Acisoma variegatum Kirby 1898
Creators: name: Mens, Lotte P.
name: Schütte, Kai
name: Stokvis, Frank R.
name: Dijkstra, Klaas-Douwe B.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Odonata
Libellulidae
Acisoma
Acisoma variegatum

description: Acisoma variegatum Kirby, 1898 —Slender Pintail
(Figs. 4 A, 5A–D, 6A, 7A, 8A, 10A)
Material. Tanzania: 8 males, Mpanda, 11-x-1970, J. Kieland (RMNH); 5 males, Sibweza, 20–23- v-1966/ 26 - ix1966/ 24-vi-1968 / 21-xi-1968, J. Kieland (RMNH); 1 male, Korogwe, 07-ii-1964, G.M.L. Bergers (RMNH).—D.R. Congo: 1 male, Katanga, Mutwale, 06-iv-1961, J.J. Symoens (RMNH); 1 male, Katanga, Mulandi, 11-ii-1963, J.J. Symoens (RMNH); 1 male, Katanga, Kiubo, 05-ix-2011, K.-.D. B. Dijkstra (RMNH).— Kenya: 2 males, Amboseli, viii-1980, collector unknown (RMNH).— Uganda: 1 male, Entebbe, botanical garden, 30-iii-1999, V. Clausnitzer (RMNH).— South Africa: 2 males, KwaZulu-Natal, Ndumo Game Reserve, Mgagabhuleni, 31-ii-2014, K.-.D.B. Dijkstra (RMNH); 1 male, KwaZulu-Natal, 7 km ESE of Manguzi, Kosi Bay area, inflow of Nhlange and Amanzimnyama lakes, 02-iv-2014, K.-.D.B. Dijkstra (RMNH); 1 male, KwaZulu-Natal, 15 km NE of Manguzi, Kosi Bay estuary, 03-iv-2014, K.-.D.B. Dijkstra (RMNH).
Male diagnosis. Typical of the group lumped formerly under A. panorpoides by the (a) extensively white labrum, labium, thorax and underside of S3–7; (b) low number of Fw Ax, most often 7½ but sometimes 8½; (c) 1 cell in Fw triangle, but 2 cells in 24% of examined wings; (d) long Fw Pt, about 13–16% as long as Hw; (e) abdomen that narrows abruptly on S 5 in lateral view, with S6–10 slender (Fig. 7 A); (f) fragmented and frayed white markings on S2–5 and large white lateral spots on S7 (Fig. 7 A); and (g) broad and triangular lobe of hamule (Fig. 8 A). Unique within the genus by the (1) most slender abdomen, with the tergite of S5 below the lateral carina almost invisible in lateral view and S6 always more than 2.5x as long as high, and the ventral borders of S5 and S6 confluent (Fig. 7 A); (2) almost always partly white ventral carina of S4, extending to an always white corner with the apical carina; and (3) always largely white and thus never wholly black lateral carina of S5. Overlaps with A. inflatum in eastern and southern Africa with which it shares the (4) sublateral black marking concentrated on the basal side of S4 (Fig. 7 A); and (5) rather wide base of the hook of the hamule (Fig. 8 A); but differs by the unique characters mentioned as well as its generally (6) larger size, with Hw 21–25 mm.
Range and ecology. More localised than A. inflatum, ranging from Ethiopia to Katanga and northern South Africa (Fig. 9 B). Although the distribution seems to follow the more elevated Afromontane part of the continent, the species appears to favour more open and eutrophic and often low-lying and expansive marsh habitat where it overlaps with A. inflatum, such as flood plains.
description: Published as part of Mens, Lotte P., Schütte, Kai, Stokvis, Frank R. & Dijkstra, Klaas-Douwe B., 2016, Six, not two, species of Acisoma pintail dragonfly (Odonata: Libellulidae), pp. 153-172 in Zootaxa 4109 (2) on page 159, DOI: 10.11646/zootaxa.4109.2.3, http://zenodo.org/record/271419