal hooks vestigial or lacking on all segment (Figures 1a1, 1a2) - 2
Fig. 1a1: O. howei exuvia (6x dorsal view), from New River, Grayson Co., WV, collected by J. H. Kennedy on 07 May 1977. UMMZODO-0809.
Fig. 1a2: Ibid., (6x, lateral view).
1b. Middorsal abdominal hooks well-developed on some abdominal segments (Fig. 1b1) - 3
Fig. 1b1: Ophiogomphus rupinsulensis larva (6x, lateral view), collected from Hearted River, Luce Co., MI, by the Institute of Fisheries Research on 18 October 1950. UMMZODO-0870.
2a.(1b). Lateral spines present on Ab7 (Figure 2a1); base of Ant4 broad, appearing to completely cap that of Ant3 (Figure 2a2); cerci about 0.5x the length of epiproct (Figure 2a3); large, mature specimens 27-32 mm - O. susbehcha
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. Lateral spines absent or vestigial on Ab7 (Figure 2b1); base of Ant4 narrow, much narrower than that of Ant3 (Figure 2b2); cerci > 0.7x length of epiproct (Figure 2b3); small, mature specimens 19-23 mm - O. howei
Fig. 2b1: O. howei exuvia (12.5x, dorsal view), from New River, Grayson Co., WV, collected by J. H. Kennedy on 07 May 1977. UMMZODO-0809.
Fig. 2b2: Ibid., (25x, dorsal view).
Fig. 2b3: Ibid., (25x, dorsal view).
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3a.(1b). Ant4 broadly capping distal end of Ant3, Ant3 not distally narrowed (Figure 3a1) - O. anomalus
Fig. 3a1: Ophiogomphus anomalus larva (25x, dorsal view), from Paint River, Iron Co., MI, collected by D. L. Cuthrell and D. A. Hyde (Michigan Natural Features Inventory) on 19 June 1996. UMMZODO-2029.
3b. Ant4 minute, considerably narrower than Ant3, Ant3 distally narrowed (Figure 3b1) - 4
Fig. 3b1: O. carolus larva (25x, dorsal view), from Paint River, Iron Co., MI, collected by D. L. Cuthrell and D. A. Hyde (Michigan Natural Features Inventory) on 19 June 1996. UMMZODO-2032.
Back to beginning of key
Note: Ab10 is often telescoped within, and partially concealed by, Ab9. To accurately measure the middorsal length of Ab10, it may be necessary to gently extend this portion of the abdomen out so that the anterior border of Ab10 is visible. This can be done by gently but firmly grasping with forceps both Ab9 and Ab10, and pulling these apart until the anterior border of Ab10 becomes visible. Often, particulate matter accumulates along the border, and this should be cleaned with a fine haired brush.
4a.(3b). Length of cerci 2x the middorsal length of Ab10, their basal width not less than 0.5x the 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. 4a1: Ophiogomphus carolus larva (12.5x, dorsal 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. 4a2: Ophiogomphus rupinsulensis larva (6x, lateral view), collected from Hearted River, Luce Co., MI, by the Institute of Fisheries Research on 18 October 1950. UMMZODO-0870.
4b. Length of cerci 2.5x the middorsal length of Ab10, their basal width < 0.5x the 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 view more gradually tapered (Figure 4b2) - 6
Fig. 4b1: Ophiogomphus colubrinus 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).
Back to previous couplet
(2); Back to beginning of
5a.(4a). In lateral view middorsal hooks on Ab7-9 appressed, those on 8 and 9 low and nearly flat (Figure 5a1); Ant3 spatulate, length about 2.0-2.5x that of width (Figure 5a2); cerci about 0.61-0.71x that of epiproct; dorsal knob on Ab2 a rounded knob, somewhat backwards aslant (Figure 5a3) - O. carolus
Fig. 5a1: Ophiogomphus carolus larva (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 lateral view 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 more upright - O. rupinsulensis
Fig. 5b1: Ophiogomphus rupinsulensis larva (12.5x, lateral view), collected from Hearted River, Luce Co., MI, by the Institute 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 labium barely divergent to parallel (Figure 6a1); dorsal hooks on Ant 8 and 9 apically acutangulate or rectangulate in dorsal view (Figure 6a2); length of lateral spines on Ant8 and 9 equal (Figure 6a3) - O. colubrinus
Fig. 6a1: Ophiogomphus colubrinus 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).
lateral 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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Harvey, F. L. 1898. Contributions to the Odonata of Maine II. Entomological News 9(3):59-64.
Kennedy, J. H., and H. B. White. 1979. Description of the nymph of Ophiogomphus howei (Odonata: Gomphidae). Proceedings of the Entomological Society of Washington 81(1):64-69.
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Tennessen, K. J. 1993. New distribution records for Ophiogomphus howei (Odonata: Gomphidae). The Great Lakes Entomologist 26(3)245-249.
Vogt, T. E. and W. A. Smith. 1993. Ophiogomphus susbehcha spec. nov. from North Central United States (Anisoptera: Gomphidae). Odonatologica 21(2):141-152.
Walker, E. M. 1933. The nymphs of the Canadian species of Ophiogomphus Odonata, Gomphidae. The Canadian Entomologist 65:217-229.
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