Styxia Hull, 1943

Mengual, Ximo, Miranda, Gil Felipe G. & Thompson, F. Christian, 2018, Unraveling Ocyptamus and the Baccha legacy (Diptera: Syrphidae): redefinition of groups and new species descriptions, Zootaxa 4461 (1), pp. 1-44 : 15

Genus Styxia Hull, 1943 stat. rev.

Figs 52–54 .

Styxia Hull, 1943b: 46 , as a subgenus of Baccha . Type species: Styxia eblis Hull, 1943b (original designation).

Ocyptamus (Styxia) . Mengual et al. (2012).

Ocyptamus eblis species group. Miranda et al. (2016).

Diagnosis. Wide face (half the width of the head). Eyes usually pilose. Frons swollen and antennal pits separated. Ventral lobe of calypter black. Wing dark with hyaline, bare quadrangular areas. Abdomen spatulate. Abdominal terga with half of basolateral margins pale.

Comments. Although the most distinct and unique feature of Styxia are the pilose eyes, GFGM is aware of undescribed species that are very similar to S. eblis but have completely bare eyes.

The original taxonomic status of this name is confusing. In the original key and description (Hull 19 43b: 45– 46) the name is referred to “n. subgen.” but the type species is described as “ Styxia eblis ” ( Hull 1943b: 65) . Following the International Code of Zoological Nomenclature (1999), Article 23.6, “ the first nomenclatural act taken in respect of a name or a nominal taxon ... constitutes the only valid such act ”. Thus, Styxia was originally proposed as a subgenus of Baccha and its relative priority is equal to the other subgenera proposed by Hull in that article ( Hull 1943b).

Species list (3): S. ariela ( Hull, 1944c) , S. cerberus ( Hull, 1943b) , S. eblis ( Hull, 1943b) .

Figures

FIGURES 46–54. 46: Pseudoscaeva diversifasciata (Knab), male, habitus, dorsal view, by Alice Abela. 47: Ocyptamus megafemur Thompson sp. nov. [male holotype, USNMENT 00249222], habitus, lateral view. Scale = 4 mm. 48: Ocyptamus megafemur Thompson sp. nov. [male holotype, USNMENT 00249222], head, frontal view. Scale = 1 mm. 49: Ocyptamus megafemur Thompson sp. nov. [male holotype, USNMENT 00249222], head, dorsal view. Note: Arrow indicates the mesonotal collar or fringe. 50: Ocyptamus megafemur Thompson sp. nov. [male holotype, USNMENT 00249222], habitus, dorsal view. Scale = 1 mm. 51: Pelecinobaccha transatlantica (Schiner) [female, INPA-DIP0000253], antenna. 52: Styxia eblis (Hull) [male, DEBU01088838], wing, lateral view. 53: Styxia eblis [paratype male, CNC No 19270], habitus, dorsal view. 54: Styxia eblis [male, DEBU01088838], head, frontal view.