Mecolaesthus grandis ( González-Sponga, 2009 )

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 101-105

publication ID

https://doi.org/10.5852/ejt.2020.718.1101

publication LSID

lsid:zoobank.org:pub:F9E9A91E-488C-4DB1-9361-E788E9AC5BC1

DOI

https://doi.org/10.5281/zenodo.4343783

persistent identifier

https://treatment.plazi.org/id/03E887AD-FFB4-7A69-FE70-FE72F9CFF926

treatment provided by

Valdenar

scientific name

Mecolaesthus grandis ( González-Sponga, 2009 )
status

 

Mecolaesthus grandis ( González-Sponga, 2009)

Figs 338–340 View Figs 338–345 , 346–355 View Figs 346–347 View Figs 348–355 , 367 View Figs 367–372 , 373–375 View Figs 373–381 , 1043

Nasuta grandis González-Sponga, 2009: 6 , figs 3a–j (♂ ♀).

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

Diagnosis

Distinguished from most congeners [except M. multidenticulatus ( González-Sponga, 2003) and M. tuberculosus ( González-Sponga, 2009) ] by armature of male chelicerae ( Fig. 354 View Figs 348–355 ; pair of large frontal processes curved downwards and set with ~5 modified hairs each, and two small modified hairs more distally on weakly sclerotized area), by shape of main bulbal process ( Figs 351–353 View Figs 348–355 ; two large sclerites visible in prolateral view), by transparent process on procursus distally bent toward retrolateral ( Fig. 349 View Figs 348–355 ), and by shape of epigynum ( Fig. 373 View Figs 373–381 ; short but wide plate, pair of anterior internal sclerites extending towards lateral); from the very similar M. multidenticulatus and M. tuberculosus by male cheliceral apophysis with conspicuous projection towards median (arrow in Fig. 367 View Figs 367–372 ); from M. tuberculosus also by absence of conspicuous lateral process on male cheliceral apophysis and by larger distance between pair of rounded sclerites in female internal genitalia (arrows in Fig. 374 View Figs 373–381 ).

Type material

VENEZUELA – La Guaira • ♂ holotype, 4 ♀♀, 7 juvs (see Notes below), MIZA 105663 View Materials ( MAGS 1215 ), Hacienda El Limón (10.475° N, 67.283° W), 1200 m a.s.l. (see Notes below), 27 Oct. 1990 (A.R. Delgado de G., M.A. González-S.); examined GoogleMaps .

New records

VENEZUELA La Guaira • 3 ♂♂, 5 ♀♀, ZFMK (Ar 21899–21900), and 3 ♀♀, 2 juvs in pure ethanol, ZFMK (Ven18-155), El Limón , above road Colonia Tovar-Puerto Cruz (10.4566° N, 67.2548° W), 1535 m a.s.l., 9 Nov. 2018 (B.A. Huber, O. Villarreal M.) GoogleMaps 2 ♂♂, ZFMK (Ar 21901), and 1 ♀ in pure ethanol, ZFMK (Ven20-173), El Limón , ‘site 2’ (10.4774° N, 67.2819° W), 1235 m a.s.l., forest along stream, 21 Feb. 2020 (B.A. Huber, O. Villarreal M.). – Aragua GoogleMaps 2 ♂♂, 2 ♀♀, ZFMK (Ar 21902), and 2 ♂♂, 2 juvs in pure ethanol, ZFMK (Ven02/100-32), Henri Pittier National Park , “site 2” (10.350° N, 67.692° W), ~ 1000 m a.s.l., 11 Dec. 2002 (B.A. Huber) GoogleMaps 1 ♂, 1 ♀, ZFMK (Ar 21903), Henri Pittier National Park , “site 3” (10.360° N, 67.720° W), ~ 730 m a.s.l., 11 Dec. 2002 (B.A. Huber) GoogleMaps .

Notes

The original description mentions 11 specimens: 1 ♂ holotype, 1 ♀ paratype, eight (non-type) females, and 1 juvenile. The 12 specimens listed under ‘Type material’ above are all joined in one vial, so it is no longer possible to distinguish the female paratype from the other females.

The original coordinates are probably accurate or close to accurate. We were not able to exactly identify the original collecting site. Our 2020 collecting site above (“El Limón, site 2”) is within 300 m from the coordinates in the original publication.

Redescription

Male (ZFMK Ar 21899)

MEASUREMENTS. Total body length 4.3, carapace width 1.5. Distance PME–PME 100 µm; diameter PME 120 µm; distance PME–ALE 100 µm; diameter AME 30 µm; distance AME–AME 20 µm. Leg 1: 37.9 (9.0 +0.6 +9.3+16.6 + 2.4), tibia 2: 5.8, tibia 3: 4.7, tibia 4: 5.1; tibia 1–4 diameters: 120 µm, 155 µm, 180 µm, 160 µm; tibia 1 L/d: 78.

COLOR (in ethanol). Carapace pale ochre-gray with wide median and lateral marginal dark bands, ocular area mostly not darkened, clypeus with wide dark brown mark; sternum pale ochre-grey; legs ochre to light brown, with barely visible darker rings on femora subdistally and on tibiae proximally and subdistally, femora and tibiae with light tips; abdomen pale bluish-gray, dorsally and laterally densely covered with dark bluish marks, ventrally with brown mark in gonopore area, brown book lung covers, pair of lateral anterior brown plates opposing fourth coxae, and large bluish marks in front and behind gonopore; with light brown plate above pedicel opposing carapace inflation (arrow in Fig. 338 View Figs 338–345 ).

BODY. Habitus as in Figs 338–339 View Figs 338–345 . Ocular area distinctly raised. Carapace anteriorly with distinct thoracic groove, posteriorly slightly inflated. Clypeus unmodified. Sternum wider than long (0.95/0.75). Abdomen slightly elongated, pointed at spinnerets.

CHELICERAE. As in Figs 354 View Figs 348–355 and 367 View Figs 367–372 , with pair of large frontal apophyses set with ~5 slightly hooked short hairs, with two additional short hairs on whitish area below main apophysis, and small unsclerotized ridge.

PALPS. As in Figs 346–347 View Figs 346–347 ; coxa with retrolateral apophysis, trochanter with very small ventral process, femur proximally with large retrolateral process, distally with prominent rounded ventral process, retrolateral trichobothrium of tibia in very distal position; procursus ( Figs 348–350 View Figs 348–355 ) at basis with bifid dorsal process with branches of unequal length, with small retrolateral apophysis, distally with pair of membranous processes: retrolateral process distally bent towards retrolateral, prolateral process with pointed tip; genital bulb complex ( Figs 351–353 View Figs 348–355 ), distally mostly membranous/whitish but with distinctive distal sclerites (very similar M. multidenticulatus ).

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 3.5%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~35 pseudosegments, mostly distinct.

Male (variation)

Tibia 1 in nine males: 8.7–10.5 (mean 9.5); most males with light to dark brown book lung covers, but anterior brown plates opposing fourth coxae indistinct or absent in some males, unrelated to body size. Brown plate above pedicel also absent in some males.

Female

In general similar to male ( Fig. 340 View Figs 338–345 ), also with variably dark book lung covers but never with brown plates opposing fourth coxae and never with brown plate above pedicel. Tibia 1 in nine females: 5.7–6.6 (mean 6.3). Epigynum ( Fig. 373 View Figs 373–381 ) small, light brown, wider than long, internal sclerites partly visible in uncleared specimens (possibly indistinguishable from M. multidenticulatus and M. tuberculosus ). Internal genitalia ( Figs 355 View Figs 348–355 , 374–375 View Figs 373–381 ) with pair of anterior sclerites extending towards lateral, median receptacle, pair of pore plates tilted into almost vertical position, and pair of round ventral sclerites (arrows in Fig. 374 View Figs 373–381 ).

Distribution

Known from several localities in the Venezuelan states La Guaira and Aragua (Fig. 1043).

Natural history

González-Sponga (2009) found the species under decaying logs. The new specimens from El Limón were collected in a forest fragment from strongly curved webs close to the ground. When disturbed, the spiders ran away rather than shaking or vibrating their bodies.

ZFMK

Germany, Bonn, Zoologische Forschungsinstitut und Museum "Alexander Koenig"

ZFMK

Zoologisches Forschungsmuseum Alexander Koenig

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Pholcidae

Genus

Mecolaesthus

Loc

Mecolaesthus grandis ( González-Sponga, 2009 )

Huber, Bernhard A. & Villarreal, Osvaldo 2020
2020
Loc

Mecolaesthus grandis

Huber B. A. & Colmenares P. A. & Ramirez M. J. 2014: 417
2014
Loc

Nasuta grandis González-Sponga, 2009: 6

Gonzalez-Sponga M. A. 2009: 6
2009