Key to species of Heriades for the Neotropical region of Mexico and Central America

Males

1 Posterior margin of S1 on ventral view truncate medially (Fig. 2E, J, K, L), (with two small, triangular sublateral projections for H. nora sp. nov. (Fig. 2M), or medially with broad emargination forming two lobes (Fig. 2A, D, G). (Sometimes the morphological posterior margin is hidden by a large transversal process)......................................... 2

- Posterior margin of S1 on ventral view medially produced to a rounded or pointed apex (Fig. 2C, F, H, I, N), sometimes produced with minute emargination at apex (Fig. 2B, O)...................................................... 9

2 (1) S 1 in profile with strong ventral process (Fig. 2A, D, G, J, M)................................................. 3

- S 1 in profile with rounded low angle (Fig. 2E, K, L)......................................................... 7

3 (2) S2 and S3 with long, white, plumose hairs; apex of S5 with posterior margin wavy and with two small tufts of capitate hairs directed laterally, on posterior-lateral angles (Fig. 27E); apex of S6 with a single central tuft of hooked hairs, increasing its length outwards (Fig. 27F)........................................................... Heriades nora sp. nov.

- S2 and S3 bare, without long, white, plumose hairs; apex of S5 with two rectangular lobes, subtriangular medially, one transverse line of capitate hairs increasing in length towards sides (Fig. 7E, 17E, 25E, 31E); apex of S6 with two tufts (Fig. 25F, 30F) or a line of hairs (Fig. 7F, 17F)............................................................................ 4

4 (3) Process of S 1 in posterior view with one cusp, rounded, quadrate or slightly acute (Fig. 2 Ac, Gc, Jc)................... 5

- Process of S 1 in posterior view with two rounded cusps, divided by a soft small emargination (Fig. 2D)................................................................................................ Heriades briceida sp. nov.

5 (4) Flagellum brown dorsally and yellow ventrally (Fig. 31A); pronotal lobe with white, thin, plumose pubescence as in rest of mesosoma; ocelli large, 2.5 times diameter of a puncture (Fig. 31B); process on S 1 in posterior view with acute apex (Fig. 2 Gc).......................................................................... Heriades viridiana sp. nov.

- Flagellum light brown (Fig. 17A, 24A); pronotal lobe with patch of distinctly thick, yellow, or white plumose hairs contrasting with the rest of mesosoma; ocelli small, 1.5 times diameter of a puncture (Fig. 17B, D, 24B, D); process on S 1 in posterior view with subquadrangular apex (Fig. 2 Ac, Jc).................................................................. 6

6 (5) Outer surface of mandible with two strong tubercles, increasing in size from base to apex and abruptly truncate in middle of mandible; clypeus with yellowish plumose hairs, in profile forming a positive diagonal (Fig. 17A); apex of gonostylus subquadrangular with preapical, long, plumose hairs (Fig. 17G, H); apical margin of S6 with transverse line of capitate hairs (Fig. 17F)...................................................................... Heriades danuncia sp. nov.

- Outer surface of mandible smooth, without tubercles; clypeus with white plumose hairs, in profile without a clear pattern (Fig. 25A); gonostylus rounded without hairs (Fig. 25G, H); S6 with two tufts of hooked hairs directed anteriorly (Fig. 25F)......................................................................................... Heriades micheneri

7 (2) Large-sized bees (7.2–7.7 mm); Head and mesosoma with plumose, thin, long, white, scattered hairs, evenly distributed on its entire surface (Fig. 33B); S5 with two tufts of capitate hairs directed medially (Fig. 33E); S6 with two subapical, dense tufts of simple hairs directed downward (Fig. 33F); restricted to Mexico (Fig. 32)................... Heriades vulcanica sp. nov.

- Small-sized bees (4.2–6 mm); Head and mesosoma with plumose, thin, short, white hairs, densely distributed in tufts, and frons, scutum and mesepisternum with large disc areas with simple, very short hairs on each puncture (Fig. 15B, 23B); posterior margin of S5 with one line of scattered, capitate hairs and simple hairs medially (Fig. 15E), or two lines of dense, capitate hairs (Fig. 23E); posterior margin of S6 with one line of capitated hairs (Fig. 15F) or two spikes (Fig. 23F).................. 8

8 (7) Clypeus, frons and paraocular area with golden, plumose hairs (Fig. 23A); interantennal distance 1.6 times antennocular distance; posterior margin of S5 with two dense lines of capitate hairs (Fig. 23E); posterior margin of S6 with two subapical, long, thin spikes enlarged at base and quadrate al tip (Fig. 23F); restricted to Costa Rica (Fig. 22)........... Heriades mariana sp. nov.

- Clypeus, frons and paraocular area with white, plumose hairs (Fig. 23A); interantennal distance 1.8 times antennocular distance; posterior margin of S5 with one line of capitate hairs (Fig. 15E); posterior margin of S6 with one preapical line of capitate hairs (Fig. 15f).............................................................................. Heriades currani

9 (1) Pedicel and scape yellowish (Fig. 11A)................................................. Heriades cristina sp. nov.

- Pedicel and scape black............................................................................... 10

10 (9) Posterior margin of S5 with simple hairs medially (Fig. 9E); apical terga on metasoma with orange pubescence (Fig. 9B)......................................................................................... Heriades bruneri

- Posterior margin of S5 with capitate hairs medially (Fig. 5E, 13E, 19E, 21E, 29E); apical terga on metasoma with white pubescence......................................................................................... 11

11 (10) Posterior margin of S1 with minute emargination (Fig. 2 Bb, Ob)............................................... 12

- Posterior margin of S1 entire, without minute emargination (Fig. 2 Fb, Hb, Nb)................................... 13

12 (11) Apical margin of clypeus entire, without emargination; apex of S6 with two tufts of short, simple hairs (Fig. 13F); S6 with acute apex (Fig. 13F)......................................................................... Heriades crucifera

- Apical margin of clypeus with emargination; apex of S6 with two tufts of 3 to 4 thick, long hairs resembling a spike (Fig. 5F); S6 with rounded apex (Fig. 5F)...................................................... Heriades amanda sp. nov.

13 (10) Clypeus with plumose, white hairs on its entire surface or at least dense on inferior half; posterior margin of S5 without projections, with two tufts of capitate hairs directed medially, of different lengths (Fig. 18E, 28E).................... 14

- Clypeus with plumose hairs seemly absent; posterior margin of S5 with two small, sub quadrangular projections, with few short, capitate hairs on top (Fig. 21E).................................................... Heriades luisa sp. nov.

14 (13) Clypeus with white, plumose hairs on apical half; S 1 in profile, with ventral angle more than one third of distance from apex to base (Fig. 2F)........................................................................... Heriades leavitti

- Clypeus with white, plumose hairs on its entire surface; S 1 in profile, with ventral angle one third or less of distance from apex to base (Fig. 2H)......................................................................... Heriades texana

Females

1 Outer surface of mandible with one or more tubercles, or a strong elevation at base of outer and/or condylar ridge........ 2

- Outer surface of mandible without tubercle or any noticeable elevation at base of outer and condylar ridge (except in a few specimens of H. bruneri, they can be identified by small elevation on outer ridge and orangish hairs on posterior terga).... 6

2 (1) Posterior edge of malar area with large, strong, subtriangular angle, similar-sized to condyle (Fig. 13C, 29C); distance from posterior ocellus to preoccipital ridge large (2.50–3.35 times LO) (Fig. 13D, 29D); punctures on T3 medium-sized or large (~0.66 DOP of scutum)................................................................................ 3

- Posterior edge of malar area without large, strong subtriangular angle (Fig. 15C, 23C, 33C); distance from posterior ocellus to preoccipital ridge short (1.25 times LO) (Fig. 15D, 23D, 33D); punctures on T3 small and sparse (0.40–0.45 times DOP of scutum)............................................................................................ 4

3 (2) Ventral margin of mandible with well-defined angle (Fig. 29C arrow); outer surface of mandible without notorious tubercle, the angle is joining point at base of outer and condylar ridges......................................... Heriades texana

- Ventral margin of mandible straight without angle (Fig. 13C); outer surface of mandible with notorious semicircular tubercle at base of outer and condylar ridges, from base of mandible to interior margin........................ Heriades crucifera

4 (2) Outer surface of mandible with notorious tubercle at base of condylar ridge, and a low Y-like tubercle at base of outer ridge; interior margin of mandible with tooth-like elevation; apical margin of clypeus with two medium-sized to prominent tubercles................................................................................ Heriades currani

- Outer surface of mandible with one notorious tubercle at base condylar ridge and outer ridge; interior margin of mandible with carina (without tooth-like elevation); apical margin of clypeus with five or more small tubercles, sometimes as irregular crenulations......................................................................................... 5

5 (4) Apical margin of clypeus with emargination; hairs on posterior terga yellowish to orange (Fig. 33D)... H. vulcanica sp. nov.

- Apical margin of clypeus straight, without emargination; hairs on posterior terga white (Fig. 23D)... Heriades mariana sp. nov.

6 (1) Punctures on T3 small (0.33–0.40 DOP as on scutum [except on H. luisa sp. nov.: 0.60 DOP as on scutum, which punctures are small) (Fig. 3K)...................................................................................... 7

- Punctures on T3 medium-sized or large (~1 DOP as on scutum) (Fig. 3J)......................................... 9

7 (6) Apical margin of clypeus with two prominent or small tubercles on frontal view (Fig. 9C); pubescence on posterior terga orangish (Fig. 9D)....................................................................... Heriades bruneri

- Apical margin of clypeus with five or more small tubercles on frontal view (Fig. 5C); pubescence on posterior terga white (Fig. 5D, 20D)............................................................................................ 8

8 (7) Frons with hooked, bright, golden hairs; punctures on base of clypeus large (~0.33 times OD) (Fig. 5C); punctures on scutum medium-sized (0.38 times OD) (Fig. 3E); metepisternum with few plumose, white, erected, thin hairs and disc with tuft of plumose, bright white, short hairs (Fig. 3D)............................................ Heriades amanda sp. nov.

- Frons with simple, white hairs; punctures on base of clypeus small (~0.25 times OD) (Fig. 21C); punctures on scutum small (~0.20 times OD) (Fig. 3D); metepisternum with few plumose, white, erected, thin hairs without tuft (Fig. 21D)........................................................................................... Heriades luisa sp. nov.

9 (6) Apical margin of clypeus with two prominent tubercles (Fig. 11C, 19C); apical terga fasciae with rows of thin, white hairs (Fig. 3L)............................................................................................... 10

- Apical margin of clypeus with five or more small tubercles (Fig. 17C); apical terga fasciae with a tidy row of thick, white hairs (Fig. 3J)........................................................................................... 11

10 (9) Frons in front of ocelli with small punctures (0.05 mm) and on T3 medium-sized (0.19 times OD); surface of T3 dull; wings usually dusky............................................................................ Heriades leavitti

- Frons in front of ocelli and T3 with large punctures (0.06 mm, 0.30 times OD); surface of T3 bright; wings clear......................................................................................... Heriades cristina sp. nov.

11 (9) Base of propodeum with large pits (~ 0.07 mm) (Fig. 3I); punctures on posterior surface of propodeum abundant reaching superior edge or carina............................................................... Heriades nora sp. nov.

- Base of propodeum with small to middle pits (~ 0.04 mm) (Fig. 3G, H); punctures on posterior surface of propodeum scarce on superior edge or carina............................................................................... 12

12 (11) Punctures on frons in front of ocelli and vertex large (0.7–0.9 times OD); middle ocelli smaller than laterals; dorsolateral angles of pronotum with rounded tuft of plumose, orangish to white-yellowish, thick hairs (Fig. 25D, 17D); punctures on T3 large (~0.5 times OD)..................................................................................... 13

- Punctures on frons in front of ocelli and vertex medium-sized (0.2–0.4 times OD); middle ocelli as large as laterals; dorsolateral angles of pronotum with few plumose, white, thin hairs joining hairs on pronotum but not forming a rounded tuft (Fig. 7D, 31D); punctures on T3 medium-sized (~0.4 times OD)...................................................... 14

13 (12) Scape thin, 3.1 times longer than wide (Fig. 25C); punctures on mesepisternum medium-sized (0.4 times OD) and slightly sparse (0.3 times DOP)................................................................. Heriades micheneri

- Scape thick, 2.7 times longer than wide (Fig. 17C); punctures on mesepisternum large (0.6 times OD) and dense (0.2 times DOP)......................................................................... Heriades danuncia sp. nov.

14 (12) Apical margin of clypeus with tubercles in the middle; ocelli medium-sized (Fig. 3B); punctures on scutum medium-sized (0.4 times OD) (Fig. 3E).............................................................. Heriades briceida sp. nov.

- Apical margin of clypeus without tubercles in the middle; ocelli large (Fig. 3C); punctures on scutum large (0.5 times OD) (Fig. 3F)........................................................................... Heriades viridiana sp. nov.