Enallagma clausum
(Alkali Bluet)


Order: Odonata
Suborder: Zygoptera
Order Description:
Damselflies
Family: Coenagrionidae
Family Description: Bluet

Description:
   Naiad- This is a small naiad about one inch (21 to 24 mm) long. It has the typical slender shape of immature damselflies. They range in color from green to light brown.
   Adult-This is a small damselfly 1 ¼ to 1 ½ inches (31 to 37 mm) long. The males are predominately blue on the sides of the thorax, and the upper side of the abdomen, except for segments five, six, seven, and ten, which are predominantly black. Females are pale blue to greenish-yellow. The upper side of the abdomen is mostly black, except for segment eight, which is blue.

Range:
This species is found from southern British Columbia east to Manitoba, and south to Kansas, Utah and Washington. In Idaho it occurs in the southern half of the state.

Habitat:
This damselfly occurs at lakes, ponds, and marshes that have alkaline or even salty water.

Adult Flight Season:
June 24 to August 12

Diet:
   Naiad- Naiads eat a wide variety of aquatic insects, including mosquito larvae, mayfly larvae, and other aquatic fly larvae.
   Adult- Adults eat a wide variety of small soft-bodied flying insects, such as mosquitoes, mayflies, flies and small moths. They will also pick small insects such as aphids from plants.

Ecology:
The Alkali Bluet is found near alkaline or salty lakes or marshes, and therefore it is common in southeast Idaho where these bodies of water are more common. The naiads have been found in water that has over half the salt content of seawater. The adults are difficult to net because they fly very close to the ground, and are more wary than most damselflies.

Reproduction:
The males set up territories at choice breeding sites. After males and females mate, the female Alkali Bluet oviposits in tandem on floating mats of decaying algae.

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 Unpublished M. S. thesis.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.