Survey of Linyphiidae spiders (Arachnida: Araneae) from Wulipo National Nature Reserve, Chongqing, China

Abstract. An extensive survey of Linyphiidae spiders from Wulipo National Nature Reserve (NNR), Chongqing has been conducted, in which 24 species belonging to 16 genera are recorded including two new genera and eight new species described here as: Agyneta Hull, 1911, A. orthogonia sp. nov. (♂♀); Dicristatus gen. nov., D. minutus gen. et sp. nov. (♂♀); Dicymbium Menge, 1868, D. pingqianense sp. nov. (♂♀); Himalaphantes Tanasevitch, 1992, H. azumiensis (Oi, 1979) (♂♀); Indophantes Saaristo & Tanasevitch, 2003, I. wushanensis sp. nov. (♂♀); Ketambea Millidge & Russell-Smith, 1992, K. nigripectoris (Oi, 1960) (♂♀); Molestia Tu, Saaristo & Li, 2006, M. pollicaris sp. nov. (♂♀); Neriene Blackwall, 1833, N. calozonata Chen & Zhu, 1989 (♀), N. cavaleriei (Schenkel, 1963) (♂♀), N. emphana (Walckenaer, 1841) (♂♀), N. japonica (Oi, 1960) (♂♀), N. limbatinella (Bösenberg & Strand, 1906) (♀), N. longipedella (Bösenberg & Strand, 1906) (♂♀), N. oidedicata van Helsdingen, 1969 (♀); Prosoponoides Millidge & Russell-Smith, 1992, P. sinense (Chen, 1991) (♂♀); Ryojius Saito & Ono, 2001, R. simplex sp. nov. (♂♀); Stemonyphantes Menge, 1866, S. bifurcus sp. nov. (♂); Syedra Simon, 1884, S. oii Saito, 1983; Tapinopa Westring, 1851, T. guttata Komatsu, 1937 (♀); Tenuiphantes Saaristo & Tanasevitch, 1996, T. ancatus (Zhu, Li & Sha, 1986) (♂♀); Walckenaeria Blackwall, 1833, Walckenaeria asymmetrica Song & Li, 2011 (♂♀); Wuliphantes gen. nov., W. guanshan (Irfan, Wang & Zhang, 2022) gen. et comb. nov. (♂♀), W. tongluensis (Chen & Song, 1988) gen. et comb. nov. (♂♀), W. trigyrus gen. et sp. nov. (♂♀). Male of Tenuiphantes ancatus (Zhu, Li & Sha, 1986) is described here for the first time as new to science. The taxonomic status of Bathyphantes guanshan Irfan, Wang & Zhang, 2022 and Bathyphantes tongluensis (Chen & Song, 1988) is revised and proposed here as: Wuliphantes tongluensis (Chen & Song, 1988) gen. et comb. nov. (♂♀) and Wuliphantes guanshan (Irfan, Wang & Zhang, 2022) gen. et comb. nov. (♂♀), respectively. Morphological descriptions, photos of body and copulatory organs, as well as the locality map are provided.

CheliCerae. Yellowish-brown, excavated; retromargin at the base of fang with a rectangular projection; promargin and retromargin with two teeth.  abdoMen. Uniformly brown.
palp (Fig. 1). Retrolateral tibial apophysis long, with blunt end; with two retrolateral and on dorsal trichobothria. Cymbium retrolateral margin with a shallow depression at the base; prolateral margin with a small tubercle; proximal cymbial apophysis somewhat rectangular in prolateral view. Paracymbium with well-developed anterior and apical pocket; apical pocket with two projections. Distal suprategular apophysis with medially bears a transparent column with small pit-hook; median membrane welldeveloped with serrated margin. Radix with a small transparent projection at the base of embolus, with sclerotized curved tip (white arrow indicates the position); lamella characteristca simple, without any spikes, relatively sclerotized, apically with serrated margin; anterior terminal apophysis flap-like, widened proximally, tip with several teeth; posterior terminal apophysis sclerotized, broad with smooth tip; embolus moderately bent, with a long, needle-shaped tooth at its base. Embolus relatively large, with Fickert's gland present proximally. Embolus proper set apically, with serrated margin; thumb long reaching almost equal to the embolus proper, with blunt end.

Differential diagnosis
Dicristatus minutus gen. et sp. nov. can be diagnosed by the lower projection of dorsal tibial apophysis with seven teeth and the upper projection with six teeth; anterior radical process comma-shaped in retrolateral view in male palp. Dorsal plate outline anteriorly V-shaped in epigyne.

Distribution
Known from type locality.

Etymology
This epithet derives from the type locality.
Cephalothorax. Carapace brown; cephalic region slightly elevated; fovea, cervical and radial grooves distinct. Clypeus 0.13 high. abdoMen. Oval, light gray, densely covered with fine spines, ventral side light gray. palp (Fig. 7). Patella as long as tibia, relatively broad at distal end. Tibia narrowed distally; with vimineous bifurcate prolateral tibial apophysis strongly curved to retrolateral side; with complicated retrolateral tibial apophysis composed of triangular upper and nether part; with two retrolateral and one prolateral tibial trichobothria. Paracymbium sclerotized, distal arm hook-shaped (Fig. 2). Protegulum reduced or absent. Suprategulum with two apophyses, marginal suprategular apophysis arc-shaped with blunt end; distal suprategular apophysis trifurcate, the small branch of which is mostly covered by the outer two large branches. Anterior radical process long and narrow, with membranous lower surface. Tailpiece curved upwards, oval in prolateral view. Embolus two loops, with a narrow membrane along the inner margin.

Distribution
Known from type locality.

Differential diagnosis
The new species resembles Indophantes halonatus  in having the similar radix and pit hook in male palp and epigyne with quadrangular pseudoscape (
palp . Patella shorter than tibia, dorsally with a long spine; tibia conic, with two retrolateral and one dorsal trichobothria; proximal cymbial apophysis thumb-shaped with blunt end; paracymbium sclerotized, U-shaped, distal arm margin with two small lobes, narrowing apically; distal part of suprategulum protruding above, with claw-like pit hook. Lamella characteristca with basal sclerite, with three chitinised branches and one additional more or less transparent extension with frayed margin. Terminal apophysis short with pointed end. Embolus with bifurcated tip with pointed end. Embolus proper sclerotized with pointed tip. Thumb tomb-like, with pointed apex.

Distribution
Known from type locality.

Differential diagnosis
The new species can be distinguished from all other congeners by the tibia with a thumb-shaped retrolateral tibial apophysis; terminal apophysis wing-shaped with pointed end; embolus proper minute, lateral margin highly sclerotized, round in male palp (Figs 20-21); scape C-shaped; posterior median plate trapezoid (Fig. 23E).

Etymology
The epithet is derived from the Latin adjective 'pollicaris' meaning 'of or belonging to a thumb' and referring to the tibia with a thumb-shaped retrolateral tibial apophysis in male palp (
CheliCerae. With two promarginal and two retromarginal teeth. palp . Patella shorter than tibia with a long dorsal spine; tibia conic, distal margin much broader than proximal end, with two retrolateral and one dorsal trichobothria, with a thumbshaped retrolateral tibial apophysis with blunt end; proximal cymbial apophysis short, with blunt end; prolateral margin of cymbium provided with an outgrowth. Basal part of paracymbium with somewhat triangular projection with sharp pointed end; distal arm grooved, distally narrow with blunt end. Distal suprategular apophysis relatively strong sclerotized, distal end grooved. Radix longer than wide, with a long proximal radical apophysis. Lamella characteristca with basal sclerite, with two chitinised branches and one additional more or less transparent extension with frayed margin. Fickert's gland present within radix. Terminal apophysis sclerotized, wing-shaped with pointed end. Embolus broad; distally relatively round with minute embolus proper and unmodified thumb.

Distribution
Known from type locality.

Etymology
The epithet is derived from the Latin adjective 'bifurcus' meaning 'bifurcate' and referring to the distal end of radix being bifurcated with two radical processes in male palp ( Fig. 46A-B, D).
CheliCerae. With four promarginal and three retromarginal teeth. abdoMen. Oval, grey, dorsally with black and white patches extending laterally, ventral side grey. palp (Fig. 46). Patella as long as tibia, slightly curved, dorsally with long thick spine; tibia longer than wide, with two retrolateral and one dorsal trichobothria; ventral tibial apophysis slightly curved with blunt end. Cymbial process broad, D-shaped in ventral view. Paracymbium J-shaped, with thick spines on proximal part. Tegulum with three anterior tegular apophyses, gradually narrow towards distal end with notched tip. Embolic division: radix longer than wide, anterior radical process bifurcated. Embolus long and thin, whip-like.

Female
Unknown.

Remarks
Shennongjia Forest Region (type locality) situated in Hubei Province adjacent to the Wulipo (NNR), Chongqing, all of the specimens examined here belong to the Tenuiphantes ancatus (Zhu, Li & Sha, 1986). The genus Tenuiphantes can be diagnosed by the important synapomorphies of (1) the embolus of the male comprising a dentigerous protrusion about halfway down and (2) the epigyne proscapus being broadened at either side by a lateral wing-like extension of the median part of the scapus (Saaristo & Tanasevitch 1996). Tenuiphantes ancatus shares these snyapomorphies: the embolus of the male of T. ancatus shows a dentigerous protrusion at the base, and the epigyne of the species has lateral winglike extensions of the median part of the scapus that support the placement of this species in the genus Tenuiphantes. Walckenaeria asymmetrica Song & Li, 2011: 176, figs 1a-g, 2a-g (Dmf).

Diagnosis
Wuliphantes gen. nov. can be diagnosed by the following synapomorphies as: (1) in male palp, distal end of tegulum narrow, extending forward, long with a conspicuous membranous protegulum; (2) distal suprategular apophysis absent; (3) embolic plate with two projections (dorsal and ventral); (4) embolus very long, forming more than one coil (depending on the species, the coil number goes from two to four or even more). Female can be diagnosed by: (1) the scape and parmula absent in epigyne; (2) copulatory ducts transparent, with several tightly coiled coils before entering the spermathecae; (3) spermathecae compact to helical.

Etymology
The genus name is derived from the type locality (Wulipo) and the generic name Bathyphantes. Gender is masculine.

Remarks
Bathyphantes can be diagnosed with the following set of synapomorphies proposed by Ivie (1969) : in male palp, (1) tegulum with terminal extension of distal suprategular apophysis; (2) embolic plate with relatively large, flat lamella comprise of anterior and dorsal projections; (3) embolus ordinarily stout and coiled at base and becoming slender toward tip. Epigynum consisting of (1) atrium, a large cavity opening posteriorly, with ventral covering below and dorsal wall above; (2) scape, posterior extension of ventral rim of atrium often long and slender, in some cases short and blunt, in others absent, usually with a small pit near distal end; (3) parmula, posterior extension of atrial plate, usually slender, with small pit near distal end; (4) spermathecae, one on each side in anterior part of internal epigynum.

Etymology
The epithet is derived from the Latin prefix 'tri' and the noun 'gyrus' meaning 'three and coils' and referring to the embolus with three circles in male palp (Fig. 61A).

Description
Male (holotype, Figs 62, 63A) MeasureMents. Total 1.87 long; carapace 0.70 long, 0.73 wide; abdomen 1.17 long, 0.71 wide. Eye sizes and interdistances: AME 0.06, ALE 0.09, PME 0.08, PLE 0.09, AME-AME 0.02, PME-PME 0.04, AME-ALE 0.03, PME-PLE 0.04, ALE-ALE 0.33, PLE-PLE 0.36, ALE-PLE 0.01, AME-PME 0.07. abdoMen. Oval, gray, dorsally with transverse dark chevrons, ventral side gray.  (Fig. 61). Tibia conic, with two retrolateral and one dorsal trichobothrium, with many short and long spine-like hairs on all surfaces. Paracymbium sclerotized, simple, proximal end wide with thick spines, distal arm slightly curved extending towards cymbium with relatively broad tip covered by lateral margin of cymbium; tegulum longer than wide with a well-developed protegulum bulge on ectal side, eight small teeth present at the base of protegulum; embolic plate highly developed, with a short finger-shaped dorsal projection of embolic plate and a long ventral projection of embolic plate extending towards distal end with curved pointed tip; embolic plate dorsally with a long, thick spine (pointed with white arrow on the Fig. 5A); embolus with three coils, originating at 12 o'clock on prolateral side of palp.
CheliCerae. With three promarginal and five retromarginal teeth. abdoMen. Same as in male. epigyne (Fig. 62). Ventral plate unmodified; dorsal plate somewhat rectangular; copulatory opening inconspicuous, present posteriorly; copulatory ducts forming seven coils before joining the spermathecae; spermathecae compact, present at the apex of the dorsal plate; fertilization ducts extending mesally.

Distribution
Known from type locality.

Discussion
The Chongqing region has a lot of nature reserve areas, with an extremely rich insect diversity that provides an excellent food resource for predators, including Linyphiidae spiders. Due to the vast landscape and diverse habitats, the actual number of species of Linyphiidae in Chongqing is expected to be higher than previously reported. This is the first ever extensive survey of Linyphiidae spiders conducted in the Wulipo NNR and is of great significance to provide the basis for future studies in the region.
In addition to the specimens reported in this article, several putative new species in the genera Bifurcia, Gongylidioides and Taibaishanus were recorded as single females. These will be described separately, once additional material, in particular the matching males, becomes available. Additionally, several specimens of both sexes of another species of Walckenaeria, close or identical to W. antica/alticeps, was collected in Wulipo NNR. A more extensive description of this material will be published separately, with a detailed discussion of habitat preferences and zoogeographical relationships.
In their phylogenetic analysis of the genus Oedothorax, Lin et al. (2022) report Oedothorax collinus as incertae sedis. They state that the entire type series of the species is lost, meaning that the specimens reported here are the only known extant material. A detailed morphological analysis of this material in European Journal of Taxonomy 871: 1-85 (2023) the context of the analysis by Lin et al. (2022) will be required to clarify the phylogenetic placement of the species, and this will also be published separately.