Hyleotermes brevipilus (Emerson, 1925), comb. nov.

Figs. 2–3, 5–7

Nasutitermes (Nasutitermes) brevipilus Emerson 1925: 395–397 (imago, figs. 63a,b; soldier, figs. 63c,d). Nasutitermes brevipilus, Krishna et al. 2013: 1660 (catalog)

Redescription

Imago (Fig. 2A–C). Head capsule with dense coverage of short fine decumbent hairs and few long scattered erect bristles. Labrum covered by short erect hairs, with two long erect bristles on its midline, and with few shorter bristles at the apex. Pronotum with erect bristles along lateral and posterior margins, and many short fine decumbent hairs over its entire surface. Wing scales with erect bristles, more abundant over costal margin, and with shorter decumbent bristles over entire surface. Meso- and metanotum with many short fine decumbent hairs. Tergites with dense coverage of fine decumbent short bristles, plus row of erect bristles on posterior margin. Sternites with erect bristles over entire surface, plus decumbent ones. Head capsule yellow-brown, with visible lighter frontal marks. Postclypeus yellowish with middle line brown. Labrum pale yellowish. Antennal articles yellow-brown. Legs yellowish. Thoracic nota and tergites yellowish brown; sternites lighter-colored than tergites.

Measurements of two females and five males from sample USNM 2019, range and mean (mm): width of head without eyes 0.73–0.77 (0.74), diameter of eye 0.37, length of ocellus 0.13–0.17 (0.15), width of ocellus 0.10–0.13 (0.12), eye-ocellus distance 0.03, width of pronotum 0.83–0.90 (0.86), length of pronotum 0.53–0.60 (0.57), length of hind tibia 1.47–1.53 (1.50).

Soldier (Fig. 2 D-E). Head capsule with lateral margins convex, no constriction behind antennal insertion. Dorsal surface of head capsule in profile, converging towards base of nasus with no depression or elevation; vertex outwards in profile. Anterior margin of pronotum rounded, not emarginated. Very short hairs over surface of head capsule, postmentum, legs, and antennae; four short erect bristles on base of nasus; two erect bristles on vertex. Thoracic nota with short hairs over margins. Tergites with decumbent short hairs over surface and a row of four decumbent bristles at posterior margin. Sternites with decumbent short hairs over surface and erect bristles. Head capsule, antenna and postmentum yellowish brown, nasus darker near tip. Thoracic nota, tergites, sternites and legs yellow whitish.

Measurements of 38 soldiers from five samples, range and mean (mm): length of head with nasus 1.56–1.80 (1.68), length of head without nasus 0.88–1.03 (0.95), width of head 0.73–0.90 (0.80), width of pronotum 0.37–0.47 (0.42), length of hind tibia 0.83–1.05 (0.94).

Worker (Figs. 2 F-H, 3, 5–6). Head capsule, including postclypeus, with dense coverage of short hairs and eight long erect bristles; postclypeus with two long erect bristles on anterior margin, some short hairs over surface and shorter bristles on posterior margin; pronotum with short hairs on anterior and posterior margins; meso- and metanotum with short hairs; tergites with a row of bristles on posterior margin and many hairs over surface.

Measurements of workers from four colonies, range and mean (mm); see Fig. 4 for morphometric differences between the two worker types. Type 1 (n = 25): width of head 0.68–0.77 (0.72), width of pronotum 0.38–0.43 (0.40), length of hind tibia 0.70–0.87 (0.79); Type 2 (n = 19): width of head 0.67–0.77 (0.74), width of pronotum 0.44–0.48 (0.46), length of hind tibia 0.80–0.95 (0.89). Left mandible index (n = 23): 0.70.

Distribution (Fig. 7). Amazon region of Brazil, Colombia, Ecuador, Guyana, and Venezuela.

Material examined. Type material: Holotype: female imago, Guyana, Bartica District, Kartabo (6.38N 58.7W), 16.viii.1920, A. E. Emerson coll. and det., AMNH, #214. Paratypes: same data sample as holotype, imagos, soldiers (including a “morphotype”), and workers (AMNH); and another sample from the same locality, 19.vii.1920, A. E. Emerson coll. and det., imagos, soldiers, workers, larvae and presoldier (USNM-2019). Other material: BRAZIL. State of Amazonas. São Gabriel da Cachoeira (0.13S 67.089W): soldiers, workers, 15.x.2007, D.R.M. Mendonça leg. (UnB-7613). State of Mato Grosso. Juruena: Rohden Lignea (10.469S 58.582W): soldiers, workers, 03.vii.2002, R. Constantino leg. (UnB-3334). COLOMBIA. Caquetá. San Vicente del Caguan (2.114N 74.769W): soldiers and workers, 19.iv.2018, Daniel Castro leg. (UFTC-CO914). ECUADOR. Orellana Province. Tiputini River (0.675S 76.369W): soldiers, workers, 01.vi.2011, R.H. Scheffrahn leg. (UFTC-EC1165). VENEZUELA. State of Bolívar. La Culebra—Auyantepui (6.683N 66.967W): soldiers, workers, 24.i.1991, C.J. Rosales leg. (UnB-2014).