Key to the soldiers of Labiotermes

1. Left mandible with two conspicuous marginal teeth (Fig. 11 B) ................................. 2

­ Left mandible with vestigial teeth (Fig. 11 A) ............................................................. 6

2. Front coxa with a distinct projection on outer margin near base (Fig. 9 E) ................. 3

­ Front coxa without a distinct projection near base (Fig. 3 F) ...................................... 5

3. Cutting margin of apical tooth on left mandible C­shaped (Fig. 11 I) L. orthocephalus

­ Cutting margin of apical tooth on left mandible S­shaped (Fig. 11 B) ........................ 4

4. Frontal tube distinctly conical, with a narrow tip oriented anteriorly; dimorphic (Fig. 5) ........................................................................................................... L. laticephalus

­ Frontal tube short with a broad tip oriented upward; monomorphic (Fig. 2) .................

..................................................................................................................... L. emersoni 5. Head with numerous hairs; front femur without short spines (Fig. 8) ........................... ............................................................................................... L. oreadicus, new species

­ Head with very few hairs; front femur with an irregular row of short spines (Fig. 3) ... ..................................................................................................... L. guasu, new species

6. Head densely covered with microscopic hairs (Fig. 6 A) or with long, fine hairs ....... 7

­ Head with sparse bristles but without fine or microscopic hairs (Figs. 1 A, 7A) ........ 8

7. Head densely covered with fine long hairs ................................................. L. pelliceus

­ Head densely covered with microscopic hairs (Fig. 6) ............................. L. leptothrix

8. Right mandible with two distinct marginal teeth (Fig. 11 D); sides of head convex and converging towards front; part of labrum with hyaline border elongate and with 2 distinct bristles near tip ..................................................................................... L. labralis

­ Right mandible with a single marginal tooth (Figs. 11 A, 11G); sides of head nearly straight and parallel; part of labrum with hyaline border short and with 4 bristles along the line between sclerotized part and hyaline part ...................................................... 9

9. Labrum clearly longer than wide; head with only a few sparse bristles (Fig. 7); front coxa with a small and rounded projection near base ............................... L. longilabius

­ Labrum about as wide as long; head with numerous bristles of variable size (Fig. 1); front coxa with a conspicuous conical projection near base .................... L. brevilabius