Orthetrum umbratum Dijkstra & Mézière, 2015
Shadow Skimmer

Type locality: Moukoumbi, Gabon

Diagnosis

Male recalls the sympatric O. saegeri by (a) moderate size, Hw 27.5-31.0 mm (n = 7); (b) the absence of cell-doublings in the radial planate and thus a single row of cells there; (c) all subcostal Ax dark; (d) medium-sized dark brown Pt that are about 11 % of Hw length, 3.0-3.4 mm; (e) Hw base faintly yellow, but never with a dark brown patch; and (f) abdomen slender, although shorter than Hw. When not pruinose also similar by (g) the dorsa of S4-7 with pairs of pale subapical spots that lie closer to the dorsal than lateral carinae, while S8-10 are all dark. However, (1) the hook of the hamule tapers and curves gradually toward a sharp tip that is turned back- and outward, appearing like a claw or talon beside a rather narrow and distinctly higher lobe, with a wide space between the hook and lobe, and thus the overall shape is somewhat intermediate between O. hintzi and O. machadoi; and (2) the appendages are always wholly black and never (partly) pale in young specimens, although sympatric O. saegeri can be similarly dark. [Adapted from Dijkstra, Kipping & Mézière 2015]

Habitat description

Streams and standing waters shaded by forest. Usually with coarse detritus and often with a soft (like muddy) bottom and dead trunks or branches, probably especially pools in stream beds with often blackwater, emergent vegetation and/or overhanging branches. From 400 to 800 m above sea level.

Distribution

confirmed: 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.


Barcode specimen(s):


Male; Democratic Republic of Congo, Province Orientale, Lower Lomami © Dijkstra, K.-D.B.


Male; Democratic Republic of Congo, Katanga, Upemba National Park © Dijkstra, K.-D.B.


Male; Gabon, Haut-Ogoué, route Moanda-Lastourville env. 4km après Moukoumbi © Mézière, Nicolas


Male; Gabon, Haut-Ogoué, route Moanda-Lastourville env. 4km après Moukoumbi © Mézière, Nicolas


Adult, male; Gabon, Haut-Ogoué, Parc de la Lékédi, Module 3 © Mézière, Nicolas ; Julien, Renoult

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/ [2018-09-24].