Conservation of Aquatic Insects. 

• State of Illinois. Conducted 4-yr survey of 72 Watchlisted Ephemeroptera, Plecoptera, and Trichoptera species as part of a State Wildlife Grant in support of the Illinois State Wildlife Action Plan. Sixty of 72 species were found, most listed as Endangered (NatureServe Subnational ranking S1), Threatened (S2), Vulnerable (S3), but 8 as SX (extirpated), 4 others not imperiled or data deficient. We found 73% of the 416 EPT species known from Illinois and added 22 new state records for a total of 438 EPT now known from the state.
• Midwest USA. Gathered over 38,000 museum and contemporary records of stonefly specimens from IA, IL, IN, MI, MN, OH, WI. Using these to model the pre-European settlement distribution of stoneflies using Maxent. These will inform where additional populations of rare species may be found and help us answer questions about the predicted range of the specie under climate change scenarios.
• USA Gulf South. Working for the USFWS Scott Grubbs (W Kentucky University) and I are assessing the range and conservation status of a spring and brook inhabiting stonefly, Leuctra szczytkoi Stark & Stewart, 1981 (described from N Louisiana) and a probable synonym, L. paleo Poulton & Stewart, 1991 (described from S Arkansas). The latter was confirmed as a junior synonym by DNA barcoding. We have also added locations in W Louisiana and E Texas. We propose that the species is vulnerable. This begins the long process of the USFWS determining if protection under the USA Endanger Species Act is warranted.
• Northeast USA States. This project is to conduct conservation status assessments of 33 stoneflies currently classified as Regional Species in Greatest Conservation Need (RSGCNs) in the states of CT, DE, MA, MD, ME, NH, NJ, NY, PA, RI, VA, VT, WV. Collaborators include Scott Grubbs (WKY) and Luke Myers (SUNY-Plattsburgh). The project begins January, 2023 and continues through 2026. Field collecting, gathering of museum records, habitat association, distribution modeling of species, and NatureServe conservation ranking at state, national, and global scales will be conducted.

Plecoptera Species File. This nomenclatural and taxonomic database capture information about the world's stonefly names, literature, distributions, images, and sounds. The database is a global resource and the most complete of its kind.  It is shared with the Catalogue of Life and the Global Biodiversity Information Facility, forming the backbone of name services for most large biodiversity infrastructure across the world. It has been cited hundreds of times.

http://plecoptera.speciesfile.org

My laboratory studies changes in the distribution of aquatic insects using our extensive research collections at the Illinois Natural History Survey and new collections from throughout North America. Current projects are to determine the pre-settlement range of stoneflies (Plecoptera) throughout the Midwest using museum specimens from throughout the region, a wealth of GIS data and distribution modeling. These historical expectations help my colleagues and I to interpret current distributions. Additional work includes modification of some of the model climate data to predict changes in species distributions related to climate change.

An unrelated project seeks to reconstruct past dispersal patterns of stoneflies after the most recent glaciation. Ice-covered areas were devoid of most species that occur there today. What routes did they take to get there after the glaciers receded, are there species-specific characteristics that influence migration patterns? This information is also useful in identifying populations that are most diverse genetically and allows researchers to pick populations for reintroduction that most closely match the genetic structure of historic populations lost from a region.

Illinois Experts Profile

Standing Committee of the International Society of Plecopterologists
Past President and Current Treasurer Illinois State Academy of Science

Pessino, M., E. T. Chabot, R. Giordano and R. E. DeWalt. 2014. Refugia and postglacial expansion of Acroneuria frisoni Stark & Brown (Plecoptera∶ Perlidae) in North America. Freshwater Science. on-line edition. http://www.jstor.org/stable/10.1086/675306.

Grubbs, S. A., B. C. Kondratieff, and R. E. DeWalt. 2013. A review of the Nearctic genus Zealeuctra Ricker (Plecoptera, Leuctridae), with the description of a new species from the Cumberland Plateau region of eastern North America. Zookeys 344: 17-47.

Cao, Y., R. E. DeWalt, J. L. Robinson, T. Tweddale, L. Hinz, and M. Pessino. 2013. Using Maxent to model the historic distributions of stonefly species in Illinois streams and rivers: the effects of regularization and threshold selections. Ecological Modelling, 259: 30–39.

Webb, J. M. Jacobus, L. M. D. H. Funk, X. Zhou, B. Kondratieff, C. J. Geraci, R. E. DeWalt, D. J. Baird, B. Richard, I. Phillips, P. D. N. Hebert. 2012. A DNA Barcode Library for North American Ephemeroptera: Progress and Prospects. PLoS ONE 7(5): e38063. doi:10.1371/journal.pone.0038063/

DeWalt, R. E., Y. Cao, T. Tweddale, S. A. Grubbs, L. Hinz, M. Pessino, J. L. Robinson. 2012. Ohio USA stoneflies (Insecta, Plecoptera): species richness estimation, distribution of functional niche traits, drainage affiliations, and relationships to other states. ZooKeys 178: 1–26. doi: 10.3897/zookeys.178.2616.

DeWalt, R. E., M. D. Maehr, U. Neu-Becker and G. Stueber. 2013. Plecoptera Species File. Version 5.0/5.0. http://plecoptera.speciesfile.org/

Taxonomy Fair Participant and Plecoptera Expert for Taxonomic Certification Program for Society for Freshwater Science.

PhD, Aquatic Entomology, University of North Texas, 1992
MS, Biology, University of Akron, Ohio, 1986
BA, Biology, Hiram College, Ohio, 1983