Progomphus
borealis
(Gray 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 ¼ 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.
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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.