Gomphus
externus
(Plains Clubtail)
Description:
Naiad-
This is a large naiad with a
maximum length of 1 5/16 inches (33 mm). The abdomen is thick for most of its
length, then tapers to a rounded point at the end of segment ten. There is a
single, rear-facing spine on each side of abdominal segments six through nine.
There are no dorsal hooks.
Adult-
This is a medium to large dragonfly with a length of 2 1/16 to 2 3/8 inches
(52 to 59 mm). The base color is brownish
black. The face is marked with yellow. The top of the thorax behind the
head is marked with a parallel pair of yellow stripes, and each side of the
thorax is marked with several diagonal yellow stripes. The base of the wings
may be clouded with yellow where they attach to the body. The abdomen is black
and marked with a line of yellow dashes along the top. As with other Clubtails,
the segments at the tip of the abdomen are wider than the rest.
Range:
This species is found from
Manitoba south through Wisconsin and Minnesota to New Mexico and Texas, and
in northeastern Utah and the southeast corner of Idaho. The population in Utah
and Idaho is isolated from the main range of this species by several hundred
miles.
Habitat:
This dragonfly can be
found near large, slow, muddy streams and rivers.
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 bare sand. They perch with their abdomen elevated and their wings drooping
so the tips just touch the ground.
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, lakes, or slow streams while hovering
above it. Lab experiments have found that females are capable of laying over
5000 eggs.
Conservation:
Populations
are widespread, abundant, and secure.
![]() |
![]() |
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.