Trachecymbius umbella, Haddad & Lyle, 2024

Haddad, Charles R. & Lyle, Robin, 2024, Three new genera of arboreal dark sac spiders from southern Africa (Araneae: Trachelidae), Zootaxa 5399 (5), pp. 451-504 : 499-500

Trachecymbius umbella sp. nov.

Figs 221 , 234, 235

Etymology. This species name is the Latin noun umbella , meaning umbrella or sun-shade, referring to the shape of the epigynal anterior ridges; noun in apposition.

Diagnosis. The female can be easily recognised by the large semicircular ridges surrounding the copulatory openings that converge mesally, giving the appearance of an umbrella, and by the relatively posteriorly positioned ST II compared to congeners ( Fig. 234 ). Male unknown.

Female (holotype, Hogsback, TMSA 23995). Measurements: CL 1.14, CW 0.97, AL 2.11, AW 1.21, TL 3.24, FL 0.08, SL 0.74, SW 0.60, AME-AME 0.03, AME-ALE 0.01, ALE-ALE 0.19, PME-PME 0.06, PME-PLE 0.06, PLE-PLE 0.31. Length of leg segments (sequence from femur to tarsus, and total): I 0.87 + 0.46 + 0.67 + 0.59 + 0.40 = 2.99; II 0.79 + 0.39 + 0.60 + 0.56 + 0.38 = 2.72; III 0.68 + 0.33 + 0.44 + 0.56 + 0.30 = 1.91; IV 1.00 + 0.43 + 0.84 + 0.82 + 0.38 = 3.47.

Carapace deep yellow-brown ( Fig. 221 ); carapace finely wrinkled dorsally, finely granulate on slopes; fovea short, narrow, dark brown, at ¾ CL. Eye region with black rings around eyes; AER procurved; clypeus height equal to ¾ AME diameter; ALE slightly larger than AME; AME separated by distance equal to ½ their diameter; AME separated from ALE by distance equal to ⅛ AME diameter, almost touching; PER strongly recurved; PLE slightly larger than PME; PME separated by distance equal to ¾ their diameter; PME separated from PLE by distance approximately ¾ PME diameter. Chelicerae deep yellow-brown, labium and endites pale yellow-brown, with grey mottling; sternum yellow, with faint grey mottling, yellow-brown around borders; surface smooth, sparsely covered with short, fine setae. Abdomen elongate-oval, dorsum and venter uniform creamy-grey ( Fig. 221 ); two pairs of indistinct slender sigilla, first pair at ¼ AL and second pair at midpoint of abdomen; dorsum covered in fine appressed setae, longer along midline. Legs yellow, with darker yellow-brown bands with faint grey mottling distally on femora and patellae, and proximally and distally on tibiae; metatarsi and tarsi with uniform faint grey mottling. Epigyne with broad, recurved semicircular ridges at anterior of epigyne, converging mesally; copulatory openings situated laterally in ridges, with short looping copulatory duct entering lateral globose ST II; long duct linking ST II and posterior bilobed ST I, initially corresponding to external ridges, converging anteromesally and running posteriorly, where they diverge slightly before entering ST II ( Figs 234, 235 ).

Type material. Holotype ♀: SOUTH AFRICA: Eastern Cape: Amatola Mountains, Hogsback, Arboretum , 32°35.388'S, 26°56.123'E, 1200 m a.s.l., 26.III.2011, leg. C. Haddad, V. Swart, D. Fourie & R. du Preez (canopy fogging 1, Podocarpus falcatus ) ( TMSA 23995 ).

Paratypes: SOUTH AFRICA: Eastern Cape: Amatola Mountains, Hogsback, Arboretum , 32°35.356'S, 26°56.147'E, 1235 m a.s.l., 2.IV.2012, leg. C. Haddad, J. Neethling & R. du Preez (canopy fogging 6, Quercus sp. ), 2♀ ( NCA 2014 /550); Same locality, Arboretum, 32°35.283'S, 26°56.151'E, 1250 m a.s.l., 2.IV.2012, leg. C. Haddad, J. Neethling, V. Swart & R. du Preez (canopy fogging, P. falcatus ), 2♀ ( NCA 2014 /680) .

Other material. SOUTH AFRICA: Eastern Cape: Amatola mountains, Hogsback, Arboretum , 32°35.283'S, 26°56.151'E, 1250 m a.s.l., 2.IV.2012, leg. C. Haddad, J. Neethling, V. Swart & R. du Preez (canopy fogging, P. falcatus ), 5♀ ( NCA 2014 /600); Same locality, Tyume Forest , 32°35.987'S, 26°55.880'E, 1140 m a.s.l., 3.IV.2012, leg. C. Haddad, J. Neethling, A. van Rooyen & R. du Preez (canopy fogging, Afromontane forest , Xymalos monospora ), 1♀ ( NCA 2014 /455) .

Distribution. Only known from the type locality ( Fig. 236 ).

Figures

FIGURE 236. Distribution of Trachecymbius felis sp. nov. (blue circles), T. peterwebbi sp. nov. (green triangle) and T. tyume sp. nov. (yellow triangles) in southern Africa. Black star indicates Hogsback, where T. bosselaersi sp. nov., T. felis sp. nov., T. tyume sp. nov. and T. umbella sp. nov. occur sympatrically.

FIGURES 215–221. Digital microscope photographs of dorsal habitus of Trachecymbius spp. 215. T. bosselaersi sp. nov., female; 216, 217. T. felis sp. nov., male (216) and female (217); 218. T. peterwebbi sp. nov., male; 219, 220. T. tyume sp. nov., male (219) and female (220); 221. T. umbella sp. nov., female. Scale bars = 1.0 mm.

FIGURES 230–235. Trachecymbius tyume sp. nov., male (230, 231) and female (232, 233), and T. umbella sp. nov. female (234, 235): 230. Left palp, ventral view; 231. Same, retrolateral view; 232, 234. Epigynes, ventral view; 233, 235. Same, dorsal view. Scale bars = 0.1 mm.