Miobdelus humilis, Hu, 2020

Hu, Fang-Shuo, 2020, New distributional records of Staphylinina in Taiwan, including a new species of Miobdelus Sharp (Coleoptera: Staphylinidae: Staphylininae: Staphylinini), Zootaxa 4768 (3), pp. 334-360 : 339-340

Miobdelus humilis sp. nov.

( Figs. 8 , 20–26 , 51 )

urn:lsid:zoobank.org:act:7A51734E-3850-4F31-A0C7-EECF94EF0A44

Type material. Holotype in TFRI: TAIWAN: New Taipei City: male, Happen Nature Reserve (ŃƦdńaessȅ), Wulai Dist. , N 24°46’, E121°34’; XII-2001, leg. W. Huang By pitfall trap . Paratypes in FMNH , FSHc, NHMW, NMNS, TARI, TFRI: TAIWAN: Hualien County: 1 male, Danongadafu (± Ȓ ±ở), 23°37’33.8”N, 121°25’06.9”E, 26-XII-2015, leg. T. R . Chen By FIT ( NMNS); 1 female, Danongadafu (± Ȓ ±ở), 23°35’56.4”N, 121°24’04.1”E, 15-XI~ 04-XII-2015, leg. T. R . Chen By FIT ( NMNS). New Taipei City: 3 males, 2 females, same data as holotype ( TFRI); 2 females, same data as holotype except IV-2001 ( TFRI); 2 females, same data as holotype except II-2001 ( TFRI); 1 female, Xinzhuang senior high school (Kƛ Ḃď), Xinzhuang Dist. , 25.0480, 121.4436, 25-XII-2019; leg. T . H. Lin ( FMNH); 1 female, Kuishanhu (ṵȁé), Jinshan Dist., 25.2286, 121.5952, 11-XII-2019, leg. L. C. Huang ( NHMW); 1 male, Shuiniukeng (ử+ḿ), Linkou Dist., 25.1181, 121.3134, 06-II-2020, leg. Y. H. Ho, K. W. Chan, B. L. Gan, Y. C. Huang (FSHc). Taipei City: 1 male, Dagang River (±äữ), Neihu Dist. , 14-I-2019, leg. K. W. Chan ( NHMW); 1 male, Taipei Zoo (Ɖẇ市ḦƗhvƌ), Wenshan Dist. , 24.9966, 121.5807, 28-XII-2019, leg. L. C. Huang (FSHc). Taoyuan City: 1 female, Hutou Mt. (ẋḆƜ), Taoyuan Dist., 15-V-2019, leg. C. K. Liu leg (FSHc). Yilan County: 1 female, Fushan Botanical Park [DƜōhvƌ], 09–16.IV.2006, leg. C.-S. Tung ( TARI); 1 female, Zhenshan Village (ḪƜḢ), Yuanshan To., 04-IV-2019, leg. M. S. Chan ( FMNH) .

Measurements. BL: 18.36 (16.70–20.40); HL: 2.65 (2.42–2.90); HW: 3.28 (3.01–3.65); EyL: 0.92 (0.85–1.00); TL: 1.19 (1.06–1.35); PL: 3.18 (2.90–3.37); ElL: 3.74 (3.42–4.02) (mm).

Description. Large species. Habitus ( Fig. 8 ) with black body; head and neck covered with yellowish-golden tomentose pubescence, denser on tempora; pronotum covered with black tomentose pubescence mixed with very sparse yellowish-golden tomentose pubescence; each elytron with two spots of yellowish-golden tomentose pubescence on humeral area and middle of lateral margin; scutellum black and shiny with black tomentose pubescence; tergites 3–5 covered black tomentose pubescence with sparse spots of yellow-golden tomentose pubescence on anterior parts, three to five spots of yellow-golden tomentose pubescence on posterior margin; tergite 6 covered with large patch of yellowish-golden tomentose pubescence but without two spots in the middle, with black tomentose pubescence on lateral parts of tergite 6; tomentose pubescence on tergite 7 similar to tergites 3–5 but yellow-golden tomentose pubescence denser; tergite 8 with black tomentose pubescence mixed with yellowish-golden tomentose pubescence; lateral margin of each sternite covered with dense yellow-golden tomentose pubescence; legs pale brick red with yellow tomentose pubescence, much denser on fore legs; antennae brick red but 6–11 gradually become paler, first segment covered with yellowish-golden tomentose pubescence.

Head obtusely quadrangular, not obviously dilated posteriad, with rounded posterior angles, wider than long (ratio: 1.24); presence of a large pit-like puncture behind each eye; presence of few relatively small pit-like puncture on tempora; eyes large but slightly convex, tempora slightly longer than length of eyes in dorsal view (ratio: 1.29); dorsal surface of head densely covered with fine punctation. Antennae moderately long, segment 1 (scape) markedly longer than other segments; segment 2 and segment 3 slightly shorter than segment 1, but markedly longer than other segments; segments 4–10 wider than long, proportionally similar to each other; last segment longer than wide, asymmetrically emarginate.

Thorax. Pronotum longer than wide, slightly dilated in anterior part; disc of pronotum with narrow and indistinct impunctate midline in front of posterior margin of pronotum, some individuals without impunctate midline; punctation similar to that on head but slightly denser. Scutellum small, with black setae. First four segments of front tarsus markedly dilated, sub-bilobed, covered dense setae ventrally, without distinct difference between sexes. Elytra markedly longer than wide; slightly longer than pronotum (ratio: 1.18); anterior margin of humeral area not dilated; slightly dilated posteriad. Hind wing well developed.

Abdomen. Tergite 7 (fifth visible) with apical palisade fringe; tergite 2 (anteriad of first fully visible tergite) with fine punctation; general punctation of tergites moderately fine and dense, spread evenly on each tergite.

Male. Sternite 8 ( Fig. 23 ) with shallowly, obtusely medioapical emargination; sternite 9 ( Fig. 24 ) with long and slender basal portion, apical portion with shallow medioapical emargination. Tergite 10 ( Fig. 25 ) subtrapezoidal, apex with short, triangular projection; numerous brownish setae on posterior margin. Aedeagus ( Figs. 20–21 ) with both median lobe and paramere asymmetrical; lateral margin of median lobe gradually dilated from base to apical portion in ventral view; left side of apical portion of median lobe with asymmetrical torsion in ventral view; in ventral view apical portion with large, remarkably deep emargination, emargination without tooth-like protrusion. Paramere spoon-like, very large, with asymmetrical torsion; apical portion of underside of paramere ( Fig. 22 ) without sensory peg setae but bearing numerous long setae on the margins of both sides.

Female. Genital segment tergite 10 ( Fig. 26 ) subtrapezoidal, with strongly projecting but rounded and narrow apex.

Etymology. The specific epithet means “low” in Latin. It refers to the fact this this species is the only representative Miobdelus to occur in lowland habitats such as plains or basins. The specific name is registered under ZooBank LSID urn:lsid:zoobank.org:act:7A51734E-3850-4F31-A0C7-EECF94EF0A44 .

Diagnosis. Miobdelus humilis sp. nov. is similar to M. insignitus Smetana, 2011 and M. insolens Smetana, 2011 from mainland China. It can be distinguished from M. insignitus by the presence of darker yellowish-golden tomentose pubescence on the fourth visible tergite; from M. insolens it can be distinguished by the larger size and well developed pubescence of the entire body. It can also be distinguished from both species by the lack of a toothlike protrusion on the apical margin of the median lobe of aedeagus in ventral view.

In Taiwan, M. humilis sp. nov. can be distinguished from other species of Miobdelus by the presence of yellowish-golden tomentose pubescence on the forebody, larger size, and much larger elytra.

Bionomics. Based on an import of locality name into Google Earth from collection data, the species occurs from 10– 650 m. The type series from Happen Nature Reserve was collected by rat corpse-baited pitfall traps set on a grassland near Happen River (Wenbe Huang, personal communications, May, 2019). The paratype from Shuiniukeng was collected from a grassland near the seashore in the morning, this suggests that this species may be diurnal and can live near the sea. The paratype from Danongadafu was collected by FIT which was set on a grassland mixed with various species of trees. Based on this record, well developed hind wings and the presence of the apical seam of palisade fringe on tergite 7, this species may have good flight ability. In conclusion, the species most likely occurs in grasslands in either plains, basins or low mountainous areas.

Distribution. Miobdelus humilis sp. nov. is only known from Taiwan but widespread on the island. The species at present is known from New Taipei City, Taipei City, Taoyuan City, Yilan County and Hualien County. Due to its occurrence in the lowlands and its presumed strong flight ability, the species is presumably widely distributed in lowland areas of Taiwan.

Remarks. Outside of genus Miobdelus , M. humilis sp. nov. is closely similar to some members of Dinothenarus (Parabemus) (etc. D. ganglbauerianus (Bernhauer) and D. insignis (Müller)) . However, these species do not perfectly fit Dinothenarus (Parabemus) , especially the male genital characters as given in Smetana (2002). Both these species of Dinothenarus (Parabemus) have a slender and long basal portion of male sternite 9, shallow medioapical emargination and markedly large and torsional paramere, inconsistent with other species of the genus. These characters instead are found also in M. insignitus and M. insolens , two species that are similar to M. humilis sp. nov. The presence of pit-like puncture on the head may be one of the most reliable characters to distinguish Miobdelus from other genera ( Smetana & Davies 2000), however, all members of Dinothenarus (Parabemus) also possess one large pit-like puncture behind the eye (Aleš Smetana, personal communication, 2020). The generic position of these species should be resolved by an analysis of molecular data in a future study.

Figures

FIGURES 8–13. 8. Miobdelus humilis sp. nov.: male, paratype. 9. Miobdelus taiwanensis taiwanensis: male. 10. Nelmanwasus ornatus: male. 11–12. Sphaerobulbus miwai comb. nov.: male, lectotype of Staphylinus (Xanthocypus) miwai and attached labels; male. 13. Naddia taiwanensis: female. Scale bar: 3 mm

FIGURES 20–26. Miobdelus humilis sp. nov. 20. Aedeagus in ventral view; 21. Aedeagus in lateral view; 22. Apical portion of underside of paramere with sensory peg setae 23. Sternite 8, male; 24. Sternite 9, male; 25. Tergite 10, male; 26. Tergite 10, female. Scale bar: 0.5 mm

FIGURES 50–53. Live specimens of Staphylinina in Taiwan: 50. Agelosus auricomus (Photo by J.-M. Chen); 51. Miobdelus humilis sp. nov., paratype (Photo by K.-W. Chan); 52. Sphaerobulbus miwai comb. nov.; 53. Thoracostrongylus formosanus.