Background: Tenebrionidae (Insecta: Coleoptera) are a conspicuous component of desert fauna worldwide. In these ecosystems, they are significantly responsible for nutrient cycling and show remarkable morphological and physiological adaptations. Nevertheless, Tenebrionidae colonizing individual deserts have repeatedly emerged from different lineages. The goal of our study was to gain insights into the phylogenetic relationships of the tenebrionid genera from the Atacama Desert and how these taxa are related to the globally distributed Tenebrionidae. Methods: We used newly generated transcriptome data (47 tribes, 7 of 11 subfamilies) that allowed for a comprehensive phylogenomic analysis of the tenebrionid fauna of this hyperarid desert and fills a gap in our knowledge of the highly diversified Tenebrionidae. We examined two independent data sets known to be suitable for phylogenomic reconstructions. One is based on 35 neuropeptide precursors, the other on 1,742 orthologous genes shared among Coleoptera. Results: The majority of Atacama genera are placed into three groups, two of which belong to typical South American lineages within the Pimeliinae. While the data support the monophyly of the Physogasterini, Nycteliini and Scotobiini, this does not hold for the Atacama genera of Edrotini, Epitragini, Evaniosomini, Praociini, Stenosini, Thinobatini, and Trilobocarini. A suggested very close relationship of Psammetichus with the Mediterranean Leptoderis also could not be confirmed. We also provide hints regarding the phylogenetic relationships of the Caenocrypticini, which occur both in South America and southern Africa. Apart from the focus on the Tenebrionidae from the Atacama Desert, we found a striking synapomorphy grouping Alleculinae, Blaptinae, Diaperinae, Stenochinae, and several taxa of Tenebrioninae, but not Tenebrio and Tribolium. This character, an insertion in the myosuppressin gene, defines a higher-level monophyletic group within the Tenebrionidae. Conclusion: Transcriptome data allow a comprehensive phylogenomic analysis of the tenebrionid fauna of the Atacama Desert, which represents one of the seven major endemic tribal areas in the world for Tenebrionidae. Most Atacama genera could be placed in three lineages typical of South America; monophyly is not supported for several tribes based on molecular data, suggesting that a detailed systematic revision of several groups is necessary.

Specimens of Gyriosomus (Tenebrionidae, Nycteliini) are conspicuous darkling beetles of the Chilean Atacama desert. Most species of this genus have restricted ranges and emerge as adults only after extensive rainfall. During the last blooming of the desert in 2017, we collected several specimens in the Monumento Natural Paposo Norte (Antofagasta region), which showed morphological differences, such as elytral pilosity pattern and shape of the pronotum, when compared with the sympatric Gyriosomus angustus and G. curtisi as well as other morphologically similar species (G. chango and G. barriai). We analyzed external morphology, female and male external genitalia, and the COI sequences of these specimens and compared these data with those of other species in that subregion. The results support the description of a new species, Gyriosomus camanchacasp. nov., which is more closely related to G. chango than to the sympatric species of the Monumento Natural Paposo Norte. The evolutionary history of Gyriosomus in the Paposo region and its importance for conservation are discussed.

Aim: We investigated the biogeographic pattern of the species‐rich genus Psectrascelis (Coleoptera: Tenebrionidae) in the Central Andes and the Chilean Atacama Desert as an example for insect evolution in such a geologically and climatically highly dynamic arid region. The main aim was to test two alternative hypotheses about the main drivers of diversification of biotas from deserts in the region: Andean uplift versus Pleistocene fragmentation/dispersal.Location: South America, Central Andes, Atacama Desert.Taxon: Psectrascelis (Coleoptera: Tenebrionidae).Methods: A phylogenetic tree based on cytochrome oxidase I, 16S and Wg genes was prepared for multiple individuals from 36 populations of the region representing 14 species or subspecies. Divergence times, ancestral ranges and biogeographic events that may have led to the current distribution and species diversity were estimated.Results: The first split within the genus is not directly related to the Andean uplift but began at the time of global cooling at ~3.5 Ma, when the Andes had already reached their current altitude. Further differentiations of Psectrascelis lineages were mostly caused by common and more global drivers resulting in major clusters of diversifications at ~2.6–2.2 Ma, ~1.3–0.7 Ma and several subsequent events during the mid‐ to late Quaternary. Today, the two main clades of Psectrascelis almost meet each other after presumably synchronous range expansions along the Western Cordillera.Main conclusions: Diversification of Psectrascelis has primarily been affected by global climate changes since the mid‐Pliocene and has involved multiple vicariance and jump dispersal events. We hypothesize that jump dispersal events have occasionally been accompanied by adaptation to stronger aridity, which paved the way for range expansion into previously unsuitable habitats and eventually led to synchronous colonizations without spatial overlap along different isohyets in the Western Cordillera during the late Pleistocene.

The Last Glacial Maximum (LGM) has affected the population size and spatial distribution of a number of organisms in southern Patagonia. It has been h

The arrival and establishment of the spider Steatoda nobilis (Thorell) (Araneae: Theridiidae) in Chile is reported. This record is the first for this alien species in the Southern Hemisphere. A brief diagnosis to recognise the species is provided and the possible ways of entry of this spider to Chile are discussed.