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Ophiogomphus occidentis
Sinuous Snaketail
Family: Gomphidae
Species account author: Robert Cannings.
Extracted from Introducing the Dragonflies of British Columbia and the Yukon (2002)


Photograph

© Jeremy Gatten     (Photo ID #5901)

Map

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

Species Information


Description

Coloured much like the Boreal Snaketail, except its face is yellow-green with no stripes and its thorax has no stripe behind the forewing base (though there is sometimes a thin line on the side in front of the hindwing base). A conspicuous brown stripe in front of the forewing base is divided by wavy pale line – this gives the species its English name. Length: ♂ 50 mm, ♀ 51 mm.


Flight Period

B.C., early June to early October.

Genus Description


Most snaketails live in eastern North America. The three species in B.C. fly along clear streams and lakeshores; uncommon in settled areas, at least partly because the burrowing larvae are sensitive to changes in water flow and siltation, and they are especially affected by poor logging practices. The mature adult’s thorax is green; younger adults are more yellow. The abdomen has white or yellow marks on the sides and yellow spots on top; this snake-like pattern gives the genus its English and scientific names (ophio is Greek for “snake” and gomphos means “bolt” or “arrow”). The hindwings have a three-celled anal loop. Male’s upper appendages are short and usually pointed in side view.

Biology

Family Description

A large family, but poorly represented in our region. B.C. has only six species and the Yukon appears to have none (although two species may live in the southeast). Compared to some other families, clubtails are not common here, but they are easily recognizable by their widely separated eyes and their green or yellow bodies striped in brown and black. The tip of the abdomen, especially in males, is enlarged, giving them their English name. Females lack an ovipositor and drop their eggs directly into clear streams and along the sandy shallows of larger lakes; they lay their eggs without the protection of their mates. Larvae burrow in the bottom sediments of these water bodies.
Field Notes

Uncommon denizen of sunny stream banks and sandy lakeshore beaches at low elevations. The only clubtail on Vancouver Island, where the best place to see it is along the Nanaimo River.

Distribution


Montane. Widespread in B.C. south of about 51°N.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
NativeS3BlueNot Listed



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