Mesabolivar difficilis (Mello-Leitão, 1918)

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: 111

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Mesabolivar difficilis (Mello-Leitão, 1918)


Mesabolivar difficilis (Mello-Leitão, 1918) 

Figs 459View FIGURES 459–469, 522–524View FIGURES 520–537

Physocyclus difficile Mello-Leitão, 1918: 112  , figs 28–29 (♀, Brazil: Rio de Janeiro). Physocyclus difficilis: Bonnet 1958: 3650  .

Mesabolivar difficilis: Huber 2000: 235  , figs 924–933 (♂ ♀). Machado 2007: 52. Huber & Rheims 2011: 281. Castanheira et al. 2016: 13.

Misidentification (see Note below)

Mesabolivar difficilis: Bonaldo et al. 2009: 220  .

Type material. BRAZIL: Rio de Janeiro: 4♂ 4♀ syntypes (? – see Huber 2000), MNRJ, Pinheiro [22.52°S, 44.00°W], leg. C. de Mello-Leitão, examined (Huber 2000).GoogleMaps 

New records. BRAZIL: Rio de Janeiro: 2♂ 2♀, ZFMK (Ar 19201), Reserva Ecológica Rio das Pedras (22°59.5’S, 44°06.0’W), 50 m a.s.l., night, 25.ix.2009 (B.A. Huber)GoogleMaps  ; 1♂, ZFMK ( Ar 19202), same data but day, 26.ix.2009GoogleMaps  ; 3♀ in pure ethanol, ZFMK ( Br 09-110), same locality, 25–26.ix.2009 (B.A. Huber)GoogleMaps  ; 2♂ 4♀, ZFMK ( Ar 19203) and 1♂ 1♀, MNRJ (14320), same locality at 22°59.5’S, 44°06.0’–06.8’W, 50–200 m a.s.l., day, 26.ix.2009 (A. Giupponi)GoogleMaps  . 1♂ in pure ethanol, ZFMK (G009), Itatiaia [22.49°S, 44.57°W], 8– (H. Japyassú).GoogleMaps 

São Paulo: 1♀, ZFMK (Ar 19204), Ubatuba, Fazenda Angelim (23°23.6’S, 45°03.7’W), leaf litter, 16– 18.xii.2003 (B.A. Huber).GoogleMaps 

Description (amendments; see Huber 2000). Tibia 1 in six newly examined males: 4.3–5.1 (mean 4.7); in eight females: 3.2–4.0 (mean 3.7). Male leg femora 2 and 3 wider than others (diameters femora 1–4 in one male: 0.20, 0.28, 0.26, 0.19). Male eye measures: distance PME-PME 75 µm, diameter PME 125 µm, distance PME-ALE 60 µm, distance AME-AME 20 µm, diameter AME 30 µm.

Natural history. The spiders were found in leaf litter and under logs.

Distribution. Known from several localities in the Serra da Mantiqueira Mountains, Rio de Janeiro and São Paulo sates, Brazil ( Fig. 738View FIGURES 738–739); the species may be even more widely distributed, assuming that Machado’s (2007) record for Minas Gerais state is correct.

Note. The female specimens from Reserva Ducke (Manaus) identified by Bonaldo et al. (2009) as M. difficilis  were reexamined (3♀, SMNK-ARA 3008, 12794, 12821). They clearly belong to a different species, most easily distinguished from M. difficilis  by the epigynum in lateral view (apophyses shorter and directed towards ventral, not towards frontal (compare Figs 522 and 528View FIGURES 520–537). In addition, the sternum in these females is provided posteriorly with much longer and slightly stronger hairs; in M. difficilis  , all hairs on the female sternum are more or less of equal length. Newly collected females from a nearby locality (Amazonas, Presidente Figueiredo, near Maroaga Cave, 2.050°S, 59.972°W) (2♀, ZFMK Ar 19205, and 1♀ in pure ethanol, ZFMK, Br16-342) are very similar to the females from Reserva Ducke but have slightly stronger epigynal apophyses ( Figs 525–527View FIGURES 520–537). Legs of Amazonian specimens tend to be shorter than in M. difficilis  (tibia 1 in five females: 2.7–3.0, mean 2.8). Since no males of these Amazonian species are known, they are not formally described here.


Museu Nacional/Universidade Federal de Rio de Janeiro


Zoologisches Forschungsmuseum Alexander Koenig














Mesabolivar difficilis (Mello-Leitão, 1918)

Huber, Bernhard A. 2018

Mesabolivar difficilis:

Huber & Rheims 2011 : 281