Pachomius areteguazu sp. nov. (araneae: salticidae: freyina), and the first description of the epigynum of a member of the nigrus group

Abstract

Our latest collections in northeastern Argentina include new species of jumping spiders (Salticidae) that indicate that the diversity of this group in Argentina is indeed underestimated. This paper describes and illustrates a new species, Pachomius areteguazu sp. nov., an inhabitant of the grasslands of northeastern Argentina. Within the genus Pachomius, this new species is placed in the nigrus group (Edwards 2015) because it has a sclerotized lateral subterminal apophysis (LSA) next to the embolus, spine-shaped, possibly derived by loss of the membranous part of the LSA. Previously no females in the nigrus group were known, so we also present the first description of an epigynum for this group and discuss its relationship to the LSA with respect to copulation.