Williamsonia lintneri is newly recorded for Michigan, and additional Michigan sites are given for W. fletcheri. Both species appear to be bog/fen- obligate inhabitants, and adults may appear as early as late April in Michi- gan. In addition, the North American distributions of both species are sum- marized.
Ross, Stephen and O'Brien, Mark F.
"Williamsonia Lintneri (Odonata: Corduliidae) - A First Michigan Record With Additional Notes on W. Fletcheri,"
The Great Lakes Entomologist, vol 32
Available at: https://scholar.valpo.edu/tgle/vol32/iss2/10