Afroeudesis Franz, 1963

Jałoszyński, Paweł, 2019, Taxonomy of the ' Afroeudesis group' of glandulariine ant-like stone beetles (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 4612 (2), pp. 205-220 : 218-219

Afroeudesis Franz

Afroeudesis Franz, 1963: 16 (as subgenus of Pseudoeudesis ). Type species: Pseudoeudesis basilewskyi Franz, 1963 (des. orig.). Recognized as a member of Glandulariini and elevated to genus rank by Jałoszyński (2015a), who also gave an emended diagnosis and divided the genus into subgenera ( Jałoszyński 2015a, 2016b).

Revised diagnosis. Afroeudesis differs from all genera of Glandulariini in a unique autapomorphy: frons and vertex with a subtriangular elevated 'platform' covered with scale-like microsculpture and with longitudinal median groove, the platform is anteriorly demarcated by a deep frontal impression ( Fig. 12 ). Additionally, the following combination of synapomorphies characterizes Afroeudesis : body (Figs 5–8) moderately stout, distinctly constricted between head and prothorax and between prothorax and elytra; head ( Fig. 12 ) about as long as broad or slightly elongate, with the most convex site of eye closer to occipital constriction than to mandibular bases; posteromedian impression on vertex present, setae on frons and vertex forming a largely symmetrical pattern; lateral margins of anterior portion of clypeus divergent anterad; antennal insertions distant from mandibular bases; pronotum broadest in front of middle or subequal in width between posterior and anterior third, lacking lateral and sublateral carinae, with transverse antebasal groove or impression connecting a pair of inner lateral pits and with a pair of outer lateral pits; bristles on head and pronotum absent; mesoventral intercoxal process carinate, narrow; anterior metaventral process present; metaventral intermetacoxal process with a pair of long spines; and aedeagus with free, slender parameres.

Remarks. Species of Afroeudesis are similar in the general appearance, but show a significant variability in some structures. They can have the mandibles planar or with a dorsal preapical tooth, the hypostomal ridges complete or incomplete, the hypomeral ridges present or absent; the anterior metaventral process broad or narrow, the lateral metaventral carinae present or absent, the mesoscutellum exposed or hidden under the posterior pronotal margin; one, two or even none basal elytral foveae, and an even or odd number of the pronotal antebasal pits. Differences in these characters are used in subgeneric diagnoses and were compiled in a table by Jałoszyński (2016b).

Interestingly, differences between subgenera of Afroeudesis seem to be bigger than those between Meridaphes , Pseudoraphes and Stenichnoconnus , maintained here as separate genera. It would be possible to divide Afroeudesis into four genera, especially that the split between the sub-Himalayan, African and South American components of this clade may be very ancient. However, the subgenera of Afroeudesis share the unique elongate, subtriangular and unusually microsculptured 'platform' on the frons and vertex, a structure that has clearly evolved only once within the Glandulariini. The subgeneric classification of Afroeudesis species is here maintained.

Composition and distribution. Afroeudesis comprises five species in four subgenera: Afroeudesis s. str. with one species ( Tanzania); subgen. Eburneus Jałoszyński, 2016b with one species ( Ivory Coast); subgen. Eudesoides Jałoszyński, 2016b with one species ( Brazil); and subgen. Nanoscydmus Jałoszyński, 2009 with two species ( China: Yunnan, and Nepal) ( Fig. 41 ). A specimen from the northern, sub-Himalayan region of India (Darjeeling) representing an undetermined species was also seen.

Figures

FIGURE 41. Distribution of 'Afroeudesis group'.

FIGURES 9–12. Examples of the symmetrical setal pattern on frons and vertex in representatives of the 'Afroeudesis lineage' (insertions of setae, including those broken off, marked by circles).Meridaphes venezolanus (9); Stenichnoconnus huijbregtsensis (10); Pseudoraphes minor (11); Afroeudesis (Nanoscydmus) baoshana (12).