Genus Diastatomma Burmeister, 1839
Type species: Aeshna tricolor Palisot de Beauvois, 1807
Endemic to Africa, the six species are large (hindwing 33-42 mm) with less distinctly clubbed abdomen than the related Gomphidia and Ictinogomphus, behaving more furtively and perching low in sunspots on shady forest streams. D. multilineatum has been found near blackwater forest swamps, D. soror on open grassy streams. Diastatomma males possess a unique structure on the underside of abdominal segment 1, anterior to and curving over the secondary genitalia, called Hagen’s turbercle. It is typically bilobed and differs in shape and size between species, but can be reduced to mere knobs in any species. [Adapted from Dijkstra & Clausnitzer 2014]
Male of genus is similar to Gomphidia by (a) dorsal border of metepisternum, close to Hw base, with robust spine; (b) triangles of 3-4 cells; (c) anal triangle of 5 cells, although rarely 4 to 7; (d) S8 without foliations. However, differs by (1) cells below Pt usually about 0.7x as wide, rather than about the same width, as underlying cells; (2) S1 ventrally usually with bilobed process, known as Hagen’s tubercle; (3) cerci with inner branch. [Adapted from Dijkstra & Clausnitzer 2014]
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.
- Dijkstra, K.-D.B. (in prep). A review of Afrotropical lindeniine Gomphidae (Odonata). Zoologische Mededelingen.
- Pinhey, E.C.G. (1961). Dragonflies (Odonata) of Central Africa. Occasional Papers Rhodes-Livingstone Museum, 14, 1-97. [PDF file]
- Fraser, F.C. (1949). Gomphidae from the Belgian Congo (order Odonata). Revue Zoologie Botanique Africaines, 42, 101-138. [PDF file]
- Schouteden, H. (1934). Annales Musee Congo belge Zoologie 3 Section 2, 3, 1-84. [PDF file]
Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2020-02-16].