Notes on two Stiphropus species from China (Araneae, Thomisidae)

Abstract Background The spider genus Stiphropus Gerstaecker, 1873 currently includes 21 extant species that are distributed in Africa (12) and Asia (9). Four species, S.falciformus Yang, Zhu & Song, 2006, S.myrmecophilus Huang & Lin, 2020, S.ocellatus Thorell, 1887 and S.soureni Sen, 1964, are currently known from China. New information The mismatched female of S.falciformus is reported as a new species: S.qianlei sp. n. (♂♀). The unknown male of S.soureni Sen, 1964 is described for the first time. Photos and morphological descriptions are provided.


Introduction
The crab spider family Thomisidae Sundevall, 1833 contains 171 genera and 2172 known species worldwide (World Spider Catalog 2023). The subfamily Stiphropodinae Simon, 1895 includes three genera: Stiphropus Gerstaecker, 1873, Stiphropella Lawrence, 1952 andHeterogriffus Platnick, 1976, which possess peg-like setae on the chelicerae (Benjamin 2011), Stiphropus with the type species S. lugubris Gerstaecker, 1873, described from east Africa, being one of its easily recognised taxa. The type species can be distinguished by the stout and fused metatarsus and tarsus with densely plumose hairs (Ono 1980).
Stiphropus currently comprises 21 species, distributed in Asia and Africa. Recently, a large number of new spider species have been reported from China (Li 2020, Yao et al. 2021, Lu et al. 2022, Zhao et al. 2022), but Stiphropus is poorly studied in the region. Until now, only four species are known from China, three species are endemic, whereas S. ocellatus Thorell, 1887 is recorded from China, Myanmar and Vietnam (Sen 1964, Ono 1980, Yang et al. 2006, Zhu and Shan 2007, Huang and Lin 2020. During the examination of Stiphropus specimens from China (Guizhou, Tibet and Yunnan), we found the undescribed male of S. soureni Sen, 1964 from Tibet and determined that the supposed female of S. falciformus Yang, Zhu & Song, 2006 described from Guizhou is mismatched and, in actuality, constitutes a new species: S. qianlei sp. n. is the new species and is closely allied with the ant species Aphaenogaster smythiesii (Forel, 1902). The goal of this paper is to provide description of this new species and the undescribed female of S. soureni.

Materials and methods
All specimens were preserved in 80% ethanol. The spermathecae were cleared in trypsin enzyme solution to dissolve non-chitinous tissues. Specimens were examined under a Leica M205C stereomicroscope. Photomicrographs were taken with an Olympus C7070 zoom digital camera (7.1 megapixels). Laboratory habitus photographs were taken with a Sony A7RIV digital camera, equipped with a Sony FE 90mm Goss lens. Photos were stacked with Helicon Focus® (Version 7.6.1) or Zerene Stacker® (Version 1.04) and processed in Adobe Photoshop CC2022®. The distribution map was generated with ArcGIS v. 10.2 (ESRI Inc.).
All measurements are in millimetres (mm) and were obtained with an Olympus SZX16 stereomicroscope with a Zongyuan CCD industrial camera. All measurements of body lengths do not include the chelicerae. Eye sizes are measured as the maximum diameter from either the dorsal or frontal view. Leg measurements are given as follows: total length (femur, patella, tibia, metatarsus, tarsus). The type materials are deposited in the Institute of Zoology, Chinese Academy of Sciences in Beijing (IZCAS).

Taxon treatments
Palp (Fig. 1). Patella almost as long as tibia. Tibia with 2 apophyses, ventral tibial apophysis blunt, little curved; dorsal tibial apophysis as long as ventral tibial apophysis, terminal sharp. Cymbium almost as long as wide. Cymbium covered with sparse plumose setae at dorso-prolateral half. Tutaculum with two sub-triangular projections in ventral view. Tegulum crescent-shaped. Embolus falciform, wrinkled and rounded distally in retrolateral view, widest at the middle, originating from 11:30 o'clock position and its tip ending at 3:00 o'clock position, opening dorsally at tip.
Epigyne (Fig. 2) raised near middle of the abdomen, with a transversal, sub-oval and wrinkled depression anteriorly, two creviced and arched copulatory openings located at sides of posterior margin of the wrinkled depression, touching each other. Copulatory ducts strongly sclerotised at parts next to ducts and almost as long as spermathecae. Spermathecae almost spherical, with irregularly distributed projections on the surface, spaced by less than 1 radius. Fertilisation ducts originated near mesal sides of spermathecae.

Diagnosis
The male is similar to S. ocellatus Thorell, 1887 by the curved and wide embolus and long, terminal sharp dorsal tibial apophysis (see Ono 1980, figs. 22-27). However, the new species can be distinguished from S. ocellatus by the embolus strongly curved as C-shaped and widest at the middle [vs. no significant change in the width of the embolus in S. ocellatus (Ono 1980, figs. 22 and 25) and dorsal tibial apophysis pointed dorsally [vs. point anteriorly in S. ocellatus (Ono 1980, figs, 23, 24, 26 and 27). For diagnosis of females, see Li et al. (2010).

Etymology
The species is named after one of the collectors.

Biology
All specimens were collected in two different nests of Aphaenogaster smythiesii (Forel, 1902). S. qianlei sp. n. can be classified as a myrmecophile or myrmecophage. The collectors did not search for S. qianlei sp. n. outside the ant nests, but evidence suggests that the discovery of S. qianlei sp. n. in ant nests is typical (Fig. 6).

Notes
The oval fan-shaped folds, the 90° folded copulatory duct and accessory gland point posteriorly show the females of S. falciformus in Li et al. (2010) are mismatched.

Diagnosis
The male is similar to that of S.  (1980). In habitus, S. soureni sp. n. with orange opisthosoma in male (Fig. 5b) (black in S. ocellatus).

Biology
This species live under the bark of trees.

Notes
The male is described here for the first time.