Octavius pinnaculus Janák, 2025

Janák, Jiří, 2025, Overview of Octavius of Mpumalanga and Limpopo Provinces, South Africa (Coleoptera: Staphylinidae: Euaesthetinae) with descriptions of eight new species, Zootaxa 5737 (1), pp. 105-126 : 116-117

publication ID	https://doi.org/10.11646/zootaxa.5737.1.5
publication LSID	lsid:zoobank.org:pub:03EFBC3F-FDE3-4F66-B1A6-9D4DD42B40C0
DOI	https://doi.org/10.5281/zenodo.18021057
persistent identifier	https://treatment.plazi.org/id/8D1B879F-FFAF-AF1C-CD94-FD68FB1AF8AB
treatment provided by	Plazi
scientific name	Octavius pinnaculus Janák
status	sp. nov.

Treatment

Octavius pinnaculus Janák sp. nov.

Figs. 46–50 View FIGURES 42–50 , 91–92 View FIGURES 89–94 , 95 View FIGURE 95

Type locality. South Africa, Mpumalanga, Pinnacle Rock , 24°54.71', S 30°51.24'E .

Type material ( 8 specimens). Holotype ♂: “ RSA, Mpumalanga 22.xi.2023 / 24°54.71'S 30°51.24'E, Pinnacle / Rock , tree ferns sifting / ca 1430m, J. Janák lgt.”, “Berlese extraction / leaf & log litter / sifting”, “ HOLOTYPUS Octavius pinnaculus sp. nov. J. Janák det. 2025” ( TMSA) GoogleMaps . Paratypes: 4 ♂, 3 ♀: same data as the holotype ( JJRC, PPRI). All paratypes with additional labels: “ PARATYPUS Octavius pinnaculus sp. nov. J. Janák det. 2025” GoogleMaps .

Description. Body length 1.9–2.2 mm (M 2.2 mm, HT 1.9 mm), forebody length 0.9–1.0 mm (M 1 mm, HT 1 mm). Microphthalmous, apterous, dark rusty, head dull, pronotum, elytra and abdomen shiny ( Fig. 46 View FIGURES 42–50 ).

Head ( Fig. 46 View FIGURES 42–50 ) slightly narrower than pronotum (R 0.91–0.94, M 0.92, HT 0.91), eyes relatively large, temples about two times as long as eyes (R 2.08–2.38, M 2.22, HT 2.21), sides of head rounded, moderately widened behind eyes to maximal width, then moderately narrowed towards posterior angles, posterior angles moderately rounded, median impression on disc very short, visible only as a shallow elongate impression between eyes, lateral parts of head moderately granulose, median part densely and deeply, but finely reticulate, frons with small shiny fields.

Pronotum ( Fig. 46 View FIGURES 42–50 ) slightly broader than long (R 1.16–1.25, M 1,21, HT 1.19), strongly narrowed posteriorly; anterior angles angular, dorsal impressions moderately deep, transverse impression very deep, lateral impressions deep, delimited by sharp longitudinal ridge laterally; lateral parts beside lateral impressions moderately densely granulose, surface between dorsal impressions sparsely but coarsely granulate and reticulate, thus more shiny than remaining surface, anterior part before transverse impression finely and densely reticulate.

Elytra ( Fig. 46 View FIGURES 42–50 ) subquadrate, much broader than long (R 1.59–1.71, M 1.66, HT 1.71), with two sharp longitudinal ridges laterally; between latter and suture sparsely and coarsely granulate, thus shiny.

Abdomen subparallel, slightly widened to segment V, with one paratergite and very fine microsculpture consisting of triangular or rhomboid field, finely setose.

Male. Sternite VIII deeply triangularly emarginated in posterior quarter ( Fig. 49 View FIGURES 42–50 ), sternite IX as in Fig. 50 View FIGURES 42–50 . Aedeagus asymmetrical, moderately long ( 0.57–0.60 mm, M 0.58 mm, HT 0.57 mm) and wide, with narrow hook-shaped projection, with two long and narrow strongly sclerotised internal structures; parameres shorter than median lobe, with 10–15 setae in widened apical fifth ( Figs. 47–48 View FIGURES 42–50 ).

Differential diagnosis. Octavius pinnaculus Janák , sp. nov. belongs among species with moderately large eyes, with temples at about two times as long as eyes, with the head moderately dilated posteriorly, with moderate body and the disc of the head with very short shallow median impression limited only between eyes. In the most recent key of South African Octavius ( Janák 2014) is to be arranged at the couplet 125 (126) near O. spiralifer Puthz, 2006 , but it differs from this species by being shinier, more coarsely and sparsely granulate pronotum and by different shape of the aedeagus.

Derivatio nominis. This name of the species refers to the type locality.

Distribution. Octavius pinnaculus Janák , sp. nov. is currently recorded only from the Pinnacle Rock, Mpumalanga Province, South Africa ( Fig. 95 View FIGURE 95 ).

Bionomics. All examined specimens were collected in siftings of litter under tree ferns at the elevation of about 1400 m a.s.l. and with the abundance 2.3 specimens per kg of sifted material ( Figs. 91–92 View FIGURES 89–94 ).