Lepthyphantes chilalo, Tanasevitch, 2025

Tanasevitch, Andrei V., 2025, Survey of the Ethiopian linyphiid spider fauna. II. Subfamily Micronetinae Hull, 1920 (Arachnida: Araneae: Linyphiidae), European Journal of Taxonomy 976, pp. 255-282 : 266-269

Lepthyphantes chilalo sp. nov.

urn:lsid:zoobank.org:act:5DC1B0C6-8AFE-4A42-9323-EED2CAF0E781

Figs 5–6

Diagnosis

The species probably belongs to the tropicalis species-group, but, unlike other members, its epigyne lacks lateral lobes of the posterior median plate. Lepthyphantes chilalo sp. nov. is very similar to L. legatus sp. nov. (see below), a true member of the tropicalis group. The male differs by the shape of the cymbial posterodorsal outgrowth, which lacks apical denticles, vs serrate ( Fig. 6A–C cf. Fig. 9A–C ), as well as by the shape of the lamella characteristica, which has several branches, vs entire ( Fig. 6H cf. Fig. 9H ). The female differs by a triangular and shield-shaped scapus, vs oval ( Fig. 6J cf. Fig. 9J ).

Etymology

The species name is a noun in apposition, referring to Chilalo-Terara, an isolated extinct volcano, the terra typica of the new species.

Material examined

Holotype

ETHIOPIA • ♂; Oromia Region, Asela Zone, 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.

Paratypes

ETHIOPIA • 3 ♀♀, together with holotype; same data as for holotype; ZMMU • 1 ♀; Asela Zone, ca 32 air-km SE of Asela, Arsi Mountains N.P. , road from Digelu to Ticho , top of mountains ; 7.82472° N, 39.41659° E; 3780–3866 m a.s.l.; 18 Oct. 2022; A. Tanasevitch leg.; Erica arborea bushes , sedge , Alchemilla sp. , green mosses , sifting humus and mosses; [Eth010]; MHNG .

Description

Male (holotype, Eth016, ZMMU)

Total length 2.70. Carapace unmodified, 1.25 long, 1.05 wide, pale yellow, with grey median stripe and darkened margins, as in Fig. 5A . Eyes not enlarged. Chelicerae 0.50 long. Stridulatory ridges distinct, as in Fig. 5B . Legs pale yellow to pale brown. Leg I 7.06 long (1.95 +0.38 +1.83 + 1.80 +1.10), IV 6.53 long (1.80 +0.38 +1.55 +1.85 + 0.95). Chaetotaxy. FeI: 0-1-0-0, FeII–IV: 0-0-0-0; TiI: 2-1-1-3, II: 2-1-1-3(4), III–IV: 2-1-1-1(2); Me: I–IV: 2(1)-1-1-0. Length of tibial spines 2.5–3.5 × diameter of corresponding leg segment. Metatarsi I–III each with trichobothrium. TmI 0.19. Palp ( Fig. 6A–I ): patella with long spine dorsally. Tibia unmodified. Cymbium with short, bent posterodorsal outgrowth pointed apically. Paracymbium relatively large, its apical pocket transformed into sharp and dentiform lobe. Distal suprategular apophysis short, abruptly truncated, its ventral hook broad and stout. Pit-hook slender, pale, poorly sclerotized, relatively long and slightly curved. Lamella characteristica well sclerotized, large, straight, tapering distally, with a slender, needle-shaped, pale process. Terminal apophysis membranous, vague in shape. Embolus with slender stem, thumb well developed, bent distally, embolus proper bifid. Fickert’s gland small. Abdomen 1.53 long, 0.85 wide, dorsal pattern as in Fig. 5C .

Female (Eth016, ZMMU)

Total length 2.95, habitus as in Fig. 5 D–F . Carapace unmodified, 1.30 long, 1.05 wide. Chelicerae 0.75 long. Leg coloration as in male. Leg I 6.88 long (1.80 +0.45 +1.68 +1.80 + 1.15), IV 6.11 long (1.73+0.40 +1.45 +1.63 + 0.90). Chaetotaxy. FeI: 0-1-0-0, FeII–IV: 0-0-0-0; TiI–II: 2-1-1-3(4), III– IV: 2-1-1-2(1); Me: I–IV: 2-1-1-0. Length of tibial spines 2.5–3.5 × diameter of corresponding leg segment. Metatarsi I–III each with trichobothrium. TmI 0.17. Abdomen 1.88 long, 1.25 wide, dorsal pattern as in Fig. 5D–G . Epigyne ( Fig. 6J–M ). Scapus triangular shield. All of its parts: proscapus, both median and distal, merged. Bursa copulatrix opening near middle of internal surface of scapus. Stretcher rudimentary, short, without pit. Posterior median plate large, broad, without lateral branches.

Distribution

Known from the the Chilalo-Terara Volcano and from the Arsi Mountains N.P., Oromia Region, Ethiopia, altitude ranging from 3080 to 3866 m a.s.l.

Figures

Fig. 5. Photographs of Lepthyphantes chilalo sp. nov. A–C. Holotype, ♂ (ZMMU). D. Paratypes, ♀♀ (Eth010; ZMMU). E–G. Paratypes, ♀♀ (Eth016; ZMMU). A. Prosoma, dorsal view. B. Same, frontolateral view. C, G. Abdomen, dorsal view. D–F. Habitus, dorsal views. Scale bars = 0.5 mm.

Fig. 6. of Lepthyphantes chilalo sp. nov. A–I. Holotype, ♂ (Eth016; ZMMU), palpal structure. J–M. Paratypes, ♀ (Eth010; ZMMU), epigyne. A. Right palp, retrolateral view. B–C. Posterodorsal outgrowths, dorsal and prolateral view, respectively. D–F. Distal suprategular apophysis, retrolateral, prolateral and frontal view, respectively. G. Embolic division, lateral view. H. Lamella characteristica, ventrolateral view. I. Embolus, lateral view. J–M. Epigyne. J, L. Ventral view. K. Dorsal view. M. Dorsolateral view. Scale bars = 0.1 mm. Abbreviations: see Material and methods.

Fig. 9. Lepthyphantes legatus sp. nov., paratypes (Eth005; ZMMU). A–I. ♂, palpal structure J–K. ♀, epigyne. A. Right palp, retrolateral view. B. Posterodorsal outgrowth, dorsal view. C. Tibia and posterodorsal outgrowth, posterodorsal view. D–F. Distal suprategular apophysis, retrolateral, prolateral and frontal view, respectively.G. Embolic division, lateral view.H. Lamella characteristica, ventrolateral view. I. Embolus, lateral view. J–K. Epigyne, ventral and dorsal view, respectively. Scale bars = 0.1 mm. Abbreviations: see Material and methods.