Lepthyphantes bituberculatus Bosmans 1978
Creators: name: Tanasevitch, Andrei V.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Lepthyphantes
Lepthyphantes bituberculatus

description: Lepthyphantes bituberculatus Bosmans, 1978
Figs 3–4
Lepthyphantes bituberculatus Bosmans, 1978: 264, figs 30–36 (♂).
Remarks
The species was described based on the male holotype from the highlands of Simien Mountains N.P. (3300 m a.s.l.), northern Ethiopia (Bosmans 1978). Bosmans established a new species-group within Lepthyphantes (s. lat.), the tropicalis -group, where, in addition to L. bituberculatus, Bosmans included four other species: L. acuminifrons Bosmans, 1978, L. biseriatus Simon & Fage, 1922, L. tropicalis Tullgren, 1910, and L. tullgreni Bosmans, 1978. This group contains many more Afrotropical species than currently known (Tanasevitch, in preparation).
The diagnosis of the tropicalis -group was based on the characters of the male only. The discovery of the corresponding female allows us to clarify the diagnosis regarding the structure of the epigyne. This appears to be characterized by two main features:
(1) the median and distal parts of the scapus (Saaristo & Tanasevitch 1996) reduced to different degrees, merged to each other and attached to the proscape;
(2) the posterior median plate large and showing well developed lateral branches which embrace the scapus and cover the entire aperture of the epigyne from the scape to lateral walls. This type of posterior median plate is far from unique, as it can be found in several taxa of micronetines, e.g., Mughiphantes Saaristo & Tanasevitch, 1999; Bolyphantes C.L. Koch, 1837; Incestophantes Tanasevitch, 1992.
Diagnosis
Based on the structure of the palp and epigyne, L. bituberculatus seems to be especially similar to L. bryocola sp. nov. (see below), another unambiguous member of the tropicalis -group, and to L. coomansi Bosmans, 1979, known from Mount Kenya N.P., 2659 m a.s.l. (Bosmans 1979). The female of L. bituberculatus can easily be distinguished from L. coomansi by the much longer scape distinctly broadened apically. The male differs by the shape of the posterodorsal cymbial outgrowth, the presence of a stout tooth on the paracymbium, as well as the shape of the lamella characteristica.
Material examined
ETHIOPIA • 7 ♂♂, 3 ♀♀; Addis-Ababa, Russian Embassy Area; 9.03593° N, 38.78579° E; 2478 m a.s.l.; 7 Oct. 2022; A. Tanasevitch leg.; Juniperus, Acacia, Eucalyptus, bushes, sifting litter and humus; [Eth002]; ZMMU • 5 ♂♂, 4♀♀;same data as for preceding; 9.03638° N, 38.78541° E; 2470 m a.s.l.; 8 Oct. 2022; A. Tanasevitch leg.; Eucalyptus grove with Juniperus, bushes, sifting litter and humus; [Eth003]; ZMMU • 21 ♂♂, 12 ♀♀; same data as for preceding; 9.0350476° N, 38.7836601° E; 2467 m a.s.l.; 10 Oct.–4. Nov. 2022; A. Tanasevitch leg.; Eucalyptus grove with Juniperus, Acacia, bushes, sifting litter and humus; [Eth004]; ZMMU • 42 ♂♂, 56 ♀♀; same data as for preceding; 9.03617° N, 38.78549° E; 2467 m a.s.l.; 11 Oct. –14 Nov. 2022; A. Tanasevitch leg.; grove with Juniperus, Eucalyptus, palm trees, bushes, sifting litter and humus; [Eth005]; ZMMU • 20 ♂♂, 20 ♀♀; same data as for preceding; MHNG • 2 ♂♂, 4 ♀♀; same data as for preceding; 9.03491° N, 38.78236° E; 2446 m a.s.l.; 12 Oct. 2022; A. Tanasevitch leg.; grove with Eucalyptus, Juniperus, bushes, tall grass, sifting litter and humus; [Eth006]; ZMMU • 6 ♂♂, 8 ♀♀; same data as for preceding; 9.03519° N, 38.78506° E; 2453 m a.s.l.; 13 Oct. 2022; A. Tanasevitch leg.; grove with Acacia, palm trees, Eucalyptus, Juniperus, bushes, sifting litter; [Eth007]; ZMMU • 16 ♂♂, 6 ♀♀; same data as for preceding; 9.03568° N, 38.78553° E; 2465 m a.s.l.; 4 Nov. 2022; A. Tanasevitch leg.; Eucalyptus grove with Juniperus, palm trees, bushes, tall grass, sifting litter and humus; [Eth021]; ZMMU •> 36 ♂♂, 67 ♀♀; same data as for preceding; 9.03541° N, 38.7854° E; 2457 m a.s.l.; 7 Oct.–14 Nov. 2022; A. Tanasevitch leg.; Eucalyptus grove with Juniperus, palm trees, bushes, tall grass, sifting litter and humus; [Eth022]; ZMMU • 2 ♂♂, 7 ♀♀; same data as for preceding; 9.03468° N, 38.78379° E; 2454 m a.s.l.; 9 Nov. 2022; A. Tanasevitch leg.; Eucalyptus grove with sporadic Juniperus, Acacia, bushes, sifting litter and humus; [Eth023]; ZMMU • 1 ♂, 4 ♀♀; same data as for preceding; 9.0344° N, 38.78427° E; 2448 m a.s.l.; 9 Nov. 2022; A. Tanasevitch leg.; Acacia grove with sporadic Eucalyptus, bushes, sifting litter and humus under Acacia; [Eth024]; ZMMU • 1 ♂, 2 ♀♀; ca 7–8 air-km SE of Asela, Chilalo-Terara Volcano, Chilalo Mt, canyon, steep northern slope; 7.93524° N, 39.19368° E; 3080 m a.s.l.; 24 Oct. 2022; A. Tanasevitch leg.; Hypericum revolutum bushes with sporadic Schefflera abyssinica, grass, green mosses, sifting litter and mosses; [Eth016]; ZMMU • 1 ♂; Oromia Region, Asela Zone, ca 30 air-km SE of Asela, Arsi Mountains N.P., road from Digelu to Ticho; 7.81944° N, 39.35429° E; 3500–3505 m a.s.l.; 30 Oct.2022; A. Tanasevitch leg.; Erica arborea bushes, grass, green mosses, sifting mosses; [Eth018]; ZMMU.
Redescription
Male (Eth005, ZMMU)
Total length 2.20, habitus as in Fig. 3A. Carapace unmodified, 1.03 long, 0.80 wide, yellow to pale brown, with darken margins. Eyes not enlarged. Chelicerae 0.38 long. Stridulatory ridges well developed, as in Fig. 3B–C. Legs pale yellow to pale brown. Leg I 5.44 long (1.40 +0.33 + 1.33 +1.48 +0.90), IV 5.01 long (1.30+0.30 +1.23 + 1.38 +0.80). Chaetotaxy. FeI: 0-1-0-0, FeII–IV: 0-0-0-0; TiI: 2-1-1-0; TiII–III: 2-0-1-0, IV: 2-1-1-0, MeI–IV: 1-0-0-0. Length of tibial spines 1.5–3 × diameter of corresponding leg segment. Metatarsi I–III each with a trichobothrium. TmI 0.19. Palp (Figs 3C, 4A–G): patella with long spine dorsally. Tibia unmodified. Cymbium with posterodorsal outgrowth of two lobes. Paracymbium relatively large, its proximal pocket (Saaristo & Tanasevitch 1996) transformed into large and stout tooth; other pockets reduced. Distal suprategular apophysis short, its ventral hook well developed. Pit-hook small claw. Lamella characteristica large, with two main branches, and few short and pointed twigs. Terminal apophysis membranous, vague in shape. Embolus small, with narrow stem; thumb well developed; embolus proper bifid. Fickert’s gland very small. Abdomen 1.28 long, 0.80 wide, dorsal pattern as in Fig. 3D.
Female (Eth005, ZMMU)
Total length 2.53. Carapace unmodified, 1.13 long, 0.95 wide, coloration as in male. Chelicerae 0.50 long. Leg coloration as in male, leg I 5.36 long (1.38+0.35 +1.35 +1.40 + 0.88), IV 5.09 long (1.38 +0.30 +1.28 +1.33 + 0.80). Chaetotaxy. FeI: 0-1-0-0, FeII–IV: 0-0-0-0. Tibial spination different from male: TiI: 2-1-1-2; TiII: 2-1-1-2(1), TiIII–IV: 2-1-1-1. MeI–IV: 1-0-0-0. Length of tibial spines 1.5–3 × diameter of corresponding leg segment. Metatarsi I–III each with trichobothrium. TmI 0.18. Abdomen 1.70 long, 1.03 wide, dorsal pattern as in Fig. 3E–F. Epigyne as in Figs 3G–K, 4H–J. Scape a long, slender stripe, broadened distally. Median and distal parts of scape, lateral lobes, as well as stretcher totally reduced. Entrance ducts running along very edge of lateral wall of epigyne. Bursa copulatrix very small, opening on internal side of scape apex. Posterior median plate very large, with long and wide lateral branches covering entire aperture of epigyne from scape to lateral walls.
Variability
The shapes of the cymbial posterodorsal outgrowths in males varies slightly. The distal part of the scape varies from rounded to slightly pointed (Figs 3G–K, 4H–I).
Distribution
Known from Ethiopia: Amhara Region, the Simien Mountains N.P., 3300 m a.s.l. (Bosmans 1978), and from Oromia Region, altitude ranging from 2446 to 3505 m a.s.l.
description: Published as part of Tanasevitch, Andrei V., 2025, Survey of the Ethiopian linyphiid spider fauna. II. Subfamily Micronetinae Hull, 1920 (Arachnida: Araneae: Linyphiidae), pp. 255-282 in European Journal of Taxonomy 976 on pages 262-266, DOI: 10.5852/ejt.2025.976.2795, http://zenodo.org/record/14937582