The genus Platydracus Thomson in Hainan, South China (Coleoptera, Staphylinidae, Staphylininae) Author Huang, Jia-Yi https://orcid.org/0009-0005-4612-5313 College of Life Sciences, Shanghai Normal University, 100 Guilin Road, 1 st Educational Building 323 Room, Shanghai, 200234, China Author Chen, Jia-Wei https://orcid.org/0009-0001-4757-9406 Diaoluoshan Branch, Hainan Tropical Rainforest National Park Administration, Lingshui County, Hainan, 572400, China Author Tang, Liang 0000-0002-6731-4544 College of Life Sciences, Shanghai Normal University, 100 Guilin Road, 1 st Educational Building 323 Room, Shanghai, 200234, China text ZooKeys 2024 2024-09-16 1212 129 141 journal article 10.3897/zookeys.1212.128295 DF37117E-FC2E-4CE1-8790-6984780771CA Platydracus zhouchenglini sp. nov. Figs 21–24 Material examined. Holotype . China – Hainan Prov. • ♂ ; glued on a card with two labels as follows: “ China : Hainan , Lingshui County , Diaoluoshan N. R . ; 18 ° 42 ' 2.66 ″ N , 109 ° 53 ' 19.32 ″ E ; alt. 700 m ; 9–16 Nov. 2022 ; rotten meal trap ; Cai & Zhou leg. ” “ Holotype / Platydracus zhouchenglini / Huang, Chen & Tang ” [red handwritten label]; SHNU . Paratypes . China – Hainan Prov. • 2 ♂♂ 1 ♀ ; Lingshui County , Diaoluoshan N. R . ; 18 ° 42 ' 2.66 " N , 109 ° 53 ' 19.32 " E ; alt. 950–1050 m ; Aug. 2023 ; FIT ; Zhao leg.; SHNU • 2 ♂♂ ; Lingshui County , Diaoluoshan N. R . ; 18 ° 42 ' 2.66 " N , 109 ° 53 ' 19.32 " E ; alt. 700 m ; 9–16 Nov. 2022 ; rotten meat trap ; Cai & Zhou leg.; SHNU • 1 ♀ ; Lingshui County , Diaoluoshan N. R . , Houshan ; 18 ° 43 ' 46.81 " N , 109 ° 51 ' 38.52 " E ; alt. 900–1250 m ; 13–14 Nov. 2022 ; Cai & Zhou leg.; SHNU • 1 ♀ ; Lingshui County , Diaoluoshan N. R . , Houshan ; 18 ° 43 ' 46.81 " N , 109 ° 51 ' 38.52 " E ; alt. 900–1250 m ; 11–12 Nov. 2022 ; Cai & Zhou leg.; SHNU • 3 ♂♂ 7 ♀♀ ; Ledong County , Jianfengling , Mingfenggu ; 18 ° 44 ' N , 108 ° 50 ' E ; alt. 950 m ; 30 Apr. 2012 ; Peng & Dai leg.; SHNU • 1 ♂ ; Wuzhishan Mt. , Guanshandian ; 18 ° 53 ' N , 109 ° 41 ' E ; alt. 650 m ; 20 Apr. 2012 ; Yin Ziwei leg.; SHNU • 1 ♂ ; Lingshui County , Diaoluoshan Mt. , Winding Road ; 18 ° 42 ' N , 109 ° 52 ' E ; alt. 600–1000 m ; 26 Apr. 2012 ; Peng & Dai leg.; SHNU • 1 ♂ ; Wuzhishan Mt. , Guanshandian ; 18 ° 53 ' N , 109 ° 41 ' E ; alt. 700 m ; 21 Apr. 2012 ; Peng & Dai leg.; SHNU • 1 ♀ ; Ledong County , Jianfengling N. R . , Mingfengfu ; 18 ° 44 ' 30 " N , 108 ° 50 ' 29 " E ; rainforest, decaying log; alt. 995 m ; 28 Jan. 2015 ; Peng , Yin , Tu , Song , Shen , Zhou & Wang leg.; SHNU • 1 ♀ ; Changjiang County , Bawangling N. R . ; 11 Apr. 2010 ; alt. 1000 m ; YIN Z. W. leg.; SHNU • 5 ♂♂ 6 ♀♀ ; Lingshui County , Diaoluoshan N. R . ; 18 ° 42 ' 2.66 " N , 109 ° 53 ' 19.32 " E , alt. 700 m ; 9–16 Nov. 2022 ; FIT , Cai & Zhou leg; SHNU • 65 ♂♂ 36 ♀♀ ; Lingshui County , Diaoluoshan N. R . ; 18 ° 42 ' 2.66 " N , 109 ° 53 ' 19.32 " E ; alt. 950–1050 m ; Aug. 2023 ; FIT ; Zhao leg; SHNU , NHMD . Diagnosis. The new species can be easily recognized from other Chinese species by abdominal tergites III – VII with median golden tomentose patches that are continuous along the midline (Fig. 21 ). Habitus and aedeagus of Platydracus 21–24 P. zhouchenglini 25 – 28 P. subirideus 21, 25 dorsal habitus 22, 26 ventral habitus 23, 27 aedeagus in ventral view 24, 28 aedeagus in lateral view. Scale bars: 2.0 mm ( 21, 22, 25, 26 ), 0.2 mm ( 23, 24, 27, 28 ). Description. Measurements of male: BL : 9.6–16.8 mm , FL : 6.67–9.22 mm . HL : 1.42–1.85 mm , HW : 1.91–2.53 mm , EYL : 0.74–0.93 mm , TL : 0.37–0.74 mm , PL : 2.41–3.27 mm , PW : 2.34–3.02 mm , EL : 2.84–3.70 mm , EW : 2.84–3.76 mm . HW / HL : 1.24–1.39, TL / EYL : 0.40–0.80, PL / PW : 1.03–1.08, EL / EW : 0.94–1.02. Measurements of female: BL : 11.7–16.7 mm , FL : 6.78–9.00 mm. HL : 1.48–1.79 mm , HW : 1.91–2.41 mm , EYL : 0.93 mm , TL : 0.37–0.62 mm , PL : 2.41–3.15 mm , PW : 2.28–2.96 mm , EL : 2.78–3.52 mm , EW : 2.90–3.64 mm . HW / HL : 1.29–1.40, TL / EYL : 0.40–0.67, PL / PW : 0.95–1.06, EL / EW : 0.94–0.97. Body dark brown, pronotum reddish-brown along the margins, elytra reddish-brown with dark marks, maxillary palpi, labial palpi and mandibles reddish-brown, legs reddish-yellow, except for the trochanters and base of femora blackish, tibial spurs dark brown, tarsomeres more or less dark. Head 1.24–1.40 times as wide as long, eyes large, tempora 0.40–0.80 times as long as eye; surface with punctation dense and umbilicate; pubescence mostly brownish; antennomeres 1–3 distinctly longer than wide, antennomere 4 slightly shorter than wide, antennomeres 5–10 distinctly transverse, gradually incrassate, segments 4 to 11 covered with dense pubescence; maxillary palpi slender; mandibles relatively slender, inner edge of left mandible with two acute teeth and two teeth on lower plane, inner edge of right mandible with round tooth and acute tooth on upper plane and acute tooth on lower plane. Pronotum 1.03–1.08 times as long as wide; punctation and pubescence similar to that of head; disc with narrow impunctate midline in posterior one-fifth; scutellum with dense rugulose punctation and black pubescence. Elytra 0.94–1.02 times as long as wide, punctation fine and dense, pubescence comprised of two types of setae, long setae mostly brownish, short setae mostly whitish. Abdomen with tergites densely punctate; tergites III – VII each with median golden tomentose patch and a pair of large dark tomentose spots, the lateral portions covered with long brown setae and short white setae, tergite VIII covered with golden pubescence which is distinctly sparse in apical third, tergite VII with apical palisade fringe. Male. Abdominal sternite VIII with posterior margin emarginate in the middle; aedeagus (Figs 23 , 24 ) asymmetrical, twisted to right side in ventral view; median lobe with broad and round tip; paramere broad, with apical setae, subapical portion with cavity to accommodate apical tooth of the median lobe. Etymology. This species is named in honor of Mr Cheng-Lin Zhou who collected many Platydracus specimens. Distribution. China ( Hainan ).