Ophiogomphus severus
(Pale Snaketail)

Description:
   Naiad- This is a large, robust naiad with a length of 1 inch (25 to 27 mm). There is a curved hook on the top of each abdominal segment two through nine, and there is a single, rear-facing spine on each side of abdominal segments seven through nine. The abdomen turns up at the tip.
   Adult- This is a medium-sized dragonfly with a length of 2 inches (49 to 52 mm). The face and thorax are yellowish green. The top of the thorax may be marked with black while each side is unmarked. 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 and is swollen as in other members of this family. The female's abdomen may appear olive brown to yellowish green, especially when viewed from the side.

Range:
This species is found from southern British Columbia east to Alberta, extending south to northern California, Colorado, and Nebraska. In Idaho, it is found throughout the state in river systems at lower elevations.

Habitat:
This dragonfly occurs near low elevation rivers and streams.

Adult Flight Season:
Mid-May 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:
Clubtail naiads can be very selective in their habitat choices and will often occur only in certain stretches of a particular river or stream. Sinuous Snaketail naiads seem to be more tolerant of higher stream gradients and lower water temperatures than most members of this family, and are often found in cold trout streams. 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, Clubtail naiads generally emerge as adults during the day.
Adults generally fly from mid-May to September, and are commonly seen perching on gravel bars. They can not tolerate cooler temperatures and are rarely seen flying on cool or cloudy days. This is probably the most common member of the Gomphidae family in Idaho.

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 rivers or streams while perching on a rock.

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.