Genus Ceriagrion Selys, 1876
citrils

Synonyms:

• scientific: Brachybasis Selys, 1869 [rhomboidale = glabrum?]: not valid?
• vernacular: waxtails (Asia)

Type species: Agrion cerinorubellum Brauer, 1865

Introduction

Genus occurs from Africa, through Eurasia, to Australia with about 50 species, nineteen are Afrotropical, one (C. tenellum) Western Palearctic and most others Oriental, where known as waxtails. Most African species are small to medium-sized (hindwing 14-24 mm) and instantly recognised by their wholly orange to red abdomen, an identification confirmed by the transverse ridge between the antennae. Black markings are mostly absent, although the localised C. annulatum, C. kaamborae, C. platystigma and C. rubellocerinum blacken partly with age, but abdominal segments 2 and 8-10 remain (largely) red, while C. obfuscans darkens completely. All species favour marshy, mostly stagnant, habitats. Morphologically and ecologically, C. annulatum, C. platystigma, C. rubellocerinum and C. varians form a distinctive group occurring at shaded forest swamps from northern Zambia and western Kenya to western Africa. The recently discovered C. obfuscans appears to be closely related and is often the most numerous damselfly in flooded forest in the Congo Basin. The remaining species are generally in more open habitats, although C. corallinum, C. ignitum, C. whellani and especially C. citrinum and C. tricrenaticeps are often in or near forest, while C. suave is in drier and more seasonal habitats. C. whellani and especially C. bakeri and C. junceum are fond of flooded grass, C. katamborae of extensive marshes, C. sakejii of boggy areas with little open water, and C. ignitum and C. kordofanicum of floating vegetation like Salvinia and Pistia respectively. C. glabrum is the orange damselfly found at almost any standing water in Africa. Its head and thorax are (brownish) orange in open areas to bright yellow in forest. Colours used for identification apply to mature living males, e.g. green or blue may turn yellowish, brown or grey when preserved. Differentiation of discoloured specimens is sometimes difficult, and is aided by examining the penis. The largely (brownish) orange species like C. suave may conceal additional species, separated (often with difficulty) mainly by the shape of penis and appendages. For example, C. banditum and C. junceum were just discovered, but occur widespread alongside C. sakejii and C. suave, while the true status and distribution of C. mourae remains unclear. [Adapted from Dijkstra & Clausnitzer 2014]

Diagnosis

Male of genus is similar to Teinobasis by (a) Hw under 35 mm, Abd under 40 mm; (b) transverse ridge on frons present; (c) postocular spots absent; (d) transverse ridge present on frons anterior to antennae or Abd extensively orange or red and without blue, or both; (e) thorax without interpleural band; (f) black markings generally scarce, humeral and metapleural sutures at most with dark spots in fossae; (g) cerci rarely longer than paraprocts and never forcipate. However, differs by (1) being more widespread; (2) thorax without middorsal band; (3) body of normal build, rather than being exceptionally slender; (4) distal border of quadrilateral aligned with 1st underlying cross-vein, but 2nd shifted distinctly proximal, creating kink in anal vein; (5) anal vein originates at or proximal to Cux; (6) cux about halfway Ax1-2, rather than being closer to Ax2 than to Ax1; (7) cerci without lower branch. [Adapted from Dijkstra & Clausnitzer 2014; this diagnosis not yet verified by author]

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

• Pinhey, E. (1963). Notes on both sexes of some tropical species of Ceriagrion Sélys (Odonata). Annals & Magazine of Natural History, 13, 17-28. [PDF file]
• Dijkstra, K.-D.B. (2005). A review of continental Afrotropical Ceriagrion (Odonata: Coenagrionidae). Journal of Afrotropical Zoology, 2, 3-14. [PDF file]
• Dijkstra, K.-D.B. (2007). Erratum in ‘A review of continental Afrotropical Ceriagrion (Odonata: Coenagrionidae)’. Journal of Afrotropical Zoology, 3, 162-163. [PDF file]
• Pinhey, E.C.G. (1964). Dragonflies (Odonata) of the Angola-Congo borders of Rhodesia. Publicacoes culturais Companhia Diamantes Angola, 63, 95-130. [PDF file]
• Ris, F. (1921). The Odonata or Dragonflies of South Africa. Annals South African Museum, XVIII, 245-452. [PDF file]
• Pinhey, E.C.G. (1961). Dragonflies (Odonata) of Central Africa. Occasional Papers Rhodes-Livingstone Museum, 14, 1-97. [PDF file]
• Barnard, K.H. (1937). Notes on dragon-flies (Odonata) of the S. W. Cape with descriptions of the nymphs and of new species. Annals South African Museum, 32, 169-260. [PDF file]
• Pinhey, E.C.G. (1967). Odonata Zygoptera. Exploration Hydrobiologique Bassin Lac Bangweolo Luapula, 14, 1-43. [PDF file]
• Schouteden, H. (1934). Annales Musee Congo belge Zoologie 3 Section 2, 3, 1-84. [PDF file]
• Schmidt, E. (1951). Libellen aus Portugiesisch Guinea, mit Bemerkungen über andere aethiopische Odonaten. Arquivos Museu Bocage, 20, 125-200. [PDF file]

Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2024-11-15].