Ancyloscelis, Latreille, 1829

Schaller, A. & Roig-Alsina, A., 2021, A revision of the bee genus Ancyloscelis (Hymenoptera: Apidae) in Argentina, Zootaxa 4980 (3), pp. 521-540 : 536-537

Key to Males

1. Proboscis at repose surpassing posterior coxa. Clypeus strongly protuberant, clypeocular distance 0.72–0.96 times MOD. Hypostomal carina with strong, anterior spiniform projection ( Fig. 12C )................................. A. halictoides

- Proboscis at repose barely surpassing anterior coxa. Clypeus less protuberant, clypeocular distance 0.3 times MOD or less. Hypostomal carina anteriorly at most with rounded elevation ( Fig. 12D )......................................... 2

2. First and second segments of labial palpus with modified, hooked setae.......................................... 3

- First and second segments of labial palpus with simple setae, not hooked. …...................................... 6

3. Scape without yellow mark ( Fig. 3A ). Ventral part of mesopleuron without projection in front of mid coxa. Posterior basitarsus with rounded apex ( Fig. 10A ). Posterior tibia with under surface nearly glabrous and ventral inner margin with tubercule continued apically by carina up to tibial spur. T3–T5 with brownish hairs on discs and distinct white to yellowish apical bands ( Fig. 2A )..................................................................................... A. bonariensis

- Scape with yellow mark ( Fig. 3C ). Ventral part of mesopleuron with projection in front of mid coxa. Posterior basitarsus with pointed apex ( Fig. 3B–D ). Posterior tibia with under surface densely pilose and ventral inner margin without tubercule nor carina, or with carina medially, not reaching to tibial spur. Discs of T2–T5 and apical bands with yellow-golden hairs ( Fig. 2C–D )............................................................................................. 4

4. Posterior basitarsus with inner curved tooth between basal third and middle of basitarsus ( Fig. 10D )..... A. mesopotamica

- Posterior basitarsus without inner tooth ( Figs. 10C , 5A )...................................................... 5

5. S6 strongly emarginate ( Fig. 4A ). Under surface of basitarsus clothed with hairs to apex. Femur dark, with light brown dorsolateral mark ( Fig. 2C )....................................................................... A. holmbergi

- S6 weakly emarginate ( Fig. 5B ). Under surface of basitarsus clothed with hairs on basal half; apical half bare. Femur light brown without evident light mark................................................................ A. ursinus

6. Posterior basitarsus with basal inner tooth ( Fig. 11A–B ). S6 with emarginate apex. Smaller species, length of forewing 4.0–6.0 mm ................................................................................................ 7

- Posterior basitarsus with basal inner rounded projection followed by median tooth ( Fig. 11C–D ). S6 with truncate apex. Larger species, length of forewing 6.1–7.6 mm ................................................................... 8

7. Scape and pedicel black ( Fig. 8B ). Pronotal lobe black. Femora and tibiae black to dark brown ( Fig. 7B ).... A. nigricornis

- Scape and pedicel orange to light brown ( Fig. 8A ). Pronotal lobe orange to light brown. Femora and tibiae orange to light brownish ( Fig. 7A )......................................................................... A. apiformis

8. Scape and pedicel orange ( Fig. 8C ). Forewing with dark spot apical to marginal cell, remainder of wing margin lighter (as in Fig. 6C ). Posterior basitarsus with rounded apex ( Fig. 11C )........................................... A. romeroi

- Scape and pedicel black ( Fig. 8D ). Forewing with entire apical margin darkened (as in Fig. 6D ). Posterior basitarsus with pointed apex ( Fig. 11D )....................................................................... A. saltensis

Figures

FIGURE 2. Males, A. ursinus species group, lateral view. A, A. bonariensis Brèthes. B, A. halictoides (Holmberg). C, A. holmbergi sp. n. D, A. mesopotamica (Holmberg). Scale line= A, C and D, 0.1 mm; B, 0.2 mm.

FIGURE 3. Males, A. ursinus species group, head, frontal view. A, A. bonariensis Brèthes. B, A. halictoides (Holmberg). C, A. holmbergi sp. n. D, A. mesopotamica (Holmberg). Scale lines = 0.5 mm.

FIGURE 4. Ancyloscelis holmbergi sp. n., male. A, S6, ventral view. B, genital capsule, ventral view. C, S7, ventral view. D, S8, ventral view. Scale lines = A, C, and D, 0.2 mm; B, 0.5 mm.

FIGURE 5. Ancyloscelis ursinus, holotype (NHMUK 10265363). A, right posterior basitarsus, lateroventral view. B, ventral view of apex of metasoma. (Photographs, attention of David Notton, Natural History Museum, London). Scale lines = 0.2 mm.

FIGURE 6. Females, A. apiformis species group, lateral view. A, A. apiformis (Fabricius). B, A. nigricornis Rodríguez & Roig- Alsina. C, A. romeroi (Holmberg). D, A. saltensis Rodríguez & Roig-Alsina. Scale lines = 0.1 mm.

FIGURE 7. Males, A. apiformis species group, lateral view. A, A. apiformis (Fabricius). B, A. nigricornis Rodríguez & Roig- Alsina. C, A. romeroi (Holmberg). D, A. saltensis Rodríguez & Roig-Alsina. Scale lines = 0.1 mm.

FIGURE 8. Males, A. apiformis species group, head, frontal view. A, A. apiformis (Fabricius). B, A. nigricornis Rodríguez & Roig-Alsina. C, A. romeroi (Holmberg). D, A. saltensis Rodríguez & Roig-Alsina.

FIGURE 10. Males, A. ursinus species group, posterior basitarsus, ventral view. A, A. bonariensis Brèthes. B, A. halictoides (Holmberg). C, A. holmbergi sp. n. D, A. mesopotamica (Holmberg). Scale lines = 0.2 mm.

FIGURE 11. Males, A. apiformis species group, posterior basitarsus, ventral view.A, A. apiformis (Fabricius). B, A. nigricornis Rodríguez & Roig-Alsina. C, A. romeroi (Holmberg). D, A. saltensis Rodríguez & Roig-Alsina. Scale lines = 0.2 mm.

FIGURE 12. A–B, dorsal view of female pronotal lobe (p, pronotal lobe). A, A. bonariensis Brèthes. B, A. mesopotamica (Holmberg). C–D, lateral view of male head showing hypostomal carina (h). C, A. halictoides (Holmberg). D, A. bonariensis Brèthes. Scale lines = A–D, 0.2 mm.