Edessa quadridens Fabricius 1803

Key to males of the H. quadridens group of species

1. Pronotum without black stripe on anterolateral margin....................................................... 2

- Pronotum with black stripe along anterolateral margin........................................................ 4

2. Species from Central America................................................................ H. eburatulus

- Species from South America............................................................................ 3

3. Pygophore. Dorsal rim strongly projected caudally, far exceeding level of posterolateral angles; lateral margin deeply excavated (Fig. 7A,C)........................................................................... H. excavatus sp. n.

- Pygophore. Dorsal rim not projected caudally, not reaching level of posterolateral angles; lateral margin not excavated laterally (Fig. 13A,C)......................................................................... H. runcinatus sp. n.

4. Pygophore strongly excavated laterally; expansions of ventral rim strongly developed, narrow, and subparallel (Fig. 10C,D; Nunes et al. 2020 – Fig. 2A,C)........................................................................... 5

- Pygophore not or barely excavated laterally; expansions of ventral rim rounded or acuminated and never strongly developed as above (Figs. 9D, 12D)................................................................................. 6

5. Dorsal rim of the pygophore medially concave; anterior lobe of the paramere dorsoanteriorly expanded; posterior face of the proctiger without expansions (Nunes et al. 2020 – Fig. 2A,C).......................................... H. boerneri

- Dorsal rim of the pygophore medially convex; anterior lobe of each paramere rounded and expanded dorsally; posterior face of the proctiger with lateral margins remarkably expanded ventrally (Fig. 10A–D).................... H. omegoides sp. n.

6. Pygophore. Expansions of the ventral rim curved downwards; posterior face of the proctiger with median lateral swellings (Fig. 6B–D; Nunes et al. 2020, Fig. 6A–C)..................................................................... 7

- Expansions of ventral rim directed caudally; posterior face of the proctiger without lateral expansions (Fig. 9B–D)....... 8

7. Dorsal rim of the pygophore concave; head of each paramere rounded with distal margin projected in a distinct tooth; lateral swellings of the posterior face of proctiger developed (Nunes et al. 2020, Fig. 6A–C)................... H. necopinatus

- Dorsal rim of the pygophore slightly sinuous or almost straight; head of each paramere subtriangular; lateral swellings of the posterior face of proctiger barely developed (Fig. 6A–D).................................. H. dorsocarinatus sp. n.

8. Pygophore. Posterior face of proctiger expanded ventrally, longer than wide, dorsally with a pair of swellings; expansions of ventral rim broad and rounded (Fig. 12A–D; Nunes et al. 2020 – Fig. 3A–C)...................................... 9

- Pygophore. Posterior face of the proctiger not projected ventrally, wider than long, dorsally without swellings; expansions of ventral rim rounded to acuminated (Figs. 9B–D, 15B–D)..................................................... 10

9. Pygophore. Posterior face of the proctiger with ventral margin rounded and notched medially, dorsal swellings somewhat developed; head of the paramere broadening distally (Fig. 12B–D)................................ H. rugulosus sp. n.

- Pygophore. Posterior face of the proctiger with ventral margin projected caudally in a rounded lip, dorsal swellings strongly developed; head of the paramere not broadening at the apex (Nunes et al. 2020, Fig. 3A–C)................ H. claricolor

10. Pygophore. Superior process of the genital cup squared, subrectangular, oblong or laminar, without secondary processes, and not adjacent to dorsal rim (Figs. 3B–C, 5B–C)............................................................. 11

- Pygophore. Superior process of the genital cup curved or straight, with secondary processes, and adjacent to dorsal rim (Figs. 1B–C, 15B–C, 17B–C)............................................................................... 15

11. Pygophore. Dorsal rim with two rounded projections close to medial line; superior process of the genital cup oblong and broad; paramere spatulate (Fig. 9A–C)....................................................... H. nigrosinuatus sp. n.

- Pygophore. Dorsal rim concave, without projections; superior process of the genital cup and paramere different from above (Figs. 3A–C, 5A–C)................................................................................. 12

12. Pygophore. Superior process of genital cup laminar, narrow; head of the paramere broad and posterolaterally projected (Figs. 3A–C, 5A–C)....................................................................................... 13

- Pygophore. Superior process of genital cup square or subrectangular; head of the paramere anteriorly projected and narrow (Fig. 8A–C)........................................................................................ 14

13. Pygophore. Paramere projected laterally almost reaching lateral wall; expansions of ventral rim acuminated and narrower than in the species below (Fig. 3B–D)......................................................... H. clavatum sp. n.

- Pygophore. Paramere slightly projected laterally clearly distant from lateral wall; expansions of ventral rim rounded and broader than in the species above (Fig. 5B–D).................................................... H. cristatus sp. n.

14. Pygophore. Superior process of genital cup square; anterior lobe of the paramere slightly curved; expansions of ventral rim slightly developed, almost level with posterolateral angles in ventral view (Nunes et al. 2020, Fig. 4A–B)...... H. dolosus

- Pygophore. Superior process of genital cup subrectangular; anterior lobe of the paramere curved; expansions of ventral rim developed, far exceeding posterolateral angles in ventral view (Fig. 8A–C)........................ H. flexuosus sp. n.

15. Pygophore. Paramere golf club-like, posterior lobe narrow, more developed than anterior lobe, with a conspicuous carina on ventral margin; anterior lobe rounded, barely developed, directed to the base of the proctiger (Figs. 11B–C, 14B–C)..... 16

- Pygophore. Paramere with head broad; anterior lobe rounded and short; posterior lobe wide, acuminated or rounded or truncated (Figs. 4B–C, 16B–C)............................................................................ 19

- Pygophore. Paramere subtriangular in caudal view, anterior lobe well-developed and directed dorsally; posterior lobe triangular and little developed (Figs. 1B–C, 17B–C)................................................................ 22

16. Pygophore. Superior process of the genital cup laminar; posterior lobe of the paramere narrow and long (Nunes et al. 2020, Fig. 8A–C).................................................................................. H. trabeculus

- Pygophore. Superior process of the genital cup curved ventrally and concave; posterior lobe of the paramere short and tapering (Figs. 2B–C, 11B–C, 14B–C).......................................................................... 17

17. Pygophore. Dorsal rim with two developed lateral swellings; expansions of ventral rim slightly developed; proctiger with posterior face barrel-shaped (Fig. 2A–D)...................................................... H. bitumidus sp. n.

- Pygophore. Dorsal rim without lateral swellings; expansions of ventral rim developed; proctiger with posterior face subpentagonal (Figs. 11A–D, 14A–D)......................................................................... 18

18. Pygophore. Paramere narrow and curved dorsally; superior process of the genital cup trilobate (Fig. 11B–C).............................................................................................. H. pentagonalis sp. n.

- Pygophore. Paramere broad and straight; superior process of the genital cup bilobate, half-moon-shaped (Fig. 14B–C)............................................................................................ H. similis sp. n.

19. Pygophore. Paramere dorsally acuminated; posterior lobe small and triangular (Nunes et al. 2020, Figs. 1B, 7B)........ 20

- Pygophore. Paramere dorsally sinuous; posterior lobe large, wide, rounded or acuminated (Figs. 4B–C, 16B–C)......... 21

20. Pygophore. Superior process of the genital cup expanded anteriorly, with a ventromedial process; dorsal surface of proctiger with a broad distal carina; expansions of ventral rim acuminated and flat (Nunes et al. 2020, Fig. 1A–C).... H. quadridens

- Pygophore. Superior process of the genital cup barely expanded anteriorly; dorsal surface of proctiger without carina; expansions of ventral rim widely rounded and swollen (Nunes et al. 2020, Fig. 7A–C)......................... H. offuscatus

21. Pygophore. Superior process of the genital cup curved; paramere with anterior lobe slightly developed; expansion of the ventral rim widely rounded and not swollen; inner margin with distal right angle (Fig. 4B–D)........ H. crassimarginatum sp. n.

- Pygophore. Superior process of the genital cup almost straight; paramere with anterior lobe developed; expansion of the ventral rim rounded and swollen; inner margin not angulated (Fig. 16B–D)........................... H. unguiculatus sp. n.

22. Pygophore. Posterolateral angles barely developed; superior process of genital cup tapering caudally; posterior face of proctiger swollen laterally (Figs. 1A–D, 17A–D).................................................................. 23

- Pygophore. Posterolateral angles developed and acute; superior process of genital cup enlarged and rounded caudally; posterior face of proctiger not or barely swollen laterally (Fig. 15A–C)................................. H. trilobulatus sp. n.

23. Pygophore. Superior process of genital cup arched dorsally; paramere with anterior lobe shorter than posterior lobe; margin of the median excavation of ventral rim emarginated (Fig. 1B–D).................................. H. angulatus sp. n.

- Pygophore. Superior process of genital cup slightly arched dorsally; paramere with anterior lobe longer than posterior lobe; margin of the median excavation of ventral rim not emarginated (Fig. 17B–D)............. H. ventrotuberculatus sp. n.