Epigean Tenebrionids (Coleoptera: Tenebrionidae) from Leones and Tova-Tovita Islands (Chubut, Argentina) and Its Comparison with the Mainland Assemblage

Abstract

The Parque Interjurisdiccional Marino Costero Patagonia Austral (PIMCPA) protects over 180 km of Patagonian Atlantic coastline of northern San Jorge gulf, including an archipelago that comprises more than 39 islands. In this work, we studied the darkling beetles (Coleoptera: Tenebrionidae) of the two largest islands in the PIMCPA archipelago: Leones and Tova-Tovita. Tenebrionids are reported for first time in these islands, in addition, we described their species assemblage. Likewise, a comparison between the islands and the mainland was also performed. The GLM, MDS, ANOSIM and PCA methods were employed. Islands share the same tenebrionid species assemblage but they differ from that displayed on the mainland. Considering both islands as a whole, the insular assemblage shows lower species richness and diversity than those seen in the mainland. We identified eight species in the islands which belong to eight genera and four tribes. We also found that six of these species were shared among islands. Psectrascelis punctipennis Kulzer was exclusively recorded from the Tova-Tovita, while Platesthes kuscheli Kulzer from the Leones island. The island assemblage is mainly composed of nocturnal or crepuscular species [including Praocis (Hemipraocis) sellata bergi Burmeister, Patagonogenius quadricollis (Fairmaire), Emmallodera crenaticostata crenaticostata Blanchard and Scotobius akidioides akidioides Waterhouse], while several diurnal species of Nyctelia Berthold are the most common and diverse darkling beetles among mainland fauna. Additionally, we discuss the effects of the mainland distance, paleoclimate, and the origin of insular assemblages. Finally, other insular implications of tenebrionid beetles are discussed.