Seven new species of the genus Trilacuna Tong & Li, 2007 from Yunnan, China (Araneae, Oonopidae)

Abstract Seven new species of the genus Trilacuna Tong & Li, 2007: Trilacunabawan Tong, Zhang & Li, sp. n. (male, female), T.datang Tong, Zhang & Li, sp. n. (male, female), T.fugong Tong, Zhang & Li, sp. n. (male, female), T.gongshan Tong, Zhang & Li, sp. n. (male, female), T.longling Tong, Zhang & Li, sp. n. (male, female), T.wuhe Tong, Zhang & Li, sp. n. (male, female), and T.xinping Tong, Zhang & Li, sp. n. (male, female) are described from Yunnan Province, China.


Introduction
Oonopidae is a diverse spider family with 1807 extant described species in 115 genera (WSC 2019;Li and Quan 2017). They have a nearly worldwide distribution, occurring mainly in the leaf lit ter, under bark, and in the tree canopy (Jocqué and Dippenaar-Schoeman 2006;Ubick and Dupérré 2017).
Trilacuna Tong & Li, 2007 currently comprises 22 species. Members of this genus are known from Iran, China, and south to Sumatra (WSC 2019). Only four species of Trilacuna are known in China: T. angularis Tong & Li, 2007, T. simianshan Tong & Li, 2018 and T. songyuae Tong & Li, 2018 from Chongqing, and T. rastrum Tong & Li, 2007 from Yunnan Province. In this paper seven new Trilacuna species collected form Yunnan Province, are described and illustrated.

Materials and methods
The specimens were examined using a Leica M205C stereomicroscope. Details were studied under an Olympus BX51 compound microscope. Photos were made with a Canon EOS 550D zoom digital camera (18 megapixels) mounted on an Olympus BX51 compound microscope. Vulvae were cleared in lactic acid. Scanning electron microscope images (SEM) were taken under high vacuum with a Hitachi S-4800 after critical point drying and gold-palladium coating. All measurements were taken using an Olympus BX51 compound microscope and are in millimeters.
The   A prolateral view B, D, F distal part of palpal bulb, prolateral, dorsal and retrolateral views C, E palpal bulb, dorsal and retrolateral views. Abbreviations: blp = basal leaf-shaped projection; bth = basal thin "hairs"; dbh = dorsal brush of "hairs"; dth =distal thick "hairs"; lcb = lateral curved branch; lh = lateral "hairs"; lmb = long medial branch; vbl = ventral broad lobes. basal part (blp) (Fig. 2B, D). T. hansanensis has a pair of chitinized ridges on posterior area of sternum (Seo 2017: fig. 1B), epigastric region and ventral surface of abdomen not elevated (Seo 2017: fig. 1B), and has a strongly bent terminal hook on basal part of bulb (Seo 2017: fig. 1K). Females of the new species are similar to those of T. songyuae Tong & Li, 2018, but can be distinguished by the absence of the large dark knob marking in ventral surface of genital area (Tong et al. 2018: fig. 10H).
Distribution. Known only from the type locality. Etymology. The specific name is a noun in apposition taken from the type locality. Diagnosis. The new species is similar to T. rastrum Tong & Li, 2007, but males can be distinguished by the strongly elevated epigastric region (Fig. 4I), the long, very thick setae (lts) between the anterior spiracles ( Fig. 4H) and 2 basal broad blade-like lobes (bll) and one long distal broad lobe (dbl) of embolus system (Fig. 5B), and the females by the smooth carapace and rugose surface of the sternum. Trilacuna rastrum males have flat epigastric region, without thick setae between the anterior spiracles, and have rake-like lobes of embolus system, and females have granulated sides of carapace and pitted surface of the sternum.
Female. As in male except as noted. Habitus as in Fig. 9A. Slightly larger than male. Body length 1.68; carapace 0.71 long, 0.63 wide; abdomen 1.01 long, 0.63 wide. Endites unmodified; epigastric region not sharply elevated from lateral view. Etymology. The specific name is a noun in apposition taken from the type locality.

Diagnosis.
The new specie is similar to T. rastrum Tong & Li, 2007, but can be distinguished by the presence of three pairs of spines on male tibiae I and II, the leafshaped projection (blp) and three long, tooth-like lobes (tll) on the embolus system (Fig. 11B, D), and the several longitudinal wrinkles on sternum surface of female. Trilacuna rastrum has four pairs of ventral spines on male tibiae I and II, lacking the leaf-shaped projection, has a rake-shaped lobes on the embolus system, and has a pitted surface on sternum of female (Tong and Li 2007: fig. 7-10).
Distribution. Known only from the type locality. Etymology. The specific name is a noun in apposition taken from the type locality. Diagnosis. The new species is similar to T. xinping sp. n., but males can be distinguished by the numerous rows of small ridges (sri) in posterior part of sternum (Fig.  16E), four long, finger-like lobes (fll) and a cluster of long, thick "hairs" (lth) on embolus system (Fig. 17B), and the females by the "angled" transversal sclerite (tsc) of the endogyne (Fig. 25A). Trilacuna xinping sp. n. males have a cluster of short setae (css) in posterior part of sternum (Fig. 19E), comb-shaped lobes (csl) on embolus system (Fig.  20B), and females there is no the transversal sclerite (tsc) (Fig. 25C).
Distribution. Known only from the type locality. Etymology. The specific name is a noun in apposition taken from the type locality. Diagnosis. The new species is similar to T. rastrum Tong & Li, 2007, but males can be distinguished by the cluster of short setae (css) on posterior part of sternum (Fig. 19E), and the kidney-shaped palpal bulb (Fig. 23E, G), and the females by the absence of the transverse sclerite (tsc) of endogyne (Fig. 25D). T. rastrum males are lacking cluster of short setae on posterior part of sternum, and have pear shaped palpal bulb, and the females have the transverse sclerite (Tong and Li 2007: figs 6-10).
Distribution. Known only from the type locality.