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 chicha
Huber
sp. nov.
urn:lsid:zoobank.org:act:
F0D1196A-2958-46E1-BFA7-54F38F06063C
Figs 277–279
,
283–290
,
300–302
, 1042
Diagnosis
Easily distinguished from known congeners (including the otherwise very similar
M. parchita
Huber
sp. nov.
) by armature of male chelicerae (
Fig. 289
; pair of pointed apophyses proximally arising from round humps and pair of blunt processes more distally) and by epigynum (
Fig. 300
; only median area sclerotized, widening posteriorly,
not
divided into two median sclerites as in
M. parchita
Huber
sp. nov.
).
From most congeners (except
M. parchita
Huber
sp. nov.
) also by two dark rings on leg femora (instead of only one or none).
Etymology
The species name refers to
chicha
, a Latin American beverage. In
Venezuela
it is made of boiled rice, milk, and sugar, has the consistency of eggnog, and contains no alcohol as it is
not
fermented; noun in apposition.
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.
Type
material
VENEZUELA
–
Mérida
•
♂
holotype
,
ZFMK
(Ar 21891),
between Bailadores and Pregonero
(
8.1701° N
,
71.8990° W
),
2960 m
a.s.l.
,
forest along stream
,
9 Feb. 2020
(
B.A. Huber
,
O. Villarreal M.
,
Q. Arias C.
)
.
Other material examined
VENEZUELA
–
Mérida
•
5 ♂♂
,
7 ♀♀
,
5 juvs
,
ZFMK
(Ar 21892–93), and
1 ♂
,
5 ♀♀
,
7 juvs
in pure ethanol,
ZFMK
(Ven20-116), same collection data as for holotype
.
Description
Male
(
holotype
)
MEASUREMENTS. Total body length 2.8, carapace width 1.2. Distance PME–PME
120 µm
; diameter PME
110 µm
; distance PME–ALE
90 µm
; diameter AME
25 µm
; distance AME–AME
20 µm
. Leg 1: 25.6 (6.0 +0.5 +6.1+10.8 + 2.2), tibia 2: 3.9, tibia 3: 3.0, tibia 4: 3.5; tibia 1–4 diameters:
120 µm
,
130 µm
,
140 µm
,
135 µm
; tibia 1 L/d: 51.
COLOR (in ethanol). Carapace pale gray, lateral margins and ocular area darker brown, indistinct posterior internal triangular dark mark (in live specimens with large greenish central mark;
Fig. 277
); clypeus dark brown; sternum whitish; legs ochre-yellow, 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 brown mark in gonopore area, light brown book lung covers, and large bluish median marks in front and behind gonopore; without dark mark above pedicel.
BODY. Habitus as in
Fig. 277
. Ocular area distinctly raised. Carapace anteriorly with distinct but shallow thoracic groove;
not
visibly inflated. Clypeus unmodified. Sternum wider than long (0.76/0.58). Abdomen oval, pointed at spinnerets.
CHELICERAE. As in
Fig. 289
, with pair of pointed apophyses proximally arising from round humps and pair of blunt processes 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. parchita
Huber
sp. nov.
; coxa with retrolateral apophysis, trochanter with small rounded ventral process, femur proximally with large retrolateral process, distally with short obtuse ventral process (arrow in
Fig. 283
), retrolateral trichobothrium of tibia in very distal position; procursus (
Figs 283–285
) at basis with bifid dorsal process, with distinct retrolateral process, simple tip partly membranous; genital bulb complex (
Figs 286–288
), distally mostly membranous/whitish but with distinctive distal sclerites (largely identical to
M. parchita
Huber
sp. nov.
; similar
M. peckorum
).
LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 5%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~40 pseudosegments, mostly distinct.
Male
(variation)
Tibia
1 in
six males (incl.
holotype
): 6.1–6.3 (mean 6.2); posterior internal mark on carapace sometimes absent.
Female
In general similar to male (
Fig. 278
). Tibia
1 in
seven females: 4.4–5.1 (mean 4.7). Epigynum (
Fig. 300
) slightly protruding, only median area sclerotized, laterally whitish, sclerotized area widening posteriorly; posterior plate short and wide. Internal genitalia (
Figs 290
,
301–302
) with Y-shaped sclerite connected
Figs 283–290.
Mecolaesthus chicha
Huber
sp. nov.
; from Mérida, between Bailadores and Pregonero (type locality; ZFMK Ar 21892–93).
283–285
. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views (arrow: ventral femur apophysis).
286–288
. Left genital bulb, prolateral, dorsal, and retrolateral views.
289
. Male chelicerae, frontal view.
290
. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.
to median posterior sclerite, pore plates tilted into almost vertical position and converging dorsally and anteriorly; with complex system of anterior folds and arcs.
Distribution
Known from
type
locality only, in
Venezuela
,
Mérida
(Fig. 1042).
Natural history
Most adult specimens were found close to the ground, by beating overhanging mosses growing on the rocks or overhanging masses of leaf litter near a small forest stream. They lived in small, relatively flat sheet webs with a diameter of ~
10 cm
. Juveniles were much lighter than adults (
Fig. 279
) and were mostly found higher in the vegetation, on trunks of tree ferns or even on the undersides of green leaves.