Ocyolinus principalis ( Bernhauer, 1911 ) Chatzimanolis, 2017

Chatzimanolis, Stylianos, 2017, An Update to the Diagnosis and Key to the Species of Ocyolinus Sharp (Coleoptera: Staphylinidae: Staphylininae: Staphylinini), with the Inclusion of Torobus principalis (Bernhauer), The Coleopterists Bulletin 71 (4), pp. 805-809 : 806

Ocyolinus principalis ( Bernhauer, 1911) , new combination

( Figs. 1–6 )

Trigonopselaphus principalis Bernhauer 1911: 416 . Torobus principalis (Bernhauer) ; Herman 2001b: 29.

Diagnosis. Ocyolinus principalis can be easily recognized from all other species of Ocyolinus based on the shape of the head. In O. principalis , the eyes are approximately one-third the total length of the head, whereas in all other species the eyes are at least half the total length of the head. Additionally, the head of O. principalis is much larger than any other known species and has a single dorsal tooth on the median lobe (two in all other species in the genus). Ocyolinus principalis can be distinguished from other species in Torobus or Gastrisus Sharp based on the shape of the antennae: antennomeres 6–10 longer than wide in Ocyolinus ; quadrate or transverse in these other genera.

Redescription. Body length 18.0–20.0 mm. Coloration: Head, pronotum, and elytra metallic dark purple with blue overtones. Posterior dorsal margin of head without metallic coloration, appearing dark brown to black. Ventral surface and legs brown to reddish brown. Antennomeres 1–3 brown, 4–11 reddish brown. Mesoscutellum dark brown. Abdomen dark brown, except VIII orange. Head: Head subquadrate, width: length ratio = 1.09. Surface of epicranium matte due to micropunctures and small polygon-shaped microsculpture visible at>70X; with few medium-size and small setose punctures scattered on head. Eyes small, length of eyes: length of head ratio = 0.3, distance between eyes as wide as 2.7 times length of eye. Postgena with few small, shallow punctures, punctures not uniformly distributed. Mandibles with long medial tooth; left mandible with strongly convex triangular tooth; right mandible with smaller tooth separated into 2 horizontal planes; distal part of mandible curved. Antennomeres 1–11 longer than wide; antennomere 1 elongate, club-like, about 2.5 times as long as antennomere 2; antennomere 3 1.5 times as long as antennomere 2; antennomere 4 0.66 times as long as antennomere 3; antennomeres 6 slightly shorter than either antennomere 5 or 7; antennomeres 7–10 gradually becoming shorter; antennomere 11 slightly shorter than antennomere 10. Neck dorsally with micropunctures and microsculpture, laterally with few small punctures. Prothorax: Pronotum slightly longer than wide, width: length ratio = 0.88; antero-lateral angles obtusely rounded, curved downwards. Lateral margins of pronotum concave in dorsal aspect, pronotum broadest in apical 1/4 and narrower at basal angles. Surface of pronotum flat; matte due to microsculpture; with multiple scattered small and a few large setose punctures. Pterothorax: Mesoscutellum prominent, with microsculpture and few small punctures. Elytra longer and wider than pronotum, with large uniform punctures (about 3.5 punctures per 0.5 mm), distance between punctures 0.5 times width of puncture. Elytra appearing matte due to strong polygon-shaped microsculpture covering elytra. Legs with protarsus moderately enlarged, with yellow setae; meso- and metatarsi not enlarged. Abdomen: Abdominal terga III–VII with tergal basal carina but without subbasal (arch-like) carina. Terga and sternites III–VII with uniform punctation patterns, sparsely punctate, with shallow punctures and polygon-shaped microsculpture. Lateral tergal sclerites of abdominal segment IX long and straight, covered with long, brown macrosetae. Secondary sexual structures: Male with distal margin of sternum VII slightly broadly emarginate medially; sternum VIII with shallow U-shaped emargination medially; sternum IX with deep U-shaped emargination medially. Female without obvious secondary sexual structures. Aedeagus: Median lobe in dorsal view wide, converging to rounded apex ( Figs. 4–6 ); with a single dorsal tooth midway between parameral articulation and apex; in lateral view becoming narrower from middle to apex. Paramere in dorsal view wide, converging to rounded apex, shorter than median lobe; in lateral view, paramere almost straight, slightly concave apically; with peg setae as in Fig. 6.

Figures

Fig. 1. Habitus of the type of Trigonopselaphus principalis. Total length = 19 mm.

Figs. 2–3. Ocyolinus principalis. 2) Head and pronotum; 3) Details of the antenna.

Figs. 4–6. Ocyolinus principalis, aedeagus. 4) Lateral view; 5) Dorsal view; 6) Paramere, ventral view.