Habitats Supporting Dytiscid Life

Predaceous diving beetles (Dytiscidae) are a highly speciose group of insects occurring in a large variety of habitat types, where they often form multispecies assemblages, due to their high diversity and large variation in the degree of habitat specificity. While most species have broad habitat preferences, some are specialized for life under extreme habitat conditions. In this chapter, we provide an overview of the main habitats in which dytiscids occur and summarize some of the habitat variables that contribute most to shaping the distribution of dytiscids across habitats and landscapes. These include a range of abiotic conditions and plant–beetle relationships, which act as major habitat selection factors. We discuss how a variety of habitats in agricultural and urban landscapes can contribute to maintain high dytiscid diversity. We then describe some of the most peculiar habitats where dytiscids occur, including phytotelmata, subterranean and interstitial habitats, rockpools, and terrestrial habitats. Over the past couple of decades, examination of habitats that had been typically underexplored for dytiscids has led to the discovery of new species and even new genera. These studies suggest that further exploration of these habitats and the increasing availability of phylogenetic data will provide important insights into the ecology and evolutionary history of species colonizing extreme habitats. This is in turn critical to improve our understanding of the vulnerability of dytiscids to global environmental changes associated with changes in habitat characteristics and availability.