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 bienmesabe
Huber
sp. nov.
urn:lsid:zoobank.org:act:
E2F910BC-0121-43EB-A536-5BE7625F5EF2
Figs 386–387
,
410–417
,
424–426
, 1043
Diagnosis
Distinguished from congeners by combination of: armature of male chelicerae (
Fig. 416
; pair of large, rounded frontal processes set with many hairs, 5–7 of them slightly stronger, and 2–3 small modified hairs more distally on weakly sclerotized area; very similar to
M. longipes
Huber
sp. nov.
); by shape of procursus (
Figs 410–412
; very indistinct retrolateral process; distinctive pair of membranous distal processes, more slender than in
M. longipes
Huber
sp. nov.
and straight), by shapes of distal bulbal sclerites (relatively long and slender median sclerite; arrow in
Fig. 413
); by epigynum (
Fig. 424
; wider than long trapezoidal to semicircular brown plate), and by internal female genitalia (
Figs 417
,
425–426
; Y-shaped sclerite connected to median posterior sclerite, pore plates on strong sclerite tilted into vertical position, wing-like anterior sclerites).
Etymology
The species name refers to bienmesabe (Spanish: it tastes good to me), a sweet Venezuelan dessert prepared with honey, egg yolk, and coconut; noun in apposition.
Type
material
VENEZUELA
–
Lara
•
♂
holotype
,
ZFMK
(Ar 21922),
~
5 km
SW of Guarico
,
between Barquisimeto and Boconó
(
9.5906° N
,
69.8343° W
),
1370 m
a.s.l.
,
20 Nov. 2018
(
B.A. Huber
,
O. Villarreal M.
)
.
Other material examined
VENEZUELA
–
Lara
•
7 ♂♂
,
8 ♀♀
,
ZFMK
(Ar 21923–24), and
1 ♂
,
3 ♀♀
in pure ethanol,
ZFMK
(Ven18-204), same collection data as for holotype
•
1 ♂
,
ZFMK
(Ar 21925),
Yacambú National Park
,
Sendero Ecológico
(
9.708° N
,
69.583° W
), ~
1550 m
a.s.l.
,
15–16 Dec. 2002
(
B.A. Huber
,
A. Pérez González
,
O. Villarreal
M.,
B. Striffler
,
A. Giupponi
)
.
Description
Male
(
holotype
)
MEASUREMENTS. Total body length 3.6, carapace width 1.25. Distance PME–PME
80 µm
; diameter PME
130 µm
; distance PME–ALE
100 µm
; diameter AME
25 µm
; distance AME–AME
25 µm
. Leg 1: 44.1 (10.3+0.5+10.7 + 20.1 +2.5), tibia 2: 6.3, tibia 3: 4.7, tibia 4: 5.7; tibia 1–4 diameters:
100 µm
,
120 µm
,
130 µm
,
140 µm
; tibia 1 L/d: 107.
COLOR (in ethanol). Carapace pale ochre-gray with wide median and lateral marginal dark bands, ocular area medially
not
darkened, clypeus with wide dark brown mark; sternum pale ochre-yellow; legs ochre to light brown, without darker rings; 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; without dark mark above pedicel.
BODY. Habitus as in
Fig. 386
. Ocular area distinctly raised. Carapace anteriorly with distinct thoracic groove, posteriorly slightly inflated. Clypeus unmodified. Sternum wider than long (0.80/0.60).Abdomen elongated, pointed at spinnerets.
Figs 410–417.
Mecolaesthus bienmesabe
Huber
sp. nov.
; from Lara, between Barquisimeto and Boconó (type locality; ZFMK Ar 21923–24).
410–412.
Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views.
413–415.
Left genital bulb, prolateral, dorsal, and retrolateral views (arrow: median sclerite on bulbal process).
416
. Male chelicerae, frontal view.
417
. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.
CHELICERAE. As in
Fig. 416
, lateral view as in
M. longipes
Huber
sp. nov.
(cf.
Fig. 408
), rounded frontal processes set with many hairs, five of them slightly stronger, and two small modified hairs more distally on weakly sclerotized area.
PALPS. In general similar to
M. longipes
Huber
sp. nov.
(cf.
Figs 399–400
); coxa with retrolateral apophysis, trochanter with small ventral process, femur proximally with large retrolateral process, distally with prominent rounded ventral process (shorter than in
M. longipes
Huber
sp. nov.
), retrolateral trichobothrium of tibia in very distal position; procursus (
Figs 410–412
) at basis with bifid dorsal process with branches of unequal length, with very indistinct retrolateral process, distally with membranous dorsal process and proximally slightly sclerotized, distally pointed ventral process; genital bulb complex (
Figs 413–415
), distally mostly membranous/whitish but with distinctive distal sclerites.
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 ~40 pseudosegments, mostly distinct.
Male
(variation)
Tibia
1 in
seven males (incl.
holotype
): 9.6–10.7 (mean 10.1); most males with light to dark brown book lung covers, but anterior brown plates opposing fourth coxae absent in some males. Number of modified hairs on chelicerae slightly variable (5–7 on large rounded processes; 2–3 distally).
Figs 418–426.
Mecolaesthus
Simon, 1893
; epigyna, ventral views and cleared female genitalia, ventral and dorsal views.
418–420
.
M. niquitanus
(González-Sponga, 2011)
; from Trujillo, Laguna Negra (ZFMK Ar 21912).
421–423
.
M. longipes
Huber
sp. nov.
; from Mérida, Mucuy (type locality; ZFMK Ar 21916).
424–426
.
M. bienmesabe
Huber
sp. nov.
; from Lara, between Barquisimeto and Boconó (type locality; ZFMK Ar 21924).
Female
In general similar to male (
Fig. 387
), also with variably dark book lung covers but never with brown plates opposing fourth coxae. Tibia
1 in
five females: 6.3–7.4 (mean 6.9). Epigynum (
Fig. 424
) wider than long, trapezoidal to semicircular brown plate, internal structures and posterior median dark sclerite variably visible in uncleared specimens. Internal genitalia (
Figs 417
,
425–426
) with Y-shaped sclerite connected to median posterior sclerite, pore plates on strong sclerite tilted into vertical position, and wing-like anterior sclerites.
Distribution
Known from two localities in the Venezuelan state
Lara
(Fig. 1043).
Natural history
At the
type
locality the spiders built their strongly curved dome-shaped webs close to the ground in a forest fragment along a small stream.