ABSTRACT The last comprehensive study of the species of Recent Progress on the Study of (Insecta: Ephemeroptera) in the state of Minnesota occurred in the 1940s: there were Minnesota Mayflies approximately 60 species identified at that time. We have compiled an updated list of 105 (Insecta: Ephemeroptera) species through the inclusion of new and historical data, including our own fieldwork and Andrew K. Usher & Luke M. Jacobus review of extensive collections at the University of Minnesota. This number is now comparable Div. Science, Indiana Univ. Purdue Univ., Columbus, IN 47203 to adjoining states, yet there are still over a Figs. 4, Above & 5, Below: Two dozen counties that have no records and require representative sampling locations during further fieldwork for accurate sampling. The field work, Sept. 2014 upper Mississippi River and lower South Western counties in particular are worthy of attention in order to determine whether some of the rarely reported species are still present in the state.

Fig. 2, Left: Part of the University of Minnesota’s Ephemeroptera collection, Sept. 2014; Fig. 3, Above: subadult, Callibaetis sp. Checklist of Families & Genera (# of Species) Fig. 1: A mayfly larva, Maccaffertium sp. ACKNOWLEDGMENTS Ameletidae (cont.) This study is funded by an IUPUC Office of Student Research grant to FIELDWORK PLANNED FOR 2015 Arthropleidae (1) Attenella (2) Maccaffertium (8) AU, with LMJ as the faculty mentor. RP Randolph (Univ. California, A visit to the University of Minnesota in Dannella (1) Macdunnoa (1) Davis) and WP McCafferty (Purdue Univ., retired) assisted with some Acentrella (2) Nixe (1) background research. Thanks to Jason Neuswanger (Univ. Alaska, September 2014 to study their Ephemeroptera Drunella (2) Fairbanks) for the mayfly images. Acerpenna (1) Raptoheptagenia (1) collection, as well as in state sampling and Baetis (5) Ephemerella (5) Rhithrogena (1) recent incorporations into the master data Callibaetis (4) Eurylophella (8) Stenacron (3) REFERENCES Heterocloeon (1) source, have pinpointed several Minnesota Serratella (1) Stenonema (1) Daggy, R.H. (1945) “New Species of Previously Undescribed Naiads of some Minnesota counties with no historical observations of Iswaeon (1) Teloganopsis (1) Isonychiidae Mayflies (Ephemerpotera)”, Annals Entomological Society of America, 38: 373- 396. Labiobaetis (1) Isonychia (3) mayflies. Guenther, J. L. and W. P. McCafferty. (2005) Mayflies (Ephemeroptera) of the Great Paracloeodes (1) Plains. III: North Dakota. Transactions of the American Entomological Society 131: These counties are clustered in three Ephemera (2) 491-508. Plauditus (4) Tricorythodes (1) distinct regions of the state: the North West, Procloeon (4) Hexagenia (2) Guenther, J. L. and W. P. McCafferty. (2008) Mayflies (Ephemeroptera) of the Great Plains. IV: South Dakota. Transactions of the American Entomological Society 134: West Central and South West areas. Baetiscidae Litobrancha (1) Choroterpes (1) 147-171. It is planned to make a coordinated visit to these Baetisca (3) Pentagenia (1) Leptophlebia (2) Behningiidae Lager, T. M., M. D. Johnson, and W. P. McCafferty. (1982) Ephemeroptera of locations and collect specimens in order to Heptageniidae Paraleptophlebia (5) northeastern Minnesota. Proceedings of the Entomological Society of Washington 84: (1) Metretopodidae 729-741. Epeorus (1) complete sample records of Ephemeroptera in Siphloplecton (1) Heptagenia (3) McCafferty, W. P., T. H. Klubertanz, R. P. Randolph, A. V. Provonsha, H. R. Lawson, Roseau, Lake of the Woods, Marshall, Caenis (5) Polymitarcyidae and B. C. Kondratieff. (2001) Mayflies (Ephemeroptera) of the Great Plains. I: Leucrocuta (3) Nebraska. Transactions of the American Entomological Society 127: 5-29. Pennington, Grant, Douglas, Stevens, Todd, Big Sparbarus (1) (1) McCafferty, W. P., T. Hubbard, T. H. Klubertanz, R. P. Randolph, and M. Birmingham. Stone, Lincoln, Murray, Nobles, Cottonwood The above list was compiled (2003) Mayflies (Ephemeroptera) of the Great Plains. II. Iowa. Transactions of the throughout the course of this (2) American Entomological Society 129: 77-105. and Watonwan counties. project using existing This targeted fieldwork will be undertaken Randolph, R. P. and W. P. McCafferty. (1998) Diversity and distribution of the mayflies literature, the collections of Parameletus (1) (Ephemeroptera) of Illinois, Indiana, Kentucky, Michigan, Ohio, and Wisconsin. Ohio Siphlonurus (3) Biological Survey Bulletin New Series 13 (1): vii + 188pp. via three nights spent in the cities of Thief River Purdue University and the United States Geological Survey (USGS). “Mayflies of Minnesota”; retrieved online, Falls, Alexandria and Worthington, MN in May University of Minnesota, as January 2014 from: http://www.npwrc.usgs.gov/resource/distr/insects/mfly/mn/toc.htm 2015. well as fieldwork during 2014.