Ischnura
cervula
(Pacific Forktail)
Description:
Naiad-
This is a small naiad about ¾
inch (15 to 18 mm). It has the typical slender immature damselfly shape. It
is dark with light bands.
Adult-
This is a small damselfly about 1
to 1 ½ inches (26 to 32 mm). The male has pale blue on the side of the thorax,
4 blue spots on top of the thorax, and a black abdomen with segments eight and
nine colored bright blue. Most females are brown, but some are colored very
similarly to males. Both color forms of the females become pruinose with age.
Range:
This species is found from
southern British Columbia east to Alberta, and south to New Mexico and Baja
California. In Idaho it is found throughout the state.
Habitat:
This damselfly occurs
at almost all lowland still-water habitats in the state, but is most abundant
in semi-arid areas at alkaline ponds.
Adult Flight Season:
April 15 to October
15
Diet:
Naiad-
Naiads eat a wide variety of aquatic insects, including mosquito larvae, mayfly
larvae, and other aquatic fly larvae.
Adult-
Adults eat a wide variety of small soft-bodied flying insects, such as mosquitoes,
mayflies, flies and small moths. They will also pick small insects such as aphids
off of plants.
Ecology:
Naiads of this species
are often found in aquatic vegetation. This is the first damselfly to emerge
in the spring, and one of the last seen in the fall.
Reproduction:
The males set up territories
at choice breeding sites. After males and females mate, the female Western Forktail
oviposits, or lays eggs, singly (without the male attached) in floating vegetation.
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 Unpublished M. S. thesis.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.