Key to the species of the subgenus Centris (Wagenknechtia)

Females

1 Metasoma with metallic blue or greenish reflections (Figs. 2, 18, 22 and 26)....................................... 2

- Metasoma without metallic reflections (Figs. 6, 10 and 14)..................................................... 5

2 Mesoscutum and scutellum with whitish or yellowish brown to orange hair (Figs. 2 and 18); metasoma with bluish or greenish reflections; eyes black (in live specimens); fore elaiospathe located on the distal half of the basitarsus (Fig. 29); hind elaiospathe with the hairs of the primary comb separate (Fig. 30); distal edge of 4th labial palpomere truncate................. 3

- Mesoscutum and scutellum with dark brown hairs (Figs. 22 and 26); metasoma with blue violet reflections; eyes red (in live specimens); fore elaiospathe extending for the entire length of the basitarsus or strongly modified with abundant, short and dense pilosity on its ventral surface (Fig. 33); hind elaiospathe formed by overlapping hairs; distal edge of 4th labial palpomere rounded............................................................................................. 4

3 Mesoscutum and scutellum with whitish hairs (Fig. 2); metasoma with bluish metallic reflections; fore elaiospathe with the secondary comb formed by three giant spatulate hairs (Fig. 29).......................... Centris cineraria Smith, 1854

- Mesoscutum and scutellum with light brown to orange hairs (Fig. 18); metasoma with blue greenish metallic reflections; fore elaiospathe with the secondary comb formed by four giant spatulate hairs................... Centris orellanai Ruiz, 1940

4 Clypeus with denser punctation in the upper half, sparser on the lower half; labrum triangular (Fig. 25); fore elaiospathe highly modified with short, dense and branched hairs on the ventral surface and on the anterior margin of the basitarsus (Fig. 33)......................................................................... Centris vardyorum Roig-Alsina, 2000

- Clypeus with dense and relatively uniform punctation; labrum semicircular; fore elaiospathe with compact primary and secondary combs positioned along the basitarsus................................... Centris rhodophthalma Pérez, 1911

5 Body covered mainly with whitish pilosity, at least on head and mesosoma (Fig. 14); basitibial plate with one concavity near the anterior and one near the posterior margin, without secondary plate (Fig. 37)......... Centris muralis Burmeister, 1876

- Body completely covered with dark brown or yellowish pilosity (Figs. 6 and 10); basitibial plate with a central concavity in the distal half of the primary plate, secondary plate present, with the lower edge concave................................ 6

6 Body completely covered with dark brown hairs (Fig. 6); maxillary palpus five segmented; fore and hind elaiospathe normally developed with compacted combs; distal edges of terga and sterna not broadly translucent....................................................................................................... Centris escomeli Cockerell, 1926

- Body covered with yellowish pilosity (Fig. 10); maxillary palpus four segmented; fore and hind elaiospathe vestigial, with both primary combs formed by separated hairs (Figs. 31 and 32); distal edges of terga and sterna broadly translucent............................................................................ Centris moldenkei Toro & Chiappa, 1989