Cordulia shurtleffi
(American Emerald)


Order: Odonata
Suborder: Anisoptera
Order Description:
Dragonflies
Family: Corduliidae
Family Description: Emerald

Description:
   Naiad- This is a medium-sized naiad, or immature dragonfly, with a length of 13/16 to 1 inch (20 to 23 mm). The abdomen is rounded, giving it a short, stocky appearance known as the sprawler form. The color is uniform brown, with each side of the thorax marked with stripes. There are short, knobby projections along the back, and a single, rear-facing spine on each side of abdominal segments eight and nine.
   Adult- This is a medium-sized dragonfly with a length of 1 3/4 to 2 inches (43 to 50 mm). It is metallic bronze-green and lacks any additional markings.

Range:
This species is found from Alaska east across Canada to Labrador, extending south to California, Ohio, and Connecticut. In Idaho, it is found in the panhandle region.

Habitat:
This dragonfly can be found near mountain lakes, bogs, and marshes.

Adult Flight Season:
Mid May to late June

Diet:
   Naiad- Naiads feed on a wide variety of aquatic insects, such as mosquito larvae, other aquatic fly larvae, mayfly larvae, and freshwater shrimp. They will also eat small fish and tadpoles.
   Adult- The dragonfly will eat almost any soft-bodied flying insect including mosquitoes, flies, butterflies, moths, mayflies, and stoneflies.

Ecology:
The naiads live in submerged vegetation and woody debris on the bottom of lakes or bogs, and seem to tolerate very cold water. They do not actively pursue prey but wait for it pass by, a strategy which affords them protection from other predators. Naiads may require several years to mature, and typically emerge as adults at night. It is one of the first dragonfly species to emerge in the spring.

Reproduction:
Males patrol along the water's edge searching for receptive females. After males and females mate, the female flies singly, without the male attached, to lay her eggs by dipping the tip of her abdomen on the surface of the water while hovering above it.

Conservation:
Populations are widespread, abundant, and secure.
Status: Unprotected nongame species
Global Rank: G5
State Rank: S?

References:
Corbet, P. S. 1999. Dragonflies: Behavior and Ecology of Odonata. Cornell University Press, Ithaca, New York, USA, 829pp.

Logan, E. R. 1967. The Odonata of Idaho. Unpublished M. S. thesis. University of Idaho, Moscow, Idaho, USA, 105 pp.

Needham, J. G. and M. J. Westfall. 1955. Dragonflies of North America. University of California Press, Berkely, California, USA, 615 pp.

Paulson, D. R. 1999. Dragonflies of Washington. Seattle Audubon Society, Seattle, Washington, USA, 32 pp.

Walker, E. M. and P. S. Corbet. 1975. The Odonata of Canada and Alaska, Vol. III. University of Toronto Press, Toronto, Ontario, Canada, 307 pp.


Written by Mark Lung and Stefan Sommer, 2001
Photos by Dennis Paulson, 2001
Design by Ean Harker, 2001.

HTML by Marty Peck, 2001.