Boyeria irene (Fonscolombe, 1838)
Western Spectre
Type locality: S Europe, no locality data available.
Diagnosis
This aeshnid is characterised by its slow, inconspicuous, shade-hugging streamside patrols. Nonetheless, at dusk it may be seen more in the open, whizzing wildly to and fro in pursuit of prey. Aside from behaviour, identified by generic characters in most of range and unlikely to be mistaken (see above). Size between Aeshna mixta and A. cyanea, near A. isoceles. Greyish-brown marked, with rather weakly contrasting greyish or bluish pale-green blotches. Pattern characteristic, including broadly green bases of S2-9 and all-green upperside of S9-10, forming 5-7 rings and a ‘tail-light’. Frons marked above with an indistinct dark blotch. Eyes green. Not important. Extent of wing markings varies. The female has two forms: the typical form has very long appendages (about 6mm, three times the length of S10), while they are only about 2mm (as long as S10) in f. brachycerca. Despite its name, the typical form is scarcer, constituting at most half of the females at a site. [Adapted from Dijkstra & Lewington 2006]
Habitat description
Rivers and (headwater) streams shaded by or in open areas in (gallery) forest. Often with emergent vegetation, submerged roots, dead trunks or branches, coarse detritus, rocks and/or probably overhanging branches. From 0 to 2100 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
- de Fonscolombe, M.B. (1838). Annales Societe Entomologique France, 7, 75-106.
Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2024-11-04].