1 Ohio Biological Survey Notes 9: 1–15, 2019. © Ohio Biological Survey, Inc. New Ohio and Indiana Records of Aquatic Insects (Ephemeroptera, Plecoptera, Trichoptera, Coleoptera: Elmidae, Diptera: Chironomidae) Michael J. Bolton 1 , Sarah K. Macy 2 , r. edward dewalt 3 , and luKe M. JacoBuS 4 1 Ohio Environmental Protection Agency, Division of Surface Water, 4675 Homer Ohio Lane, Groveport, OH 43125, Michael.Bolton@epa. ohio.gov; 2 Formerly with the Ohio Environmental Protection Agency; current e-mail: sarahk5678@gmail.com; 3 University of Illinois, Illinois Natural History Survey, 1816 S Oak St., Champaign, IL 61820, dewalt@illinois.edu; 4 Indiana University–Purdue University Columbus, 4601 Central Avenue, Columbus, IN 47203, lukemjacobus@alumni.purdue.edu. Abstract: New state records and additional locations for rarely collected species are reported for Ephemeroptera (mayfies), Plecoptera (stonefies), Trichoptera (caddisfies), Coleoptera: Elmidae (riffe beetles), and Diptera: Chironomidae (chironomids, non-biting midges, midges). These specimen records result primarily from Ohio Environmental Protection Agency biomonitoring of Ohio streams and from records found in the Purdue University Entomological Research Collection and the Illinois Natural History Survey Insect Collection; a few records were derived from material housed in two other collections. New state records for Ohio consist of the mayfies Acentrella rallatoma Burian & Myers, Acerpenna pygmaea (Hagen), Anafroptilum album (McDunnough), Anafroptilum minor group species 1, Anafroptilum minor group species 2, Anafroptilum victoriae (McDunnough), Heterocloeon (Jubilatum) species B McCafferty et al., Heterocloeon (Jubilatum) species D McCafferty et al., Labiobaetis longipalpus (Morihara & McCafferty), Plauditus punctiventris (McDunnough), Ephemera guttulata Pictet, Habrophlebia vibrans Needham, and Anthopotamus verticis (Say); the stonefy Isoperla frisoni Illies; the caddisfies Brachycentrus nigrosoma (Banks), Homoplectra doringa (Milne), Ceraclea nepha (Ross), and Fabria inornata (Banks); the riffe beetle Oulimnius nitidulus (LeConte); and the chironomids Cricotopus (Isocladius) sp. “Ozarks” Epler, Cricotopus (Isocladius) sp. “Santa Fe” Epler, Fittkauimyia sp. [probably F. serta (Roback)], Parakiefferiella sp. F Epler, and Saetheria hirta Sæther. A previous report of the mayfy Macdunnoa persimplex (McDunnough) from the Ohio River, adjacent to Ohio, is substantiated with record data. The caddisfy Goerita betteni Ross is confrmed in Ohio. New state records for Indiana consist of the mayfies Heterocloeon (Jubilatum) species D McCafferty et al. and Leucrocuta walshi (McDunnough) and the chironomids Cricotopus (Isocladius) sp. “Ozarks” and Fittkauimyia sp. [probably F. serta (Roback)]. Recent Indiana records of the mayfies Homoeoneuria ammophila (Spieth) and Pentagenia vittigera (Walsh) are also included because these species are rarely collected and most existing records are old. These records represent signifcant range extensions north for Cricotopus (Isocladius) sp. “Santa Fe” Epler, Fittkauimyia sp. [probably F. serta (Roback)], Parakiefferiella sp. F Epler, and Saetheria hirta Sæther. Keywords: Ohio, Indiana, state records, Ephemeroptera, Plecoptera, Trichoptera, Coleoptera, Elmidae, Diptera, Chironomidae Introduction The aquatic insects of Ohio and Indiana are comparatively well known. For Ohio, many treatments have been published over the past two decades, including checklists, analyses of species richness patterns, taxonomic treatments, distributional atlases, and compendia of other biological information. Bolton (2010) summarized published records of Ohio Ephemeroptera (mayfies), Plecoptera (stonefies), Trichoptera (caddisfies), and Coleoptera (beetles), along with documenting new state records known at that time. Since then, Armitage et al. (2011) published a checklist and distributional atlas of Ohio caddisfies; Bolton (2012) listed all known chironomid taxa from Ohio and included supplemental identifcation keys; DeWalt et al. (2012) published an analysis of Ohio’s stonefy diversity; and DeWalt et al. (2016) published an Ohio stonefy atlas. In addition to the orders mentioned above, Glotzhober and McShaffrey (2002) provided a review of Ohio Odonata (dragonfies and damselfies) including identifcation keys, a synopsis, and an atlas. A comprehensive list of Indiana mayfy records was presented in Randolph and McCafferty (1998). Additional records can be found in McCafferty et al. (2004), Jacobus and McCafferty (2006), McCafferty (2009), and DeWalt et al. (2016). The most recent comprehensive list of Indiana mayfies was by Jacobus (2016). Bednarik and McCafferty (1977) provided a comprehensive list of Indiana stonefies. That list was updated in Grubbs (2004) and DeWalt and Grubbs (2011). Waltz and