Dr. Greg Courtney, Iowa State University, Department of Entomology
Abstract. Little is known about the distribution and diversity of psammophilic ("sand-loving") aquatic insects in the upper Midwest. This fauna contains some of the most bizarre insects in terms of structural and behavioral adaptions to life in unstable shifting-sand and sand-bar habitats. Despite a long history of interest in psammophilic taxa, especially regarding mayflies, knowledge about their distribution and ecology remain poor, and has led to a general assumption that taxa are rare. The main objective of this survey was to provide baseline data on psammophilic insects in Iowa and the upper Midwest, focusing on shifting-sand and sand-bar habitats in local rivers. Collections confirm that many of these psammophiles are not rare, but merely rarely captured by standard collecting methods. Accurate assessment of the presence and abundance of these insects requires collection methods that effectively survey the habitat, as well as appropriate timing of sampling (e.g., when nymphs are present). Collection data suggest further that habitat degradation (e.g., clean sand replaced by mud) and environmental change (e.g., more frequent and "poorly timed" floods, increasing temperatures, decreasing precipitation) may impact local populations of psammophilic insects, potentially before we can even document their presence.