A New Species of the Genus Otacilia Thorell, 1897 (Araneae: Phrurolithidae) from Southern China

T genus Otacilia Thorell, 1897 has a wide distribution with 99 species only in the Asian regions (World Spider Catalog, 2020). The total number of species in Otacilia has increased approximately 72 % in the past ten years and still continues to grow (Fu et al., 2010; Jäger and Wunderlich, 2012; Wang et al., 2012, 2015; Yang et al., 2013; Fu, 2016; Fu et al., 2014, 2015, 2016a, b; Jin et al., 2016; Jäger and Dimitrov, 2019; Liu et al., 2019; World Spider Catalog, 2020; Zamani and Marusik, 2020). So far there are 74 species (about 75% of the total) reported from China. Out of these, 70 species have been reported from southern China: Hainan (6 species), Taiwan (2 species), Zhejiang (4 species), Yunnan (10 species), Guangxi (2 species), Guizhou (5 species), Sichuan (8 species), Chongqing (9 species), Hunan (19 species), Hubei (4 species) and Taiwan (1 specie) provinces in southern China (Li and Lin, 2016; World Spider Catalog, 2020). No one species were recorded from other provinces in this huge country (World Spider Catalog, 2020). The genus Otacilia is not easy to be distinguished from Phrurolithus C.L. Koch, 1839 in the past years. In recent years, additional characters were found and documented not only in Otacilia, but also in Phrurolithus (Wang et al., 2015; Fu, 2016; Fu et al., 2016a, b; Jin et al., 2016; Liu et al., 2019; World Spider Catalog, 2020;

The genus Otacilia is not easy to be distinguished from Phrurolithus C.L. Koch, 1839 in the past years. In recent years, additional characters were found and documented not only in Otacilia, but also in Phrurolithus (Wang et al., 2015;Fu, 2016;Fu et al., 2016a, b;Jin et al., 2016;Liu et al., 2019;World Spider Catalog, 2020;Zamani and Marusik, 2020). As more attention was paid in recent years, the definition between them is getting clearer since Zamani and Marusik (2020) published their work. According to morphological and sexual dimorphic characters, Otacilia species can be divided into five species groups including the armatissima group, ambon group, longituba group, and pseudostella group as well as a group of unplaced species (Jin et al., 2016;Liu et al., 2019).
Until now, no Otacilia species have been recorded from Jiangxi province (World Spider Catalog, 2020). However, while studying materials from Dadong Mountain in Jiangxi, we recognised a species new to science, which we describe below.

MATERIALS AND METHODS
All specimens were collected from Jiangxi Province by Ke-Ke Liu, Yuan-Hao Ying, Yu-Xin Xiao, Jing Yan, and Meng-Zhen Zhang using the sieving method.

O n l i n e F i r s t A r t i c l e
Specimens were examined using a Zeiss Stereo Discovery V12 stereomicroscope with a Zoom Microscope System. Both male palps and female epigynes were detached and examined using a Zeiss Axio Scope A1 compound microscope with a KUY NICE CCD. For photographs of the vulva, the epigynes were first digested with pancreatin for 10 h of digestion and immerged in 95 % ethanol. Body parts were placed on a clean slide in Silicon for photography. For SEM photographs, the specimens were dried on filter paper and photographed with the ZEISS EVO LS15 scanning electron microscopes under a low vacuum. The specimens were subsequently stored in 75% ethanol after SEM. All the specimens are deposited in the Animal Specimen Museum, Jinggangshan University (ASM-JGSU). All morphological measurements were taken using a stereomicroscope (AxioVision SE64 Rel. 4.8.3) and are given in millimetres. The body length of each specimen does not include the spinnerets or the chelicerae. Terminology of the male and female genitalia follows Jäger and Wunderlich (2012), Liu et al. (2019) and Zamani and Marusik (2020). Promarginal and retromarginal teeth on the chelicerae are given as first, second, third, etc. from the base of the fang to the distal groove. Leg spines were documented by dividing each leg segment into two aspects: prolateral (p) and retrolateral (r) and indicating the ventral (v) spines as single (1)
Colouration (Fig. 1A, B): prosoma yellow brown to dark brown, with radial, irregular dark brown mottled markings on surface. Fovea distinct, black. Chelicerae, endites, labium and sternum yellow brown. Legs yellow. Opisthosoma yellowish to dark brown, with pair of round and oval markings located on posterior dorsal scutum and three light chevron-shaped stripes on posterior part, and yellowish transverse stripe in front of anal tubercle; venter yellowish to dark brown, with paired dark brown stripes.
Palp (Figs. 1C−F, 3C−G, 4A−C). Femora slightly depressed retrolaterally, with well-developed ventral knob-like extension. Patella unmodified. RTA with stout, triangular base directed upward with slender, slightly curved, blunt apical projection forming right angle with base and pointing forward. Cymbium more than 2 times longer than wide, prolaterally with subapical spine; anterior margin with dense group of thick setae partly covering embolus. Bulb oval, with long U-shaped sperm duct. Embolus spine-like, thick, with broad triangular base, apart from subterminal apophysis and terminal apophysis. Subterminal apophysis straight, thicked, fingershaped, submedial part covered by terminal apophysis, with slightly curved apex, pointed at embolus tip. Terminal apophysis membranous, oval.

Etymology
The specific name refers to the type locality, Chinese Pinyin 'dadongshan'; adjective.

O n l i n e F i r s t A r t i c l e
New Species of Otacilia from Southern China