A SYSTEMATIC STUDY OF THE HIGHLY ENDEMIC SPIDER BEETLE FAUNA (COLEOPTERA: PTINIDAE: PTININAE) FOUND IN THE COASTAL DESERTS OF PERÚ

Spider beetles are small, often flightless insects that occur in hyperarid environments around the world. They exhibit interesting morphology and behavior that allows them to conserve water they obtain from plant material, dung, and other detritus. One hyperarid region in which they are found is the Pacific coast of Perú and northern Chile. The Sechura Desert, Peruvian Coastal Desert, and Atacama Desert make up the arid coast where spider beetles occur from north to south. Through multiple years of field work and museum collections, populations of spider beetles were found along the coast in isolated pockets of vegetation, separated by barren desert. Most populations were determined to represent separate species based on morphological and molecular evidence. Five new species of Cordielytrum Philips are described from the Sechura, Peruvian Coastal, and Atacama Deserts. New genera have also been discovered, Furcillifer (undescribed and in manuscript) and Achenotus gen. nov. (Chapter 2), from south and north of the city of Lima, Perú, respectively. To understand how these small, isolated populations might have evolved, I analyzed morphological adaptations and proposed a phylogeny using mitochondrial and nuclear ribosomal DNA sequences and multiple analyses. Each Peruvian genus included in the phylogeny is discussed, with special attention to polyphyletic groups, basal clades, and biogeographical distributions. I also created a Timetree to compare taxon splits with geological events that may have facilitated the current diversity of species. Note that names of taxa herein and not yet published should be considered invalid and not accepted as per the rules in the Zoological Code of Nomenclature.