Leucorrhinia hudsonica
(Hudsonian Whiteface)

Order: Odonata
Suborder: Anisoptera
Order Description:
Family: Libellulidae
Family Description: Whiteface

   Naiad- This is a small naiad with a length of 5/8 to 3/4 inch (16 to 18 mm). The abdomen is rounded, giving it a short, stocky appearance known as the sprawler form. It is brown with three dark stripes marking the length of the underside of the abdomen. There may be very small hooks on the tops of abdominal segments three through six, or they may be absent. Each side of abdominal segments eight and nine has a spine that points out away from the abdomen.
   Adult- This is a small dragonfly with a length of 1 1/16 to 1 3/16 inches (27 to 30 mm). The male is black and marked with red on the thorax and abdomen; the marks on the abdomen are elongated spots, possibly pointed on one end, which form a line along the length of the top side of the abdomen. The female is brownish black and marked similarly to the male except the markings are yellow instead of black. The face of both sexes is creamy white.

This species is found from Alaska east to Labrador, extending south to Oregon, Utah, and Pennsylvania. In Idaho, it occurs in the northern and central portions of the state, primarily at higher elevations.

This dragonfly can be found at marshy lakes, ponds, and bogs at higher elevations.

Adult Flight Season:
Late May to mid-August

   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 flying ants or termites.

The naiads live in submerged vegetation. They do not actively pursue prey but wait for it to pass by, a strategy which affords them protection from other predators. Naiads emerge as adults at night. Although records are sparse, adults are believed to fly from late May to mid-August. Hunting occurs from perches on shoreline vegetation. Specimens from Idaho tend to be larger than those found further north. Adults have been known to swarm over sphagnum bogs in the northern part of its range.

After mating, a male will actively guard a female to prevent other males from mating with her. He does this by flying above her while she lays her eggs, and by driving away other potential mates or even dragonflies of other species. The female lays her eggs by dipping the tip of her abdomen in the water while hovering just above its surface.

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 by Ean Harker, 2001.

HTML by Marty Peck, 2001.