Odonata from the Tibesti Mountains and the Ounianga Lakes in Chad, with notes on Hemianax ephippiger accumulating in the desert

摘要

Fourteen species of Odonata were collected in Ounianga and Tibesti (Chad, Africa) in March 2014. Among them, only one zygopteran (Ischnura saharensis, with a Saharan distribution), one gomphid (the eremian Paragomphus sinaiticus), and two aeshnids (Anax imperator and Hem ianax ephippiger) were present. The latter species was not only the most common dragonfly, but also the most abundant insect seen in the desert. It is likely that it was in a phase of accumulating individuals, possibly as a prelude to another massive trans-Sahara and even trans-Mediterranean migration, for which the species is well-known. The 10 libellulids recorded were almost all Afrotropical species, but several expand to the Maghreb and even Mediterranean Europe. Only Orthetrum cf. hintzi is a tropical African species that had never been recorded from the desert before.