Aceratobasis macilenta (Lesser Pendant) – a new species of damselfly for REGUA!

Handsome Aceratobasis macilenta male, Vecchi, 5 February 2020 (© Paul Hopkins)
And the no less wonderful female Aceratobasis macilenta, Vecchi, 5 February 2020 (© Paul Hopkins)

On 26 January Tom Kompier, accompanied by fellow Odonatologists Magnus Billqvist, Paul Hopkins and Agnes Ludwig, visited the large pond at Vecchi, where he caught and photographed a fresh female of a damselfly species unknown to him. Back at the lodge the riddle was solved using the excellent Damselfly Genera of the New World by Garrison et al. (2010).

This mystery damsel was a member of the genus Aceratobasis. This genus is endemic to the Atlantic Forest, with four known species largely restricted to the lowlands. Although recorded from Rio de Janeiro state, it had so far not been confirmed from REGUA.

Tom quickly wrote to Natalia von Ellenrieder, who provided a paper she wrote with Rosser Garrison in 2008 with additional information on the genus. The specimen turned out to be Aceratobasis macilenta, the smaller of two very similar species. As these damsels, unlike many of their fellow Coenagrionids, hang of leaves and twigs, “Pendant” seems an apt name.

A second visit a few days later failed to turn up more specimens, but luckily a third visit on 5 February by Magnus, Paul and Susan Loose produced a mature male and a mature female, of which Paul was able to take some great photos. It looks like a small population has gained a foothold in the area!

This is species 208 for the reserve odonata list.