Key to the Colletes species of West Africa

Females

The female of C. aragorn sp. nov. is unknown.

1 Antennal flagellum ventrally brown to blackish (Fig. 4E); T2 medioapically distinctly depressed with clearly defined, truncated premarginal line (Fig. 4F); T1 and T2 apically with conspicuous transverse band of orange appressed hairs, contrasting with the lighter hair of the rest of the metasoma (Fig. 3E, 4F)...................................... C. microdontus Cockerell

- Antennal flagellum ventrally bright yellowish (Figs 4A, C); T2 medioapically either not or only slightly depressed, without or only with weakly defined premarginal line (Figs 4B, D); T1 and T2 without conspicuous transverse band of orange appressed hairs, not contrasting with white to cream-colored pilosity of the rest of the metasoma (Figs 3A, C, 4B, D).............. 2

2 Malar area longer than width of the base of the mandible; clypeus densely and finely punctate (Fig. 4C).................................................................................................... C. diodontus Benoist

- Malar area about ½ as long as width of the base of the mandible; clypeus sparsely and coarsely punctate (Fig. 4A).......................................................................................... C. bytinskii Noskiewicz

Males

For a reliable identification of males, it is essential to dissect genitalia and S7.

1 Antennal flagellum ventrally brown to blackish (Figs 1A, 3F); discs of T1 and T2 either without short appressed hair (Figs 1–D) or only partially covered so that the surface sculpture remains visible (Fig. 5E).................................... 2

- Antennal flagellum ventrally bright yellowish (Figs 3B, 3D); discs of T1 and T2 at least partly densely covered with short appressed hair hiding the surface sculpture (Figs 5A, C)....................................................... 3

2 Body hair yellowish to orangish brown (Fig. 1A); T1 and T2 apically slightly depressed, premarginal line not truncated (Figs 1C, D); S7 as in Figs 2A, B..................................................... C . aragorn Kuhlmann sp. nov.

- Body hair whitish to cream-colored (Fig. 3F); T1 and T2 apically deeply depressed with clearly defined, truncated premarginal line (Fig. 5E); S7 as in Fig. 5F. ....................................................... C . microdontus Cockerell

3 Malar area about twice as long as width of the base of the mandible; T7 apically narrowly rounded, with a pair of short, backward-facing spines, which may be partially covered by hair; S7 as in Fig. 5D.................. C . diodontus Benoist

- Malar area about as long as width of the base of the mandible; T7 apically broadly rounded, without spines; S7 as in Fig. 5B.................................................................................. C . bytinskii Noskiewicz