The water scorpion Nepa apiculata Uhler was considered rare in Wiscon- sin by Hilsenhoff (1984), who collected only 11 individuals during a 25-year period. All of his collections were from overwintering sites, especially debris in streams, during early spring or autumn (Hilsenhoff, pers. comm.). He concluded that the species was restricted to southern Wisconsin. Recent collections indicate that N. apiculata is more widely distributed. These records, summarized below, are documented with specimens in the University of Wisconsin-Madison insect collection.
Cochran, P. A.; Gripentrog, A. P.; and Stack, K. M.
"Distribution of the Water Scorpion Nepa Apiculata (Hemiptera: Nepidae) in Wisconsin,"
The Great Lakes Entomologist, vol 25
Available at: https://scholar.valpo.edu/tgle/vol25/iss2/3