Abstract The north of Neuquén province shares with the south of Mendoza province the subprovince Payunia of the biogeographical province of Patagonic steppe, which is characterized by the presence of approximately 800 volcanoes. Although we have conducted several samplings in volcanoes of Mendoza in past years to recognize the biodiversity of tenebrionids, it is still pending which is the role that these mountains have in the biota of tenebrionids in Neuquén. In this work we reported the results of two consecutive years of prospection in two volcanoes separated by 120 km between each other, Tromen and Auca Mahuida which have 3978 and 2215 meters above sea level respectively. We found that Auca Mahuida harbours a total diversity of 10 tenebrionid species and Tromen 9, but these communities were significantly different between them. From these prospections two new endemic species of Tenebrionidae are described: Scotobius aucamahuidensis Silvestro sp. nov. (Tenebrioninae: Scotobiini) from Auca Mahuida and Psectrascelis tromensis Flores sp. nov. (Pimeliinae: Nycteliini) from Tromen. Photographs for these two new species are included, with comparisons to other known species of these genera. Based on these results we discuss the role of different factors that influence tenebrionid diversity and their implications to conserve biodiversity.

The Neotropical genus Scotobius Germar (Tenebrioninae: Scotobiini) comprises 61 species distributed from central Peru and southern Brazil to southern Argentine and Chile. In this contribution two species of Scotobius: S. punctatus Eschscholtz, 1831 and S. andrassyi Kaszab, 1969, that inhabit in western San Juan, Mendoza, and Neuquén provinces (Argentina) and in central Chile, along the “Cordillera de los Andes” and extra-Andean mountains in Argentina, are revised. Redescriptions using new morphological data and photographs of habitus and pronota are provided. This article informs about the geographic distribution, altitudinal ranges and the biogeographic provinces that these species inhabit. A predictive model of species distribution is presented to propose hypothesis about the factors that influence the space distribution and the allopatry of these two species.

El género neotropical Scotobius Germar (Tenebrioninae: Scotobiini) comprende 61 especies distribuidas desde el centro de Perú y sur de Brasil hasta el sur de Argentina y Chile. En este trabajo, revisamos dos especies de Scotobius que habitan el oeste de las provincias de San Juan, Mendoza y Neuquén (Argentina) y en Chile central, a lo largo de la Cordillera de los Andes y las montañas extra-andinas en Argentina: S. punctatus Eschscholtz, 1831 y S. andrassyi Kaszab, 1969. Se proveen redescripciones utilizando nuevos caracteres morfológicos y se proporcionan fotografías de los adultos y de los pronotos. Se consigna la distribución geográfica, rangos altitudinales y las provincias biogeográficas en las que habitan estas especies. Se utiliza un modelo predictivo de distribución de especies para proponer hipótesis sobre los factores que influencian la distribución espacial y que explicarían la alopatría de ambas especies.