Key for the species of Centris (Xanthemisia) occurring in the Mesoamerican Dominion and the Mexican Transition Zone

*The male of C. maya sp. nov. is currently unknown.

1 Females ............................................................................................ 2

- Males.............................................................................................. 5

2 Mesoscutum covered by intense yellow pubescence (Figs. 2, 10). Distal terga and sterna with blackish hairs, including fimbriae (Figs. 4, 12). F1 longer than F2‒F4 together (Figs. 1, 5)....................................................... 3

- Mesoscutum with blackish pubescence. Distal terga and sterna with light yellowish brown, golden brown or yellow hairs. Fimbriae orange or yellow. F1 slightly shorter than F2‒F4 together (Fig. 13)...................................... 4

3 Clypeal surface strongly coriaceous, with coarse and dense punctation on disc, sparser near upper margin (Fig. 9). T4 with fine and dense punctation on anterior half, scattered towards distal margin (Fig. 12). Central area of the epistomal suture almost as arched as the central lower margin of clypeus (Fig. 9). Primary basitibial plate elliptical; secondary relatively rhomboidal (Fig. 11)............................................................................... Centris maya sp. nov.

- Clypeal surface coriaceous, with coarse and dense punctation at lateral sides; disc shiny with an irregular perpendicular unpunctated area in the middle (Fig. 1). T4 with relatively uniform punctation, except at distal margin (Fig. 4). Central area of the epistomal suture more arched than the central lower margin of clypeus (Fig. 1). Basitibial plates relatively rhomboidal with rounded lateroinferior margins (Fig. 3)................................................ Centris jakalteka sp. nov.

4 Clypeus dark reddish brown. Lower paraocular area and labrum with whitish hairs. Mesoscutellum and fimbriae with yellow pubescence.................................................................. Centris carolae Snelling, 1966

- Clypeus blackish (Fig. 13). Lower paraocular area and labrum with blackish hairs (Fig. 13). Mesoscutellum with blackish pubescence (Fig. 14). Fimbriae orange (Figs. 14, 16)................................... Centris purhepecha sp. nov.

5 Mesoscutum with dark brown to black pubescence (Fig. 17). Second and third mandibular teeth separated from the first tooth by a gap............................................................................................ 6

- Mesoscutum with intense yellow pubescence (Figs. 6, 8). Metasoma covered mainly by blackish hairs (Fig. 8). Second and third mandibular teeth not separated from the first tooth by a gap (Fig. 7)..................... Centris jakalteka sp. nov.

6 Mesoscutellum with yellow pubescence. Metasoma covered mainly by golden hairs........ Centris carolae Snelling, 1966

- Mesoscutellum with blackish pubescence (Fig. 18). Metasoma with blackish hairs on anterior terga; apical segments with yellow pilosity (Fig. 18).......................................................... Centris purhepecha sp. nov.