Key to adult males of Lestes known from Brazil

1. Paraprocts long, reaching end of cerci or slightly shorter (Fig. 21) ............................. 2

1’. Paraprocts short, 2/3 or less than the length of cerci .................................................... 3

2. Internal lamina of cerci, in dorsal view lacking teeth or with teeth small and poorly developed (Fig. 22) ................................................................................. L. bipupillatus

2’. Internal lamina of cerci, in dorsal view with well­developed teeth (Fig. 23)................... ........................................................................................................................ L. forficula

3. Distal end of cerci in spiral form (Fig. 24) ......................................................... L. helix

3’. Distal end of cerci not in spiral form ............................................................................ 4

4. Cerci in lateral view, undulate (Fig. 25) ..................................................... L. undulatus

4’. Cerci in lateral view, not undulate ................................................................................ 5

5. Internal lamina of cerci with basal spine ...................................................................... 6

5’. Internal lamina of cerci without basal spine ................................................................ 8

6. Distal end of internal lamina with a larger spine (Fig. 26) ............................ L. minutus

6’. Distal end of internal lamina without spine (Fig. 27) ................................................... 7

7. Latero­ventral carina with a median ventral spot (Fig. 28) .......................... L. jurzitzai

7’. Latero­ventral carina without a median ventral spot (Fig. 29) .................... L. paulistus

8. Medium­ventral groove on venter of thorax with two small black spots (Fig. 30) ........ ................................................................................................................ L. dichrostigma

8’. Medium­ventral groove on venter of thorax without black spots ................................ 9

9. Latero­ventral carina with a long, forked anterior spot (Fig. 31) .................... L. tricolor

9’. Latero­ventral carina with a short, linear anterior spot ............................................... 10

10. Medium­ventral groove on venter of thorax with a blackish stripe ............................ 11

10’. Medium­ventral groove on venter of thorax without a blackish stripe ...................... 12

11. Blackish stripe of medium­ventral groove not exceeding level of basal portion of latero­ventral carina (Fig. 32) .............................................................................. L. auritus

11’. Blackish stripe of medium­ventral groove reaching distal end of the groove (Fig. 33). ......................................................................................................................... L. falcifer

12. Latero­ventral carina with triangular black spot at posteriodistal end (Fig 34) L. pictus

12’. Latero­ventral carina without triangular black spot at posteriodistal end ................. 13

13. Latero­ventral carina with a median ventral black spot (Fig.35) ........ L. quadristriatus

13’. Latero­ventral carina without a median ventral spot (Fig. 36) .................. L. fernandoi