Mecolaesthus niquitanus (González-Sponga, 2011)

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 113-117

Mecolaesthus niquitanus (González-Sponga, 2011)

Figs 382–383 , 388–398 , 418–420 , 1043

Moraia niquitanus González-Sponga, 2011b: 43 , pl. 5, figs 1–10 (♂ ♀).

Mecolaesthus niquitanus – Huber et al. 2014a: 417.

Diagnosis

Distinguished from congeners by armature of male chelicerae ( Figs 396–397 ; pair of large frontal processes narrowing towards tip and set with 2–4 modified hairs each, and pair of sclerotized bulging plates slightly more distally with 3–5 modified hairs each); also by shape of distal bulbal process (distinctively curved towards prolateral in dorsal view, Fig. 394 ), by shape of epigynum ( Fig. 418 ; large whitish area with small brown plate narrowing posteriorly and pair of lateral sclerites), and by internal female genitalia ( Figs 398 , 419–420 ; wing-shaped lateral sclerites and rounded pore plates); from the similar M. longipes Huber sp. nov. also by much shorter legs (male tibia 1 length ~6–8 versus ~ 10–12 in M. longipes Huber sp. nov.).

Type material

VENEZUELA – Trujillo • 3 ♂♂, 5 ♀♀, types (see Notes below), MIZA 105788 ( MAGS 1289 ), Niquitao (9.117° N, 70.398° W), 2000 m a.s.l. (see Notes below), 16 Feb. 1991 (A.R. Delgado de G., E. González S., A. González S., M.A. González S.); examined .

Other material examined

VENEZUELA – Trujillo • 6 ♂♂, 10 ♀♀, ZFMK (Ar 21911–12), and 3 ♀♀ in pure ethanol, ZFMK (Ven18-213), near Boconó , Laguna Negra (9.3054° N, 70.1752° W), 1870 m a.s.l., 21 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 2 ♀♀, 3 juvs, MIZA 105580 ( MAGS 1414 ), Dtto. Boconó, Guaramacal National Park, Laguna de los Cedros [9.245° N, 70.220 ° W, 1840 m a.s.l.], 13 Sep. 1996 (A.R. Delgado, J.A. González D., M.A. González). – Lara • 6 ♂♂, 12 ♀♀, ZFMK (Ar 21913–14), and 2 ♂♂, 2 ♀♀ in pure ethanol, ZFMK (Ven02/100-60), Yacambú National Park , Sendero Ecológico (9.709° N, 69.580° W), ~ 1550 m a.s.l., 15–16 Dec. 2002 (B.A. Huber, A. Pérez González, O. Villarreal M., B. Striffler, A. Giupponi) .

Notes

Contrary to the original description, the holotype is not physically separated from the paratypes; the specimens above are thus simply treated as types. The three males appear indistinguishable, so there is currently no need to designate a lectotype.

The coordinates in the original publication are probably accurate or close to accurate but this point is at about 1870 m a.s.l. rather than at 2000 m a.s.l. The actual collecting site was possibly on the mountain slope SE of Niquitao, at approximately 9.104° N, 70.394° W. The two closest new localities above (Laguna Negra, Laguna de los Cedros) are at approximately 32 km and 24 km, respectively, NE of the type locality.

Redescription

Male (ZFMK, Ar 21911)

MEASUREMENTS. Total body length 4.8, carapace width 1.6. Distance PME–PME 100 µm; diameter PME 130 µm; distance PME–ALE 100 µm; distance AME–AME 25 µm; diameter AME 25 µm. Leg 1: 32.5 (7.6 +0.6 +7.7+14.1 + 2.5), tibia 2: 4.6, tibia 3: 3.6, tibia 4: 4.2; tibia 1 L/d: 55; tibia 1-4 diameters: 140 µm, 190 µm, 220 µm, 240 µm.

COLOR (in ethanol). Carapace pale gray with wide median dark band including ocular area and pair of wide lateral marginal dark bands; clypeus with wide median brown band; sternum ochre-yellow, anteriorly light brown; legs ochre, with darker rings on femora subdistally and tibiae proximally; abdomen pale greenish gray, dorsally and laterally with many dark bluish marks, anteriorly above pedicel with brown plate (opposing inflation of carapace), ventrally with small dark mark in gonopore area, dark brown book lung covers, brown plate anteriorly close to pedicel, and bluish internal marks in front and behind gonopore area.

BODY. Habitus as in Fig. 382 . Ocular area moderately raised. Carapace inflated posteriorly, with shallow but distinct thoracic groove. Clypeus unmodified. Sternum wider than long (0.90/0.80), unmodified. Abdomen slightly elongate, pointed at spinnerets.

CHELICERAE. As in Figs 396–397 , with pair of large frontal processes curved downwards and set with 2–4 modified hairs each, and pair of bulging plates slightly more distally with 3–5 modified hairs each.

PALPS. As in Figs 388–389 ; coxa with retrolateral apophysis, trochanter with small ventral process, femur proximally with large retrolateral apophysis, distally with prominent rounded ventral process, retrolateral trichobothrium of tibia in very distal position; procursus ( Figs 390–392 ) at basis with bifid dorsal process, with small retrolateral apophysis, distally with pair of processes, dorsal process membranous, ventral process slightly sclerotized; genital bulb complex ( Figs 393–395 ), distally mostly membranous/whitish, with distinctive distal sclerite curved towards prolateral.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 3%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~40 pseudosegments, mostly very distinct.

Male (variation)

Tibia 1 in 11 males: 6.4–7.7 (mean 7.1); anterior dark plates ventrally and dorsally on abdomen sometimes indistinct or barely visible. Large anterior cheliceral apophyses in males from Laguna Negra slightly wider at basis than in types and in males from Yacambú, both in frontal and lateral views; otherwise apparently indistinguishable.

Female

In general similar to male ( Fig. 383 ), never with anterior brown plates ventrally and dorsally on abdomen; tibia 1 also in females thinner than other tibiae (e.g., in one female measured: tibiae 1 and 4 diameters: 110 µm, 140 µm). Tibia 1 in 21 females: 4.5–5.3 (mean 4.9). Epigynum ( Fig. 418 ) large whitish area with distinctive pair of lateral sclerites and small brown plate narrowing posteriorly to narrow median sclerite. Internal genitalia ( Figs 398 , 419–420 ), with wing-shaped lateral sclerites and large oval pore plates.

Distribution

Known from four localities in the Venezuelan states Trujillo and Lara (Fig. 1043).

Natural history

At Laguna Negra, this species was abundant; it was found in relatively small, strongly curved domed webs close to the ground, usually in small sheltered spaces under logs or large dead leaves on the ground.

Figures

Figs 382–387. Mecolaesthus Simon, 1893; live specimens. 382–383. M. niquitanus (González-Sponga, 2011); male and female with egg sac from Trujillo, Laguna Negra. 384–385. M. longipes Huber sp. nov.; male and female from Mérida, Mucuy. 386–387. M. bienmesabe Huber sp. nov.; male and female from Lara, between Barquisimeto and Boconó.

Figs 388–389. Mecolaesthus niquitanus (González-Sponga, 2011); type from Trujillo, Niquitao (MIZA 105788; MAGS 1289); left male pedipalp, prolateral and retrolateral views. Scale line: 0.3 mm.

Figs 390–398. Mecolaesthus niquitanus (González-Sponga, 2011); from Trujillo, Laguna Negra (ZFMK Ar 21911–12). 390–392. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 393–395. Left genital bulb, prolateral, dorsal, and retrolateral views. 396–397. Male chelicerae, frontal and lateral views. 398. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 418–426. Mecolaesthus Simon, 1893; epigyna, ventral views and cleared female genitalia, ventral and dorsal views. 418–420. M. niquitanus (González-Sponga, 2011); from Trujillo, Laguna Negra (ZFMK Ar 21912). 421–423. M. longipes Huber sp. nov.; from Mérida, Mucuy (type locality; ZFMK Ar 21916). 424–426. M. bienmesabe Huber sp. nov.; from Lara, between Barquisimeto and Boconó (type locality; ZFMK Ar 21924).