Tetragona clavipes species-group

Diagnosis (worker): clypeus yellow, with or without brown maculations, and sometimes divided by a longitudinal brown line. Basal triangle of the clypeus, when present, from dark brown to black. Paraocular area with yellow maculation, not extending above middle tangent of the antennal socket (except in T. perangulata). Forewing with apical half of membrane hyaline (with whitish microtrichia) and basal half slightly yellow (with yellowish-brown microtrichia). Setae on the sixth tergum about 1.5x–2x or more the length of the setae of fourth tergum, more abundant than in fifth tergum (except in T. korotaii sp. nov.). T2–T6 black with contrasting yellow band on apical third.

Key of T. clavipes species-group species (workers)

1. Hairs or setae inconspicuous and sparse on T2–T5 (Fig. 20C), being longer on the apical area of the terga; central area of T6 only with short branched hairs, smaller than the diameter of the flagellum; mandibular condyle yellowish brown (Fig. 20B); malar area and contour of the clypeus yellow (Fig. 20B); only known from Suriname .......... Tetragona korotaii sp. nov.

- Hairs or setae conspicuous and abundant on T2–T5 (Fig. 13C); central area of T6 with elongated simple setae, larger than the diameter of the flagellum; mandibular condyle black (Fig. 13B); malar area and contour of the clypeus black (Fig. 13B); Neotropical region and beyond.......................................................................... 2

2(1). Paraocular maculation blurry (smoky) yellow (Fig. 18B) or not superiorly (Figs. 16B), from the vicinity of the epistomal suture obliquely upwards towards compound eye in line or below the inferior tangent of the antennal socket.................. 3

- Paraocular maculation yellow from the vicinity of tentorial pit obliquely upwards towards compound eye in line or below the inferior tangent of the antennal socket.................................................................... 4

3(2). Paraocular maculation yellow, from the upper portion of the epistomal suture to compound eye to the middle tangent of the antennal socket (Fig. 16B); T2 with a yellow longitudinal central line wider or equal to the diameter of the flagellum (Fig. 16C); T3 with a thin longitudinal central yellow line; metatibia yellow with brown or black areas; found in Central America, Colombia and Ecuador .............................................................. Tetragona perangulata

- Paraocular maculation smoky yellow superiorly, from the upper portion of the epistomal suture to compound eye to the inferior tangent of the antennal socket (Fig. 18B); T2 without yellow longitudinal central line, or with a yellow line less wide than the diameter of the flagellum (Fig. 18C); T3 without a thin longitudinal central yellow line; metatibia completely yellow; found in Brazilian Cerrado................................................................ Tetragona mourei sp. nov.

4(2). Metafemur, metatibia and metabasitarsus yellow (Fig. 13A, D); nest entrance usually in the form of a narrow vertical gap with landing area made of rigid cerumen around (Fig. 15A); found in eastern and southeastern Amazon, central and southeastern Brazil ............................................................................ Tetragona quadrangula

- Metafemur, metatibia and metabasitarsus brown with at least one black marking (Fig. 1A, D); nest entrance very variable, usually in form of slit in tree trunk without projections (Fig. 6A, B, D); with wide distribution from the eastern Andes to Uruguay ................................................................................................................................................................................. Tetragona clavipes