Three new species of Patrus Aubé with additional records of Gyrinidae from China (Coleoptera, Gyrinidae)

Three new species of Patrus Aubé, 1838 are described from China: Patrus hainanensis sp. nov. from Hainan; Patrus jiangxiensis sp. nov. from Jiangxi; Patrus shangchuanensis sp. nov. from Guangdong. Eight species / subspecies of Gyrinidae are recorded from China for the fi rst time: Metagyrinus vitalisi (Peschet, 1923), Orectochilus argenteolimbatus Peschet, 1923, Orectochilus murinus Régimbart, 1892, Patrus haemorrhous (Régimbart, 1892), Patrus marginepennis angustilimbus (Ochs, 1925) from Yunnan; Patrus coomani (Peschet, 1925) from Guangdong; Patrus procerus (Régimbart, 1884) from Guangxi; Patrus annandalei (Ochs, 1925) from Hainan. Additional faunistic data of Gyrinidae from China are provided. A key to Chinese species of Patrus Aubé based on examined specimens from China is given.


Introduction
HABITUS AND COLOUR (Fig. 1A-C). Medium-sized species, oblong-oval in shape, widest just before middle, moderately convex in lateral view. Dorsal side black with strong bronze sheen, stronger on elytron than on head and pronotum. Pronotum and elytra with yellow lateral borders. Ventral side mostly black, with legs and rear of abdomen ferruginous, epipleuron yellow.
HEAD. Labrum wide and short, ⅓ as long as wide, with anterior margin straight; anterior surface smooth; posterior surface with strong punctate-tomentose. Micro-reticulation on surface of clypeus distinct with polygonal meshes. Micro-reticulation on frons and vertex rather distinct, with meshes transverse or oblique (Fig. 3E), gradually obliterated backwards. Punctation absent on head.
THORAX. Pronotum regularly attenuated from base to apex, with margins weakly convex. Surface of pronotal glabrous region with weak and subtle micro-reticulation formed by elongate transverse or oblique meshes (Fig. 3F); punctation absent on pronotum. Lateral pubescence anteriorly expanded inward onto pronotal disc to middle of dorsal eye, posteriorly narrower and parallel to lateral borders. Scutellum wide and short, ½ as long as wide, with surface smooth. Lateral pubescence on elytra anteriorly strongly reduced, distinctly narrower than on basal pronotum until middle of elytra, then abruptly expanded and reaching suture just before truncature (Fig. 3A). Pronoto-elytral glabrous region irregular oval, terminating posteriorly with obtuse and wide angle. Surface of elytral glabrous region covered by distinct and rather dense punctation formed by elongate transverse or oblique strioles and with several narrow longitudinal stripes, micro-reticulation invisible under optical microscope, but visible under SEM, similar to that on pronotum (Fig. 3G). Strioles at outer side of elytra much longer than that at inner side. Truncature of elytra straight; epipleural angle almost 90°, acute; sutural angle almost 90°, narrowly rounded.  MALE GENITALIA (Fig. 3D). Median lobe shorter than parameres, extending ¾ of their length, basal half parallel, strongly laterally expanded in apical ⅓, apical part regularly narrowed toward apex, apex point shortly narrowed. FEMALE REPRODUCTIVE TRACT (Fig. 6A). Gonocoxosternite elongate, apically narrowly rounded, anterior process elongate; laterotergite elongate, slightly curved apically; vagina elongate; spermatheca elongate, reniform; fertilization duct broad and fl attened, forming several compact hairpin hoops; accessory gland short and slender, inserting dorsally on bursa. SEXUAL DIMORPHISM. This species exhibits very little sexual dimorphism. Protibia of both sexes rather short and wide, basal third regularly expanded from base to apex, apical two-thirds subparallel, anteroexternal angle rather obliterated. Protarsus in male expanded, sub-oval, slightly more than ½ as long as protibia, slightly wider (Fig. 3B), inner margin straight, external margin convex, ventral side with large sucking disc on top of adhesive setae (Fig. 3C), while not expanded and without adhesive setae in female.
This species is also a member of Group 2 in Vazirani's (1984) key. It can be further assigned to the wuisubgroup proposed by Mazzoldi (1998) by the very large protarsus in the male. This species closely resembles Patrus wangi (Mazzoldi, 1998) described from Zhejiang and Anhui. These two species both have a well-developed protarsus which is distinctly longer than the protibia. However, it can be easily distinguished from the latter by the shape of the protarsus in the male (Fig. 4B) and of the elytral glabrous region in the female. Besides, it is larger in size, the truncature of the protibia is more oblique and the median lobe of the aedeagus lacks the hook-like process (Fig. 4D).
The new species is also similar to P. wui (Ochs, 1932). Compared to P. wui, this species is larger in size, the protarsus is also larger, longer than the protibia, the glabrous region is less broad posteriorly, and the median lobe of the aedeagus is broader.

Etymology
This species is named after the type locality ʻJiangxi Provinceʼ.
HABITUS AND COLOUR (Fig. 1D-F). Medium-sized species, oblong-oval in shape, widest just before middle, moderately convex in lateral view. Dorsal side black with strong bronze sheen. Pronotum and elytra with yellow lateral borders. Ventral side mostly reddish brown to dark brown, with legs and epipleura yellow to reddish yellow, last abdomen ferruginous.
HEAD. Labrum wide and short, ⅓ as long as wide, with anterior margin straight; anterior surface smooth; posterior surface with strong punctate-tomentose. Clypeus slightly shorter than labrum, with anterior margin straight. Fronto-clypeal suture distinct. Surface of clypeus with weak micro-reticulation anteriorly, while distinct posteriorly, among meshes of micro-reticulation with dense irregular punctation. Surface on frons and vertex with strong micro-reticulation formed by isodiametric polygonal meshes, gradually obliterated backwards. Amongst meshes of the micro-reticulation strong irregular-shaped punctation (Fig. 4E).
THORAX. Pronotum regularly attenuated from base to apex, with margins weakly convex. Surface of pronotal glabrous region with distinct micro-reticulation formed by isodiametric polygonal meshes and strong irregular punctation (Fig. 4F), much of which merges in rows to form distinct wrinkles. Lateral pubescence anteriorly expanded inward onto pronotal disc to external third of eye, posteriorly weakly reduced backwards in concave line. Scutellum wide and short, less than ½ as long as wide, with surface smooth. Pronoto-elytral glabrous region regular oval, terminating posteriorly with obtuse but not very wide angle (Fig. 4A). Lateral pubescent band in male anteriorly as wide as pronotal one, subparallel to elytral margin backwards until middle of elytron, then regularly expanded, reaching suture at about onetenth of distance from truncature; in female anteriorly as wide as pronotal one, parallel to elytral margin backwards until ⅔ of elytron, then regularly expanded, reaching suture at about 1 /12 of distance from truncature, so that elytral glabrous region in female slightly wider. Surface of elytral glabrous region covered by weak micro-reticulation formed by transverse or oblique and slightly elongate polygonal meshes and by strong punctation formed by short transverse or oblique strioles (Fig. 4G). Truncature of elytra straight; epipleural angle obtuse, narrowly rounded, sutural angle almost 90°, narrowly rounded. MALE GENITALIA (Fig. 4D). Median lobe shorter than parameres extending 4 /5 of their length, basal third parallel, then slightly narrowed until apical third, sub-apex parallel, apical part regularly narrowed, apex point shortly narrowed. FEMALE REPRODUCTIVE TRACT (Fig. 6B). Gonocoxosternite elongate, apically narrowly protruding, anterior process short; laterotergite elongate, slightly narrowed towards apex; vagina elongate; spermatheca elongate, C-shaped, strongly curved; fertilization duct slender, forming several loose hairpin hoops; accessory gland short and slender, inserting dorsally on bursa. SEXUAL DIMORPHISM. Male slightly larger in size than female; protibia in male short and wide, short triangular, strongly expanded exteriorly towards apex, apex of protibia obliquely truncate, anteroexternal angle obtuse, rounded ( Fig. 4B), while shorter and less expanded, and apex straight-truncate in female. Protarsus of male large, strongly expanded, distinctly longer than protibia, slightly narrowed towards apex, ventral side with dense adhesive setae and small suction discs (

Diagnosis
This species can be diagnosed by the following characters combined: 1) labrum less than ⅓ as long as wide, with anterior margin straight; 2) pronotal setose region anteriorly expanded inward onto pronotal disc to external third of dorsal eye; 3) dorsal surface with strong and dense micro-punctation, much stronger on elytron ( Fig. 5F-H); 4) pronoto-elytral glabrous region regularly oval in male, terminating posteriorly with obtuse but not very wide angle, with two postero-lateral expansions in females ( Fig. 5A-B); 5) elytral apex straight, epipleural angle obtuse; 6) male protarsus as in Fig. 5C-D, adhesive pallet with dense adhesive setae and small suction discs, almost as long as protibia; 7) aedeagus as in Fig. 5E, median lobe shorter than parameres, extending 4 / 5 length, apical part notably narrowed, sub-apically slightly constricted; 10) female reproductive tract as in Fig. 6C, spermatheca elongate, C-shaped; fertilization duct rather slender and fl attened, forming several loose hairpin hoops.
This species is also a member of the wui-subgroup. It closely resembles Patrus wangi (Mazzoldi, 1998) and P. wui (Ochs, 1932). All these three species show a distinct sexual dimorphism in the shape of the elytral glabrous region. Two postero-lateral expansions are shown in female of both, the new species and P. wangi but much weaker in this species than in P. wangi so that the lateral pubescence on the elytra is visible from above throughout (Figs 2D, 5B). Besides, the protarsus in the male is less developed, at most as long as protibia in this species (Fig. 5C-D). The elytral glabrous region in the female is much broader posteriorly than in male P. wui, whereas postero-lateral expansions are not present in this species. The male genitalia of these three species are also distinctly different from each other.

Etymology
This species is named after the type locality ʻShangchuan Islandʼ.
HABITUS AND COLOUR ( Fig. 2A-E). Medium-sized species, oval in shape, widest just before middle, moderately convex in lateral view. Dorsal side black with strong bronze sheen. Pronotum and elytra with yellow lateral borders. Ventral side mostly black, with legs and epipleura yellow to reddish yellow. HEAD. Labrum wide and short, slightly less than ⅓ as long as wide, with anterior margin straight; anterior surface smooth; posterior surface strongly punctate-tomentose. Clypeus slightly shorter than labrum, with anterior margin slightly concave. Fronto-clypeal suture distinct. Surface of clypeus with strong micro-reticulation formed by isodiametric polygonal meshes, among meshes with strong and dense punctation. Surface of frons and vertex with strong micro-reticulation formed by isodiametric polygonal meshes, gradually obliterated backwards. Amongst meshes of micro-reticulation strong irregular-shaped punctation (Fig. 5F).
THORAX. Pronotum regularly attenuated from base to apex, with margins weakly convex. Surface of pronotal glabrous region with strong irregular-shaped punctation, some of which merges in rows to form distinct wrinkles (Fig. 5G), micro-reticulation on median disc strong, formed by isodiametric polygonal meshes, obliterated towards margins. Lateral pubescence anteriorly expanded inward onto pronotal disc to external third of dorsal eye, posteriorly weakly reduced backwards in concave line. Scutellum wide and short, less than ½ as long as wide, with surface smooth. Pronoto-elytral glabrous region in male regularly oval. Lateral pubescent area in male anteriorly as wide as on pronotum, parallel to elytral margin backwards until the middle of elytron, then regularly expanded, reaching suture at about ⅛ to truncature (Fig. 5A). Pronoto-elytral glabrous region in female in characteristic shape, with weak postero-lateral expansion at each side (Fig. 5B). Lateral pubescence in female anteriorly two-fi fths slightly narrowed backwards, then regularly narrowed in concave line, apical fi fth suddenly expanded, reaching suture at same position as in male. Surface of elytral glabrous region covered by distinct micro-reticulation formed by transverse or oblique and slightly elongate polygonal meshes and by strong punctation formed by short transverse or oblique strioles (Fig. 5H). Truncature of elytra straight; epipleural angle obtuse, narrowly rounded, sutural angle almost right angle, narrowly rounded.
MALE GENITALIA (Fig. 5E). Median lobe notably shorter than parameres, basal third parallel, then slightly narrowed backwards until apical third, slightly expanded subapically, apical part regularly narrowed, apex form obtuse angle. FEMALE REPRODUCTIVE TRACT (Fig. 6C). Gonocoxosternite elongate, apically narrowed, anterior process short and broad; laterotergite elongate, slightly narrowed towards apex; vagina elongate; bursa rather broad; spermatheca elongate, C-shaped, strongly curved; fertilization duct rather slender and fl attened, forming several loose hairpin hoops; accessory gland short and slender, inserting dorsally on bursa. SEXUAL DIMORPHISM. Protibia in male short and wide, short triangular, strongly expanded exteriorly towards apex, apex of protibia obliquely truncate, antero-external angle obtuse, narrowly rounded (Fig. 5C), while slender and less expanded, and apex straight-truncate in female. Protarsus of male large, strongly expanded, almost as long as protibia, basal four-fi fths subparallel, apical fi fth regularly narrowed, ventral side with dense adhesive setae and small suction disks (Fig. 5D); elytral glabrous region regularly oval in male and with two weak postero-lateral expansion in female.

Distribution
Only known from the type locality Shangchuan Island, Guangdong Province, China.

Distribution
Widely distributed in the Palaearctic Region. Known from Heilongjiang, Jilin, Liaoning, Xinjiang in China. New for Guangdong and Inner Mongolia.

Remarks
As it is a typical northern species, the occurrence of this species from Guangdong, such a southern province is quite questionable. However, the material we examined did not differ from material from the northern provinces of China. Although it is possible that the four specimens from Guangdong were wrongly labelled, we have treated the material from Guangdong as G. minutus here. Ochs, 1927 Gyrinus paykulli Ochs, 1927: 39. Metagyrinus sinensis (Ochs, 1924) Paragyrinus sinensis Ochs, 1924: 231 (original description).

Distribution
Endemic to China (Fujian, Guangdong, Hong Kong). New for Guangxi, Jiangxi and Zhejiang.
Patrus procerus (Régimbart, 1884) comb. nov. Fig. 16 Orectochilus procerus Régimbart, 1884: 415 (original description  Patrus is a typical Oriental group and all species of the genus are distributed in the Oriental Region except for one unusual species occurring in central Africa. In China specifi cally, all species are only known from south of the Qinling-Huaihe Line, which is typically considered the northern border of the Oriental region in China (Cox 2001). The species diversity of the genus in China is rather high (37 species known to date), especially in Fujian, Guangdong, Guangxi and Yunnan Provinces, probably because of the warmer climate condition. In contrast to the Indian and Indochinese peninsular fauna, 21 Chinese species were only known from China, some of which seem to be very local and are likely endemic (e.g., P. emmerichi, P. chinensis). Habitats of Patrus show that many species live on the surface of running water, some living on the surface of standing water or small ponds by rivers, covered with grass (e.g., P. productus). Based on our experiences during fi eld collection, it seems that species occurring in standing water tend to have larger ranges than species in running waters. This assumption needs to be tested in further studies.
Yunnan is an interesting area for the Chinese fauna of Patrus, where abundant species occur. Yunnan is a border province neighbouring several countries of the Indochinese Peninsula without obvious geographical barriers, making its Patrus fauna more similar to that of the Indochinese Peninsula than to other areas of China. Of the seven species of Patrus known from Yunnan, six are shared with the Indochinese Peninsula fauna, while none is shared with other areas in China. Unfortunately, the fauna of Patrus of the Indochinese Peninsula is currently even less known when compared to the Chinese fauna. Hence, any future revisionary work on Chinese Patrus fauna should include as many species as possible occurring in adjacent countries in the Indochinese Peninsula.