Aeshna interrupta
(Variable Darner)

Order: Odonata
Suborder: Anisoptera
Order Description:
Family: Aeshnidae
Family Description: Darners

   Naiad- This is a large naiad with a length of 1 1/2 to 1 3/4 inches (39 to 42 mm). It is long and slender like other Darner naiads. It is mottled green and brown and has a single, rear-facing spine on each side of abdominal segments six through nine.
   Adult- This is a large dragonfly with a length of 2 1/2 to 2 3/4 inches (65 to 70 mm). The male is dark brown to black. The top of the thorax is marked with two greenish dashes. Each side of the thorax is marked with a pair of diagonal stripes or with two pairs of elongated spots arranged in diagonal rows. In either case, half of the marks are greenish and half are bluish. The abdomen is spotted with green and blue. The female is marked similarly; however, the base color is brown and the abdominal marks are green. The common name for this species refers to the variable marks on the thorax.

This species is found from Alaska and the Yukon Territories east across Canada to Nova Scotia, extending south to California, New Mexico, and northern New York. In Idaho, it is found throughout the state.

This dragonfly can be found near lakes, ponds, and marshes, primarily in prairie and sagebrush steppe habitats.

Adult Flight Season:
Early June - October

   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. It has also been known to prey on immature dragonflies (naiads) of other species found resting on blades of grass.

Like other Darners, the naiads are active predators, and are able to swim by jet propulsion - squirting water out from the ends of their abdomens. They generally take several years to mature, and when they emerge, or change into adult dragonflies, they do so at night. This behavior probably evolved to avoid being eaten be daytime predators. Adults generally fly from early June to October. This Darner often gathers in swarms over dirt roads. It flies long after dark on warm summer evenings, and can spot flying insects when it's too dark for a person to see them. Adults are able to regulate their body temperature which enables them to fly in temperatures too cold for most dragonflies.

Males establish and defend territories along the shores of ponds and marshes. After males and females mate, females fly singly, without the male attached, to lay their eggs in the stems and leaves of aquatic plants. Unique individuals resembling females but having male reproductive organs have been collected. Such individuals are called androgynomorphs.

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

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/HTML by Ean Harker, 2001.