Coleópteros epígeos (Insecta: Coleoptera) asociados a ecotopos dunarios de la cordillera de la costa de Chile

Abstract

The coastal mountain range of Los Choros (Coquimbo Region) is a natural system with geomorphological characteristics (e.g., dunes, ravines and extensive plains at sea level) which allow for a flora and fauna adapted to arid conditions. These ecosystems are part of Chile's transitional coastal desert, an area characterized by high arthropod species diversity and endemism. In this work we examine the taxonomic composition and density-activity of the assemblage of epigean coleopterans in the following ecotopes of the coastal range of Los Choros: paleodunes (E1), ravine (E2) and plain (E3). In each of these ecotopes, captures were conducted using pitfall traps, which remained active for three days during August, October, and December of 2007. A total of 361 specimens were captured, representing 21 species distributed in 16 genera and 4 families. The most diverse families were Tenebrionidae and Curculionidae, with 12 and 6 species, respectively, whereas the most abundant were Curculionidae (69.7% of total capture) and Tenebrionidae (31.0%). The most diverse ecotope was the paleodune (14 species), followed by the plain (10 species) and ravine (9 species). The ecotope that contributed the highest number of epigean coleopterans to the capture throughout the study period was the paleodune (75.9%), followed by the plain (14.1%) and ravine (10.0%). The highest number of specimens were captured on October (63.2%), probably explained by the vegetation dynamics of the sites under study. The higher richness and abundance of epigean coleopterans observed in the paleodune ecotope may be related to the characteristics of the substrate, which would provide ideal conditions for the life cycle of these insects. We document the importance of dune ecotopes as arthropod diversity and endemism hotspots in the area. For all of the above reasons, it is necessary to protect and preserve the biota of these ecosystems that are constantly subject to anthropic modification. This work is a contribution to the knowledge of the communities of epigean coleopterans present in the coastal mountain range of the semiarid region of Chile. © 2014 Universidad de Tarapacá.