Progomphus borealis
(Gray Sanddragon)


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

Description:
   Naiad- This is a large naiad with a length of 1 inch (25 to 27 mm). It is sandy brown in color and has short legs covered with stiff bristles. The abdomen turns up at the tip, and there is a single, rear-facing spine on each side of abdominal segments three through nine.
   Adult- This is a medium to large dragonfly with a maximum length of 2 ╝ inches (57 mm). The face and thorax are grayish to yellowish brown, and the thorax may be marked with black. The abdomen is black and marked with yellow on the top of each segment. The underside of the tip of the abdomen is marked with yellow as well, and the abdominal tip is swollen as in other members of this family.

Range:
This species is found from eastern Oregon and southwestern Idaho south to California and Texas. It is also found in Sonora and Chihuahua and south to Jalisco in Mexico. In Idaho, it is found at desert streams in the southwest corner of the state.

Habitat:
This dragonfly can be found near sandy streams in desert areas.

Adult Flight Season:
Early June to September

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:
Naiads can be very selective in their habitat choices and will often occur only in certain stretches of a particular river or stream. They burrow into the sand, 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 other species the Clubtail naiads emerge as adults during the day. Although records are sparse, the adults are believed to fly from early June to September. They can not tolerate cooler temperatures and are rarely seen flying on cool or cloudy days.

Reproduction:
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 the shallows of small streams 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.