Key to the species of the megacantha clade

1. Oviscape less than 7 mm long, less than 1.5 times as long as mesonotum.......................................... 2

- Oviscape approximately 10 mm long, more than 2 times as long as mesonotum. Brazil (Amazonas)..... megacantha Zucchi

2. Cell c length (measured from crossvein h to subcostal break)/pterostigma length (distance between apices of veins Sc and R1) less than 1.0. Apex of vein M extended to S-band (Figs. 40–41, 44–46). Aculeus tip slightly tapered then bluntly triangular and minutely serrate (Figs. 94, 96)........................................................................... 3

- Cell c length/pterostigma length greater than 1.1. Apex of vein M not extended to S-band (Figs. 42, 47–49). Aculeus tip gradually tapered or with large subapical notch, nonserrate (Figs. 95, 97–99)........................................... 4

3. Setae red brown to black (Figs. 9–10). Oviscape 2.42–2.67 mm long, 0.70–0.76 times as long as mesonotum. Aculeus 2.06–2.19 mm long; tip (Fig. 96) 0.075–0.105 mm long, 1.07–1.23 times as long as wide, apical 0.48–0.53 bluntly triangular and finely serrate. Ecuador ............................................................... hyperacantha, n. sp.

- Setae orange to orange brown, sometimes red brown on head (Fig. 7). Oviscape 4.21–4.52 mm long, 1.09–1.14 times as long as mesonotum. Aculeus 3.80 mm long; tip (Fig. 94) 0.13–0.145 mm long, 1.53–1.71 times as long as wide, distal 0.17–0.23 minutely serrate. Ecuador ................................................................ hadracantha, n. sp.

4. Vein M relatively strongly curved apically; cell r4+5 0.84–0.95 times as wide at apex as at level of dm–cu (Figs. 47–49). Oviscape 4.40–5.96 mm long, 1.26–1.39 times as long as mesonotum. Aculeus 4.16–5.55 mm long; tip (Figs. 97–99) 0.06–0.08 mm long, 0.04–0.05 mm wide, 1.2–2.0 times as long as wide, slightly tapered but with large notch on distal third......... 5

- Vein M weakly curved apically; cell r4+5 1.16–1.19 times as wide at apex as at level of dm–cu (Fig. 42). Oviscape 2.30–2.36 mm long, 0.76–0.77 times as long as mesonotum. Aculeus 2.00 mm long; tip (Fig. 95) 0.23–0.24 mm long, 0.07–0.08 mm wide, 3.00–3.29 times as long as wide, elongate triangular, gradually tapered, without notches. Setae orange to orange brown, sometimes red brown on head. Ecuador ...................................................... haplacantha, n. sp.

5. Setae orange (Fig. 24). Aculeus tip slightly constricted subapically, with weak apical notches (Figs. 97, 98). Trinidad .............................................................................................. inaequalis, n. sp.

- Setae dark red brown (Fig. 11). Aculeus tip gradually tapered, with distinct apical notches (Fig. 99). Ecuador, Brazil (Amazonas)................................................................................. macracantha, n. sp.