Mesabolivar argentinensis ( Mello-Leitão, 1938 )

Huber, Bernhard A., 2018, The South American spider genera Mesabolivar and Carapoia (Araneae, Pholcidae): new species and a framework for redrawing generic limits, Zootaxa 4395 (1), pp. 1-178: 98-100

publication ID

https://doi.org/10.11646/zootaxa.4395.1.1

publication LSID

lsid:zoobank.org:pub:B43C234D-45C4-4A6D-9836-8A7524A5B291

persistent identifier

http://treatment.plazi.org/id/160AC713-C615-FFE6-2A9C-987F30BF7D39

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Plazi

scientific name

Mesabolivar argentinensis ( Mello-Leitão, 1938 )
status

 

Mesabolivar argentinensis ( Mello-Leitão, 1938) 

Figs 411–418View FIGURES408–418, 441–442View FIGURES 433–446

Litoporus argentinensis Mello-Leitão, 1938: 92  , fig. 3 (♀, Argentina: Buenos Aires Province).

Mesabolivar argentinensis (Mello-Leitão)  : Huber 2000: 215, figs 840–842 (♀). Huber 2014: 139 (except specimen from P.N. El Palmar and part of specimens from Santa Maria; see Notes below).

Blechroscelis globulosus ( Nicolet, 1849)  : Mello-Leitão 1941: 108, figs 5–6 (misidentification; see Notes below). Mesabolivar globulosus ( Nicolet, 1849)  : Huber 2014: 139 (misidentification; see Notes below).

Notes. In a recent summary on the Pholcidae  of Argentina (Huber 2014), I followed Mello-Leitão’s (1941) assignment of the widespread Argentinean Mesabolivar  to M. globulosus (Nicolet)  . A more detailed study of the available specimens and of Nicolet’s (1849) original description suggests that this was wrong. Nicolet’s (lost) specimen(s) had a globular abdomen and a monochromous carapace; the Argentinean specimens (in Huber 2014 and below) have a slightly elongated abdomen (similar to M. iguazu  , M. chapeco  , etc.; cf. Figs 378–385View FIGURES378–389) and a pale carapace with distinct brown median mark.

At the same time, the female type specimen of M. argentinensis  shares with the specimens listed below two characters that distinguish this species from similar relatives: the absence of paired humps on the anterior epigynal plate ( Figs 417–418View FIGURES408–418, 441–442View FIGURES 433–446) and the absence of lateral dark marks on the carapace. It seems thus justified to assign all the Argentinean specimens below to M. argentinensis  , even though none of them is even close to the type locality, Monte Veloz in Buenos Aires Province. New material from Buenos Aires Province is needed to test this assignment.

Two specimens assigned to M. argentinensis in Huber (2014)  (one male from P.N. El Palmar and one of two males from Santa Maria) are in fact M. uruguayensis Machado et al., 2013  .

Mello-Leitão’s (1941) drawing of the palp of “ Blechroscelis globulosus  ” (his fig. 5) clearly shows the distal spine-like process of the procursus distinctive for what is here considered to be M. argentinensis  (cf. Figs 411– 414View FIGURES408–418). His drawing of the epigynum appears different (compare Mello-Leitão 1941: fig. 6 with Fig. 417View FIGURES408–418 herein) but this is due to different angles of view: his drawing is in ventro-posterior view, the drawing herein is in ventral view.

The identity of Mesabolivar globulosus ( Nicolet, 1849)  (type locality: Chile, Valdivia) remains a mystery.

Diagnosis. (amendments; see Huber 2000). Distinguished from similar congeners ( M. iguazu  , M. uruguayensis  , M. chapeco  ) by absence of dark lateral marks on carapace, by absence of paired humps on anterior epigynal plate ( Figs 417–418View FIGURES408–418, 441–442View FIGURES 433–446), by male cheliceral armature ( Figs 415–416View FIGURES408–418; proximal processes short, rounded, and directed towards lateral; distal apophyses barely visible in lateral view), by details of male palp (tarsus with low but distinct retrolateral hump, procursus with distinctive distal spine-like process and prolaterodorsal sclerite; Figs 411–414View FIGURES408–418), and by first leg femora wider than other leg femora.

Type material. ARGENTINA: Buenos Aires: ♀ holotype, MLPAbout MLP (14031), Monte Veloz [35.45°S, 57.28°W], without date, leg. C. Bruch, examined (Huber 2000).GoogleMaps 

Other material examined. ARGENTINA: Misiones: 1♀, MACNAbout MACN (part of Ar 4350), Parque Nacional Iguazú, Área Cataratas [25°40.7’S, 54°26.9’W], xi.1954 (R.D. Schiapelli, J.A. De Carlo, J.M. Viana, M.E. Galiano)GoogleMaps  . 1♂, MACN (part of Ar 4879), Santa María [27.89°S, 55.35°W, 150 m a.s.l.], x.1956 (M.J. Viana).

Catamarca: 2♂ 1♀ several juvs, MACNAbout MACN (Ar 19940, 20050), Mutquin [28.317°S, 66.117°W], 2000 m a.s.l., i.1996 (O. de Ferrariis)GoogleMaps  . 1♀ 2 juvs, MACN (Ar 20015), El Rodeo [28.217°S, 65.867°W, 1100 m a.s.l.], i.1957 (M.E. Galiano).

Santiago del Estero: 1♂, MACNAbout MACN (Ar 4319), Weisburd [27.33°S, 62.60°W, 160 m a.s.l.], 23.ix.1947 (W. Partridge).GoogleMaps 

Mendoza: 1♀, MACNAbout MACN (Ar 19958), [Dpto. Las Heras: 32°51’S, 68°49’W], Papagallos, vii.1975 (A. Roig)GoogleMaps  . 1♀, MACN (Ar 22139), Ruta Provincial 52, camino a Villavicencio (32°32.8’S, 68°57.4’W) 1250 m a.s.l., 30.viii.2008 (C. Grismado, M. Izquierdo, A. Ojanguren, Martínez).

Tucuman: 1♀, MACNAbout MACN (Ar 20076), Amaichá del Valle [26.60°S, 65.92°W, 1900 m a.s.l.], 17.viii.1995 (M.J. Ramírez, P.A. Goloboff).GoogleMaps 

La Rioja: 1♀ 1 juv., MACNAbout MACN (Ar 20109), Chilecito [29.17°S, 67.5°W, 1100 m a.s.l.], 27–30.i.1956 (M.E. Galiano)GoogleMaps  . 1♀, MACNAbout MACN (Ar 20064), Ruta 40 camino a Famatina [~ 28.92°S, 67.52°W, 1700 m a.s.l.], ix.1981 (A. González)GoogleMaps  . 1♀, MACNAbout MACN (part of Ar 20023), La Rioja, no further locality data, xi.1959 (J.M. Viana). 

Salta: 1♀, MACNAbout MACN ( Ar 20115), La Salamanca, 7 km S Alemanía [~ 25.67°S, 65.60°W, 1300 m a.s.l.], 18.vii.1995 (P.A. Goloboff, M.J. Ramírez)GoogleMaps  . 1♂ in pure ethanol, MACNAbout MACN ( Ar 32453), Alemanía, Ruta Provincial 68, km 80 [25.62°S, 65.61°W], 3.xi.2004 (C.J. Grismado, L.A. Compagnucci).GoogleMaps 

San Juan: 1♂ 2♀ 3 juvs, MACNAbout MACN ( Ar 20036), 50 km N Marayes [~ 31.0°S, 67.25°W, 700 m a.s.l.], 12.iv.1979 (A. Roig).GoogleMaps 

Cordoba: 1♀ several juvs, MACNAbout MACN ( Ar 13530), 2 km E Nono (31°48’S, 64°59’W), 900 m a.s.l., 3–9.ii.2008 (M. Ramírez).GoogleMaps 

Description. Male ( MACNAbout MACN Ar 20036)

MEASUREMENTS. Total body length 4.1, carapace width 1.6. Distance PME-PME 160 µm, diameter PME 130 µm, distance PME-ALE 120 µm, distance AME-AME 30 µm, diameter AME 55 µm. Sternum width/length: 1.0/ 0.6. Leg 1: 35.0 (9.5 + 0.7 + 9.2 + 13.6 + 2.0), tibia 2: 6.1, tibia 3: 4.9, tibia 4: 6.1; tibia 1 L/d: 54. Femora 1–4 width (at half length): 0.30, 0.29, 0.25, 0.25.

COLOR. Specimen bleached, mostly pale ochre-yellow, carapace with distinct brown median mark, without lateral marks, clypeus not darkened, sternum and legs light brown; leg femora and tibiae with subdistal darker rings; abdomen pale gray, dorsally and laterally densely covered with purple marks, ventrally with small light brown area in front of gonopore.

BODY. Habitus as in M. iguazu  (cf. Fig. 382View FIGURES378–389); ocular area raised; carapace with distinct median furrow; clypeus unmodified; sternum unmodified.

CHELICERAE. With two pairs of frontal apophyses ( Figs 415–416View FIGURES408–418), proximal pair weakly sclerotized, rounded and distinctively diverging in frontal view; distal pair similar to putative close relatives, strongly sclerotized and close to median line, barely visible in lateral view.

PALPS. In general similar to M. iguazu  and M. chapeco  (cf. Huber 2000: figs 830, 833; Figs 390–391View FIGURES 390–396 herein); coxa apophysis as in M. iguazu  (not with distinct distal process as in M. chapeco  ), tarsus with low but distinct retrolateral hump; procursus weakly curved, with distinctive distal elements (spine-like process, prolatero-dorsal sclerite, membranous elements; Figs 411–414View FIGURES408–418).

LEGS. Without spines, without curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 3%; prolateral trichobothrium present on tibia 1; tarsus 1 with>25 pseudosegments, distally fairly distinct.

Male (variation). Tibia 1 in three other males: 8.0, 9.1, 9.2.

Female (amendments; see Huber 2000)

Tibia 1 in nine females: 6.1–7.8 (mean 7.1). Epigynal plate evenly protruding towards posterior, with median pocket near posterior margin, without humps ( Figs 417–418View FIGURES408–418; 441–442); posterior epigynal plate large but barely visible. Some females with slightly more prominent ‘scape’ (process carrying epigynal pocket) than others.

Distribution. Apparently widely distributed in northern Argentina ( Fig. 736View FIGURES 736–737). Mello-Leitão’s (1941) records suggest that this species ranges even further north into Jujuy Province.

MLP

Museo de La Plata

MACN

Museo Argentino de Ciencias Naturales Bernardino Rivadavia

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Pholcidae

Genus

Mesabolivar

Loc

Mesabolivar argentinensis ( Mello-Leitão, 1938 )

Huber, Bernhard A. 2018

2018
Loc

Litoporus argentinensis Mello-Leitão, 1938 : 92

Mello-Leitão, 1938 : 92

Loc

Blechroscelis globulosus (

Mello-Leitão 1941 : 108