Trithemis legrandi Dijkstra, Kipping & Mézière, 2015
Robust Dropwing

Type locality: Campo-Ma’an NP, Bitandé River, Nkoélon, Cameroon

Diagnosis

Male belongs to the basitincta-group by the combination of (a) Fw discoidal field of 3 rows at base; (b) 4-6 cell-doublings in radial planate and thus two rows of cells there; (c) hamule with long sickle-shaped hook; and (d) the genital lobe directed away from the hamule. Nearest to the sympatric T. basitincta and T. bifida by (e) the fairly large size, Hw 31.8-33.5 mm (n = 4); (f) 13½-16½ Ax in Fw; (g) the large and dark patch at Hw base that fills the cubital space to beyond Cux and extends into the anal field, although sometimes also present in the subcostal space proximal to Ax1; (h) the parallel-sided anterior lamina with a broad and deeply-notched apex; and (i) the notably slender and sabre-like hamules. Only separated reliably by (1) the apical peaks of the anterior lamina that in lateral view are not dark and pointedly rounded, but have pale flat-topped swellings, which in caudal or rostal view may appear to close the top of the cleft between them. The swelling is greater and the cleft completely closed in the sympatric T. aconita and T. congolica, while T. tropicana has a fairly flat but neither swollen nor cleft anterior lamina. Also is (2) shorter-bodied, Hw being 79-82 % of full length rather than 73-78 %; and (3) as males darken with age, the pale markings remain visible last ventrally on S4-7, while any visible dorsal markings lie on the lateral carina and are shorter than half the segments’ length. The dorsal markings that are visible last in T. bifida lie closer to the dorsal than lateral carinae and extend over almost the full segment length. The markings are intermediate in T. basitincta, with the rather short final markings lying about halfway the dorsal and lateral carinae. That species, however, can be separated by the presence of short bristles rather than long hairs at the base of the anterior lamina. T. legrandi n. sp. also often has large and distinct lateral yellow spots on the labium, postclypeus and frons even in very dark specimens, e.g. those virtually lacking pale abdominal markings. [Adapted from Dijkstra, Kipping & Mézière 2015]

Habitat description

Streams, but possibly also rivers, shaded by forest. Often with a gravelly and/or sandy bottom, and probably overhanging branches, submerged roots and/or coarse detritus. From 0 to 600 m above sea level.

Distribution

confirmed: Cameroon; Gabon

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

  • 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/ [2018-12-10].