Aeshna californica
(California Darner)
Description:
Naiad-
This is a medium-sized naiad, or immature dragonfly, with a length of 1 5/16
to 1 1/2 inches (33 to 37 mm). It is long and slender, which is the typical
shape of an immature Darner dragonfly. It is mottled green and brown and
has 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 2 1/4 to 2 1/2 inches (57
to 64 mm). The male is dark brown
to brownish black. Each side of the
thorax is marked with two blue to bluish green diagonal stripes, while the top
of the thorax is unmarked. The abdomen is marked with large blue spots alternating
with smaller greenish dots. There are several wide blue bands circling the abdomen
near where it meets the thorax. Most females
resemble the males in color, but some may have greenish
yellow markings instead of blue.
Range:
This species is found from
southern British Columbia south to Baja California and Arizona. In Idaho it
is found throughout the state.
Habitat:
This dragonfly can be
found near lakes, ponds, and marshes at lower elevations.
Adult Flight Season:
Mid April -
Late June
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 stoneflies.
Ecology:
The naiads are active
predators, and are able to swim by jet propulsion - squirting water out from
the ends of their abdomens. They generally take several years to mature, and
when they emerge, or change into adult dragonflies, they do so at night. This
behavior probably evolved to avoid being eaten be daytime predators. Adult California
Darners generally fly from mid-April through the end of June, making it one
of the first dragonflies seen each spring. Adults are able to regulate their
body temperature which enables them to fly in temperatures too cold for most
dragonflies.
Reproduction:
Males establish and defend territories along the shores of ponds and lakes.
After males and females mate, females fly singly, without the male attached,
to lay their eggs in the stems and leaves of aquatic plants. They have been
observed resting on lily pads and reaching under the lily pad with their abdomen
to deposit eggs on the underside of the pad.
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.