Mesabolivar pallens, Huber, 2018

Huber, Bernhard A., 2018, The South American spider genera Mesabolivar and Carapoia (Araneae, Pholcidae): new species and a framework for redrawing generic limits, Zootaxa 4395 (1), pp. 1-178 : 66-68

Mesabolivar pallens sp. n.

Figs 266–270 , 272 , 294–295

Diagnosis. Easily distinguished from most known congeners by pale coloration, cylindrical abdomen, and relatively small male palps and epigynum. From most similar congener ( M. kathrinae ) by wider procursus (compare Figs 272 and 273 ), presence of proximal processes on male chelicerae ( Fig. 268 ), and by presence of median pocket on epigynum ( Figs 269 , 294 ). Females are externally barely distinguishable from M. brasiliensis and M. azureus ; males of these two species have very different procursi (compare Figs 271, 272, 274–279 ).

Etymology. The specific name refers to the pale greenish coloration of this species (Latin pallens = pale, greenish); adjective.

Type material. BRAZIL: Espírito Santo: ♂ holotype, 1♀ paratype, MNRJ (14316), 1♂ 2♀ paratypes, ZFMK (Ar 19093), Vargem Alta, Fazenda Monte Verde (20°27.6’–28.2’S, 40°59.5’– 41°00.2’W), 1000–1200 m a.s.l., 2– 3.x.2010 (B.A. Huber, A. Pérez-González).

Other material examined. BRAZIL: Espírito Santo: 1♂ 1♀ in pure ethanol, ZFMK (Br10-84), same data as types.

Description. Male (holotype)

MEASUREMENTS. Total body length 3.3, carapace width 1.1. Distance PME-PME 120 µm, diameter PME 90 µm, distance PME-ALE 80 µm, distance AME-AME 30 µm, diameter AME 40 µm. Sternum width/length: 0.75/ 0.55. Leg 1: 46.8 (12.7 + 0.4 + 10.1 + 20.9 + 2.7), tibia 2: 6.9, tibia 3: 5.3, tibia 4: 6.7; tibia 1 L/d: 75. Femora 1–4 width (at half length): 0.15, 0.18 (distal third: 0.22), 0.15, 0.14.

COLOR (in ethanol). Carapace ochre-yellow, with indistinct darker mark behind ocular area; ocular area and clypeus not darkened; sternum light brown to orange; legs light to dark brown, with distinct black rings on femora (subdistally) and tibiae (proximally and subdistally), tips of femora and tibiae whitish; abdomen greenish gray, without dorsal pattern, ventrally with light brown plate in front of gonopore and indistinct darker median band behind gonopore.

BODY. Similar to M. azureus (cf. Fig. 254 ); ocular area slightly raised; carapace with shallow but distinct median furrow; clypeus and sternum unmodified.

CHELICERAE. As in Fig. 268 , with pair of simple distal apophyses close to median line and pair of small proximal processes.

PALPS. As in Figs 266–267 ; very small relative to body size; coxa with large retrolateral apophysis; trochanter barely modified; femur long, with retrolateral process proximally, widened distally; tarsus with small dorsal process; procursus strongly bent, with distinctive distal black spine and retrolateral membranous process with small tines ( Fig. 272 ); bulb with weakly sclerotized conical process, without side branch.

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 2%; prolateral trichobothrium present on tibia 1; tarsus 1 with ~50 pseudosegments, fairly distinct.

Male (variation). Tibia 1 in two other males: 10.0, 10.5.

Female. In general similar to male. Tibia 1 in four females: 7.7, 7.9, 8.0, 8.5. Epigynum very small and simple, weakly sclerotized, with small median pocket, internal blueish to greenish ‘valve’ visible through cuticle; posterior plate simple ( Figs 269 , 294 ). Internal genitalia as in Figs 270 , 295 , with round pore-plates embedded in large sclerite.

Natural history. The spiders were found in strongly domed webs freely suspended among the vegetation.

Distribution. Known from type locality only ( Fig. 730 ).

Figures

FIGURES266–270. Mesabolivar pallens sp. n. (ZFMK Ar19093). 266–267.Left male palp, prolateral and retrolateral views. 268. Male chelicerae, frontal view. 269. Epigynum, ventral view. 270. Cleared female genitalia, dorsal view. Scale lines: 0.3 (266–268), 0.2 (269–270).

FIGURES 271–279. Left procursi, retrolateral views. 271. Mesabolivar azureus (Badcock, 1932) (ZFMK Ar 19087). 272. M. pallens sp. n. (ZFMK Ar 19093). 273. M. kathrinae Huber, 2015 (ZFMK Ar 12621). 274–279. M. brasiliensis (Moenkhaus, 1898), males from Cantareira (274, ZFMK Ar 19106), Ubatuba (275, ZFMK Ar 19105), Paraty (276–277, ZFMK Ar 19109, 19116), Rio das Pedras (278, ZFMK Ar 19113), and Guapiaçú (279, ZFMK Ar 19110). Arrows point at present/absent dorsal widening possibly indicating presenceof two species.Scale line:0.2 (all at same scale).

FIGURES 292–305. Female epigyna in ventral views and cleared female genitalia in dorsal views, Mesabolivar kathrinae group and M. cyaneotaeniatus group. 292–293. M. azureus (Badcock, 1932) (ZFMK Ar 19087). 294–295. M. pallens sp. n. (ZFMK Ar 19093). 296. M. kathrinae Huber, 2015 (ZFMK Ar 12621). 297. M. sp., undescribed species (ZFMK Ar 19104), from Paraná, Fazenda Experimental Gralha Azul.298–299. M.brasiliensis (Moenkhaus, 1898), from Ubatuba (298, ZFMK Ar 19105) and Guapiaçú (299, ZFMK Ar 19110). 300–303.M.cyaneotaeniatus (Keyserling, 1891) (‘true’) from St.Hilaire/Lange (300, ZFMK Ar 19134) and Vargem Alta (301, ZFMK Ar 19136), and possible heterospecific specimens from Guapiaçú (302, ZFMK Ar 19120) and Pau Brasil (303, ZFMK Ar 19141). 304–305. M. kaingang sp. n. (ZFMK Ar 19142). Arrows point at present (300)/absent (302) dark ridges.

FIGURES 253–260. Live specimens, Mesabolivar kathrinae group and M. cyaneotaeniatus group. 253–254. M. azureus (Badcock, 1932), males from Penedo. 255–256. M. kathrinae Huber, 2015, male and female from Murici. 257–258. M. cyaneotaeniatus (Keyserling, 1891), male and female from St. Hilaire/Lange. 259–260. M. kaingang sp. n., male and female from St. Hilaire/Lange.

FIGURES 730–731. Known distribution of the Mesabolivar kathrinae group. “?”: dubious record of M. brasiliensis in Mello- Leitão (1947c).TL, type locality.