Platydracus hainanensis, Huang & Chen & Tang, 2024

Huang, Jia-Yi, Chen, Jia-Wei & Tang, Liang, 2024, The genus Platydracus Thomson in Hainan, South China (Coleoptera, Staphylinidae, Staphylininae), ZooKeys 1212, pp. 129-141 : 129-141

Platydracus hainanensis sp. nov.

Figs 1 , 13–16

Material examined.

Holotype. China – Hainan Prov. • ♂; glued on a card with two labels as follows: “ China: Hainan, Lingshui County, Diaoluoshan N. R. , forest nr., residence; 18 ° 44 ' N, 109 ° 52 ' E; rainforest, decaying log; alt. 1100 m; 4 Feb. 2015; Peng, Yin, Tu, Song, Shen, Zhou, Yan & Wang leg. ” “ Holotype / Platydracus hainanensis / Huang, Chen & Tang ” [red handwritten label]; SHNU . Paratypes. China – Hainan Prov. • 2 ♂♂; Lingshui County, Diaoluoshan N. R. , forest nr., residence; 18 ° 44 ' N, 109 ° 52 ' E; rainforest, decaying log; alt. 1100 m; 4 Feb. 2015; Peng, Yin, Tu, Song, Shen, Zhou, Yan & Wang leg.; SHNU .

Diagnosis.

The new species belongs to the Platydracus brachycerus group, and it is similar to P. smetanai Zhou, Zhao & Tang, 2024 by sharing dense punctation of the head and short protarsomere 5. Yet, it can be distinguished from the latter by the distinctly larger body size (11.6–13.7 mm in P. smetanai ) and a different aedeagus.

Description.

Measurements of male: BL: 15.3–17.8 mm, FL: 8.00– 8.11 mm. HL: 1.67–1.85 mm, HW: 2.28–2.41 mm, EYL: 0.68 mm, TL: 0.80–0.86 mm, PL: 2.47–2.65 mm, PW: 2.41–2.59 mm, EL: 3.15–3.27 mm, EW: 3.21–3.33 mm. HW / HL: 1.30–1.37, TL / EYL: 1.18–1.27, PL / PW: 1.00–1.03, EL / EW: 0.98–1.02.

Body black, elytra with distinct copper tint, abdominal segments partially brownish, maxillary palpi, labial palpi and tarsomeres brownish with apical margin of each segment lighter, antennae dark brown with antennomeres gradually lighter apicad.

Head 1.30–1.37 times as wide as long; eyes moderately large, tempora 1.18–1.27 times as long as eye; surface with punctation dense and coarse; anterior portion of frons impunctate; pubescence most brownish except that behind anterior margin and eyes silver; antennomeres 1–3 distinctly longer than wide, antennomere 4 as long as wide, antennomeres 5–10 distinctly transverse, gradually incrassate, segments 4 to 11 covered with dense pubescence; maxillary palpi stout with last segment narrowly subtruncate apically; mandibles robust, inner edge of left mandible with two teeth on upper plane and mid tooth on lower plane, inner edge of right mandible with blunt anterior tooth and sharp posterior tooth on upper plane and mid tooth on lower plane.

Pronotum 1.00–1.03 times as long as wide; disc with narrow impunctate midline, punctation distinctly sparser than that of head, pubescence brownish; scutellum with dense rugulose punctation and dark pubescence.

Elytra 0.98–1.02 times as long as wide, punctation dense and coarse, pubescence behind humeri, along suture and posterior elytral margin silver, pubescence of the rest parts brownish.

Anterior legs with tibiae and tarsomeres distinctly stouter than those of the related species, tarsomere 5 rather short.

Abdominal tergites III – VI with basal transverse depression, with punctures coarser at base, gradually become finer apicad; pubescence brownish except for that of lateral portion of tergite III which is silver.

Male. Abdominal sternite VII with large median depression bearing numerous long dark brown setae; sternite VIII with posterior margin shallowly emarginate in the middle; aedeagus (Figs 15 , 16 ) almost symmetrical, median lobe elongated with lateral sides subparallel forming broad round tip in ventral view; paramere elongated triangular, slightly curved ventrad in lateral view, without apical setae.

Etymology.

The specific epithet refers to the type locality of the new species.

Distribution.

China (Hainan).

Figures

Figures 1–4. Punctation of head and setae on the head and pronotum 1 P. hainanensis 2 P. juang 3 P. marmorellus with two types of setae 4 P. aureolus with one type of setae.

Figures 13–20. Habitus and aedeagus of Platydracus 13–16 P. hainanensis 17 – 20 P. aureolus 13, 17 dorsal habitus 14, 18 ventral habitus 15, 19 aedeagus in ventral view 16, 20 aedeagus in lateral view. Scale bars: 1.0 mm (13, 14), 2.0 mm (17, 18), 0.5 mm (15, 16), 0.2 mm (19, 20).