Key to males of Drepanoneura

Caution should be used in using this key. Identification relies on subtle differences of the cerci, paraprocts, and apex of the genital ligula. Extrusion and cleaning of anal appendages with a paint brush following relaxation of specimens will more easily allow examination of the ventral branch of the cercus in lateral view. Some species pairs, D. flinti and D. peruviensis, and D. donnellyi and D. letitia, can be separated with assurance only by characters of the genital ligula. We recommend comparison with illustrations and diagnoses before determinations are considered final.

1. Ventral branch of cercus in posterior view arising at mid-width of cercus, slightly convergent to branch of opposite cercus at tip (Figs. 30 b, f–g)..........................................................................................................2

1'. Ventral branch of cercus in posterior view aligned with inner margin of cercus at base, slightly divergent to branch of opposite cercus at tip (Figs. 30 a, c–e, h).................................................................................4

2. Ventral branch of cercus in lateral view as long as base of cercus (Fig. 28 f); in posterior view narrowing gradually to tip, with inner side approximately linear (Fig. 30 f); Orellana Prov. in Ecuador to Madre de Dios Dept. in Peru (Fig. 37)......................................................................................................... D. muzoni

2'. Ventral branch of cercus in lateral view longer than base of cercus (Figs. 28 b, g); in posterior view narrowing abruptly at base, with inner side concave (Figs. 30 b, g).................................................................3

3. Apex of genital ligula with a shallow v-shaped cleft (14a); Amazonas Dept. in Colombia (Fig. 37) .......... .......................................................................................................................................................... D. flinti

3'. Apex of genital ligula with a deep u-shaped cleft (19a); Loreto Dept. in Peru (Fig. 37)...... D. peruviensis

4. In lateral view postero-dorsal margin of S10 projected posteriorly and ventral branch of cercus shorter than base of cercus (Fig. 28 c); N Bolivia and W Brazil (Fig. 37) .............................................. D. janirae

4'. In lateral view postero-dorsal margin of S10 not or only slightly projected posteriorly and ventral branch of cercus as long as or longer than base of cercus (Figs. 28 a, d–e, h).........................................................5

5. Apex of paraproct truncate in lateral view (Figs. 28 e, h)............................................................................6

5'. Apex of paraproct truncate pointed in lateral view (Figs. 28 a, d)...............................................................7

6. Ventral branch of cercus in lateral view cylindrical, gradually narrowing distally (Fig. 28 e); usually a long yellow stripe along ventral margin of humeral suture (Fig. 2 h); Morona-Santiago Prov. in Ecuador to Madre de Dios Dept. in Peru (Fig. 37) ........................................................................................ D. loutoni

6'. Ventral branch of cercus in lateral view wide at base, laminar, and becoming abruptly truncate apically (Fig. 28 h); usually a short yellow stripe or spot at posterior end of humeral suture (Fig. 2 n); Sucumbíos to Napo Provs. in Ecuador (Fig. 37) ........................................................................................... D. tennesseni

7. Apex of genital ligula approximately linear (Fig. 13 a) and latero-apical lobes long, narrow, and directed externally (Fig. 13 c); Antioquia to Tolima Depts. in Colombia (Fig. 37)................................ D. donnellyi

7'. Apex of genital ligula with a shallow v-shaped cleft (Fig. 16 a) and latero-distal lobes short, broad, and curved medially (Fig. 16 c); Panamá Prov. in Panama (Fig. 37).................................................... D. letitia