Stemmops atratus Lin & S. Li, 2023

Li, Fengyuan, Lin, Yejie, Gao, Fan, Yao, Yanbin & Li, Shuqiang, 2023, Taxonomic notes on Stemmops O. Pickard-Cambridge, 1894 (Araneae, Theridiidae) of China, Biodiversity Data Journal 11, pp. 106208-106208 : 106208

Stemmops atratus Lin & S. Li sp. nov.

Materials

Type status: Holotype. Occurrence: catalogNumber: IZCAS-Ar44589 ; recordedBy: Fan Gao; individualCount: 1; sex: female; lifeStage: adult; occurrenceID: 6D0CB4BA-4B57-5C31-B87A-75A9CEE400FB; Taxon : scientificName: Stemmops atratus; Location : country: China; stateProvince: Jiangsu; locality: Nanjing City , Xuanwu District , Zhongshan ; verbatimElevation: 74 m; decimalLatitude: 32.078; decimalLongitude: 118.837; Identification: identifiedBy: Yejie Lin; dateIdentified: 2023; Event: year: 2019; month: 6; day: 18 Type status: Paratype. Occurrence: catalogNumber: IZCAS-Ar44590 ; recordedBy: Fan Gao; individualCount: 1; sex: female; lifeStage: adult; occurrenceID: CF399303-716E-594B-B4B7-89A38315A649; Taxon : scientificName: Stemmops atratus; Location : country: China; stateProvince: Jiangsu; locality: Nanjing City , Xuanwu District , Zhongshan ; verbatimElevation: 74 m; decimalLatitude: 32.078; decimalLongitude: 118.837; Identification: identifiedBy: Yejie Lin; dateIdentified: 2023; Event: year: 2019; month: 6; day: 18

Description

Female. Total length 2.85; carapace 0.94 long, 0.77 wide, opisthosoma 1.93 long, 1.45 wide. Eye sizes and interdistances: AME 0.05, ALE 0.06, PME 0.06, PLE 0.05, AME-AME 0.02, AME-ALE 0, PME-PME 0.02, PME-PLE 0.02, AME-PME 0.05, ALE-PLE 0.01. Endites almost as long as wide. Leg measurements: I 3.69 (1.05, 1.27, 0.80, 0.57), II 2.77 (0.79, 0.91, 0.55, 0.52), III 2.59 (0.74, 0.78, 0.51, 0.56), IV 3.93 (1.09, 1.26, 0.89, 0.69).

Colouration (Fig. 1 a, Fig. 10 a). Carapace dark-brown, covered with long sparse brown setae, eyes with black rings. Endites and labium green-brown. Sternum green-brown. Legs orange-brown, covered with sparse setae, more distinct on metatarsi and tarsi. Opisthosoma with two large white spots anteriorly and posteriorly, three pairs of small white symmetrical spots along the mid-line and a pair of white spots laterally, slightly larger than the small white spot in the middle. Spinnerets black.

Epigyne (Fig. 2 A and B). Epigynal plate almost as long as wide, with hood anteriorly, hood almost six times wider than long. Copulatory openings located on posterior portion of epigyne. First half of copulatory ducts slightly curved and second half coils around the middle of the spermathecae for four turns. Spermathecae kidney-shaped. Fertilisation ducts kidney-shaped.

Male. Unknown.

Diagnosis

The female of this new species is similar to that of S. nipponicus Yaginuma, 1969 by the split atrium (Fig. 2 A). However, it can be distinguished by the presence of hood (Fig. 2 A) (vs. absent) and the copulatory ducts coiled four times around the spermathecae (Fig. 2 B) (vs. once in S. nipponicus ). Furthermore, it differs by its habitus: S. atratus sp. n. lacks obscure yellow spots on the lateral view of opisthosoma (Fig. 1 a, Fig. 10 a Right) [vs. present in S. nipponicus , Yaginuma (1969) (Fig. 1 d)].

Etymology

The specific epithet is derived from the Latin word ātrātus, meaning darkened, referring to the colour of the new species.

Distribution

China (Jiangsu, Zhejiang) (Fig. 11 ).

Biology

All specimens were collected under stones.

Notes

The dark venter of opisthosoma and epigynal hood indicate that the illustrated female of S. nipponicus in Jin (2018) is misidentified. Herein, we determine this species as S. atratus sp. n.

Compared species and material examined.

Stemmops nipponicus , 10♂10♀, CHINA: Beijing: Chaoyang District, Olympic Forest Park, 40.0108°N, 101.2820°E, elevation 40 m, 7.VI.2022, Yejie Lin & Yunxiao Shen leg.

Figures

Figure 2. Stemmops atratus sp. n., holotype female. A Epigyne, ventral; B Vulva, dorsal. Abbreviations: CD copulatory duct; CO copulatory opening; FD fertilisation duct; H hood; S spermatheca.

Figure 11. Distribution records of Stemmops species in China: 1 S. atratus sp. n.; 2 S. lini sp. n.; 3 S. nigrabdomenus. The green circles indicate type localities.