Atlas of Ohio Aquatic Insects: Volume II, Plecoptera

We provide volume II of a distributional atlas of aquatic insects for the eastern USA state of Ohio. This treatment of stoneflies (Plecoptera) is companion to Armitage et al. (2011) on caddisflies (Trichoptera). We build on a recent analysis of Ohio stonefly diversity patterns based on large drainages (DeWalt et al. 2012), but add 3717 new records to the data set. We base most analyses on the United States Geological Survey Hierarchical Unit Code eight (HUC8) drainage scale. In addition to distributional maps for each species, we provide analyses of species richness versus HUC8 drainage area and the number of unique locations in a HUC8 drainage, species richness versus Ohio counties, analyze adult presence phenology throughout the year, and demonstrate stream size range affiliation for each species.

This work is based on a total of 7797 specimen records gathered from 21 regional museums, agency data, personal collections, and from the literature Table 1. To our knowledge this is the largest stonefly data set available for a similarly sized geopolitical area anywhere in the world. These data are made available as a Darwin Core Archive supported by the Pensoft Integrated Publishing Toolkit (DeWalt et al. 2016b). All known published papers reporting stoneflies from Ohio are detailed in Suppl. material 1. We recovered 102 species from Ohio, including all nine Nearctic families Table 2​. Two species were removed from the DeWalt et al. (2012) list and two new state records added. Perlidae (32 spp.) was most speciose, compared to the low diversity Pteronarcyidae (2 spp.) and Peltoperlidae (1 sp.). The richest HUC8 drainages occurred in northeastern, south-central, and southern regions of the state where drainages were heavily forested, had the highest slopes, and were contained within or adjacent to the unglaciated Allegheny and Appalachian Plateaus. Species poor drainages occurred mainly in the northwestern region where Wisconsinan aged lake plains climaxed to an expansive wooded wetland, the Black Swamp. The unglaciated Lower Scioto drainage (72 spp.) in south-central Ohio supported the greatest species richness. There was no relationship between species richness and HUC8 drainage size, but the number of unique locations in a drainage strongly related to species richness. All Ohio counties were represented in the data set with Hocking County (59 spp.) of the Lower Scioto drainage being the richest and most heavily sampled. Adult presence phenology was influenced by phylogenetic relationships such that the superfamily Nemouroidea (Capniidae, Leuctridae, Nemouridae, and Taeniopterygidae) generally emerged in winter and spring while the superfamilies Pteronarcyoidea (Pteronarcyidae, Peltoperlidae) and Perloidea (Chloroperlidae, Perlidae, Perlodidae) emerged later, some species continuing emergence through summer months. Species often occupied specific stream size ranges, while others were generalists. Two species once histrorically abundant in the western Lake Erie Bass Islands no longer reside there. Each of the 102 species is discussed in detail, including several that require additional collecting efforts to confirm their identities, presence, and distribution in Ohio.