Nymphs and adults of three new species of Isoperla are described from reared material. I. sagittata is known only from southeastern Texas, I. Coushatta has been collected in East Texas and Oklahoma, and I. jewetti occurs in the Basin and Range Mountains of West Texas. The male aedeagii, female subgenital plates, and nymphal mouthparts are diagnostic in all three species.
Szczytko, Stanley W. and Stewart, Kenneth W.
"Three new species of Nearctic Isoperla (Plecoptera),"
Great Basin Naturalist: Vol. 36:
2, Article 3.
Available at: https://scholarsarchive.byu.edu/gbn/vol36/iss2/3