Hersilia sumatrana (Thorell, 1890)

Hersilia sumatrana (Thorell, 1890) View in CoL

Figs 1–13 View Figs 1–2 View Figs 3–9 View Figs 10–13

Chalinura sumatrana Thorell, 1890: 319 (female).

Hersilia sumatrana Thorell, 1890: 8 View in CoL (female); Baehr & Baehr, 1993: 50 (female).

Hersilia pectinata Thorell, 1895: 58 View in CoL (male); Pococck, 1990: 241; Baehr & Baehr, 1993: 48 (male); syn. n.

REMARK. For a complete list of references see World Spider Catalog (2024).

MATERIAL EXAMINED. Vietnam: Dak Lak Prov., Buon Ma Thuot City , 12.7206°N, 108.08487°E, 531 m, 10.XI 2021, 2♂ (VNMN-ARA-HER-001 and 002), 2♀ (VNMN-ARA- HER-003 and 004), leg. H.Q. Duy. GoogleMaps

DIAGNOSIS. Male of the species Hersilia sumatrana can be distinguished from other members of the group by following characteristics: tibia with an angulated projection dorsally with a group of 4 strong spines and 2 separated spines ( Figs 5, 7 View Figs 3–9 and Fig. 32d in Baehr & Baehr, 1993), cymbium with ca. 12 (Baehr & Baehr, 1993) or 15 apical spines ( Figs 6–7 View Figs 3–9 ) (below 8 spines in others), and median apophysis without any crenulae on the retrolateral border ( Figs 6, 8 View Figs 3–9 ). The female is mostly similar to those of the species H. tibialis , however, differs by epigyne with convex posterior border ( Fig. 12 View Figs 10–13 ) vs. triangular in H. tibialis (Baehr & Baehr, 1993: fig. 34e); basal rippled pad wider and circular ( Figs 12–13 View Figs 10–13 ) (narrow and almost triangular in H. tibialis, Baehr & Baehr, 1993 : fig. 34e).

REDESCRIPTION. Male. Carapace length 3.31, width 3.77; Abdomen length 5.56, width 4.54. Clypeus height 0.64. Carapace rounded, yellowish brown with sparsely dark brown hairs, and margin dark brown. Eye area dark brown ( Fig. 3 View Figs 3–9 ). Clypeus yellow ( Fig. 4 View Figs 3–9 ) accompanied by white setae. Chelicerae dark brown, promargin with three teeth, retromargin with teen denticles. Abdomen: yellowish brown with dark brown pattern, four pairs of oval muscle impressions accompanied four pairs of sigilla each ( Fig. 3 View Figs 3–9 ). Spinnerets yellowish brown, posterior lateral spinnerets length 7.95 with blur dark annulate ( Fig. 3 View Figs 3–9 ). Legs yellowish brown, with blur dark annulate. Eye sizes and interdistances: AME 0.37, ALE 0.14, PME 0.33, PLE 0.34, AME–AME 0.22, AME–ALE 0.32, PME–PME 0.21, PME–PLE 0.30, AME–PME 0.14, ALE–PLE 0.15. Leg measurements: leg I: 42.35 (11.37; 1.80; 12.01, 11.84 + 4.39; 0.94), leg II: 38.61 (10.58; 1.63; 10.95; 10.80 + 3.64; 1.08), leg III: 9.59 (2.68; 0.75; 2.35; 2.97; 0.84), leg IV: 33.07 (8.81; 1.42; 8.36; 10.30 + 3.17; 1.01). Leg formula: I, II, IV, III.

Palp ( Figs 6–9 View Figs 3–9 ): tibia about half the cymbium length, with an angulated projection dorsally and presence of a group of 4 strong spines close together and 2 strong separate spines ( Figs 5, 7 View Figs 3–9 ). Cymbium short, bearing 15 strong spines at the top ( Figs 6–7 View Figs 3–9 ). Median apophysis large, arising from the base, directed prolaterally without any crenulae ( Figs 6, 8 View Figs 3–9 ), beneath median apophysis with countless short thorns-like on the surface of tegulum. Embolus thin, curved, and slightly bevelled with lamella-like at the end ( Figs 6–9 View Figs 3–9 ).

Female ( Figs 10–13 View Figs 10–13 ) almost similar to that of the male. Carapace length 3.58, width 4.41; Abdomen length 6.16, width 5.28. Clypeus height 0.81. Posterior lateral spinnerets length 9.02. Eye sizes and interdistances: AME 0.31, ALE 0.12, PME 0.33, PLE 0.35, AME–AME 0.25, AME–ALE 0.40, PME–PME 0.22, PME–PLE 0.33, AME–PME 0.16, ALE–PLE 0.20. Leg measurements: leg I: 33.50 (10.07; 1.83; 8.79; 7.70 + 3.76; 1.35), leg II: 32.38 (9.66; 1.87; 8.71; 8.06 + 3.17; 0.91), leg III: 9.92 (3.11; 1.06; 2.33; 2.53; 0.89), leg IV: 28.39 (7.40; 1.53; 7.09; 8.34 + 2.89; 1.14). Leg formula: I, II, IV, III.

Epigyne ( Figs 12–13 View Figs 10–13 ): large, sclerotized and presence of a median plate ( Fig. 12 View Figs 10–13 ); basal median plate strongly rippled; copulartory opening located posteriorly; primary spermathecae ovoid, separated and larger than secondary spermathecae; copulatory ducts mostly straight and partially obscured; fertilization ducts very long ( Fig. 13 View Figs 10–13 ).

DISTRIBUTION. Myanmar, Brunei, Philippines, China, Malaysia, Indonesia (Baehr & Baehr, 1993; Lin & Li, 2022), and Vietnam (new record).

NOTES. Until now, the species Hersilia pectinata and H. sumatrana were only known from opposite sexes. However, they share the same distribution areas in the Oriental region.

Moreover, they were collected together in Vietnam within a rubber plantation ( Figs 1–2 View Figs 1–2 ), and exhibit similar general habitus in both sexes. Therefore, we consider them to be conspecific.