Erpetogomphus compositus
(White-belted Ringtail)


Order: Odonata
Suborder: Anisoptera
Order Description:
Dragonflies
Family: Gomphidae
Family Description: Ringtail

Description:
   Naiad- The naiad of this species is medium sized. As with other species in this family, the tip of the abdomen is pointed up. It has small hooks on the top of abdominal segments two through nine, and a single, rear-facing spine on each side of abdominal segments six through nine.
   Adult- This is a medium-sized dragonfly with a length of 1 7/8 to 2 1/4 inches (46 to 55 mm). The face is white and the thorax is whitish yellow and striped with black. The abdomen is black, with yellowish or white rings at the segment joints. Only the male has a clubbed tip of the abdomen.

Range:
This species is found from northern Oregon east to Wyoming and south to northern Baja California and Sonoran, Mexico. In Idaho, it is found at desert streams in the southwest corner of the state.

Habitat:
This dragonfly can be found near streams and rivers in desert and sagebrush steppe areas.

Adult Flight Season:
Mid-July to mid-August

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 flying ants or termites.

Ecology:
Clubtail naiads can be very selective in their habitat choice and will often occur only in certain stretches of a particular river or stream. They burrow into the sand or mud, leaving the upturned tip of their abdomen exposed. This allows them to breathe while buried by pumping water in and out of the tip of the abdomen. Unlike most species, the Clubtail naiads emerge as adults during the day. Adults generally fly from mid-July to mid-August. They can not tolerate cooler temperatures and are rarely seen flying on cool or cloudy days. Hunting occurs from perches on rocks or twigs.

Reproduction:
Males establish and defend territories along streams. After males and females mate, the female flies singly, without the male attached, to lay her eggs by dipping the tip of her abdomen in a river or stream 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.