A single, very lucky encounter with Aciagrion africanum (Coenagrionidae) on a tiny pond at the lodge where we had just spent three nights; we were unaware of its presence, which was pointed out to us just as we were leaving. Surprisingly enough, this insignificant pond is reached via a very long descent down a staircase.
It seems to favor rain pools, and it is quite possible that this one was formed that way, from the rain over the previous days. However, Pinhey (1972) writes "Prefers swamps or marshy margins of streams".
This is a first record for Ghana.
The genus Aciagrion contains 28 species found in Oceania and Asia, and 12 in Africa. I assume they are rare, as in twenty years of fieldwork I had only observed three of them: A. pallidum in Laos, A. approximans in Thailand, and A. gracile in Australia.
Unfortunately, it was very far from me, and I was only able to take a few poor photos at 300 mm; still decent enough to be certain of the identity of this very rare odonate; prior to our photos, there were only four on iNaturalist for all of Africa, despite a broad distribution.
It is a difficult genus, whose members can be confused with Africallagma and are only distinguished by the position of a crossvein, and some might eventually be moved to another genus.
Only Aciagrion gracile (here, a specimen seen in Australia, with an atypical pointed triangular black mark on S7, though they are all said to be very variable regarding these black markings) was known in Ghana prior to our stay; it is visually very different and does not bear this type of pattern on the abdomen, in particular this incomplete black mark on the seventh segment.
Martin writes that its abdomen measures 28 mm; it is a very small Coenagrionidae, but I cannot deduce its total length because I do not have a profile view. Likely under 35 mm.
Its distribution extends from extreme southern Guinea and Liberia down to Angola and Zambia in the south; to the east and further north, it reaches Uganda.
IUCN Red List.
At the same tiny site, we observed this female; there are no photos of female Aciagrion africanum on the Web, and one must rely on Pinhey's description (1972), which matches very well, particularly regarding the distinct pattern on the last three segments and their dark markings. The small size of the site and the presence of the male in the immediate vicinity reinforce the likelihood that this is indeed the female of this species; besides, there is no alternative!
Étymology of Aciagrion africanum
The genus Aciagrion was erected by Selys (1891); it was formed from a Greek word meaning "pointed object" (acus in Latin means needle), adding to it the already famous agrion (from the Greek agrios – living in the fields, wild). Selys notes "abdomen long, excessivement grêle - abdomen long, excessively slender", an abdomen thus thin as a needle.
Africanum, from the Latin africanus, meaning belonging to Africa. The specimen described by Martin comes from Guinea-Bissau.
Aciagrion africanum female, Ghana, Ankasa Forest Reserve, 19/01/2026
Martin, 1908 – Voyage de feu Leonardo Fea dans l’Afrique occidentale. Odonates – Museo civico di storia naturale di Genova (Italy). (1870). Annali del Museo civico di storia naturale di Genova (Vol. 43, p. 659). Tip. del R. Istituto Sordo-Muti.
Pinhey (1972) - The genus Aciagrion Selys (Odonata). Occasional Papers National Museums Rhodesia B Natural Science, 5, 1-59, p. 17. [Lien Web Archive, peut être difficile à atteindre].