Mecolaesthus parchita Huber, 2020

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 91-94

Mecolaesthus parchita Huber sp. nov.

urn:lsid:zoobank.org:act:794F69EC-4158-46C4-9419-8B155DCB2998

Figs 280–282 , 291–299 , 303–305 , 1042

Diagnosis

Easily distinguished from known congeners (including the otherwise very similar M. chicha Huber sp. nov.) by armature of male chelicerae ( Figs 297–298 ; pair of weakly sclerotized, strongly protruding processes and pair of heavily sclerotized processes near median line) and by epigynum ( Fig. 303 ; protruding, mostly whitish, small anterior oval sclerite not connected to transversal sclerite at posterior rim). From most congeners (except M. chicha Huber sp. nov.) also by two dark rings on leg femora (instead of only one or none).

Etymology

The species name refers to parchita , the Venezuelan name for passion fruit; noun in apposition.

Type material

VENEZUELA – Mérida • ♂ holotype, ZFMK (Ar 21894), between Tovar and Guaraque (8.2578° N, 71.7184° W), 2490 m a.s.l., forest along stream, 11 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.) .

Other material examined

VENEZUELA – Mérida • 3 ♂♂, 3 ♀♀, 3 juvs, ZFMK (Ar 21895–96), and 2 ♀♀, 6 juvs in pure ethanol, ZFMK (Ven20-129), same collection data as for holotype .

Description

Male (holotype)

MEASUREMENTS. Total body length 3.0, carapace width 1.3. Distance PME–PME 120 µm; diameter PME 120 µm; distance PME–ALE 80 µm; diameter AME 30 µm; distance AME–AME 25 µm. Leg 1: 31.5 (7.2 +0.5 +7.3+13.4 + 3.1), tibia 2: 4.4, tibia 3: 3.4, tibia 4: 4.0; tibia 1–4 diameters: 125 µm, 140 µm, 150 µm, 140 µm; tibia 1 L/d: 58.

COLOR (in ethanol). Carapace pale gray (distinct greenish median mark of live specimens lost in ethanol), lateral margins darker brown, ocular area light brown; clypeus dark brown; sternum whitish; legs ochreyellow, with distinct dark rings on femora (centrally and subdistally) and tibiae (subproximally and subdistally); abdomen pale greenish-gray, dorsally and laterally with dark bluish marks, ventrally with large brown mark in gonopore area and bluish median mark behind gonopore; book lung covers barely darkened; without dark mark above pedicel.

BODY. Habitus as in Fig. 280 . Ocular area distinctly raised. Carapace with distinct but shallow thoracic groove; not visibly inflated. Clypeus unmodified. Sternum in holotype slightly deformed. Abdomen oval, pointed at spinnerets.

CHELICERAE. As in Figs 297–298 , with pair of weakly sclerotized, strongly protruding processes proximally and pair of heavily sclerotized processes near median line more distally.

PALPS. In general similar to M. mucuy (cf. Huber 2000: figs 1028–1029) and M. tabay (cf. Figs 257–258 ); largely indistinguishable from M. chicha Huber sp. nov., even procursus and genital bulb ( Figs 291–296 ) barely distinguishable.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 4%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~40 pseudosegments, mostly distinct.

Male (variation)

Tibia 1 in three other males: 7.0, 7.3, 7.3.

Female

In general similar to male ( Fig. 281 ). Tibia 1 in four females: 5.1, 5.1, 5.3, 5.3. Epigynum ( Fig. 303 ) protruding, mostly whitish, small anterior oval sclerite not connected to strong transversal (vertical) sclerite at posterior rim, internal Y-shaped sclerite variably visible in uncleared specimens; posterior plate short and wide. Internal genitalia ( Figs 299 , 304–305 ) with Y-shaped sclerite connected to transversal posterior sclerite, pore plates tilted into almost vertical position and converging dorsally and anteriorly, wider apart posteriorly than in M. chicha Huber sp. nov.; with complex system of anterior folds and arcs.

Distribution

Known from type locality only, in Venezuela , Mérida (Fig. 1042).

Natural history

Adult specimens were collected from weakly domed sheet webs (diameter ~ 20 cm) that on one side disappeared in mosses growing on tree trunks or in masses of leaf litter trapped on tree trunks about 0.5– 1.5 m above the ground. Both males and females were hiding in the substrate rather than hanging freely in the webs. By contrast, juveniles were lighter and usually found on live leaves, even on fern leaves.

Figures

Figs 277–282. Mecolaesthus Simon, 1893; live specimens. 277–279. M. chicha Huber sp. nov.; male, female, and juvenile from Mérida, between Bailadores and Pregonero. 280–282. M. parchita Huber sp. nov.; male, female, and juvenile from Mérida, between Tovar and Guaraque.

Figs 291–299. Mecolaesthus parchita Huber sp. nov.; from Mérida, between Tovar and Guaraque (type locality; ZFMK Ar 21895–96). 291–293. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views (arrow: ventral femur apophysis). 294–296. Left genital bulb, prolateral, dorsal, and retrolateral views. 297–298. Male chelicerae, frontal and lateral views. 299. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 300–305. Mecolaesthus Simon, 1893; epigyna, ventral views and cleared female genitalia, ventral and dorsal views. 300–302. M. chicha Huber sp. nov.; from Mérida, between Bailadores and Pregonero (type locality; ZFMK Ar 21893). 303–305. M. parchita Huber sp. nov.; from Mérida, between Tovar and Guaraque (type locality; ZFMK Ar 21896).

Figs 257–258. Mecolaesthus tabay Huber, 2000; from Mérida, Mucuy (ZFMK Ar 21886); left male pedipalp, prolateral and retrolateral views. Scale line: 0.3 mm.