1. Seventh sternite with a long median process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Seventh sternite with a short median process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2. Eighth sternite with apicomesal sclerotized projection; median process of 7th sternite usually narrowed at apex. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila virgata
Eighth sternite without apicomesal process; 7th sternite process ot narrowed. . . . . . . . . . . .3
3. Claspers short and beak like; 10th tergite longer than claspers. . . . . . . . . . . . . . . . . . . . . . 4
Claspers slender, long; 10th tergite shorter than claspers . . . . . . . . . . . . . . . . . . . . . . . . .10
4. Apical part of aedeagus divided into three processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Apical part of aedeagus divided into two processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
5. Apex of aedeagus with three long filamentous processes. Claspers long, slender closely appressed on meson; 10th tergite deeply cleft on meson. . . . . . . . Hydroptila callia
6. One rod of aedeagus bent sharply at a rt. angle at apex, other process straight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila hamata
Rods do not bend sharply, the bend is gradual and curving. . . . . . . . . . . . . . . . . . . . . . . . .7
7. Processes of apical part of aedeagus straight or nearly so; clasper short, slightly beaked at tip; 10th tergite, lateral aspect, concave with rounded end. . . . . . . . . . . . . . . . . . . . . . . . . . . . 7a
Processes of aedeagus, apical part, curled or entwined about each other. . . . . . . . . . . . . . . .8
7a. Apex of tergite X (10) complete; ventral axis of inferior appendage slender. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila sandersonis
Apex of tergite X (10) excised; ventral axis of inferior appendex stout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Hydroptila amoena
8. Aedeagus: one apical rod entwined around straight process, base of apical part imbricated. 10th tergite sides parallel, tip slightly emarginate, concave in lateral profile. Clasper apex black tipped, base of dorsal projection with one large seta. . . . . . . . . . . . . . . . Hydroptila lennoxi
Aedeagus: rods entwined about each other. Claspers dorsal-basal projection with several setae, apex more bladelike. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
9. Dorsally: 10th tergite flared laterally beyond middle, apical lobes rounded, excised deeply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila metoeca
10. Apex of aedeagus with knob beyond lateral spur at tip. . . . . . . . Hydroptila spatulata
Apex of aedeagus without knob beyond lateral spur. Beneath 10th tergite a pair of long processes which curve around the tip and over the back of the tergite. . . . . . . . . . 11
11. Tenth tergite unexpanded at apex; lateral projection of 9th segment 1/2 the length of 10th tergite. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila vala
Tenth tergite with apex divided into a pair of laterally directed sharp points, lateral process of 9th segment as long as 10th tergite. . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila armata
12. Tenth tergite bearing sclerotized hooks, curved rods, or radiating rods. . . . . . . . . . . . . . . . 13
Tenth tergite membranous, or membranous with sclerotized strips. . . . . . . . . . . . . . . . . . . 16
13. Tenth tergite apex with a pair of long, closely appressed precesses, apices pointed laterad, truncate and sclerotized. Claspers long slender hooked at apex. . . . Hydroptila waubesiana
Tenth tergite with curved rods at apex, or sharply angled downward, beak-like. . . . . . . . . . 14
14. Tenth tergite divided into a pair of lateral, slender filaments that curve under the apico-dorsal projections of the claspers. Claspers long knobbed at apex. . . . . . . . . . Hydroptila delineata
Tenth tergite with dorsally or ventrally curved rods. Claspers not knobbed. . . . . . . . . . . . . . 15
15. Tenth tergite divided into a pair of large rods that curl arojnd long sinuate rods arising from base of tergite. Claspers small, truncate, short. Heavy spines along apical margin of 8th segment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila grandiosa
Tenth tergite divided into rods that curl around straight rods; claspers large, curving mesally at apex. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila gunda
16. Claspers short; either c-shaped, broad at base and curving down at apex, small blunt ovate, or beak-like. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila jackmanni
Claspers elongate; 10th tergite usually elongate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
17. Aedeagus with a long pointed, lateral process near apex. . . . . . . . . . . . Hydroptila consimilis
Aedeagus with out this process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
18. Very long heavy spines on apico-lateral margin of 8th tergite. . . . . . . . Hydroptila lonchera
Not long spines present. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
19. Claspers, ventral aspect, with apex curved or hooked ectally so that the tips are approximately at rt. angles to main part of claspers. . . . . . . . . . . . . . . . . . . . . . . . . . . . Hypdroptila salmo
Claspers ovate, triangular, straight or nealy so, tips not at rt. angles. . . . . . . . . . . . . . . . . . 20
20. Claspers with dark sclerotized elevation on lateral margin midway wetween base and apex. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila albicornis
Claspers without such elevation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
21. Tenth tergite with 3 apical arms, membranous mesal arm projecting dorsad, lateral arms sclerotized expanded apically, apices diverging. Aedeagus stout, tapering to apex, no spiral process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptilis valhalla
Tenth tergite hood shaped, rounded or emarginate, sclerotized mesally and laterally, or may be membranous laterally and mesally. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
22. Tenth tergite with mesal sclerotized strap; membranous laterally. . . . . . . Hydroptila perdita
Tenth tergite sclerotized laterally. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
23. Claspers 4X as long from lateral projection to tip as width of clasper at this point. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydroptila ajax
Claspers less than 4X as long. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
24. Apex of aedeagus gradually curved from near base to apex. . . . . . . . . . Hydroptila strapha
Apex of aedeagus bent inot a right angled process. . . . . . . . . . . . . . . . Hydroptila angusta
Several other species of Hydroptila are given for Ohio: H. chattanooga, H. danieli, H. fowlesti, H. koryaki, H. paraxella, and H. telladaya. See Armitage et al. 2011 for their descriptions.
Key to Species of Hydroptila Adults