Mecolaesthus arepa Huber, 2020

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 130-133

Mecolaesthus arepa Huber sp. nov.

urn:lsid:zoobank.org:act:77421E73-7EA7-4540-BE34-E3E2042A2783

Figs 433–434 , 453–461 , 468–470 , 1044

Diagnosis

Distinguished from congeners by armature of male chelicerae ( Figs 459–460 ; two pairs of patches of short modified hairs and pair of low distal apophyses), by shapes of procursus and genital bulb ( Figs 453–458 ; retrolateral element distally on procursus sclerotized and bent toward dorsal; bulbal process with several distinctive sclerites), by shape of epigynum ( Fig. 468 ; anterior plate narrowing toward posterior, with pair of dark internal sclerites visible in uncleared specimens), and by internal female genitalia ( Figs 461 , 469–470 ; semicircular sclerite, pore plates in lateral position).

Etymology

The species name refers to arepa , a type of food made of ground maize dough, notable in the cuisine of Venezuela ; noun in apposition.

Type material

VENEZUELA – Táchira • ♂ holotype, ZFMK (Ar 21932), SE Pregonero, forest near La Trampa (7.9236° N, 71.7152° W), 1300 m a.s.l., 10 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.) .

Other material examined

VENEZUELA – Táchira • 5 ♂♂, 2 ♀♀, ZFMK (Ar 21933–34), same collection data as for holotype .

Description

Male (holotype)

MEASUREMENTS. Total body length 3.0, carapace width 0.9. Distance PME–PME 90 µm; diameter PME 90 µm; distance PME–ALE 80 µm; distance AME–AME 15 µm; diameter AME 20 µm. Leg 1: 40.7 (9.5 +0.4 +9.6+18.9 + 2.3), tibia 2: 5.6, tibia 3: 4.2, tibia 4: 5.2; tibia 1 L/d: 113; all femora/tibiae approximately same diameters.

COLOR (in ethanol). Carapace whitish to pale gray, with median dark band including posterior part of ocular area; clypeus with pair of brown marks; sternum light brown, with triangular whitish area posteriorly; legs light brown, with indistinct darker bands on femora subdistally and tibiae proximally, tips of femora and tibiae whitish; abdomen pale bluish, dorsally and laterally with dark bluish marks

arranged in longitudinal bands, ventrally with small brown mark in gonopore area and large median dark bluish band; book lung covers not darkened; without dark plate above pedicel.

BODY. Habitus as in Figs 433–434 . Ocular area moderately raised. Carapace not inflated posteriorly but with distinct median process (arrow in Fig. 434 ), with shallow but distinct thoracic groove. Clypeus unmodified. Sternum wider than long (0.68/0.40), unmodified. Abdomen cylindrical, pointed at spinnerets.

CHELICERAE. As in Figs 459–460 , with two pairs of patches of short modified hairs, proximal patch on low ridge, modified hairs mostly slightly hooked (bent toward median); with pair of low distal apophyses.

PALPS. In general very similar to other species of the M. grandis group (e.g., M. longipes Huber sp. nov.; cf. Figs 399–400 ); coxa with retrolateral apophysis, trochanter with small ventral process, femur proximally with retrolateral process, distally with prominent rounded ventral process; retrolateral trichobothrium of tibia in very distal position; procursus ( Figs 453–455 ) at basis with small bifid dorsal process, without retrolateral apophysis, distally with pair of processes, retrolateral process distally sclerotized and bent toward dorsal; genital bulb ( Figs 456–458 ) complex, with several distinctive sclerites.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 2%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~45 pseudosegments, distally distinct.

Male (variation)

Tibia 1 in three other males: 9.3, 9.4, 10.6; small males without or with very low median process posteriorly on carapace.

Female

In general similar to male but carapace without median process. Tibia 1 in two females: 6.8, 7.0. Epigynum ( Fig. 468 ) weakly curved plate, anterior plate narrowing toward posterior, with pair of dark internal sclerites visible in uncleared specimens; posterior plate very short, wide. Internal genitalia ( Figs 461 , 469–470 ) with semicircular sclerite, pore plates in lateral position.

Distribution

Known from type locality only, in Venezuela , Táchira (Fig. 1044).

Natural history

Most specimens were collected at a large humid rock wall in the forest, where they hang in their domed sheets ~ 0.5 m above the ground. Webs had a diameter of ~ 30 cm and were rather exposed.

Figures

Figs 427–434. Mecolaesthus Simon, 1893; live specimens. 427–428. M. trampa Huber sp. nov.; female with egg sac from Táchira, near La Trampa. 429–432. M. lechosa Huber sp. nov.; male and female from Mérida, Mesa Bolívar (arrows: dark brown book-lung cover and light brown plate close to pedicel). 433–434. M. arepa Huber sp. nov.; males from Táchira, near La Trampa (arrow: median process on carapace).

Figs 453–461. Mecolaesthus arepa Huber sp. nov.; from Táchira, near La Trampa (type locality; ZFMK Ar 21933–34). 453–455. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 456–458. Left genital bulb, prolateral, dorsal, and retrolateral views. 459–460. Male chelicerae, frontal and lateral views. 461. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 462–470. Mecolaesthus Simon, 1893; epigyna, ventral views and cleared female genitalia, ventral and dorsal views. 462–464. M. trampa Huber sp. nov.; from Táchira, near La Trampa (type locality; ZFMK 21928) (arrows: pair of posterior lateral processes). 465–467. M. lechosa Huber sp. nov.; from Mérida, Mesa Bolívar (type locality; ZFMK 21931). 468–470. M. arepa Huber sp. nov.; from Táchira, near La Trampa (type locality; ZFMK 21934).

Figs 399–400. Mecolaesthus longipes Huber sp. nov.; from Mérida, Mucuy (type locality; ZFMK Ar 21916); left male pedipalp, prolateral and retrolateral views. Scale line: 0.5 mm.