Key to genera of Edessinae and subgenera of Edessa . Modified from Grazia et al. 2015

1. Body rounded; anterior apex of metasternal process not surpassing mesocoxae, sulcate but not clearly bifurcated (Fig. 1)...................................................................................... Brachystethus Laporte

- Body with different shapes but usually elongate, lateral margins subparallel; metasternal process clearly surpassing mesocoxae, anterior part with different shapes but never only sulcate (Figs. 2–4)........................................ 2

2. Metasternal process anteriorly clearly bifurcated (Fig. 2)...................................................... 4

- Metasternal process projected anteriorly in a simple process (Figs. 3, 4).......................................... 3

3. Metasternal process long, surpassing procoxae (Fig. 3), laterally compressed, fused with sterna; humeral angles slightly projected and acute.......................................................................... Pantochlora Stål

- Metasternal process short, not reaching procoxae (Fig. 4), conical, not in contact with sterna; humeral angles projected laterally, apices sharp................................................................ Doesburgedessa Fernandes

4. Antennae four-segmented; second antennomer very long, at least three times longer than the first (Fig. 5); humeral angles globose......................................................................... Peromatus Amyot & Serville

- Antennae five-segmented (Fig. 6); second antennomer short, at most twice longer than the first; humeral angles variable in shape............................................................................................... 5

5. Posterior margin of pronotum with a large pair of spines overlapping basal angles of scutellum (Fig. 7); humeral angles long, sinuous, and laterally directed..................................................................... Olbia Stål

- Posterior margin of pronotum without large spines or other projections (Fig. 8); humeral angles variable in shape......... 6

6. Head with 6-8 solid black stripes, punctures of the head concentrated on these stripes (Fig. 9); proctiger with a medial carina on posterior face.......................................................... Grammedessa Correia & Fernandes

- Head with punctures sparse or concentrated but never on black solid lines (Fig. 10); posterior face of proctiger without medial carina............................................................................................... 7

7. Humeral angles rounded or acute but shorter than head width (Figs. 11, 12)........................................ 8

- Humeral angles globose, depressed dorsoventrally or acute and normally longer than head width (Figs. 13, 14).......... 12

8. Species elongate; humeral angles acute (Fig. 11, red arrow); abdominal segment VII projected posteriorly (Figs. 15, 16) and contrastingly dark at least in distal half (Figs. 11, 20)......................................................... 9

- Species rounded; humeral angles rounded (Fig. 12, red arrow); abdominal segment VII not posteriorly projected (Fig. 17) and concolorous with connexivum (Fig. 12)................................................................... 13

9. Legs with black stripes (Fig. 18); antennae black, except first segment with a ventral yellow spot (Fig. 18); pygophore with posterolateral angles developed and posterolaterally directed (Figs. 23–25); females with gonapophysis 9 bearing a small

tumescence at the base of gonocoxites 9 (Figs. 40, 41)........................................ Plagaedessa gen. n. - Legs unicolorous (Fig. 19); antennae yellow to light brown (Fig. 19); pygophore with posterolateral angles barely developed and posteriorly directed; females without tumescence on gonapophysis 9........................................ 10

10. Corium uniformly brown with contrastingly yellow veins sometimes strongly branched (Fig. 20); abdominal segment VII at least 1.5 times longer than wide at base (Fig. 15); proctiger with posterior face rounded; phallus with a distal constriction; capsula seminalis as big as or bigger than laterotergites 8 and 9...........................subg. Pygoda Amyot & Serville

- Corium brown variegate with whitish and blackish spots (Figs. 8, 11); abdominal segment VII at most 1.2 times longer than wide at base (Fig. 16); proctiger with posterior face flat; phallus not constricted distally; capsula seminalis smaller than laterotergitos 8 and 9.................................................................................... 11

11. Pronotum unicolorous (Fig. 11); dorsal surface of abdomen mostly metallic blue (Fig. 11); posterior part of proctiger expanded laterally in a flat plate (see Silva et al. 2013 — Figs. 2, 27); gonocoxites 8 somewhat reduced, leaving visible the sclerotized gonapophyses 8............................................................... Paraedessa Silva & Fernandes

- Pronotum with dark transversal stripe (Fig. 8); dorsal surface of abdomen never metallic blue; posterior part of proctiger not expanded laterally, posterior face thick; gonocoxites 8 never reduced, leaving visible at most a tiny membranous part of gonapophyses 8............................................................ subg. Hypoxys Amyot & Serville

12. Humeral angles long, apex acute (Fig. 13, red arrow); abdominal segment VII twisted and strongly projected posteriorly, far surpassing genital plates or pygophore; pronotum with an anterior yellow stripe (Fig. 13)...................................................................................................... subg. Dorypleura Amyot & Serville

- Humeral angles variable in length, apex globose (Fig. 14, red arrow); abdominal segment VII not twisted and not projected as far posteriorly as above, not reaching to slightly surpassing genital plates or pygophore; pronotum without anterior yellow stripe (Fig. 14) (except Edessa pictiventris Stål, 1872)...................................... subg. Edessa Fabricius

13. Pronotal disk tumid; body covered with dark punctures; arms of the metasternal process developed and sometimes slightly laterally compressed (Fig. 21); Central America (except Ascra bifida Say, 1832 also found in north part of South America).................................................................................................. Ascra Say

- Pronotal disk not tumid; body covered with concolorous or light brown punctures; arms of the metasternal process strongly laterally compressed (Fig. 22), barely developed in some species; South America (except the widespread species Edessa rufomarginata (De Geer, 1773)) ................................................. subg. Aceratodes Amyot & Serville