Key of the Trigona (Dichrotrigona) Engel, 2021 (workers).

(Adapted from Schwarz, 1948)

1. The half of the supraclypeus below the antennal cavities more or less hairy, like the half extending above the antennal cavities; mandibles mainly black, with a reddish-brown band, immediately behind the black apical teeth; wings short, forewing including tegula about 8.5 mm long; total body length approximately 6 to 7, 5 mm. ............................................ ................................................ T. (D.) venezuelana Schwarz, 1948 . - The lower half of the supraclypeus glabrous and polished; mandibles generally predominantly reddish-brown, except for the black apical teeth; wings long, the forewing including the tegula, measuring about 10.5 to 10.75 mm; total body length approximately 7, 5 a 10 mm ......................................... 2

2(1). Wing membranes and veins infuscate in the basal half, sub-marginal cell whitish (Figure 4A); T3 with relatively short setae (0.09 mm) in the middle region, with about 0.5x the scape diameter; total body length approximately 8.5 mm ..... ......................................................... T. (D.) dimidiata Smith, 1854 .

- Wing membranes and veins infuscate in approximately

2/3 basal, sub-marginal cell slightly darkened (Figure 4B); T3 with setae relatively long (0.22 mm) and dense in the median region, with about 1x the diameter of the scape; total body length approximately 9.6 mm ...................................................... .............................................. T. (D.) sesquipedalis Almeida, 1984 .