Acanthametropus pecatonica, the Pecatonica River mayfly, is a species of mayfly in the family Acanthametropodidae.

It is endemic to the Pecatonica River of Wisconsin and Illinois, with populations observed in South Carolina and Georgia.

[2][3][4] Acanthametropus pecatonica was considered extinct after 1927, but was rediscovered in 1987, about 60 years after it was considered lost.

[5] It has been found in at least five counties of Wisconsin,[6] and historically at locations in Illinois, South Carolina, and Georgia.

This mayfly related article is a stub.