Key for the species of Nogueirapis Moure, 1953 (workers)

1. Bees predominantly ferruginous or yellowish, poorly contrasted with the yellowish areas and the rest of the body; metatibia yellowish with a dark spot on the apical third and/or posterior area (Figs. 16–18, 20); vein Rs almost completely vestigial; metabasitarsus with posterior angle projected downward or not; sculpture of head integument smooth and shiny, with or not pilligerous punctation (Figs. 21–23 and 25)................................................................. 2

- Bees predominantly black or dark brown, with strong contrast between the yellowish areas and the rest of the body; metatibia completely darkened (Fig. 19); Rs vein failed only in the central portion; metabasitarsus with posterior angle not projected downward; sculpture integument of head with rugose aspect (Fig. 24)...................... Nogueirapis batistai sp. nov.

2(1). Mesoscutum fully dark brown with lateral areas with strong contrasting yellowish coloration (Figs. 7 and 9); terga with apical third brown; integument of the head with fine pilligerous punctation; metabasitarsus with posterior angle not projected downward, or if projected, not exceeding the line of encounter with the following tarsus; mandible yellow with black condyles (Figs. 1, 2 and 4)........................................................................................... 3

- Mesoscutum yellowish or at least the anterior third brown, with lateral areas with little contrasting yellowish coloration (Figs. 11 and 15); terga with apical half brown; integument of head smooth and shiny; metabasitarsus with posterior angle projected downward, exceeding the line of encounter with the following tarsus; mandible usually yellow completely (Figs. 3 and 5)... ................................................................................................... 5

3(2). Small bees, approximately 3.5 mm; paraocular spot usually not surrounding completely the antennal socket (Fig. 1); clypeus with non-paraboloid margin below the tentorial fovea (Fig. 1); clypeus with uniform in length hairs; metabasitarsus with posterior angle not projected downward................................. Nogueirapis minor (Moure & Camargo, 1982) .

- Larger bees, approximately 4.5 mm; paraocular spot surrounding completely the antennal socket (Fig. 2); clypeus with paraboloid margin below the tentorial fovea (Fig. 2); clypeus with some setae about 2x the length of hairs; metabasitarsus with posterior angle slightly projected downward................................................................ 4

4(3). Dark area on frons completely divided medially in front of median ocellus, without longitudinal black line to the area near the tentorial fovea; mesotibia yellow; metatibia yellow with area brown, dark-brown or black............................................................................................... Nogueirapis mirandula (Cockerell, 1917) .

- Dark area on frons not completely divided medially in front of median ocellus, with longitudinal black line to the area near the tentorial fovea; mesotibia brown; metatibia entirely dark-brown............ Nogueirapis costaricana Ayala & Engel, 2014

5(2). Mesoscutum with anterior third brown (Fig. 11); metatibia with apical third from dark brown to black (Fig. 18); terga with apical third dark brown; yellow paraocular spot surrounding completely the antennal socket (Fig. 3); dark area on frons not completely divided medially in front of median ocellus (Figa 3)..................... Nogueirapis butteli (Friese, 1900) .

- Mesoscutum yellowish or with anterior third yellowish brown (Fig. 15); metatibia with apical third and with posterior half brown to yellowish-brown (Fig. 20); terga with apical third yellowish-brown to reddish-brown; yellow paraocular spot not surrounding completely the antennal socket (Fig. 5); dark area on frons completely divided medially in front of median ocellus (Fig. 5)...................................................................... Nogueirapis rosariae sp. nov.