Octavius clarkei Janák, 2024

Janák, Jiří, 2024, On Octavius from Maloti-Drakensberg and Golden Gate National Parks, South Africa (Coleoptera: Staphylinidae: Euaesthetinae), Zootaxa 5443 (4), pp. 495-522 : 497-499

Octavius clarkei Janák , sp. nov.

Figs. 11–15 , 120, 129

Type locality. South Africa, KwaZulu-Natal Province, Maloti-Drakensberg Park, Injisuthi .

Type material (188 specimens). Holotype ♂: “ South Africa, KwaZulu-Natal, Maloti-Drakensberg Park, 1700m; 29°7.5ʼS, 29°25.4ʼE, Injisuthi ; ind. forest patch, 5.i.2019, J. Janák lgt.”, “Berlese extraction, leaf & log litter, sifting”, “ HOLOTYPUS Octavius clarkei sp. nov. J. Janák det. 2021”. Paratypes: 105 ♂, 79 ♀ (TMSA, JJRC, 2 ♂ in 96% alcohol) ; 2 ♂: “ South Africa, KwaZulu-Natal, Maloti-Drakensberg Park, 1500m; 29°7.2ʼS, 29°26.2ʼE, Injisuthi; Yellowwood forest , 5.i.2017, J. Janák lgt.”, “Berlese extraction, leaf & log litter, sifting” ( JJRC, 1 ♂ in 96% alcohol) . 1 ♂, 1 ♀: “S. AFRICA: KwaZulu-Natal: Drakensberg, Giants Castle G. R. (Injisuti), off Grindstone cave Tr., 1660m, 29°07.7ʼS, 29°25.3ʼE / 6.ii.2004, afromontane forest in head ravine: FMHD #2004-043, berl., leaf & log litter, Clarke, Solodovnikov 1087, FIELD MUS. NAT. HIST” ( FMNH, ♂ stored in glycerine). All paratypes with additional labels: “ PARATYPUS Octavius clarkei sp. nov. J. Janák det. 2021”.

Description. Body length 1.4–2.2 mm (M 1.7 mm, HT 1.6 mm), forebody length 0.8–0.9 mm (M 0.8 mm, HT 0.8 mm). Macrophthalmous, apterous, rusty, head dull, pronotum slightly shiny, elytra and abdomen moderately shiny ( Fig. 11 ).

Head ( Fig. 11 ) slightly narrower than pronotum (R 0.88–0.92, M 0.91, HT 0.92), eyes relatively large, temples about half longer than eyes (R 1.42–1.79, M 1.60, HT 1.52), sides of head very slightly rounded, hardly widened behind eyes to maximal width, then slightly narrowed towards posterior angles, posterior angles moderately angular, median impression on disc absent, lateral parts of head moderately granulose, median part densely and moderately finely reticulate.

Pronotum ( Fig. 11 ) slightly broader than long (R 1.05–1.12, M 1.10, HT 1.05), strongly narrowed posteriorly; anterior angles rounded, dorsal impressions moderately deep, transverse impression shallow, lateral impressions deep, delimited by sharp longitudinal ridge laterally; lateral parts beside lateral impressions moderately densely granulose, remainder of surface moderately densely and finely reticulate.

Elytra ( Fig. 11 ) subquadrate, much broader than long (R 1.39–1.56, M 1.48, HT 1.49), with sharp longitudinal ridge laterally; between latter and suture irregularly granulate, moderately reticulate and sparsely shortly setose.

Abdomen subparallel, slightly widened to segment IV or V, with one paratergite and microsculpture consisting of triangular or rhomboid fields, leaving here and there smooth places, finely setose.

Male. Sternite VIII hardly emarginated ( Fig. 14 ), sternite IX as in Fig. 15 . Aedeagus moderately asymmetrical, long and narrow (0.38–0.41 mm, M 0.39 mm, HT 0.39 mm), apical part pointed, internal structure elongate, strongly sclerotised; parameres moderately shorter than median lobe, with about 5–8 subapicolateral setae ( Figs. 12-13 ).

Differential diagnosis. Octavius clarkei Janák , sp. nov. belongs among species with large eyes, with temples at most twice as long as eyes, with the head not or at most slightly widened posteriorly, with large body and the disc of the head without a median impression. In the most recent of South African Octavius ( Janák 2014) is to be arranged at the couplet 160 (157), but it differs from the species arranged there (e. g. O. microps ( Kistner, 1967) and O. ruthae Janák, 2007 ) by elongate, narrow, only slightly asymmetrical aedeagus with parameres covered with apicolateral setae in apical third. The shape of aedeagus of the new species resembles that of O. pugionifer Puthz, 2006 and O. acutipennis Janák, 2014 , but it differs from the first species by broader apical part of median lobe, from the second by the median lobe markedly curved in the middle and from both species by missing apical setae on parameres (only subapical setae are present) and mainly by external characters (much larger eyes, larger body size, shallower median impression and coarsely reticulate pronotum) and much shallower emargination of male sternite VIII.

Derivatio nominis. This species is dedicated to D.J. Clarke (Memphis, USA), specialist in Staphylinidae and Curculionidae .

Distribution. Octavius clarkei Janák , sp. nov. is currently recorded only from the Injisuthi region in Drakensberg Mts., KwaZulu-Natal Province, South Africa ( Fig. 120 ).

Bionomics. All specimens were collected in siftings of forest litter in two separate patches of an indigenous forests at the elevation of about 1500–1700 m a.s.l. ( Fig. 129 , the abundance of specimens per kg of sifted material: Injisuthi: 10.5, Yellowwood: 0.1).

Figures

FIGURES 1–15. 1–10. Octavius adriani Janák: 1–3, 6, 9–10, Gxaligengwa Forest; 4–5, 7–8, Fort Nottingham, paratypes. 11–15. Octavius clarkei Janák, sp. nov., 11, 13–15, holotype, 12, paratype. 1, 11, habitus; 2–5, 12–13, aedeagus ventral; 6–8, apex of aedeagus ventral; 9, 14, male sternite VIII; 10, 15, male sternite IX. Scale 1 mm: 1, 11; scales 0.05 mm: 6–8; 0.1 mm: remaining figures. LI: lateral impression, TI: transverse impression, DI: dorsal impressions, LRP: lateral ridge on pronotum, LIR: lateral internal ridge, LOR: lateral external ridge.

FIGURES 113–121. Octavius undulatus Janák, sp. nov.; 113–116, 118–119, holotype; 117, paratype. 113, habitus; 114, fore parts; 115, fore parts lateral; 116–117, aedeagus ventral; 118, male sternite VIII; 119, male sternite IX. Scale 0.5 mm: 113; scales 0.1 mm: 114–115; 116–117; 118–119; o: ommatidium. 120: Distribution of Octavius – subgroup A. 121: Distribution of Octavius – subgroup B.

FIGURES 128–133. 128: Cathedral Peak, Masongwane river banks. 129: Injisuthi. 130: Monkʼs Cowl, Hlatikulu forest. 131: Lotheni. 132: Kamberg, locality 1. 133: Kamberg locality 2.