Platystethus cornutus ( Gravenhorst, 1802 )

Lü, Liang & Zhou, Hong-Zhang, 2015, Review of the Genus Platystethus Mannerheim (Coleoptera: Staphylinidae: Oxytelinae) in China, Zootaxa 3915 (2), pp. 151-205 : 162-166

3. Platystethus cornutus ( Gravenhorst, 1802)

( Figs. 5–9)

Gravenhorst, 1802: 109 ( Oxytelus ; Type locality: Not cited, presumably Brunsvigae ( Herman, 2001 a: 1476)); Mannerheim, 1830: 46 ( Platystethus ; Russia); Ganglbauer, 1895: 631 ( Platystethus ; Palaearctic region); Bernhauer & Schubert, 1911: 123 ( Platystethus ); Scheerpeltz, 1933: 1107 ( Platystethus ); Aleksandrov, 1934: 150 ( Platysethus; China); Tottenham, 1939: 225 ( type species of Craetopycrus ); Herman, 1970: 402 ( Platystethus ); Zheng, 1998: 255 ( Platystethus ; China); Herman, 2001 a: 1476 ( Platystethus ); Herman, 2002: 100 ( Oxytelus ; senior homonym with Oxytelus cornutus Bernhauer, 1936 ); ICZN, 2003: 238 ( Oxytelus ; senior homonym); Smetana, 2004: 518 ( Platystethus , subgenus Craetopycrus ); Yan, Li & Zheng, 2012: 342 ( Platystethus ; China).

Synonymy.

Platystethus scybalarius Runde, 1835: 19 ( Type locality: Halae); Erichson, 1839: 586 (synonym of cornutus ).

Platystethus maxillosus Peyron, 1858: 432 ( Type locality: Not cited, presumably Tarsous ( Herman, 2001 a: 1478)); Fauvel, 1872: 181 [= 1873: 23] (synonym of cornutus ).

Platystethus operosus Sharp, 1874: 91 ( Type locality: Japan); Fauvel, 1904: 46 (synonym of cornutus ); Bernhauer & Schubert, 1911: 124 (valid species); Bernhauer, 1922: 223 ( Formosa); Herman, 1970: 402 (valid species); Zheng, 1998: 255 (valid species; China); Herman, 2001 a: 1485 (valid species); Smetana, 2004: 519 (subgenus Craetopycrus ; valid species); Yan, Li & Zheng, 2012: 342 (valid species; China).

Platystethus cornutus race pallidipennis Bernhauer, 1906: 124 (preoccupied by Staphylinus pallidipennis Panzer, 1795 ; Type locality: transkaspisches Gebiet); Bernhauer & Schubert, 1911: 123 (variety of cornutus ); Scheerpeltz, 1955: 83 (aberration of cornutus ); Herman, 2001 a: 1478 (synonym of cornutus ); Smetana, 2004: 518 (subgenus Craetopycrus ; synonym of cornutus ; homonym).

Platystethus cornutus ab. nigripennis Gridelli, 1934: 72 (cited from Valle Indo: Skardu; Cachemir: Srinagar); Smetana, 1968: 236 (form of cornutus ; Mongolia); Herman, 2001 a: 1478 (Nomen nudum).

Platystethus cornutus ssp. flavipennis Zheng, 2000: 112 (preoccupied by Platystethus flavipennis Luze 1904 ; Type locality: Xinjiang, Turpan [=Tulufan, 42.95 ºN 89.19 ºE], 30.VII. 1995); Smetana, 2004: 518 (subgenus Craetopycrus ; subspecies of cornutus ; homonym); Zheng, 2004: 310 (subgenus Craetopycrus ).

Platystethus cornutus ssp. umbripennis Zheng, 2000: 112 ( Type locality: Sichuan, Wolong [ 31.03 ºN 103.18 ºE], 1830m, 14.VII. 1983); Smetana, 2004: 518 (subgenus Craetopycrus ; subspecies of cornutus ); Yan, Li & Zheng, 2012: 342 (subspecies of cornutus ).

Platystethus cornutus ssp. stramineus Zheng, 2004: 310 (replacement name for ssp. flavipennis Zheng, 2000 ); Yan, Li & Zheng, 2012: 342 (subspecies of cornutus ).

Type material examined. [race pallidipennis Bernhauer ]. Syntype ( Fig. 7 M): 1 ♀, Co-Type// Transcaspien K. Aris// v. pallidipennis Brh. Cotypus // Chicago NHMus M.Bernhauer Collection// Brit. Mus. 1956 - 709 ( BMNH).

[ssp. stramineus Zheng]. Paratypes ( Fig. 7 A–F): 1 ♂, 1 ♀, Xinjiang, Tulufan [=Turpan, 42.95 ºN 89.19 ºE], Nanchong Teacher College [former name of CWNU, not locality but depository]// 1995.7. 30, Collectors: H.-Q. Ji, L. Tan ( CWNU). [Note: all the CWNU specimens loaned from Prof. F.-K. Zheng were wrapped in ethanol cotton and preserved with labels in small glass vials sealed with adhesive tape. The identification and nature of specimens were written on the stopper and on the tape of each vial by Prof. Zheng.]

[ssp. umbripennis Zheng]. Paratypes ( Fig. 7 G–L): 1 ♂, 1 ♀, Sichuan, Zigong [ 29.34 ºN 104.78 ºE], Nanchong Teacher College [former name of CWNU, not locality but depository]// 1982.VIII, Collectors: [not mentioned in label] ( CWNU).

[ operosus Sharp ]. Lectotype [designated here, Fig. 9]: ♂, Type // Japan. G. Lewis.// Sharp Coll 1905 - 313.// Platysthetus [ sic] operosus type D. S. ( BMNH).

Other material examined. 271 specimens, 125 ♂♂, 146 ♀♀. CHINA: 1 ♀, 1927. VI. 29, E. Licent leg. (IZ-CAS); 1 ♀, 1914. V. 28, E. Licent leg. [presumable], Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS); 1 ♂, same data as previous except: 1914. VI. 16 (IZ-CAS). Beijing: 1 ♀, PEI-PING [=Beijing], 1942.X (IZ-CAS); 1 ♀, Beijing Botanical Garden [ 40.00ºN 116.21 ºE], heap trap (weed), 2011. IX. 3, D.-K. Zhou leg. ( IZ- CAS); 1 ♀, Chaoyang Dt., Datun Rd., IZ-CAS [ 40.00ºN 116.37 ºE], 50 m, 2013. IV. 24, F.- Y. Wang leg. (IZ-CAS); 31 ♂♂, 32 ♀♀, Chaoyang Dt., Datun Township [ 40.00ºN 116.41 ºE], 1996. IV. 21, H.-Z. Zhou leg. (IZ-CAS); 1 ♀, Changping, Er Bo Zi village [ 40.08 ºN 116.31 ºE], 70m, 1994. IV. 17, H.-Z. Zhou leg. (IZ-CAS); 1 ♂, Haidian, Lan Dian Chang [ 39.96 ºN 116.29 ºE], 1997. V. 16, H.-S. Zhou leg. (IZ-CAS); 1 ♀, Haidian, Yuan Ming Yuan [=Old Summer Palace, 40.00ºN 116.30 ºE], 55m, 1993. VIII. 2, H.-Z. Zhou leg. (IZ-CAS); 1 ♂, same data as previous except: 2004. III. 25, H.-L. Shi leg. (IZ-CAS); 1 ♂, 6 ♀♀, Wo Fuo Si [=Reclining Buddha Temple, 40.00ºN 116.21 ºE], 1980. IX. 5 (IZ-CAS); 1 ♀, same data as previous except: 1980. IX. 12, P.- Y. Yu leg. (IZ-CAS). Gansu: 1 ♀, Lanzhou, 1955. IV. 29, S.-J. Ma, K.-L. Xia & Y.-L. Chen legg. (IZ-CAS); 2 ♂♂, same data as previous except: 1955. IV. 30 (IZ-CAS). Hebei: 5 ♂♂, 2 ♀♀, Prov. Hopeh [=Hebei], Sienhsien [=Xianxian or Xian Co., 38.19 ºN 116.12 ºE], Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS); 1 ♂, HO-PEI [=Hebei], Sienhsien, 1937. IV. 18, Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS); 1 ♂, Sienhsien, 1936. V. 11 (IZ-CAS); 2 ♀♀, same data as previous except: 1936. VII. 5 (IZ-CAS); 1 ♂, same data as previous except: 1938. VI. 23 (IZ-CAS). Heilongjiang: 1 ♂, Harbin, 1945. V. 18, Platystethus cornutus Grav. det. P.M.Hammond 1980 (IZ-CAS). Hubei, Shenlongjia, 1 ♂, Banqiao [ 31.41 ºN 110.17 ºE], 1998. VIII. 5, H.-Z. Zhou leg. (IZ-CAS); 1 ♂, Xiagu [ 31.37 ºN 110.24 ºE], Zhaqigou, 600m, sweeping, 1998. VIII. 6, C.-J. Ye leg. (IZ-CAS). Inner Mongolia: 1 ♂, 1 ♀, Ulanqab, Jining [ 41.00ºN 113.13 ºE], 1972. VII. 5, Platystethus cornutus Grav. det. P.M.Hammond 1980 (IZ-CAS). Jiangsu: 2 ♂♂, KIANGSU [=Jiangsu Prov.], “YU-TOAN”, Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS); 1 ♂, 1 ♀, Nordwestl. China [?], Chinkiang [=Zhenjiang?], Col. Reitter, operosus Shp. Det. Bernhauer, Chicago NHMus M. Bernhauer Collection ( FMNH). Jiangxi: 1 ♂, Kiu Kiang [=Jiujiang, 29.70 ºN 116.00ºE], Sharp Coll, 1905 - 313, Platystethus cornutus var. collaris Brnh., Chicago NHMus M. Bernhauer Collection, Platystethus cornutus (Gr.) det. P.M.Hammond 1969 ( FMNH). Qinghai: 1 ♂, 3 ♀♀, Chaka Township [ 36.79 ºN 99.08 ºE], 3200 m, under rock, 2005. IX. 10, J. Wu leg. (IZ-CAS); 1 ♀, Ge’ermu [=Golmud, 36.40 ºN 94.91 ºE], 2700m, 1961. IV. 21, L.- Y. Wang leg., Platystethus cornutus Grav. det. P.M.Hammond 1981 (IZ-CAS). Shaanxi: 8 ♂♂, 9 ♀♀, Heyangqiao, Xingzhuang, 1997. V. 30, H.-S. Zhou leg. ( IZ- CAS). Shandong: 2 ♀♀, Tsinanfou [=Jinan], Long-tong, 500 à 700 m, Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS); 1 ♂, Tsingtao [=Qingdao], Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS). Shanghai: 2 ♂♂, 1947. VIII. 1, Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS); 32 ♂♂, 43 ♀♀, Prov. KIANGSU, Shanghai, Zi-ka-wei [=Xujiahui], 1939. III. 20–1940, Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS); 9 ♂♂, 13 ♀♀, “? Zi-ka-wei” (IZ-CAS). Sichuan: 2 ♂♂, 2 ♀♀, Baoxing, Longdong [ 30.47 ºN 102.71 ºE], Ruobigou, 2003. VIII. 13, grass heap by road, X.-D. Yu leg. (IZ-CAS). Tientsin [= Tianjin]: 4 ♂♂, 5 ♀♀, 1938.IV, Platystethus cornutus ssp. operosus Sharp det. P.M.Hammond, 1980 (IZ-CAS). Xinjiang: Bachu [=Maralbexi], 1350 m, 1958. IX. 18, C.-Q. Li leg., Platystethus cornutus ab. pallidipennis Bnh. det. P.M.Hammond 1980 (IZ-CAS); 2 ♂♂, 5 ♀♀, Kashi [=Kashgar, 39.45 ºN 76.01 ºE], 1959. VI. 17, from pot ale, “ 5417 4 ” [meaning unknown], Platystethus cornutus ssp. operosus Bnh. det. P.M.Hammond 1980 (IZ-CAS); 1 ♂, 1 ♀, Ku’erle [= Koria or Korla, 41.73 ºN 86.17 ºE], 2008. VI. 1, H. Huan leg.(IZ-CAS); 1 ♂, Ruoqiang [=Qarkilik, 39.02 ºN 88.16 ºE], Alagan, 850 m, 1960. V. 7, S.- Y. Wang leg., Platystethus cornutus var. pallidipenne [ sic] Brnh. det. P.M.Hammond 1981 (IZ-CAS); 2 ♂♂, Shanshanxian [=Shanshan Co. or Piqan Co. in Turpan Prefecture, 42.87 ºN 90.21 ºE], 22–350 m, 1958. VI. 22, C.-Q. Li leg., Platystethus cornutus ab. pallidipennis Bnh. det. P.M.Hammond 1980 (IZ-CAS); 2 ♂♂, Shufu [=Konaxeher, 39.38 ºN 75.86 ºE], 1200 m, 1959. VI. 20, A-Fu Tian leg., Platystethus cornutus var. pallidipenne [ sic] Brnh. det. P.M.Hammond 1981 (IZ-CAS); 4 ♀♀, same data as previous except: Jiashi [=Peyziwat or Payzawat, 39.48 ºN 76.72 ºE], 1160 m (IZ-CAS); 1 ♀, Shule Co. [ 39.40 ºN 76.05 ºE], 1959. VI. 13, oil well, 5365 4 [meaning unknown], Platystethus cornutus ssp. operosus Bnh. det. P.M.Hammond 1980 (IZ-CAS); 1 ♀, Tuokexun [=Toksun, 42.79 ºN 88.65 ºE], 1958. VI. 17, G. Wang leg., Platystethus cornutus ab. pallidipennis Bnh. det. P.M.Hammond 1980 (IZ-CAS). Xizang: 1 ♀, Lhasa, Bayi Farm [ 29.83 ºN 91.58 ºE], 3660m, 1960. V. 14, C.-G. Wang leg., Platystethus cornutus Grav. det. P.M.Hammond 1980 (IZ-CAS). BELGIQUE: 1 ♂, “Werner” [hand-writing not clear] ( IZ- CAS). FRANCE: 1 ♂, Le Bourget, 1935. VII. 7, Platystethus arenarius Fourc. det. anonym (IZ-CAS). HUNGARY: 1 ♂, Siófok, F. Lichtneckert leg. [unreliable] ( HNHM); 1 ♂, 1 ♀, “Hu. c. Dömsöd” [a village in Pest county, Hungary], “dömsödi legelő” [=Dömsöd pasture], “dömsödi szikes legelő” [=Dömsöd saline pasture], 1953. VII. 15, Z. Kaszab leg. C. cornutus (Grav.) , det. Adám 1983, ( HNHM); 1 ♀, “Hu. occ. Somogy-m. Zamárdi” [a town in Somogy county, Hungary], “Töreki láp, IX. 8, IV tó, ripicol” [Töreki moor], 1953. IX. 8, Dr. Kaszab leg. ( HNHM).

Redescription. Body black to dark brown to reddish brown; mandibles, maxillary palpi, antennae, and legs lighter; elytra ( Figs. 7 A, B, G, H, M; 8 B–E, H–J) lighter than head and pronotum, colored variously, dark brown to reddish brown to entirely pale, in some cases with various pale patterns. Length [average]: ♂, 3.3 mm; ♀, 3 mm.

Male. Head ( Figs. 5 A; 6 A) broadest at eyes or temples. Disc coriaceous, nearly glabrous, with punctures dense and coarse. Clypeus transverse and protruding beyond anterior border of supra-antennal ridges, with anterior margin truncate in middle, furnished a pair of sharp and slender spines. Epistomal suture with middle portion absent, lateral portions short but obvious and posteromedially directed. Supra-antennal ridges obviously elevated. Vertex depressed in anterior part, convex in center; mid-longitudinal suture short, posteriorly reaching occipital suture. Eyes slightly convex, shorter than temples, with fine facets; orbital sulcus feeble. Long and deep longitudinal groove sculptured throughout mesial side of eye and temple. Temple not dilated laterally. Neck not constricted. Occipital suture slightly curved, present only in middle, with large setal fovea and feeble paralateral suture lying at each end. Mandible ( Fig. 6 C) long, stout, and incurved at apex; bearing 3 small teeth on inner edge; with tiny seta at middle of dorsal surface.

Pronotum ( Figs. 5 A; 6 A) slightly wider than head, widest at near anterior margin, with mid-longitudinal sulcus present whole length, with punctures sparser and smaller than in head, with micro-striae almost absent; anterior margin slightly bi-emarginate, anterior lateral angles produced, no posterior angles; lateral and posterior margins integrated and evenly rounded, without crenulation. Scutellar impression heart-shaped, anterior margins crescent. Elytra with posterior margin truncate, elytral suture dehiscent ( Fig. 7 H) or partly overlapping ( Fig. 8 B).

Abdomen coriaceous. Sternite VII ( Figs. 5 C; 6 E) with two tiny teeth on posterior margin, between which shallowly emarginate. Sternite VIII ( Figs. 5 D; 6 F) tri-partitioned by 2 curved narrow sutures, middle part truncate on posterior margin, without mid-longitudinal internal ridge, lateral parts separated by middle part but connected at anterior margin, each with two teeth at mesial side of posterior margin: one sharp, one dull; basal ridge broken in middle and subbasal ridge with middle portion absent.

Aedeagus ( Figs. 5 G–I; 6 I –L) with median lobe inflated at base and gradually narrowed apically; apical orifice fissured to middle of ventral surface, edges of ventral fissure sharply protruding into a pair of long spines; internal sac membranous and rolling into watch-spring-shape at base ( Figs. 5 H; 6 K; 7 E, K). Paramere arm-like, basal arm with furrow on ventral surface; apical arm explanate and furnished with small seta at apex, one or two setae at near apical 1 / 3, and with pits scattered.

Female. Head and pronotum smaller ( Figs. 5 B; 6 B); clypeus more protruding, anterior margin truncate with two reduced denticles; mid-longitudinal suture nearly reduced; eyes more convex. Mandibles ( Fig. 6 D) shorter than in male, with 3 teeth prominent. Pronotal anterior margin ( Figs. 5 B; 6 B) slightly bi-emarginate or nearly straight. Abdominal sternite VII with posterior margin straight. Sternite VIII ( Figs. 5 E; 6 G) not partitioned, without teeth, with posterior margin broadly rounded and a little protruding in middle.

Spermatheca ( Figs. 5 F; 6 H) comma-formed, basal part inflated into globoid, apical part thinner and shorter, a little curved, and sharp in apex.

Distribution. China (Beijing, Gansu, Hebei, Heilongjiang, Hong Kong, Inner Mongolia, Jiangsu, Jiangxi, Jilin, Liaoning, Ningxia, Qinghai, Shanghai, Sichuan, Shaanxi, Shandong, Taiwan, Tianjin, Xizang, Xinjiang); Europe, Georgia, Russia, Mongolia, Madeira, Algeria, Canary Islands, Morocco, Algeria, Libya, Sudan, Egypt, Saudi Arabia, Syria, Turkey, Iraq, Iran, “Turkestan”, Afghanistan, Cyprus, Israel, N. & S. Korea, Uzbekistan, Kazakhstan, Tajikistan, Turkmenistan, Pakistan, India, Nepal, Myanmar, Vietnam, Japan.

Remarks. Sharp ( 1874: 91) described the species P. operosus and differentiated it from P. cornutus by “smaller and with the head less strongly punctured”. The size of P. operosus in Sharp’s description is “ 1 ½ Lin.”, which is same as the measure in Gravenhorst ( 1802: 109). Sharp declared that there were four specimens, but he did not mention their genders. We examined the male syntype specimen ( Fig. 9, designated as lectotype in this paper) of P. operosus from Sharp’s collection ( BMNH) and saw pictures of the other three syntypes ( 2 ♂♂ 1 ♀ with similar label data) in Lewis’ collection ( BMNH). Comparing them with all the P. cornutus specimens we have from Europe and China, we conclude that the type of P. operosus does not differ from P. cornutus beyond the normal range of variation of the latter ( Figs. 6–8). So we agree with Fauvel ( 1904) and re-synonymize P. operosus under P. cornutus . The following is a brief comment on the spines on aedeagal median lobe: at first sight, they look like parts of internal sac everted from the capsule of median lobe, but according to our observation, they are connected with the wall of median lobe by nearly transparent membrane. And possibly two “strips” of internal sac “touch” the inside base of the spines. Therefore they should be parts of capsule, which is logically consistent with the similar structure in other species like P. arenarius etc. The species in cornutus group have same structures and similar forms in aedeagus. Even the internal sac, normally species-specific in many situations, is hardly distinguishable. The paired spines on median lobe are variable (in lateral view) among species and stable within species. And the other useful treat is the diverse parameral apex.