Gut contents of 230 nymphs of Phasganophora Capitata (Pictet) from the Pigeon River, Otsego County, Michigan were analyzed in relation to season, current velocity, time of day, predator size and prey abundance. Diet changed seasonally, related in part to seasonal changes in prey abundance. The diet of large and small nymphs was similar except that small nymphs ate smaller individuals. At lower current velocities capitata fed primarily on mayflies whereas at higher current velocities they fed primarily on caddis and dipterans.
Kovalak, William P.
"On the Feeding Habits of Phasganophora Capitata (Plecoptera: Perlidae),"
The Great Lakes Entomologist, vol 11
Available at: https://scholar.valpo.edu/tgle/vol11/iss1/5