Key to the species of Ruptitermes based on workers

This key is based on external morphology only. The enteric valve may also be examined for confirmation (but see comments in the methods section).

1. Procoxa without spine-like bristles (Figs. 4 C, 6C); head capsule with long, curved bristles (Figs. 22 B, D)................ 2

- Procoxa with 4 or more distinct spine-like bristles on anterior surface (Figs. 2 C, 18C); head capsule without long, curved bris- tles, with a variable number of shorter, straight bristles or hairs (Figs. 22 A, C, E–M)................................ 3

2. Head capsule dark brown (Figs. 4 D–E); protibia not inflated (Fig. 4 B); Amazon forest..................... R. arboreus

- Head capsule yellow (Figs. 6 D–E); protibia short and inflated (Fig. 6 B); Atlantic forest............... R. bandeirai, sp. n.

3. Head capsule with numerous short hairs inclined anteriorly; width of head <1.3 mm (Figs. 22 G, H, J).................. 4

- Head capsule with bristles only or with a combination of bristles and sparse hairs; width of head variable (Figs. 22 A, C, E, F, I, K, L, M)............................................................................................ 6

4. Postclypeus large and inflated; procoxa with 7–10 spine-like bristles on anterior surface; protibia inflated (Fig. 11)................................................................................................ R. kaapora, sp. n.

- Posclypeus flattened; procoxa with 4–6 spine-like bristles on anterior surface; protibia not inflated..................... 5

5. Fontanelle depressed, rounded, with several irregular, concentric circles; color of fontanelle a little lighter than top of head; frontal marks very conspicuous, pale colored; tergites covered with minute hairs, about 1/10 of the length of the bristles (Fig. 12).................................................................................... R. krishnai, sp. n.

- Fontanelle not depressed, usually elongate; color of fontanelle conspicuously lighter than top of head; tergites covered with longer hairs, about 1/3 of the length of the bristles (Fig. 14)...................................... R. piliceps, sp. n.

6. Procoxa with 9 or more spine-like bristles on anterior surface (Figs. 2 C, 7C, 16C, 21F)............................. 7

- Procoxa with 4–6 spine-like bristles on anterior surface (Figs. 5 C, 9C, 13B, 18C)................................. 10

7. Profemur with two distinct lines of thick bristles along inner surface (Figs. 7 B, 7C, 21B); region between the lines of bristles flattened, pale and without bristles or hairs................................................................. 8

- Profemur without two distinct lines of thick bristles on inner surface; other characters variable....................... 9

8. Tergites sclerotized, brownish; head capsule brown (Fig. 7)....................................... R. cangua, sp. n.

- Tergites unsclerotized, hyaline; head capsule yellow to light brown (Fig. 21).......................... R. xanthochiton

9. Head capsule with sparse bristles (Fig. 22 A); postclypeus large and inflated, with only one bristle on each lobe (Fig. 2)............................................................................................ R. araujoi, sp. n.

- Head capsule with numerous bristles of variable size (Fig. 22 K); postclypeus flattened, usually with three bristles on each lobe (Fig. 16)................................................................................. R. pitan, sp. n.

10. Fontanelle indistinct; head yellow; tergites yellowish; width of head <1.2 mm (Fig. 13)................ R. maraca, sp. n.

- Fontanelle conspicuous, paler than remainder of head capsule; head capsule brown; tergites brownish; width of head variable (1–2 mm)........................................................................................... 11

11. Meso- and metacoxa with a distinct longitudinal row of 3–4 thick bristles on outer surface (almost as thick as the ones on the anterior surface of the procoxa); width of head> 1.5 mm (Fig. 5).................................... R. atyra, sp. n.

- Meso- and metacoxa without a distinct row of thick bristles; width of head <1.4 mm ............................... 12

12. Left mandible with a very shallow notch between M1 and M3; molar prominence not bilobed; head capsule with several hairs of variable size between fontanelle and vertex (best examined in profile with good illumination); fontanelle rounded (Fig. 9)............................................................................................ R. franciscoi

- Left mandible with a deeper notch between M1 and M3; molar prominence conspicuously bilobed (but may be worn); head capsule without fine hairs between fontanelle and vertex (with two distinct bristles near vertex); fontanelle small and elliptical (rarely rounded) (Fig. 18)..................................................................... R. reconditus