On Venezuelan pholcid spiders (Araneae, Pholcidae)
Author
Huber, Bernhard A.
33607F65-19BF-4DC9-94FD-4BB88CED455F
Zoological Research Museum Alexander Koenig, Bonn, Germany.
b.huber@leibniz-zfmk.de
Author
Villarreal, Osvaldo
679C385E-B068-4351-9D2F-97753E534C26
Museo del Instituto de Zoología Agrícola, Universidad Central de Venezuela, Maracay, Venezuela. & Museu Nacional / UFRJ, Rio de Janeiro, Brazil.
osvaldovillarreal@gmail.com
text
European Journal of Taxonomy
2020
2020-10-01
718
1
317
journal article
10.5852/ejt.2020.718.1101
4069574
F9E9A91E-488C-4DB1-9361-E788E9AC5BC1
Mecolaesthus trampa
Huber
sp. nov.
urn:lsid:zoobank.org:act:
CC180E54-0102-4D0A-9FD3-21EE30ED7698
Figs 427–428
,
435–443
,
462–464
, 1044
Diagnosis
Distinguished from similar congeners (
M. grandis
group) by armature of male chelicerae (
Figs 441– 442
; pair of large frontal processes divided into lateral apophysis with 3–5 modified hairs each and frontal ridge with 4–5 modified hairs each; small process more distally, with 3–4 modified hairs each), by shape of main bulbal process (
Figs 438–440
; distinctive transversal prolateral sclerite), by shape of epigynum (
Figs 462–463
; triangular plate with pair of additional low sclerotized processes laterally), and by internal female genitalia (
Figs 443
,
463–464
; distinctive pair of anterior processes).
Etymology
The species name refers to the
type
locality; noun in apposition.
Type
material
VENEZUELA
–
Táchira
•
♂
holotype
,
ZFMK
(Ar 21926),
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
•
2 ♂♂
,
3 ♀♀
,
ZFMK
(Ar 21927–28), and
1 ♂
,
1 ♀
in pure ethanol,
ZFMK
(Ven20-122), same collection data as for holotype
.
Description
Male
(
holotype
)
MEASUREMENTS. Total body length 3.5, carapace width 1.3. Distance PME–PME
110 µm
; diameter PME
120 µm
; distance PME–ALE
120 µm
; diameter AME
25 µm
; distance AME–AME
20 µm
. Leg 1: 50.7 (12.0 +0.6+12.1 + 23.1 +2.9), tibia 2: 7.9, tibia 3: 6.0, tibia 4: 6.9; tibia 1–4 diameters:
120 µm
,
140 µm
,
150 µm
,
150 µm
; tibia 1 L/d: 101.
COLOR (in ethanol). Carapace pale ochre-gray with wide median dark band and lateral marginal dark bands, ocular area and clypeus also darkened; sternum pale ochre-grey, labium darker brown; legs pale ochre, without darker rings; abdomen pale greenish-gray, dorsally and laterally with dark bluish marks, ventrally with small brown mark in gonopore area, light brown book lung covers, with large median bluish mark; without lateral anterior plates opposing fourth coxae and without plate above pedicel opposing carapace inflation.
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 435–443.
Mecolaesthus trampa
Huber
sp. nov.
; from Táchira, near La Trampa (type locality; ZFMK Ar 21927–28).
435–437
. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views.
438– 440
. Left genital bulb, prolateral, dorsal, and retrolateral views (arrows: distinctive prolateral transversal sclerite).
441–442
. Male chelicerae, frontal and lateral views.
443
. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.
BODY. Habitus similar to
M. lechosa
Huber
sp. nov.
(cf.
Figs 429–430
). Ocular area distinctly raised. Carapace anteriorly with distinct thoracic groove, posteriorly slightly inflated. Clypeus unmodified. Sternum wider than long (0.90/0.75). Abdomen slightly elongated, pointed at spinnerets.
CHELICERAE. As in
Figs 441–442
, with pair of large frontal processes divided into lateral apophysis with 3–5 modified (short conical) hairs each and frontal ridge with 4–5 modified hairs each; with pair of small processes more distally, each with 3–4 modified hairs.
PALPS. In general very similar to putative close relatives [e.g.,
M. tuberculosus
(
González-Sponga, 2009
)
; cf.
Figs 365–366
]; 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 435–437
) at basis with bifid dorsal process with branches of unequal length, with small retrolateral apophysis, distally with pair of partly membranous processes; genital bulb complex (
Figs 438–440
), distally mostly membranous/whitish but with distinctive prolateral transversal sclerite (arrows in
Figs 438–439
).
LEGS. Without spines and curved hairs; few vertical hairs; coxa 4 unmodified; retrolateral trichobothrium of tibia 1 at 3%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~40–45 pseudosegments, mostly distinct.
Male
(variation)
Tibia
1 in
two other males: 10.1, 11.7; other males with indistinct darker rings on leg femora (subdistally).
Female
In general similar to male (
Figs 427–428
) but without carapace inflation, book lung covers
not
darkened. Tibia
1 in
three females: 8.0, 8.1, 8.1. Epigynum (
Fig. 462
) relatively small, triangular, anterior margin straight, with pair of low sclerotized posterior processes laterally (arrows in
Fig. 463
); anterior part of internal receptacle visible in uncleared specimens; without posterior plate. Internal genitalia (
Figs 443
,
463–464
) with pair of distinctive anterior processes arising from sclerite with pore plates, with additional pair of anterior sclerites extending towards lateral and large median receptacle.
Distribution
Known from
type
locality only, in
Venezuela
,
Táchira
(Fig. 1044).
Natural history
Most specimens were collected in sheltered spaces near the ground, in similar webs but less exposed than
M. arepa
Huber
sp. nov.
at the same locality.