Genus Aethiothemis Martin, 1908
flashers

Synonyms:

  • scientific: Lokia Ris, 1919 [incongruens]; Cirrothemis Fisher, 1939 [bella]; Sleuthemis Fraser, 1951 [diplacoides = bella]; Nubiothemis Fraser, 1954 [bequaerti]

Type species: Aethiothemis solitaria Ris in Martin, 1908

Introduction

Twelve species are endemic to tropical Africa, one to Madagascar. The genus originally only includes small (hindwing 19- 25 mm) species with distal forewing Ax normally complete, but the medium-sized (hindwing 24-35 mm) ones with typically incomplete distal Ax (formerly in Lokia) are best included as well: venational differences are unstable, several species have intermediate features, and all have similar secondary genitalia, including the large penis that is often exposed anterior to the distinctive ‘crab shear’ hamules. Genetic research also shows that the two genera should be merged. Most species are infrequently encountered, although A. solitaria can be locally abundant at open grassy marshes. It is beautifully orange-brown when teneral, with a bold black line down the broad abdomen. Males become entirely grey-blue pruinose. The western African A. palustris is almost identical, but with marked wings. It and the small slender species A. basilewskyi, A. bella and A. bequaerti are poorly known, but probably all also reproduce in open grassy marshes, such as dambos and wet areas planted with rice, often close to forest. The habitat of A. ellioti is similar, but typically boggy. Long known only from the holotype, A. gamblesi was recently rediscovered in northern Zambia. It is the sister species A. mediofasciata, males becoming pruinose rather than orange with maturity, and probably also breeds in wet grassy depressions. The darker “Lokia” species also occur locally at swamps, but typically in forest, breeding in shady pools and streamlets with much organic material. Males make furtive rapid flights over such waters but seldom perch there, resting instead in clearings nearby. A. coryndoni is best known from a forest near Entebbe in Uganda bordering a large papyrus swamp, and A. erythromelas from blackwater swamp forest in central DR Congo to Gabon. A. incongruens occurs at rainforest streams, thus being tied to running water more than the other species, while the exact habitat of A. circe is still unknown. Mature males of all species have abdomen darkened and often pruinose dorsally at maturity, thus recalling Orthetrum, but the underside is bright yellow to red. It is important to compare the hamule to confirm identification. [Adapted from Dijkstra & Clausnitzer 2014]

Diagnosis

Male of genus is similar to Oxythemis by (a) size, Hw 23-35 mm; (b) frons and vertex of different colour (e.g. brown or red), more uniform (e.g. less contrasting yellowish dorsally and brown ventrally), or dorsum darkest; (c) occipital triangle smaller with rather concave borders, eyes touching over distance of at least half its length; (d) Pt never black-and-white and wings at most with dark tips or bases or with overall yellowish infusion; (e) Fw supratriangles without cross-veins; Fw triangle of 2-3 cells, subtriangle of 3-6 cells; (f) Fw discoidal field of 3-4 rows at base; (g) all wings with 0 cell-doublings in radial planate [0-2]. However, differs by (1) 9½-15½ Ax in Fw [9½-16]; (2) arculus at Ax2 or distal to it, rarely close to Ax1; (3) S5-8 with maturity ventrally often red or orange, contrasting with largely darkened or pruinose dorsum. [Adapted from Dijkstra & Clausnitzer 2014; this diagnosis not yet verified by author]


Aethiothemis bequaerti Ris, 1919. Male © Jens Kipping

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.


References

  • Dijkstra, K.-D.B. (in prep.). Taxonomy of the genus Aethiothemis, including Lokia (Odonata: Libellulidae). Zoologische Mededelingen. [PDF file]
  • Pinhey, E.C.G. (1961). Dragonflies (Odonata) of Central Africa. Occasional Papers Rhodes-Livingstone Museum, 14, 1-97. [PDF file]
  • Pinhey, E.C.G. (1964). Some new Odonata from West Africa. Bulletin Institut francais Afrique, 26, 1144-1153. [PDF file]
  • Schouteden, H. (1934). Annales Musee Congo belge Zoologie 3 Section 2, 3, 1-84. [PDF file]
  • Fraser, F.C. (1953). New genera and species of Libellulines from the Belgian Congo. Revue Zoologie Botanique Africaines, 48, 242-256. [PDF file]
  • Lieftinck, M.A. (1969). Odonates Anisoptères - Odonata Anisoptera. Explor. hydrob. Lac Bangweolo and Luapula, 14, 1-64. [PDF file]

Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2017-03-24].