Ubristes rex sp. n., a new microdontine hoverfly from northern Brazil (Diptera: Syrphidae: Microdontinae) Author Reemer, Menno text Zootaxa 2017 2017-12-05 4362 2 journal volume 31234 10.11646/zootaxa.4362.2.7 08f63677-9afc-43ef-8d7b-acf3fc60e2e8 1175-5326 1084084 F25C9A5C-8FB3-44D4-A4E0-CB50AAF96682 Key to the species of Ubristes The following key can be used to distinguish the species of Ubristes . For figures of the other species besides U. rex sp. n. see Reemer (2013a). 1 Abdomen partly or entirely yellow....................................................................... 2 - Abdomen black.............................................................................. U. flavitibia 2 Abdomen without fasciae of golden pile. Face ventrally weakly produced: distance between ventral eye margin and oral mar- gin maximally 1/5 of height of eye. Hind leg mixed yellow and black pilose...................................... 3 - Abdomen with fasciae of golden pile along posterior margin of tergite 3 and medially across tergite 4 (Figs 1, 8). Face strongly produced ventrally: distance between ventral eye margin and oral margin approximately 1/3 of height of eye (Fig. 4). Hind leg entirely yellow pilose........................................................................ U. rex sp. n. 3 Abdomen entirely yellow....................................................................... U. ictericus - Abdomen brownish with yellow maculae......................................................... U. jaguarinus