Thinobius yabakeinis Naomi, 1995

Makranczy, György, 2014, The Far Eastern species of Thinobius Kiesenwetter, 1844 (Coleoptera: Staphylinidae, Oxytelinae) lacking female modified genital appendage, Revue suisse de Zoologie 121 (3), pp. 319-347 : 340-342

Thinobius yabakeinis Naomi, 1995 Figs 17, 40-42, 54, 68-70, 82, 85, 87

Thinobius (Platyderothinophilus) yabakeinis Naomi, 1995: 23 . – Herman, 2001: 1758.

TYPE MATERIAL EXAMINED: CMIC, holotype (3); “[ JAPAN: Kyushu,] Chikushi; Yabakei; Fukuoka p[ref.]; 16.iii.1986; S. Nomura lg \ Thinobius ; yabakeinis; Naomi 1995 [reddish-orange label, without the word Holotype] \ CBM - ZI; 33877 \ Holotypus; Thinobius ; yabakeinis Naomi ; ver. Makranczy, 2011 \ Thinobius ; yabakeinis Naomi ; det. Makranczy, 2011”. – Paratypes (14); KUEC 1, KUEC 10, HNHM 13 1♀, MHNG 13; same data as holotype, “[ JAPAN: Shikoku,] Mt. Odami [33°32'N, 132°51'E, 950m]; Ehime-pref.; 11-13.vi.1981; S. Naomi leg. \ Paratype; Thinobius ; yabakeinis; Naomi 1995 \ Paratypus; Thinobius ; yabakeinis Naomi ; ver. Makranczy, 2012 \ Thinobius ; yabakeinis Naomi ; det. Makranczy, 2012”.

REDESCRIPTION: Measurements (n=33) HW = 0.33 (0.33-0.34); TW = 0.32 (0.315-0.32); PW = 0.38 (0.375-0.385); SW = 0.44 (0.43-0.45); AW = 0.46 (0.43-0.48); HL = 0.28 (0.26-0.29); EL = 0.11 (0.105-0.11); TL = 0.08 (0.075-0.08); PL = 0.29 (0.28-0.29); SL = 0.55 (0.52-0.56); SC = 0.47 (0.46-0.48); FB = 1.12 (1.07-1.15); BL = 1.87 (1.76-1.95); (n= 4♀) HW = 0.33 (0.32-0.34); TW = 0.31 (0.295-0.32); PW = 0.37 (0.355-0.38); SW = 0.43 (0.40-0.44); AW = 0.47 (0.45-0.48); HL = 0.27 (0.265- 0.28); EL = 0.11 (0.10-0.11); TL = 0.08 (0.075-0.08); PL = 0.27 (0.26-0.295); SL = 0.51 (0.48-0.54); SC = 0.47 (0.44-0.49); FB = 1.07 (1.00-1.12); BL = 1.77 (1.67-1.87) mm. BODY more or less unicoloured. Head and pronotum reddish dark brown, abdomen blackish dark brown, elytra medium brown except darker area around scutellum, legs medium brown. Mouthparts and antennae reddish dark brown. All main body parts with microsculpture intermixed with very fine and very dense punctation, making body gently lustrous. Forebody with inconspicuous imbricate microsculpture; middle of vertex with larger punctures. Fine and scattered punctures posteriorly on tergites, microsculpture a mixture of imbricate and substrigose. Tergite VII apical edge shinier, as well as tergite VIII (partly unexposed). Pubescence on forebody depressed, very fine, medium short; on abdomen extremely fine and medium short setae plus a row of stronger and longer setae on apices of tergites. Abdominal sides and apex with a few darker, longer and stronger bristles. Strong dark bristle on outer side of supraantennal prominence at anterior border of eye and on posterior edge of vertex adjacent to temples, similar ones right behind anterior pronotal corner and on side at 3/5 length. Direction of setation posterior on anterior part of vertex (a bristle on each side), anterior on sides of head, medial or antero-medial on rest of vertex; anterior on pronotal sides, posterior edge and midline, antero-medial on rest of disc. Posterior edge of vertex as well as middle of anterior pronotal edge with rather large setae. Elytra and abdomen with posteriorly directed setae. Antennae, legs and mouthparts with very short, not conspicuous setation, except for the stiff, darker setae around middle of each tibia and ones near apices of femora. Sides of elytra with three rather inconspicuous stiffer setae on side, middle one slightly shifted posteriorly.

Head (Fig. 17) 1.40x wider than long, temples (Fig. 42) shorter than eyes, gently curved anteriorly, narrowly rounded posteriorly. Middle of vertex with slight impression, supraantennal tubercles moderately developed. Anterior border of neck not marked with groove, only by change of microsculpture. Frontoclypeal suture appearing as fine, often shinier groove and darker line connecting supraantennal tubercles. ANTENNAE moderately elongate (Fig. 41), antennomeres 4 and 6 somewhat shorter than adjacent ones, rest of antennomeres distinctly elongate.

FIGS 62-68

(62-63) Thinobiusshavrini sp. n. 3; tergiteIX (62), sterniteIX (63). (64-66) T. ootsukai Naomi 3; sternite VIII (64), tergite IX (65), sternite IX (66). (67) T. zerchei Gildenkov 3; sternite VIII. (68) T. yabakeinis Naomi 3; sternite VIII. Scale bar = 0.1 mm for 64-65, 68, 0.12 mm for 66-67, 0.15 mmfor 62-63.

Pronotum strongly transverse, 1.50x wider than long, just a little wider than head, anterior margin almost straight, anterior corners noticeable but obtuse-angled, sides strongly arched, and although posterior corners barely marked, posterior margin appears to be much more weakly arched. Pronotal midline slightly elevated, rest of middle of disc gently impressed. Pronotal marginal bead visible on posterior margin. Scutellum large, setose and dull. ELYTRA (Fig. 40) long, one elytron slightly more than twice as long as broad, gently curved in cross-section and parallel-sided (very little dilation posteriorly). Shoulders moderately developed. Along suture only with traces of marginal bead, mostly at broadly rounded sutural corners. LEGS of medium length, tarsal lobes thin but relatively long (not reaching apex of last tarsomere), tibiae slightly fusiform, appear much wider in middle than at ends.

Abdomen very weakly fusiform (Fig. 54), sides more or less straight and parallel; widest in the middle, very slightly less wide than elytra at broadest point. Posterior margin of tergite VII with palisade fringe, strongly widening in middle.

PRIMARY AND SECONDARY SEXUAL FEATURES: Sexes only appearing very slightly different (somewhat wider temples) in regular dorsal view. Posterior corners of tergite VIII (similar in both sexes) gently protruding, posterior edge otherwise straight. Male sternite VIII as in Fig. 68, tergite IX as in Fig. 69, sternite IX as in Fig. 70. Aedeagus as in Fig. 82, female genital appendage as in Fig. 85, spermatheca as in Fig. 87.

REMARKS: A very slight sexual dimorphism is experienced in the size, therefore measurements are made separate for males and females, respectively. One paratype of this species has turned out to be a Hydrosmecta ( Staphylinidae : Aleocharinae).

DISTRIBUTION: The species is known only from the material in the original description, from Shikoku and Kyushu islands of Japan).

BIONOMICS: Unknown.