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Aeshna sitchensis
Zigzag Darner
Family: Aeshnidae
Species account author: Robert Cannings.
Extracted from Introducing the Dragonflies of British Columbia and the Yukon (2002)
Introduction to the Odonata of BC
The Families of Odonata of BC

Photograph

© Ian Lane     (Photo ID #1171)

Map

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

Species Information


Description

Small, similar to the Azure Darner, but its thorax stripes are yellow to blue, and the hind one is more zigzagged and less T-shaped; the facial T-spot has a crescent-shaped base. Male’s abdomen has large blue spots, though smaller than the Azure Darner’s. The face is yellow to green. Female’s abdominal spots are blue or yellow-green. Male’s upper appendages simple. Length: ♂ 59 mm, ♀ 56 mm.


Flight Period

B.C., late June to early October; Yukon, late June to late August.

Genus Description


Mosaic Darners are common in B.C. and the Yukon; they fly everywhere dragonflies are found. All 11 B.C. species are large and can usually be distinguished by their variations on a basic colour pattern. Generally, the body is brown, and each side of the thorax has a pair of blue, green or yellow stripes – their shape is important in identification. Look also for the colour of the face and the line across its middle. Viewed from above, the forehead bears a distinctive T-shaped mark, called the “T-spot”. The abdominal spots on males are usually blue, and on females green, yellow or blue. Male upper appendages come in three types.

Biology

Family Description

Large, swift-flying dragonflies, usually marked with blue, green or yellow. Adults hunt tirelessly for insects over ponds, lakes and streams, and wander widely in search of prey. Most species rest in a vertical position, but a few sit flat on the ground. Females have a prominent ovipositor and lay eggs in water plants or floating wood above or below the water line. Larvae are slender and sleek, with flat labia lacking bristles; they are rapacious hunters among water plants. Recently, A. californica and A. multicolor have been transferred from Aeshna to Rhionaeschna.
Field Notes

Restricted to specific peatland conditions, where it can be abundant: bogs or fens where the surface is mossy and sparsely vegetated with short, evenly spaced sedges, and where open water, if present at all, is reduced to small, shallow, mud- or moss-bottomed ponds and puddles. Adults perch on the ground, rocks and logs, or vertically, low on tree trunks.

Distribution


Northern. Widespread throughout our region.

Status Information

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



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