1. Apex of abdomen with paraprocts modified into one or more long, upwardly curved probes; vesicle usually present on sternum 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Males (2)
Apex of abdomen with simple, broadly triangular, flat paraprocts; vesicle absent from sternum 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Females (4)
2. A deep U or V-shaped cleft extends across tergum 9. . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . Zealeuctra
Tergum 9 without deep U or V-shaped cleft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Paraprocts consist of 2 or 4 closely appressed, long stylets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leuctra
Paraprocts consist of single thick probe-like structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paraleuctra sara
4. Sternum 8 bearing well developed subgenital plate, which project beyond hind margin of segment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Segment 8 with little or no development of subgenital plate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Zealeuctra
5. M-Cu crossvein in hindwing located distal to fork in Cu1 vein; dark median line of mesothorax extends from basisternum across furcasterum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Paraleuctra sara
M-Cu crossvein in hindwing located proximal to fork in Cu1 vein; dark median line of mesothorax not extending across furcasterum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leuctra (Females not described)
Key to the Adult Leuctridae of Ohio