Genus Cyanothemis Ris, 1915
Type species: Cyanothemis simpsoni Ris, 1915
Monotypic genus found only from DR Congo to western Africa. C. simpsoni males perch on sunny branches overhanging forest rivers, particularly where organic flotsam is concentrated, e.g. behind fallen logs. They are large (hindwing 37-45 mm) and robust, entirely black and strikingly bright blue on the upperside of head, thorax, and abdominal segments 1-7. Unlike other libellulids, the sky-blue colour is caused by internal pigment and not by pruinosity. Hindwing bases are broadly black. Females are dark brown with two broad greenish bands on abdominal segments 3-4 and 6, and also often perch over rivers. These markings show that, despite their superficial disparity, Cyanothemis is closely related to Porpax. [Adapted from Dijkstra & Clausnitzer 2014]
Males of genus is unmistakable, sharing its large occipital triangle with rather straight borders (eyes at most touching over distance less than half its length) with nearest relatives Acisoma and Porpax, but differs by (1) great size, Hw 37-45 mm; (2) dorsum of head, thorax and S3-7 entirely bright blue contrasting with ventral black, this blue colour is caused by internal pigment and not pruinosity; (3) Hw with large black patch extending to triangle; (4) 2 cell-rows in radial planate. [Adapted from Dijkstra & Clausnitzer 2014]
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.
- Ris, F. 81915). New dragonflies (Odonata) of the subfamily Libellulinae from Sierra Leone, W. Africa. Annals & Magazine of Natural History, 15, 213-223. [PDF file]
- Dijkstra, K.-D.B, and Clausnitzer, V. (2014). The Dragonflies and Damselflies of Eastern Africa: handbook for all Odonata from Sudan to Zimbabwe. Studies in Afrotropical Zoology, 298, 1-264.
- Schouteden, H. (1934). Annales Musee Congo belge Zoologie 3 Section 2, 3, 1-84. [PDF file]
Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2020-01-19].