Sailing Bluet, Azuragrion nigridorsum, Swartstertbloutjie.
Short Description:
Sailing Bluet, Azuragrion nigridorsum, Swartstertbloutjie is small, bright blue and black Damselfly, with a distinctive black pattern on the end of the abdomen (S8).
Family Coenagrionidae Kirby, 1890
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Key identification features:
Male:
- 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 fine blue hind margin.
- Thorax black with bright blues stripes 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:
- Female with similar head thorax patterning, blue replaced by light yellowish brown, abdomen black except for fine yellowish rings from above.
Habitat:
- Standing and often temporary waters, but also streams, in open landscapes, but sometimes in open areas in forest or shaded by gallery forest. Often with emergent and usually aquatic vegetation, and often a soft (like muddy) bottom, along streams especially at pools.
- From 0 to 2400 m above sea level, but mostly below 1700.
Behaviour:
- 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.
Compared with other species:
- Similar to the paler Swamp Bluet, Africallagma glaucum.
- S8 of A. glaucum is all blue and the S8 of A. 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 A. 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
South Africa:
- Savannas of southern and eastern Cape coast, and coastal, central and northern parts of KZN to the northern parts of South Africa.
Africa:
- Angola; Botswana; Democratic Republic of the Congo; Ethiopia; Kenya; Malawi; Mozambique; Namibia; Republic of South Africa; Rwanda; Socotra (Yemen); South Sudan; Swaziland; Tanzania; Uganda; Zambia; Zimbabwe
Further reading:
Websites of interest
The IUCN Red List of Threatened Species Least Concern
Odonata Atlas of Africa VMU Number 662630
African Dragonflies & Damselflies Online
A Visual Guide to the Damselflies and Dragonflies of South Africa
Credit for description Michael J. Samways & John P. Simaika. Manual of Freshwater Assessment for South Africa:Dragonfly Biotic Index