Modisimus Simon, 1893

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 201

Modisimus Simon, 1893

Notes

The genus Modisimus is species rich in Mexico, Central America and the Antilles. Unpublished data suggest that the 79 extant species formally described from this region are just a small fraction of the actual diversity. For example, a recent collecting trip in Mexico (Oct. 2019) resulted in ~33 species of Modisimus , of which ~28 (i.e., 85%) are considered new (B.A. Huber, A. Valdez M., unpubl. data); extensive collections in the Caribbean (mostly 2011–2014) resulted in ~98 species, of which ~72 (i.e., 73%) are considered new (B.A. Huber, I. Agnarsson, G. Binford, unpubl. data).

By contrast, available data suggest that Modisimus is poorly represented in South America. Only three species have previously been reported from mainland South America: the pantropical M. culicinus (Simon, 1893) ; M. simoni Huber, 1997 from Venezuela [including its junior synonym M. minimus ( González-Sponga, 2009) ; see below]; and M. globosus Schmidt, 1956 from Colombia. A fourth species is newly described below. The faunal turnovers seem to lie somewhere in the Darien Gap linking Panama and Colombia and between the Lesser Antilles (which have a rich unpublished fauna) and Trinidad (with no representative of Modisimus except M. culicinus known to exist in collections).

To some degree, this marked turnover is probably artificial. The pholcid fauna of Colombia is very poorly known, and the near-coastal regions of Venezuela may also be home to further species. It is unknown whether Modisimus has been largely replaced by other taxa in South America or whether it has colonized South America via Panama and the Lesser Antilles. The apparent absence of relict species (e.g., in caves and arid regions of Brazil) suggests that the second scenario is more likely.