Aeshna cyanea (Müller, 1764)
Blue Hawker
Type locality: Europe, no locality data available.
Diagnosis
Large and gaudy hawker, its dark body inlaid with bright nuggets of apple-green and sky-blue. Typically hunts low down along borders, often in the half-dark, like a phantom. Markings, morphology and behaviour render it unmistakable. One of the larger Aeshna species. Mature male has pairs of green spots on upperside of S1-7, in marked contrast to the blue spots on sides and on S8-10. The upperside of S9-10 each with a single blue band, rather than paired spots, forming a conspicuous tail-light. Markings on female and immature are (yellow-) green. Thorax with two broad, oval, green antehumeral stripes and green sides interrupted by two thick black lines, one of which is complete and one only half complete. Hind border of eyes strongly curved, revealing pale spot behind eyes even when viewed from side. In male, the anal triangle has three cells, sometimes up to six, but rarely two as in other large Aeshna species. Pterostigma is notably short (only about 3mm), and twice as long as wide. In male, upperside S10 is flat and smooth (unlike the tooth-like ridge found in other Aeshna, seen from side). Male upper appendages expand towards the end, then abruptly narrow to form a down-turned spine (seen from the side, tip appears like a bird’s head). [Adapted from Dijkstra & Lewington 2006]
Habitat description
Poorly known in Africa, in Europe mostly standing waters, but also streams and headwaters, shaded by or in open areas in (gallery) forest. Often with emergent and aquatic vegetation, submerged roots, dead trunks or branches, and/or coarse detritus, probably especially pools in stream beds. Inferred to occur from 0 to 700 m above sea level.
Distribution
Map citation: Clausnitzer, V., K.-D.B. Dijkstra, R. Koch, J.-P. Boudot, W.R.T. Darwall, J. Kipping, B. Samraoui, M.J. Samways, J.P. Simaika & F. Suhling, 2012. Focus on African Freshwaters: hotspots of dragonfly diversity and conservation concern. Frontiers in Ecology and the Environment 10: 129-134.
Reference
- Müller, O.F. (1764). Fauna insectorum Fridrichsdalina, sive methodica descriptio insectorum agri Fridrichsdalensis, cum characteribus genericis et specificis, nominibus, trivialibus, locis natalibus, iconibus allegatis, novisque pluribus speciebus additis. F. Gleditsch, Hafnia et Lipsia, 1-96.
Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2024-10-05].