Small, similar to the Zigzag Darner. Thorax stripes are pale blue or green; shape shown in figure. The face is blue or green; T-spot shown in figure. Male’s abdomen has more blue than the Zigzag Darner’s, the blue spots usually fused to form irregular stripes; upper appendages simple. Female has blue or yellow-green abdominal spots. Length: ♂ 60 mm, ♀ 57 mm.
Flight Period
B.C., mid July to mid September; Yukon, mid June to mid September.
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
The most boreal of our darners. In the Yukon, it is the only dragonfly known to breed north of the British Mountains; uncommon in the southern valleys. Yukon records are from a variety of peatlands, marshes and ponds, many with floating aquatic mosses. In B.C., it lives in subalpine peatlands with ponds. Perches low on tree trunks, or on stones, logs or moss.
Distribution
Northern. Widespread in the Yukon. In B.C., it ranges south only in the mountains and on northern plateaus to about 51°N in the Coast and Rocky mountains.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC:
Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab
for Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2023-09-24 9:15:00 AM]
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