Common Sanddragon Dragonfly Habitats: Rearward Triangle-Marked Abdomen

Summary: North American common sanddragon dragonfly habitats get dot-tipped wings, rearward triangle-marked abdomens, striped thoraxes and w-marked foreheads.

Retired science teacher Walter Sanford shares that the distinctive field marker for male common sanddragon dragonflies (Progomphus obscurus) is that their hindwings are indented near their bodies; male common sanddragon alongside Dogue Creek, Wickford Park, Fairfax County, Northern Virginia; June 8, 2016: Walter Sanford @Geodialist, via Twitter March 29, 2017

North American common sanddragon dragonfly habitats assemble sand garden-loving cultivators and niche-loving naturalists in distribution ranges from New Hampshire through Florida, New Mexico, Colorado, Nebraska, Iowa, Wisconsin, Ontario, Vermont and everywhere in-between.

Common sanddragons bear their common name for abundant populations and for sandy larval habitats and the scientific name Progomphus obscurus (first crossbow bolt [with] subdued [coloration]). Common names call upon scientific committee consensus in the Dragonfly Society of the Americas, whose 22nd Bulletin of American Odonatology covers damselflies and dragonflies in Iowa. Scienific designations defer to descriptions in 1842 by Jules Pierre Rambur (July 21, 1801-Aug. 10, 1870), Montpellier and Tours medical school-trained graduate September 1827 in Paris.

Common sanddragon life cycles expect rocky, shallow, wooded rivers with sand-sprinkled waters and sandy-bottomed, shallow, woodland lakes, ponds, rivers and streams with low-lying, weedy, woody vegetation.

April through September function as earliest to latest flight seasons even though June and July furnish wildlife mapping opportunities throughout coastal and inland common sanddragon niches.

Common sanddragons go from 10:30 a.m. to 4 p.m. on food-searching and perch-seeking flights over open, rocky, sandy, weedy, woody banks and mate-seizing patrols over riffles. They hang obliquely from ground, through understory, to treetop layers of waterside, weedy, woody vegetation, head out as fluttering, gliding, hovering hawkers and hide under bushes. Inclining abdomens upward, called obelisking, to impede sunlight exposure and temperature increase identifies common sanddragons as much as weak flights over riffles, rocks, sand and vegetation.

Ants, assassin flies, biting midges, ducks, falcons, fish, flycatchers, frogs, grebes, lizards, spiders, turtles and water beetles and mites jeopardize North American common sanddragon dragonfly habitats.

Immature adult-like, nonflying common sanddragon larvae, naiads or nymphs keep to diets of chironomid larvae and mayfly naiads and to diminutive, dull-colored sizes throughout multiple molts.

Incomplete metamorphosis links round eggs laid during 1-yard- (0.91-meter-) long oviposits by male-guarded females, multi-molting immature stages living on sand banks and bottoms and molted tenerals. Molted, shiny-winged, tender-bodied, weak-flying tenerals mature physically and sexually away from sandy metamorphosis sites to manage weedy, woody perches and roosts, mate for 15 minutes and manipulate eggs into ovipositing sites. Aphids, beetles, borers, caddisflies, copepods, crane flies, dobsonflies, gnats, leafhoppers, mosquitoes, rotifers, scuds, water fleas and worms nourish sanddragon members of the Gomphidae clubtail dragonfly family.

North American prince baskettail dragonfly habitats offer season-coldest temperatures, north- to southward, from minus 45 to 25 degrees Fahrenheit (minus 42.11 to minus 3.88 degrees Celsius).

Beech, bellflower, birch, bladderwort, cattail, daisy, grass, greenbrier, heath, laurel, madder, maple, nettle, olive, pepperbush, pine, pondweed, rush, sedge, water-lily and willow families promote common sanddragons.

Blue-gray or brown eyes and egg-thickened, unclubbed black-brown abdomens with egg-filled, egg-releasing ovipositors at darkened tips of terminal segments with claspers qualify as adult female hallmarks. Males reveal blue-gray to olive-green-yellow eyes, brown-, double-, cross-striped yellow faces, brown-, double-striped yellow thoraxes, black-brown abdomens with burning candle-like, rear-pointing triangles and dark short legs. Adults show off 2.01- to 2.16-inch (51- to 55-millimeter) head-body lengths, 1.54- to 1.69-inch (39- to 43-millimeter) abdomens and 1.22- to 1.38-inch (31- to 35-millimeter) hindwings.

Cream-colored claspers, dark-based, dot-tipped wings, brown-striped thoraxes, rear-pointing burning candle-patterned abdomens, w-marked foreheads tell common sanddragons from other odonates in North American prince baskettail dragonfly habitats.

female common sanddragon; Huntley Meadows Park, Hybla Valley southeastern Fairfax County, Northern Virginia; June 17, 2015: Walter Sanford @Geodialist, via Twitter June 26, 2015

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Retired science teacher Walter Sanford shares that the distinctive field marker for male common sanddragon dragonflies (Progomphus obscurus) is that their hindwings are indented near their bodies; male common sanddragon alongside Dogue Creek, Wickford Park, Fairfax County, Northern Virginia; June 8, 2016: Walter Sanford @Geodialist via Twitter March 29, 2017, @ https://twitter.com/Geodialist/status/847011751262638080

female common sanddragon; Huntley Meadows Park, Hybla Valley southeastern Fairfax County, Northern Virginia; June 17, 2015: Walter Sanford @Geodialist, via Twitter June 26, 2015, @ https://twitter.com/Geodialist/status/614372710039195648

For further information:

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Berger, Cynthia. Dragonflies. Mechanicsburg PA: Stackpole Books: Wild Guide, 2004.

Bright, Ethan. "Progomphus obscurus (Rambur, 1842: 170 as Diastatomma) -- Common Sanddragon." Aquatic Insects of Michigan > Odonata (Dragon- and Damselflies) of Michigan > Anisoptera Selys, 1854 -- Dragonflies > Gomphidae (Clubtails) > Progomphus Selys, 1854 (Sanddragons) .
Available @ http://www.aquaticinsects.org/sp/Odonata/sp_oom.html

Paulson, Dennis. Dragonflies and Damselflies of the East. Princeton NJ: Princeton University Press, Princeton Field Guides, 2011.

"Progomphus obscurus." James Cook University-Medusa: The Odonata - Dragonflies and Damselflies > Anisoptera > Gomphidae > Progomphus.
Available via James Cook University-Medusa @ https://medusa.jcu.edu.au/Dragonflies/openset/displaySpecies.php?spid=1775

Rambur, P. (Jules Pierre). 1842. "5. Diastatomma obscurum, mihi." Histoire Naturelle des Insectes. Névroptères: 170. Paris, France: Librairie Encyclopédique de Roret, 1842.
Available via HathiTrust @ https://hdl.handle.net/2027/mdp.39015058433833?urlappend=%3Bseq=202
Available via Internet Archive @ https://archive.org/stream/histoirenaturel53buffgoog#page/n215/mode/1up

"The 2012 USDA Plant Hardiness Zone Map." The National Gardening Association > Gardening Tools > Learning Library USDA Hardiness Zone > USDA Plant Hardiness Zone Map.
Available @ https://garden.org/nga/zipzone/2012/

Walter Sanford ‏@Geodialist. "Common Sanddragon dragonfly (male)." Twitter. March 29, 2017.
Available @ https://twitter.com/Geodialist/status/847011751262638080

Walter Sanford ‏@Geodialist. "Common Sanddragon dragonfly terminal appendages." Twitter. June 26, 2015.
Available @ https://twitter.com/Geodialist/status/614372710039195648