Sailing Bluet. Swartstertbloutjie.
Family Coenagrionidae Kirby, 1890
- Azuragrion nigridorsum (Selys, 1876)
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Small, bright blue and black Damselfly, with a distinctive black pattern on the end of the abdomen (S8).
Key identification features:
- Face bright blue. Labrum bright blue with three basal black spots. Anteclypeus bright blue. Head black from above with bright blue line running across back of head but not touching eyes.
- Eyes bright blue with small black cap. Neck black with blue collar and fineblue hind margin.
- Thorax black with bright blues tripes above, sides light blue.
- Wings clear. Pterostigmas brownish grey with indistinct fine border.
- Abdomen bright blue with black line of varying width running along top, ending half way along segment 8. Segment 9 bright blue with fine black crescent at front end. Segment 10 bright blue with wide black stripe.
- Female with similar head thorax patterning, blue replaced by light yellowish brown, abdomen black except for fine yellowish rings from above.
Compared with other species:
- Similar to the paler Swamp Bluet, Africallagma glaucum.
- S8 of A. glaucum is all blue and the S8 of Az. nigridorsum has a black patch.
- S10 of the A. nigridorsum has a big black dorsal patch and only a thin black dorsal stripe on S10 of the A. glaucum.
- Black dorsal stripe on S 3 -5 of the abdomen of the Az. nigridorsum is continuous, broken in Sapphire Bluet, A sapphirinum.
- A. nigridorsum has brown pterostigmas and normal wingtips and the Round-wing Bluet. Pseudagrion rotundipennis has round blue and black pterostigmas and round wingtips.
Distribution and habitat:
- Savannas of Southern and Eastern Cape coast, and coastal, central and northern parts of KZN to the northern parts of South Africa.
- Preferred habitat is still water, such as small ponds, dams and slow-flowing streams and rivers.
- It occurs at pools, vleis and small lake usually fringed with bushes or trees and with with an abundance of grasses, sedges and lilies. Occasionally also occurs at grassy margins of slow river reaches. It flies rapidly across the water surface, frequently landing on emergent grass stems or lily pads, often far from the bank. It gets its vernacular name from the fact that it can land directly on the water surface, where it sails on the breeze.
Credit for description
Michael J. Samways & John P. Simaika. Manual of Freshwater Assessment for South Africa:Dragonfly Biotic Index