Genus Ischnura Charpentier, 1840
bluetails

Synonyms:

  • scientific: Micronympha Kirby, 1890 [pumilio]

Type species: Agrion elegans Vander Linden, 1823

Introduction

Cosmopolitan genus of around 70 species, favouring exposed stagnant water bodies. Although eight others inhabit northern Africa, Madagascar and Mauritius, only a single species occurs in most of tropical Africa: I. senegalensis could show up anywhere, being tolerant of saline and polluted water (e.g. near hot springs), although it is absent from most forested areas. Ischnura males are small (hindwing 13-18 mm), dark damselflies with a conspicuous blue ‘tail-end’. They are easily recognised by their dissimilar pterostigmas: black or bicoloured in forewing, but plain grey or brownish in hindwing. Immature females can be conspicuously orange. [Adapted from Dijkstra & Clausnitzer 2014]

Diagnosis

Genus similar to Pinheyagrion by (a) Hw under 35 mm, Abd under 40 mm; (b) postocular spots often present; (c) transverse ridge on frons absent and Abd never with orange or red, but often with blue; (d) metapleural suture usually at most with black dot at dorsal end; (e) black markings on S8-9 usually absent or concentrated dorsally; (e) black markings usually more extensive, humeral stripe usually present, if absent body often with blue; (f) apex of S10 without black denticles, but may have lobes; (g) apex of S10 with narrow excision, bordered on each side by small rounded process; (h) cerci seldom branched; (i) paraprocts usually with distinct apical or dorsal spine and often much swollen at base, resulting in prominent inferior bulge (lateral view). However, Ishnura set apart by (1) Pt in Fw darker than in Hw, usually sharply bicoloured, rather than being similarly coloured. [Adapted from Dijkstra & Clausnitzer 2014; this diagnosis not yet verified by author]


Ischnura senegalensis (Rambur, 1842). Male © Jens Kipping


Ischnura evansi Morton, 1919. Male © Jean-Pierre Boudot

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

  • Clausnitzer, V., and Dijkstra, K.-D.B. (2005). The dragonflies (Odonata) of Ethiopia, with notes on the status of endemic taxa and the description of a new species. Entomologische Zeitschrift, 115, 117-130. [PDF file]
  • Ris, F. (1921). The Odonata or Dragonflies of South Africa. Annals South African Museum, XVIII, 245-452. [PDF file]
  • Longfield, C. (1936). Studies on African Odonata, with synonymy and descriptions of new species and subspecies. Transactions Royal Entomological Society London, 85, 467-498. [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]

Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2017-12-11].