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Ischnura perparva
Western Forktail
Family: Coenagrionidae
Species account author: Robert Cannings.
Extracted from Introducing the Dragonflies of British Columbia and the Yukon (2002)

Photograph

© Ian Lane     (Photo ID #1536)

Map

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Distribution of Ischnura perparva in British Columbia.
(Click on the map to view a larger version.)
Source: (for the static map) RBCM and BCCDC 2004 ©

Species Information


Description

Our smallest forktail. Male’s thorax has green sides, and a dark top with green stripes; appendages shown in figure. Immature female’s thorax has orange sides and stripes on top; the abdomen is black with an orange base. Mature female’s pale areas darken to olive, but eventually, the whole body is covered by grey-white pruinescence. Females have no vulvar spine. Length: ♂ 26 mm, ♀ 27 mm.


Flight Period

B.C., early May to early October.

Genus Description


Found almost everywhere dragonflies live, though mostly absent from boreal habitats; distribution in North America is decidedly southern. B.C. has four species, but only the two most widespread – the Pacific Forktail and the Western Forktail – are encountered often. None are found in the Yukon. Male forktails in B.C. are mostly black, blue and green. The abdomen is black above and has a blue tip; the last segment bears a distinct forked projection on top, which gives the group its English name. Females may be the same colour as males or may have a tan, pink or orange thorax when immature; they may darken with extensive pruinescence as they age. Larvae are similar to those of bluets, but the gills usually have long, tapered tips.

Biology

Family Description

Small damselflies that normally perch with wings closed above the abdomen. Most males are blue marked with black, but the main colour may be green, yellow, orange, red or purple. Females often have two colour forms per species, one similar to the male (usually blue). Females lay eggs in the tissues of water plants, sometimes completely submerging themselves for a long time while laying. Larave are not as long as spreadwing larave and have short labia, unstalked at the base. There are six genera and 18 species of pond damsels in our region. The American Bluets (Enallagma) and forktails (Ischnura) are the most common groups.
Field Notes

Common at low and moderate elevations, but generally less common than the Pacific Forktail. Inhabits ponds and marshy lakeshores, and is more common in slowly flowing streams than the Pacific Forktail. The stocky little females lay eggs alone, their pruinose bodies and green eyes making them easy to identify.

Distribution


Western. Southern third of B.C. to about 52°N.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
NativeS5YellowNot Listed



BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.