Onychogomphus uncatus (Charpentier, 1840)
Large Pincertail

Type locality: S Europe, no locality data available.

Diagnosis

General appearance is close to O. forcipatus, but slightly larger and the yellow abdominal markings are more extensive on average, although this varies greatly in O. forcipatus. Best distinguished as follows: (1) The vertex is all-black; there is no extra yellow bar between the yellow of frons and occiput. However, this is sometimes unclear also in O. forcipatus. (2) The ‘collar’, the transverse yellow area on the anterior ridge of the thorax, is severed by the black area along the middorsal keel. (3) The yellow antehumeral stripe dorsally connects with the broader yellow stripe before it. Thus the black stripe separating them is not connected with the black along the middorsal keel. (4) The black on the side of the thorax is more extensive; the stripes are not broken, but often partly confluent. Male anal triangle is normally four-celled, but is three-celled in most O. forcipatus. The male appendages are like those of O. forcipatus, including subbasal teeth of the lower, but lack the subterminal knobs of that appendage in O. forcipatus. Uppers curved toward each other (view from above), without the thumb-like dorsal lobe in the bend; the tips meet, but do not overlap. Female lacks tubercles behind the eyes of O. forcipatus. Its vulvar scale is reduced to a pair of finger-like processes pointing toward each other. In O. forcipatus, the vulvar scale appears as two closely apposed, roundly triangular lobes. [Adapted from Dijkstra & Lewington 2006]

Habitat description

Mostly streams, but also headwaters and sometimes rivers, shaded by or in open areas in (gallery) forest. Often faster sections with bare banks, rocks and a gravelly and/or sandy bottom. From 0 to 2000 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

• Charpentier, T. de (1840). Libellulinae Europaeae Descriptae et Depictae. Leopold Voss, Lipsiae, 1-180.

Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2024-10-31].