Mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) (a.k.a. EPT taxa) are the most environmentally sensitive of freshwater insects. They are utilized the world over as indicators of water quality in flowing waters. Their decline has been documented in Asia, Europe, and North America. A 220,321 record dataset of new and museum EPT specimen records covering much of the Midwest and Maximum Entropy (Maxent) software were used construct to current and future, climate influenced distribution models. Nearly 100 physical and historic vegetation variables and 9 BIOCLIM variables derived from downscaled climate data for the region were employed in this process. A total of 426 EPT species were modeled across Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin (117 Ephemeroptera, 95 Plecoptera and 214 Trichoptera species). Mayflies and stoneflies were predicted to increase in range and in species richness throughout the region. Caddisflies were predicted to lose range on average, decreasing in richness. Generally, areas of low to moderate richness are predicted to gain species by the end of the century. Much variation in predicted change of species range and species richness patterns were due to which climate model was used to calculate the prediction. Effort must take place to understand which climate models produce the most accurate results. Future work should center on identifying and rehabilitating pathways and barriers to dispersal of EPT taxa.
