Two new Eresus species (Araneae, Eresidae) from Xinjiang, China Author Lin, Yejie https://orcid.org/0000-0002-6789-2731 Hebei Key Laboratory of Animal Diversity, College of Life Science, Langfang Normal University, Langfang, China linyejie15@gmail.com Author Li, Shuqiang https://orcid.org/0000-0002-3290-5416 Institute of Zoology, Chinese Academy of Sciences, Beijing, China Author Zhao, Xin CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China Author Chen, Zhanqi CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China Author Chen, Haifeng https://orcid.org/0000-0001-5838-3700 Hebei Key Laboratory of Animal Diversity, College of Life Science, Langfang Normal University, Langfang, China chenhaifeng@lfnu.edu.cn text Biodiversity Data Journal 2022 2022-12-06 10 94853 94853 http://dx.doi.org/10.3897/BDJ.10.e94853 journal article http://dx.doi.org/10.3897/BDJ.10.e94853 1314-2828-10-e94853 BE54E35BFDB545508FEFA3FC5702EEC4 D32D9106D4475E459D819B00DB23BE18 Eresus da Lin & Li sp. n. Materials Type status: Holotype . Occurrence: recordedBy: Xin Zhao ; individualID: IZCAS-Ar43547; sex: female ; occurrenceID: 9B247645-5769-574E-9924-00D870022C35 ; Taxon: taxonID: urn:lsid:zoobank.org:act: A52C7C88-A951-4E80-8B28-751DDF692327 ; scientificName: Eresus da Lin & Li , sp. n.; kingdom: Animalia; phylum: Arthropoda; class: Arachnida; order: Araneae; family: Eresidae; genus: Eresus; Location: country: China ; stateProvince: Xinjiang Uygur Autonomous Region ; county: Changji Hui Autonomous Prefecture; municipality: Fukang City; locality: Wutonggou National Desert Park ; verbatimElevation: 388 m ; decimalLatitude: 44.3920 ; decimalLongitude: 87.8707 ; Identification: identifiedBy: Yejie Lin ; Event: year: 2022; month: 7; day: 25 Description Female (Holotype, IZCAS-Ar43547): Habitus as in Fig. 2 A and B. Carapace 10.88 long, 8.62 wide, 8.92 high. Carapace nearly equally wide at pars cephalica and pars thoracica. Carapace red-brown with white setae; pars cephalica elevated. Eye sizes and interdistances: AME 0.21, ALE 0.26, PME 0.51, PLE 0.33, AME-AME 0.37, AME-ALE 3.56, PME-PME 0.65, PME-PLE 2.52, AME-PME 0.11. Pars cephalica with a pointed posterior margin dorsally, almost as long as wide. Chelicerae covered with narrowed white and black setae. Legs with a white ring of setae at joints. Legs with ventral macrosetae on Ta, Mt and Ti I-IV. Leg measurements: I: 17.83 (5.17+5.90+3.94+2.82); II: 16.46 (5.54+5.89+2.94+2.09); III: 14.77 (4.80+5.68+2.63+1.66); IV: 19.53 (6.33+7.29+3.74+2.17). Abdomen dark brown, covered with black setae, with white spots, sigilla conspicuous, surrounded by white setae. Epigyne (Fig. 3 ) with sclerotised margins, longer than high. Middle plant beyond posterior edge of epigyne margin. Fissure bow-shaped. Copulatory duct translucent, with spermathecal epithelium on anterior edge. Spermathecae distinctly lobed, reaching further laterally than copulatory ducts. Male. Unknown. Diagnosis Females of Eresus da sp. n. are similar to those of E. kollari by a relatively gentle slope of the ocular area (Fig. 2 C and D; Řezac et al. 2008 , fig. 4D; Miller et al. 2012 , fig. 2F) and with the epigynal area longer than high (Fig. 3 A; Řezac et al. 2008 , figs. 2A-J). This species can be distinguished from E. kollari by the abdomen with a large number of white spots (Fig. 2 D) (vs. abdomen uniformly black in E. kollari ), the anterior edge of copulatory duct within the anterior edge of epigyne (vs. beyond the anterior edge of epigyne in E. kollari ) and the ventral of fissure curved (vs. almost straight in E. kollari ) (Fig. 4 ). Etymology The species name is a noun in apposition derived from the Chinese pinyin "da" (giant) and refers to the large size of this new species. Distribution Known only from the type locality (Xinjiang, China). Ecology The spider was found behind a clump of desert plants (Fig. 1 A). The spider habitat is under the ground, with a silk tunnel (around 20 cm in length) connecting its opening and underground nest (Fig. 1 A and B). This underground living strategy may be an adaptive strategy for escaping from the sunlight heating and extremely high temperature of the ground surface. As the silken tunnel was wrapped with dozens of empty beetle exoskeletons (Fig. 1 C and D), we assume that the desert-living beetles are the main diet of the spider, which has a thick fang to pierce the beetles while feeding. In addition, the small size of the spider's eyes suggest that the spider may adopt a sit-and-wait hunting strategy and that it does not rely on visual signals for hunting.