Metagonia triocular (González-Sponga, 2011)

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 191-195

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.4343933

persistent identifier

https://treatment.plazi.org/id/03E887AD-FF6E-7AC3-FD8D-FD60F8CFFC15

treatment provided by

Valdenar

scientific name

Metagonia triocular (González-Sponga, 2011)
status

 

Metagonia triocular (González-Sponga, 2011) View in CoL

Figs 681–682 View Figs 681–686 , 687–697 View Figs 687–692 View Figs 693–697 , 702–704 View Figs 702–707 , 1054

Porteña triocular González-Sponga, 2011b: 42 , pl. 4, figs 1–9.

Metagonia triocular View in CoL – Huber et al. 2014a: 419.

Diagnosis

Easily distinguished from known congeners by strong ventral hinged process on procursus distally sclerotized and directed toward prolateral ( Figs 688 View Figs 687–692 , 694 View Figs 693–697 ); also by pair of processes on male clypeus ( Figs 690 View Figs 687–692 , 696 View Figs 693–697 ), by modifications of male chelicerae ( Fig. 696 View Figs 693–697 ; pair of proximal lateral ridges, pair of small frontal processes, and pair of distal patches of globular hairs); and by tongue-shaped posterior sclerite of epigynum ( Figs 691–692 View Figs 687–692 , 702 View Figs 702–707 ) and elongate pore plates ( Fig. 697 View Figs 693–697 ).

Type material

VENEZUELA La Guaira • ♂ holotype and 1 ♀ paratype, MIZA 105645 View Materials ( MAGS 1349 ), Hacienda El Limón [approximately 10.475° N, 67.283°E, see Note below], 1100 m a.s.l., 25 Jan. 1992 (A.R. Delgado, M.A. González S.); examined GoogleMaps .

New record

VENEZUELA – Aragua • 4 ♂♂, 4 ♀♀, ZFMK (Ar 22046), and 5 ♀♀ in pure ethanol, ZFMK (Ven20- 164), Henri Pittier National Park , NE El Castaño (10.3475° N, 67.5850° W), 990 m a.s.l., bamboo litter, 20 Feb. 2020 (B.A. Huber, O. Villarreal M.) GoogleMaps .

Note

The exact coordinates of the type locality are unknown to us but the coordinates given above are probably within ~ 1 km of the collecting site. González-Sponga’s (2011b) coordinates of Hacienda El Limón are ~ 20 km S, in the state of Aragua.

Redescription

Male (NE El Castaño, ZFMK Ar 22046)

MEASUREMENTS. Total body length 2.2, carapace width 0.70. Distance PME–PME 70 µm; diameter PME 80 × 100 µm; distance PME–ALE 30 µm; AME absent. Leg 1: 14.5 (3.8 +0.3+ 3.5+5.9+ 1.0), tibia 2: 2.2, tibia 3: 1.5, tibia 4: 2.2; tibia 1 L/d: 50; all femora approximately same diameter.

COLOR (in ethanol). Carapace pale ochre yellow, with brown median mark of distinctive shape including ocular area and clypeus; sternum whitish; legs ochre-yellow, patellae and tibia-metatarsus joints dark brown; abdomen pale grey, with some black marks dorsally, ventrally monochromous.

BODY. Habitus as in Fig. 681 View Figs 681–686 . Ocular area barely raised. Carapace without thoracic groove. Clypeus with pair of weakly sclerotized conical processes ~ 70 µm long ( Fig. 696 View Figs 693–697 ). Sternum slightly wider than long (0.50/0.46), unmodified. Abdomen with rounded conical elongation above spinnerets.

CHELICERAE. As in Fig. 696 View Figs 693–697 , with pair of proximal lateral ridges, pair of small frontal processes, and pair of distal patches of 9–10 globular hairs on each side.

PALPS. As in Figs 687–689 View Figs 687–692 ; coxa unmodified, trochanter with short ventral apophysis; femur distally widened, without process; retrolateral trichobothrium on tibia in very distal position ( not absent as stated in original description); procursus ( Figs 693–695 View Figs 693–697 ) with large ventral hinged process distally strongly curved toward prolateral and ending in sclerotized flap with small scales on ventral face; main branch of procursus distally bifid, one part sclerotized, other part membranous and transparent; genital bulb globular, with tubular embolus ending in spine.

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium of tibia 1 at 13%; prolateral trichobothrium absent on tibia 1; tarsus 1 with ~20 pseudosegments, only distally fairly distinct.

Male (variation)

Tibia 1 in three other males 3.1, 3.3, 3.7. Number of modified hairs on chelicerae slightly variable.

Female

In general similar to male ( Fig. 682 View Figs 681–686 ) but clypeus unmodified and not darkened, ocular area with median and lateral marginal dark marks, otherwise light, posterior triangular mark similar to male but lighter; sternum in some females darker. Tibia 1 in nine females: 2.8–3.3 (mean 3.1). Epigynum ( Figs 691–692 View Figs 687–692 , 702 View Figs 702–707 ) mostly unsclerotized except posterior tongue-shaped sclerite (strongly raised in paratype), internal median receptacle and arc visible in uncleared specimens. Internal genitalia ( Figs 697 View Figs 693–697 , 703–704 View Figs 702–707 ) symmetric, with simple anterior arc and narrow pore plates.

Distribution

Known from two localities in the Venezuelan states La Guaira and Aragua (Fig. 1054).

Natural history

According to González-Sponga (2011b), the type specimens were collected from dead Cecropia leaves in the understory of a forest with coffee. Near El Castaño the spiders were found in dead bamboo culm sheaths on the ground. They were extremely well camouflaged and did not react to disturbance, i.e., were difficult to spot but easy to collect.

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

Metagonia

Loc

Metagonia triocular (González-Sponga, 2011)

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

Metagonia triocular

Huber B. A. & Colmenares P. A. & Ramirez M. J. 2014: 419
2014
Loc

Porteña triocular González-Sponga, 2011b: 42

Gonzalez-Sponga M. A. 2011: 42
2011
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