Michigan's second largest family ofdragonflies, 31 species in 8 genera have so far been recorded in ourstate. The taxonomic status of one genus,
Although adults are referred to as "clubtails,"as the abdomen is often enlarged posteriorly to resemble a club,gomphids could just as easily be called "burrowing dragonflies," inreference to the larval habit of burrowing into various substrates inlotic and lentic waters. Their larval morphology - reduced antennaesegments and strong fossorial legs, among other morphologicaladaptations - is ideally suited for concealing themselves insubstrate and loose particulate debris. It's very interesting towatch live captured individuals, when released or put into acontainer filled with silt, sand or other debris, quickly use theirlegs to conceal themselves. Most are found in silt, sand or gravel inlakes and rivers, but one species -
1b.Mesocoxae not closer together than procoxae (picture); antennalsegment 4 vestigial or a small, rounded knob (picture) -2
2b.Abdomen not so flat, more cylindrical (picture); head without pairedtubercles behind eyes (picture) -
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Fig. 3a1: Ophiogomphusrupinsulensis larva, 12xdorsal view. Specimen collected from the Salmon-Trout River,Marquette County, Michigan, by M. F. O'Brien on 21 June 1997.
3b. Wing casesparallel along back (picture); middorsal length of Ab9 clearly longerthan that of Ab8 -
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4b. Cercidistinctly shorter, at most 0.8x the length of the epiproct andparaprocts (Fig. 4b1) -
Fig. 4b1: O.susbehcha exuvia (12.5x,lateral view), from St. Croix River, Burnett Co., WI, collected by T.E. Vogt on 30 May 1990.
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Fig. 5a1. Stylogomphusalbistylus larva,collected fromMountain Stream, Marquette Co., Michigan, USA, on 30 June 1996 byBright, O'Brien and M. A. Kielb. UMMZODO-0179.
5b.Cylindrical antennal segment 3 more than 4 times as long as wide(picture) -
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Fig. 6a1: Dromogomphusspinosus larva (12x, dorsalview), collected from Third Sister Lake, outside Ann Arbor inWashtenaw County, Michigan, by F. Locke, on July 1940.UMMZODO-0562.
Fig. 6a2: Ibid, lateral view. Both images taken at 12x.UMMZODO-0562.
6b. Abdominalsegment 9 without such an acute, dark middorsal ridge bearing dorsalhook at apex (picture), and usually not markedly raised in lateralview (picture) -
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7b. Pro- andmesotibiae with burrowing hooks at outer apical angle about as longas width of tarsus (picture) -
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8b. Abdominalsegment 10 wider than long (picture) -
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