Azuragrion vansomereni, belonging to the Coenagrionidae family, is part of a genus that includes 6 species. It is one of the smallest, with a hindwing measuring 11 to 14 mm and a total length of approximately 21 to 23 mm. It is commonly known in English as the Tiny Bluet.
When viewed in profile (as seen more clearly on the female below), there is a near-total absence of black lines on the metapleural and interpleural sutures—a feature that would typically lead to its classification under Enallagma. Pinhey (1956) did precisely that, before May (2002) clarified the taxonomy of African Enallagma and Africallagma (along with other related genera) and transferred the species into this genus.
In Ghana, there is only one Azuragrion species, which makes identification straightforward, as it is visually very similar to A. nigridorsum. The distinction lies in the anal appendages: in Azuragrion vansomereni, the cerci are distinctly longer than the paraprocts, whereas they are equal in length in A. nigridorsum.
The distribution of Azuragrion vansomereni covers a broad Sahelian belt extending from West Africa (Senegal) to Central and East Africa. The species previously reached central Saudi Arabia, where it is now extinct following habitat destruction.
IUCN Red List.
They are found on still or very slow-moving waters rich in emergent vegetation. We observed a few individuals in low numbers on a shallow pond. They proved difficult to approach, as they settle on grass or emergent twigs level with the water—or even directly on the water surface—and are sensitive to the slightest movement of their perch or the observer.
They shared this habitat with a few Diplacodes luminans and Lestes dissimulans; we would not encounter these three species anywhere else.
We saw only a single female, and very briefly. Apart from Ischnura senegalensis and Lestes dissimulans, these were the only damselflies present on this pond. The identification of this female is therefore certain, given the absence of black markings on the thoracic sutures and the blue line running across the postocular area.
Etymology of Azuragrion vansomereni
Azuragrion is composed of the Latin azureus, meaning blue, and agrion, from the Greek agrios, meaning living in the fields or wild, a term frequently used to denote membership in the Coenagrionidae family. Indeed, all Azuragrion species are blue (and black).
Vansomereni honors Victor Gurner Logan van Someren, a British entomologist who collected specimens during the colonial period in Kenya and Uganda. He passed his collections to Pinhey, including the specimen from Uganda that Pinhey would later describe as Enallagma vansomereni.
May, 2002 . Phylogeny and taxonomy of the African genus Azuragrion with description of a new genus, Africallagma (Odonata: Coenagrionidae). Odonatologica, 31(3), pages 285–301.
Pinhey, 1956 . Some dragonflies of East and Central Africa and a rarity from Mauritius - Occasional Papers of the Coryndon Memorial Museum - Volume 4, pages 17–41 [accès payant].