Episinus pseudonubilus, Liang & Liu & Yin & Xu, 2025

Liang, Yun, Liu, Jinnan, Yin, Haiqiang & Xu, Xiang, 2025, On new spider species of the genus Episinus (Araneae, Theridiidae) from China and proposal of five species groups, Biodiversity Data Journal 13, pp. e 144222-e 144222 : e144222-

Episinus pseudonubilus sp. nov.

Materials

Type status: Holotype. Occurrence: recordedBy: Ailan He, Jinxin Liu, Zongguang Huang, Yun Liang, Yu Hui, Yingli Wen and Yang Liu; individualCount: 1; sex: male; lifeStage: adult; occurrenceID: C2E85AC8-9FA1-5AB8-8A8D-EE2188360C08; Taxon: scientificName: Episinus pseudonubilus ; Location: country: China; stateProvince: Shaanxi; county: Mei; verbatimLocality: Taibai Mountain National Forest Park; verbatimElevation: 1835 m; verbatimCoordinates: 34°0'48.66"N, 107°56'2.82"E; Event: year: 2022; month: 6; day: 9; Record Level: institutionID: HNU 818

Type status: Paratype. Occurrence: recordedBy: Ailan He, Jinxin Liu, Zongguang Huang, Yun Liang, Yu Hui, Yingli Wen and Yang Liu; individualCount: 3; sex: female; lifeStage: adult; occurrenceID: 4561578A-48D3-52D7-9C6F-452851F412A4; Taxon: scientificName: Episinus pseudonubilus ; Location: country: China; stateProvince: Shaanxi; county: Mei; verbatimLocality: Taibai Mountain National Forest Park; verbatimElevation: 1836 m; verbatimCoordinates: 34°0'48.66"N, 107°56'2.82"E; Event: year: 2022; month: 6; day: 9; Record Level: institutionID: HNU 819–821

Type status: Paratype. Occurrence: recordedBy: Ailan He, Jinxin Liu, Zongguang Huang, Yun Liang, Yu Hui, Yingli Wen and Yang Liu; individualCount: 1; sex: male; lifeStage: adult; occurrenceID: 17C0CFAF-73D7-548D-AF87-3C9F243DDCAC; Taxon: scientificName: Episinus pseudonubilus ; Location: country: China; stateProvince: Shaanxi; county: Feng; verbatimLocality: Ma Village; verbatimElevation: 1672 m; verbatimCoordinates: 33°51'39.04"N, 106°31'48.81"E; Event: year: 2022; month: 6; day: 6; Record Level: institutionID: HNU 822

Type status: Paratype. Occurrence: recordedBy: Ailan He, Jinxin Liu, Zongguang Huang, Yun Liang, Yu Hui, Yingli Wen and Yang Liu; individualCount: 2; sex: male; lifeStage: adult; occurrenceID: 42DB0E17-CB90-5470-85BA-CEB1E35AB273; Taxon: scientificName: Episinus pseudonubilus ; Location: country: China; stateProvince: Shaanxi; county: Mei; verbatimLocality: Honghegu National Forest Park; verbatimElevation: 1748 m; verbatimCoordinates: 34°1'6.82"N, 107°47'42.40"E; Event: year: 2022; month: 6; day: 8; Record Level: institutionID: HNU 823–824

Type status: Paratype. Occurrence: recordedBy: Ailan He, Jinxin Liu, Zongguang Huang, Yun Liang, Yu Hui, Yingli Wen and Yang Liu; individualCount: 1; sex: female; lifeStage: adult; occurrenceID: 75DFE813-A586-5BF7-A976-7B5A3050D95B; Taxon: scientificName: Episinus pseudonubilus ; Location: country: China; stateProvince: Shaanxi; county: Zhouzhi; verbatimLocality: Heihe National Forest Park; verbatimElevation: 1061 m; verbatimCoordinates: 33°53'54.33"N, 108°1'45.42"E; Event: year: 2022; month: 6; day: 10; Record Level: institutionID: HNU 825

Type status: Paratype. Occurrence: recordedBy: Ailan He, Jinxin Liu, Zongguang Huang, Yun Liang, Yu Hui, Yingli Wen and Yang Liu; individualCount: 1; sex: male; lifeStage: adult; occurrenceID: C3A07344-E155-5CF1-81B6-2CFD622D0B33; Taxon: scientificName: Episinus pseudonubilus ; Location: country: China; stateProvince: Shaanxi; county: Zhouzhi; verbatimLocality: Heihe National Forest Park; verbatimElevation: 1061 m; verbatimCoordinates: 33°53'54.33"N, 108°1'45.42"E; Event: year: 2022; month: 6; day: 10; Record Level: institutionID: HNU 826

Description

Male (Holotype): Total length 3.47, carapace 1.32 long, 1.24 wide, abdomen 2.15 long, 1.35 wide. Eye sizes and interdistances: AME 0.07, ALE 0.09, PME 0.08, PLE 0.10; AME-AME 0.11, AME-ALE 0.05, PME-PME 0.07, PME-PLE 0.08. Clypeus height 0.31. STL 0.74, STW 0.60. Legs measurements: I 5.58 (1.61, 0.55, 1.41, 1.50, 0.51); II 3.9 (1.28, 0.44, 0.82, 0.90, 0.46); III 2.99 (0.89, 0.38, 0.58, 0.68, 0.46); IV 6.01 (2.04, 0.54, 1.20, 1.66, 0.57). Leg formula IV-I-II-III.

Colouration (Fig. 5 A – C): Carapace pear-shaped, yellow-brown. Fovea and radial furrow deep (Fig. 5 A). Eyes area slightly elevated. Chelicerae light brown, without teeth. Pedipalp brown. Endite longer than wide. Labium extending, nearly rectangle. Sternum longer than wide, lateral margins sinuous and brown. Abdomen brown, dorsum with numerous white and brown spots (Fig. 5 A), venter brown, except pale posterolateral region and a slightly arched white line before spinnerets (Fig. 5 B); nearly pentagonal-shaped, with widest part at three quarters of abdominal length (Fig. 5 A) and with small hump on each side as seen in lateral view (Fig. 5 C).

Palp (Fig. 5 D – F and Fig. 6 ): tegulum (T) large, longitudinal, kidney-shaped and with sperm duct visible through cuticle. Subtegulum (St) small, almost completely covered by tegulum. Median apophysis (MA) sclerotised, croissant-shaped, with wrinkled surface. Theridiid tegular apophysis ( TTA) close to conductor, with a membranous base and five sclerotised tiny tips (Fig. 6 A). Conductor (C) sclerotised, slightly spiral, extending beyond apex of cymbium. Embolus (E) long, originating at 4 o'clock, twisting for a three-quarters turn and with sperm duct clearly visible through conductor.

Female (Paratype HNU 819): Total length 3.71, carapace 1.27 long, 1.23 wide, abdomen 2.44 long, 2.11 wide. Eye sizes and inter-distances: AME 0.09, ALE 0.12, PME 0.09, PLE 0.10; AME-AME 0.07, AME-ALE 0.04, PME-PME 0.08, PME-PLE 0.10. Clypeus height 0.20. STL 0.86, STW 0.66. Legs measurements: I 4.97 (1.43, 0.60, 1.04, 1.42, 0.48); II 3.24 (1.05, 0.44, 0.64, 0.72, 0.39); III 2.69 (0.71, 0.38, 0.52, 0.63, 0.45); IV 5.73 (1.65, 0.63, 1.17, 1.63, 0.65).

Colouration (Fig. 7 A – C): Abdomen and lateral humps larger than male. Other characteristics are similar to those of males.

Epigyne (Fig. 7 D and Fig. 8 A): with long and shallow atria (A) separated by a median septum. Vulva (Figs. 7 E – F and Fig. 8 B): copulatory ducts (CD) short, thick, with their inside sides fusing with spermathecae. Spermathecae (S) round, separated from each other by about two times the diameter of spermatheca. Fertilisation ducts (FD) originating from posterior margins of spermathecae.

Diagnosis

The new species is similar to E. nubilus Yaginuma, 1960 in having a spiral conductor and slightly oval spermathecae (compare Fig. 5 E and Fig. 7 D, with figs. 27 E – G in Kim (2021) and fig. 57 B in Zhu and Zhang (2011)), but can be distinguished from the latter by embolus originating at 4 o'clock (vs. embolus originating at 1 o'clock in E. nubilus ), relatively long and visible copulatory ducts (vs. short and indistinct copulatory ducts in E. nubilus ) (compare Fig. 5 D, E, Fig. 7 E and F with figs. 27 E – G in Kim (2021); 57 C – D in Zhu and Zhang (2011)).

Etymology

The specific epithet is a combination of the Latin prefix “ pseudo - ” and the species name “ nubilus ”, meaning that this new species is very similar to E. nubilus Yaginuma, 1960 in having a spiral conductor and is an adjective, masculine.

Distribution

Known only from the type locality, China (Shaanxi) (Fig. 9 ).

Figures

Figure 5. Episinus pseudonubilus sp. nov., holotype, male (HNU 818). A – C habitus; A dorsal view; B ventral view; C lateral view; D, E left palp; D prolateral view; E ventral view; F retrolateral view. Abbreviations: C — conductor, E — embolus, MA — Median apophysis, ST — subtegulum, T — tegulum, TTA — Theridiid tegular apophysis. Scale bars: 1 mm (A – C); 0.1 mm (D – F).

Figure 6. Episinus pseudonubilus sp. nov., holotype, male (HNU 818). A – C left palp. A prolateral view; B ventral view; C retrolateral view. Abbreviations: C — conductor, E — embolus, MA — Median apophysis, ST — subtegulum, T — tegulum, TTA — Theridiid tegular apophysis. Scale bars: 0.1 mm (A – C).

Figure 7. Episinus pseudonubilus sp. nov., paratype, female (HNU 819). A – C habitus; A dorsal view; B ventral view; C lateral view; D epigyne, ventral view; E — F vulva; E dorsal view; F dorso-posterior view. Abbreviations: At — atrium, CD — copulatory duct, FD — fertilisation duct, MS — medium septum, S — spermathecae. Scale bars: 1 mm (A – C); 0.1 mm (D – F).

Figure 8. Episinus pseudonubilus sp. nov., holotype, female (HNU 819). A epigyne, ventral view; B vulva, dorsal view. Abbreviations: At — atrium, CD — copulatory duct, FD — fertilisation duct, MS — medium septum, S — spermathecae. Scale bars: 0.1 mm (A, B).

Figure 9. Collection localities for three new species of Episinus Walckenaer, 1809 in China. 1. Episinus anfu sp. nov.; 2. Episinus implicatus sp. nov.; 3. Episinus pseudonubilus sp. nov.