Ochthephilus omalinus ( Erichson, 1840 )

Makranczy, György, 2014, Revision of the genus Ochthephilus Mulsant & Rey, 1856 (Coleoptera: Staphylinidae, Oxytelinae), Revue suisse de Zoologie 121 (4), pp. 457-694 : 577-580

Ochthephilus omalinus ( Erichson, 1840) Figs 34, 257, 267-271, 283-284, 541, 580

Trogophloeus omalinus Erichson, 1840: 802 . – Fairmaire & Laboulbène, 1856: 614.

Ancyrophorus omalinus (Erichson) . – Kraatz, 1857: 889. – Ganglbauer, 1895: 669. – Jarrige, 1949: 60. – Scheerpeltz, 1950: 60. – Palm, 1961: 11. – Smetana, 1967: 384, 388.

Ochthephilus omalinus (Erichson) . – Herman, 1970: 384. – Pope, 1977: 24. – Lohse & Lucht, 1989: 130. – Gildenkov, 2000a: 1187. – Gildenkov, 2000b: 849. – Makranczy, 2001: 180. – Lott, 2008: 18.

Ancyrophorus parvulus Eppelsheim, 1878: 124 .

TYPE MATERIAL EXAMINED: Trogophloeus omalinus – LECTOTYPE (♀, here designated): “6734 \ Tr.; omalinus; Er.; Saxon. Märk. ... \ Hist.-Coll. ( Coleoptera ); Nr. 6734 (1. ex); Trogophloeus omalinus Er. ; Saxonia, Märkel; Zool. Mus. Berlin; \ Lectotypus; Trogophloeus; omalinus Erichson ; [on the back] des. Makranczy, 1999 \ Ochthephilus ; omalinus Erichson ; det. Makranczy, 1999” ( ZMHB). Ancyrophorus parvulus – HOLOTYPE (3): “[ Georgia,] Kaukas.[us], [auch] Zalka [gennant], 5000’ [Chram *+41.58/+44.01*], leg. Leder” (coll. Eppelsheim, NHMW).

OTHER MATERIAL: see Appendix.

REDESCRIPTION: Forebody as in Fig. 541. Measurements (n=10): HW = 0.54 (0.52-0.56); TW = 0.48 (0.46-0.51); PW = 0.59 (0.54-0.63); SW = 0.73 (0.67-0.77); AW = 0.80 (0.72-0.88); HL = 0.40 (0.38-0.42); EL = 0.19 (0.18-0.21); TL = 0.06 (0.05- 0.07); PL = 0.46 (0.44-0.49); SL = 0.96 (0.89-1.02); SC = 0.88 (0.81-0.94); FB = 1.86 (1.74-1.97); BL = 3.23 (3.09-3.38) mm. Head, pronotum and abdomen blackish dark brown. Elytra reddish dark to medium brown, scutellar area to shoulders darker, blackish; occasional specimens with lighter elytra, even with lighter spot behind middle of suture. Antennae and mouthparts dark brown with occasional reddish tint, legs reddish medium to dark brown. Body with greasy lustre mostly due to elytral setation plus forebody punctation and microsculpture. Pubescence rather fine and moderately dense, shorter and stronger (regularly spaced) on elytra, abdominal tergites with finer and longer setae, especially adjacent to laterosternites. Head anteriad eyes and near inner posterior margin of eye with stronger and darker bristles, as well as pronotal margin and middle of tibiae. Elytral apex with a few slightly longer setae near sutural corners. Last tarsomere with a few setae only.

Forebody. Antenna as in Fig. 580, antennomere 6 shorter and less wide than neighbours (articles 5 and 7). Clypeus sparsely punctate (colliculate microsculptured), trapezoid, corners rounded, anterior edge gently arched; separated by an impressed transversal line (frontoclypeal suture). Supraantennal prominences well developed, feebly separated from clypeus/vertex by impressions. Vertex with two impressions in middle with setigerous pores. Temples bulging, evenly curved, little shorter than half of eye length. Neck separated by an impressed transversal groove, microsculpture much stronger than on head, with transverse cells, no setation. Pronotum with a narrow marginal bead, visible to anterior pronotal corners. Posterior pronotal angles wellformed, just slightly obtuse-angled, sides in posterior 1/2 very gently concave/- bisinuate. 'Anchor' fully formed, longitudinal midline as a slightly elevated, impunctate, weakly microsculptured line, parallel to this line two gentle, semi-longitudinal elongate elevations in anterior half of disc. In corners of anchor feeble, oblique impressions directed outwards, in middle at sides of midline two smaller impressions. Elytra slightly broadening posteriorly, sutural corners narrowly rounded; apical sides slightly oblique and in inner halves gently convex. Elytral surface rather even with two shallow, very elongate impressions behind scutellum. Head with fine coriaceous/colliculate microsculpture, fading on elevated parts, stronger in impressions, on pronotum microsculpture slightly stronger and more even. Punctation on head sparse, mostly confined to posterior part and sides, on pronotum more evenly spaced, average interspaces much larger than puncture diameters; elytral punctation more even and regularly spaced, average interspaces (with indistinct coriaceous microsculpture) about as puncture diameters, punctures discrete.

Abdomen. Compared to forebody, abdomen with much more sparse, finer, less distinct punctation, microsculpture on tergal apices fine coriaceous with moderately transverse cells. Tergite VII posterior margin with palisade fringe unmodified in middle (nearly uniform breadth). Tergite VIII (Fig. 257) basal edge evenly arched, with small concavity in middle of basal sclerotized band; apical edge with sinuate (protruding) corners, and broad, moderately deep emargination in between, slight incision in middle. Sternite VIII with rounded apical corners, apex in males shallowly concave laterally, gently sinuate in middle; in females slightly more sinuate (convex) in middle. Tergite X strongly modified, in males as in Fig. 283, in females as in Fig. 284. Aedeagus as in Fig. 267, inner sclerites as in Figs 268-269. Female ringstructures as in Figs 270-271.

COMPARATIVE NOTES: The unique formation of the apex of tergite X distinguishes this taxon from all the similar species except O. szeli , to which it is very closely related. Based on the very limited and old material the latter taxon seems distinct; the aedeagus and its inner sclerite are remarkably different as also the formation of the apical opening processes (details in the key). Separation from O. andalusiacus and O. venustulus (none of which has deeply incised apex of tergite X in both sexes) is FIGS 333-347

(333-337) Ochthephilusschuelkei sp. n.; aedeagus (333), innersclerites (334-335), femaleringstructures (336-337). (338-342) O. forticornis (Hochhuth) ; aedeagus (338), innersclerites (339-340), femaleringstructures (341-342). (343-347) O. strandi (Scheerpeltz) ; aedeagus (343), innersclerites (344-345), femaleringstructures (346-347). Scalebar = 0.05 mmfor 336-337, 341-342, 346-347, 0.1 mmfor 333-335, 338-340, 343-345.

explained under the respective species; some confusion with the similarly sized O. angustior is possible, but the antenna of the latter has article 6 similar to the neighbours, its temple more broadly rounded and longer, plus the acute (narrowly rounded) apex of tergite X provides good separation for females.

NOTE: Two syntypes of Trogophloeus omalinus were studied, these were originally attached to the same pin (No. 6734). Specimen No. 1 is from 'Saxonia'. It is a female and a characteristic O. omalinus in the current sense. Specimen No. 2 is from 'Anglia', a male O. angustior . The former female (from 'Saxonia') is chosen as lectotype, in order to conserve the current usage of the name.

DISTRIBUTION: From North Africa ( Morocco) through almost the whole of

Europe (including the British Isles) to Turkey and the Caucasus.

BIONOMICS: One of the two most common species in Europe – the other is O. praepositus that lives in more mountainous areas, typically in mountain streams. It is mostly found at lower elevations, larger, slower rivers, more muddy spots. Collected in a very wide range of situations, but most frequently (and in the highest numbers) found in vegetable debris embedded in finer wet sand on bank, often covered by a thin layer of clay. Flood debris is also where this species can be encountered in enormous numbers: Lothar Zerche (pers. comm.) counted 3313 specimens of O. omalinus in flood debris after a thunderstorm at Wechselburg. Frequent among dead grasses on banks, and various (still wet) vegetable debris, like tree-branches, decomposed wood, between stones. Unusual for this species, but found also in soaked willow moss (Fontinalis sp.) at smaller river in forest. Also collected by treading mud and by carnet. Occurs at seashores also.