Mecolaesthus guasacaca Huber, 2020

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 149-150

Mecolaesthus guasacaca Huber sp. nov.

urn:lsid:zoobank.org:act:29447A47-88C3-4BBE-97CC-FA235EF12591

Figs 532–544 , 551–553 , 1045

Diagnosis

Distinguished from congeners by combination of: armature of male chelicerae ( Figs 542–543 ; pair of long frontal processes slightly converging at tips); shape of procursus ( Figs 536–538 ; distinct retrolateral apophysis; distinctive pair of distal processes, dorsal process dark with obtuse tip, ventral process transparent with pointed tip); shapes of distal bulbal sclerites ( Figs 539–541 ; ventral sclerite with three distinctive elements); median process posteriorly on male carapace; epigynum ( Fig. 551 ; relatively small dark brown plate, roundish and protruding); and internal female genitalia ( Figs 544 , 552–553 ; complex pore plate, transversal anterior sclerite, lateral wing-like sclerites).

Etymology

The species name refers to guasacaca , a savory sauce in Venezuelan cuisine, made from avocadoes, citrus juice, parsley, garlic, coriander, and chili peppers.

Type material VENEZUELA – Falcón • ♂ holotype, ZFMK (Ar 21947), Sierra de San Luis , E Curimagua (11.1748° N,

69.6273° W), 960 m a.s.l., 18 Nov. 2018 (B.A. Huber, O. Villarreal M.).

Other material examined

VENEZUELA – Falcón • 3 ♀♀, ZFMK (Ar 21948), same collection data as for holotype .

Description

Male (holotype)

MEASUREMENTS. Total body length 3.7, carapace width 1.4. Distance PME–PME 140 µm; diameter PME 115 µm; distance PME–ALE 80 µm; diameter AME 40 µm; distance AME–AME 20 µm. Leg 1: 46.4 (11.5 +0.5+11.3 + 20.3 +2.8), tibia 2: 7.1, tibia 3: 5.5, tibia 4: 6.8; tibia 1 L/d: 84.

COLOR (in ethanol). Carapace pale ochre-gray with light brown median mark, radial lines, and lateral margins, ocular area and clypeus light brown, clypeus with whitish median marks below AME and at distal margin; sternum pale ochre-yellow, slightly darker anteriorly; legs ochre to light brown, without dark rings, tips of femora and tibiae lighter; abdomen pale gray, dorsally and laterally densely covered with dark bluish marks, ventrally with brown mark in gonopore area, light brown book lung covers, and bluish median mark behind gonopore; without dark plate above pedicel.

BODY. Habitus as in Fig. 532 . Ocular area moderately raised. Carapace anteriorly with shallow but distinct thoracic groove, posteriorly not inflated but with distinct median process. Clypeus unmodified. Sternum wider than long (0.95/0.65). Abdomen slightly elongated, pointed at spinnerets.

CHELICERAE. As in Figs 542–543 , with pair of long frontal apophyses slightly converging distally, without modified hairs.

PALPS. As in Figs 534–535 ; coxa with retrolateral apophysis, trochanter with small ventral process, femur proximally with large retrolateral-ventral process, distally with large rounded ventral process; procursus ( Figs 536–538 ) at basis with short dorsal process with obtuse tip, with distinct retrolateral process, with distinctive pair of distal processes, dorsal process dark with obtuse tip, ventral process transparent with pointed tip; genital bulb complex ( Figs 539–541 ), large distal process partly membranous/whitish, with distinctive ventral sclerite consisting of three elements (arrows in Fig. 539 ).

LEGS. Without spines and curved hairs; few vertical hairs; coxa 4 with median ventral process set with small tubercles (apparently not opposing any abdominal structure; arrow in Fig. 533 ); retrolateral trichobothrium of tibia 1 at 3%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~35 pseudosegments, mostly distinct.

Female

In general similar to male but carapace posteriorly without median process and coxa 4 without median ventral process. Tibia 1 in three females: 9.4, 9.4, 10.7. Epigynum ( Fig. 551 ) relatively small dark brown plate, roundish and protruding, whitish area in front of epigynum; posterior plate short but wide. Internal genitalia ( Figs 544 , 552–553 ) with complex pore plates that appear twisted or divided into two parts each; with transversal anterior sclerite and lateral wing-shaped sclerites.

Distribution

Known from type locality only, in Venezuela , Falcón (Fig. 1045).

Natural history

The species was found among rocks near the ground in a well preserved humid forest.

Figures

Figs 532–535. Mecolaesthus guasacaca Huber sp. nov.; male holotype from Falcón, Curimagua (ZFMK Ar 21947). 532. Habitus, dorsal view. 533. Coxae 4 and anterior part of abdomen, ventral view (arrow: median ventral process on coxa 4). 534–535. Left pedipalp, prolateral and retrolateral views. Scale line: 0.5 mm.

Figs 536–544. Mecolaesthus guasacaca Huber sp. nov.; from Falcón, Curimagua (type locality; ZFMK Ar 21947–48). 536–538. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 539–541. Left genital bulb, prolateral, dorsal, and retrolateral views (arrows: three distinctive elements of ventral bulbal sclerite). 542–543. Male chelicerae, frontal and lateral views. 544. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 545–553. Mecolaesthus Simon, 1893; epigyna, ventral views and cleared female genitalia, ventral and dorsal views. 545–547. M. graphorn Huber sp. nov.; from Aragua, Henri Pittier National Park, near La Cumbre (type locality; ZFMK Ar 21944). 548–550. M. cachapa Huber sp. nov.; from Aragua, Henri Pittier National Park, near La Cumbre (type locality; ZFMK Ar 21945). 551–553. M. guasacaca Huber sp. nov.; from Falcón, Curimagua (type locality; ZFMK Ar 21948).