Shadow Darner Dragonfly Habitats: Long Clasper, T-Spotted Forehead, Tan Head

Summary: North American shadow darner dragonfly habitats get long appendages, spotted abdomens, striped thoraxes, T-spotted foreheads and tan backs of heads.

male shadow darner dragonfly (Aeshna umbrosa); Mason Neck, southernmost Prince William County, Northern Virginia; Thursday, Nov. 17, 2016: Judy Gallagher (Judy Gallagher), CC BY 2.0 Generic, via Flickr

North American shadow darner dragonfly habitats accept shade plant-loving cultivators and naturalists in distribution ranges throughout Canada, except Nunavut, and throughout the United States, except Alaska, Arizona, Florida, Hawaii, Louisiana and Wyoming.

Shadow darners bear their common name for dark color, late-afternoon flights and knitting needle-like abdomens and the scientific name Aeshna umbrosa (misshapen [spear that is] shadowy). Common names count upon scientific committee consensus in the Dragonfly Society of the Americas, whose 11th Bulletin of American Odonatology considers damselflies and dragonflies in Alabama. Descriptions in 1908 and 1912 by Edmund Murton Walker (Oct. 5, 1877-Feb. 14, 1969), Royal Ontario Museum invertebrate collection founder in Toronto, Canada, determine scientific designations.

Shadow darner life cycles expect shaded, wooded beaver and suburban ponds, bogs, ditches, fens, lakes, marshes, slow-flowing streams, small rivers, southern upland water bodies and swamps.

June through December function as earliest to latest flight seasons even though August through October furnish wildlife mapping opportunities through coastal and inland shadow darner niches.

Shadow darners go on a series of 30-second hovers in hour-long patrols 1 foot (0.31 meter) above a wooded wetland series of shaded watersides and waters. They hang vertically from low-lying vegetation, treetop twigs or any grassy, herbaceous, weedy, woody perch in-between preceding and succeeding mixed- or same-species swarmed or solitary feeding. Food-searching, mate-seeking itineraries involve faster, higher, lower, more direct investigations from late afternoon into dusk than emerald dragonflies in overlapping, shaded banks, basins, clearings and edges.

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

Populations in and outside the Pacific Northwest, known as Aeshna umbrosa occidentalis and Aeshna umbrosa umbrosa, keep their abdomens green- and large-spotted and blue- and small-spotted.

Incomplete metamorphosis leads shadow darners from rod-shaped eggs laid by solitary females with breakable ovipositors in rotting, wet wood to larvae, naiads or nymphs and tenerals. Immature, multi-molting, nonflying stages metamorphose into shiny-winged, tender-bodied, weak-flying tenerals that mature to mate and manipulate eggs into dry or wet banks, logs, trunks or twigs. Aphids, beetles, borers, caddisflies, copepods, crane flies, dobsonflies, gnats, leafhoppers, mosquitoes, rotifers, scuds, water fleas and worms nourish mosaic darner members of the Aeshnidae dragonfly family.

North American shadow darner dragonfly habitats offer season-coldest temperature ranges, northward to southward, from minus 45 to 35 degrees Fahrenheit (minus 42.11 to 1.66 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 black-tipped darners.

Blue- or brown-eyed, blue- or brown-green faces, blue- or yellow-green-spotted black-brown, thickened abdomens, brown-tinged wings, green-yellow-marked rust-brown thoraxes and long-tipped appendages qualify as adult female hallmarks. Males reveal blue-, small- or green-, large-spotted abdomens, blue-green-topped, green-yellow-bottomed, narrow, straight front- and side-striped thoraxes, clear wings, paddle-like appendages and turquoise-eyed, blue- or brown-green faces. Adults show off 2.68- to 2.99-inch (68- to 76-millimeter) head-body lengths, 1.93- to 2.32-inch (49- to 59-millimeter) abdomens and 1.65- to 1.89-inch (42- to 48-millimeter) hindwings.

Black T-spotted foreheads, long appendages and tan backs of heads tell blue-, green-marked, brown-bodied shadow darners from other odonates in North American shadow darner dragonfly habitats.

female shadow darner dragonfly (Aeshna umbrosa); Mer Bleue Conservation Area, Ottawa, Eastern Ontario, east central Canada; Thursday, Sep. 9, 2010: D. Gordon E. Robertson (Dger), CC BY SA 3.0 Unported, via Wikimedia Commons

Acknowledgment

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

Image credits:

male shadow darner dragonfly (Aeshna umbrosa); Mason Neck, southernmost Prince William County, Northern Virginia; Thursday, Nov. 17, 2016: Judy Gallagher (Judy Gallagher), CC BY 2.0 Generic, via Flickr @ https://www.flickr.com/photos/52450054@N04/30832396080/

female shadow darner dragonfly (Aeshna umbrosa); Mer Bleue Conservation Area, Ottawa, Eastern Ontario, east central Canada; Thursday, Sep. 9, 2010: D. Gordon E. Robertson (Dger), CC BY SA 3.0 Unported, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Shadow_Darner,_female.jpg

For further information:

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"Aeshna umbrosa." James Cook University-Medusa: The Odonata - Dragonflies and Damselflies > Anisoptera > Aeshnidae > Aeshna.
Available via James Cook University-Medusa @ https://medusa.jcu.edu.au/Dragonflies/openset/displaySpecies.php?spid=43

Beaton, Giff. Dragonflies & Damselflies of Georgia and the Southeast. Athens GA; London UK: University of Georgia Press, 2007.

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

Bright, Ethan. "Aeshna umbrosa umbrosa Walker, 1908: 380, 390 -- Shadow Darner." Aquatic Insects of Michigan > Odonata (Dragon- and Damselflies) of Michigan > Anisoptera Selys, 1854 -- Dragonflies > Aeshnidae Rambur, 1842: 181 (Darners) > Aeshna Fabricius, 1775 (Mosaic Darners).
Available @ http://www.aquaticinsects.org/sp/Odonata/sp_oom.html

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Available @ https://garden.org/nga/zipzone/2012/

Walker, E. M. (Edmund Murton). A Key to the North American Species of Aeshna Found North of Mexico: 5. umbrosa, n. sp." The Canadian Entomologist, vol. XL, no. 11 (November 1908): 380. London, Canada: The London Printing and Lithographing Company Limited, 1908.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/3100245

Walker, E. M. (Edmund Murton). "Aeshna umbrosa Walker." The North American Dragonflies of the Genus Aeshna. University of Toronto Studies Biological Series, no. 11: 165. Toronto, Canada: The University Library Librarian, MCMXII (1912).
Available via Internet Archive @ https://archive.org/stream/biologicalseries10univuoft#page/165/mode/1up