D3542: What we’ve lost: Reviewing historical stonefly (Insecta: Plecoptera) distributions and species diversity trends within the Midwest, USA

Reviewing specimens archived in curated natural history museum collections provides crucial information on where species historically occurred. This baseline knowledge can be used to document how distributions have changed over time and, in turn, inform conservation prioritization. Stoneflies (Insecta: Plecoptera) are a primitive order of primarily aquatic insects well known for their sensitivity to environmental changes. Within the Midwest, USA (Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin), numerous stoneflies have undergone severe range contractions, including multiple documented regional extirpations and several species extinctions. Utilizing a rich dataset of 39,000 species occurrence records compiled from 1865 to the contemporary period, we review historical distributions of the Midwest stonefly fauna, document where species losses within the region have occurred, and identify where refugia of species diversity remain. Further, we associate species displaying narrow habitat preferences, presence of egg or nymphal diapause, and limited dispersal capabilities as undergoing the most severe distribution contractions regionally.