Zygonyx dionyx Dijkstra & Mézière, 2015
Eastern Double-hooked Cascader
Type locality: Batéké Plateau, Eaux Claires, Gabon
Male belongs to the flavicosta-complex by (a) the modest size, Hw 36.0-38.5 mm (n = 3); (b) the moderately dense venation, with 11½-12½ Ax in Fw; (c) the largely black hind legs; and (d) the pale subapical band on the dorsum of S7 that stands out against largely dark S5-6. Most similar to the probable sister-species Z. geminuncus with (e) the apex of the anterior lamina being constricted and incised to form a pair of triangular forward-curved hooks; and (f) the hamule with a low lobe and narrow base making its hook appear longer. However, (1) the anterior lamina is not swollen and raised laterally of the apical hooks to eclipse them in lateral view; (2) the apical hooks of the the anterior lamina are relatively large; (3) the hamule has a less tapering base; and (4) the epiproct is longer with a narrower tip. [Adapted from Dijkstra, Kipping & Mézière 2015]
Streams in open areas in forest. Often with a sandy bottom. Recorded at around 400 m above sea level.
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.
- Dijkstra, K.-D.B., Mézière, N., and Kipping, J. (2015). Sixty new dragonfly and damselfly species from Africa (Odonata). Odonatologica, 44, 447-678.
Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2021-01-17].