Key to Mexican Species of Eufriesea

[Females of E. pallida (KIMSEY) are unknown.]

1 Female: antennae with 12 articles; metasoma with six visible terga; metatibia flattened, developed into corbicula ..............................................................................................B

- Male: antennae with 13 articles; metasoma with seven terga; metatibia inflated with posterior slit and no corbicula .....................................................................................................H

2(1) Glossa long, reaching S2 or beyond, two or more times as long as compound eye length .....................................................................................................................................C

- Glossa short, not reaching S2, length less than twice compound eye length .................D

3(2) Head and mesosoma dark blue or dark purple; forewing medial cell not darker than remainder of wing [Mexico to northern Costa Rica] .................... E. mexicana (MOCSÁRY)

- Head and mesosoma black; forewing medial cell darker than remainder of wing [Mexico to Brazil] .............................................................................. E. surinamensis (LINNAEUS)

4(2) T3 black, purple, blue, or dark greenish, half with black setae and half with white setae .....................................................................................................................................E

- T3 brassy, coppery, yellowish green, or scarlet ..............................................................G

5(4) Head and mesosoma black, sometimes with some bluish highlights (T2–6 blue or purple greenish, with yellow setae; clypeus depressed on either side of medial ridge) [México to western Panamá] ................................................................................ E. rugosa (FRIESE)

- Head and mesosoma bright blue, purple, or dark green to yellowish green ................... 6

6(5) Mandible blue and green on basal third, as on remainder of facial area; mesoscutum and mesoscutellum with abundant pubescence, setae not dense [México to Honduras] ......... .............................................................. E. caerulescens (LEPELETIER DE SAINT FARGEAU)

- Mandible black on basal third, with only a little dark blue coloration; mesoscutum and mesoscutellum with abundant and dense black pubescence (NOTE: the mesoscutellum in some specimens has blue darker than that on mesoscutum, and with distinct purple iridescence) [west-central México] ..................................................... E. micheneri sp. n.

7(4) Clypeus with sublateral ridges, without medial ridge, area between sublateral ridges concave, impunctate and polished [México to southeastern Brazil] ................. E. concava (FRIESE)

- Clypeus with sublateral and weak medial ridges [México to southeastern Brazil] ............. ................................................................................................. E. mussitans (FABRICIUS)

8(1) Head, mesosoma, and metasoma concolorous, usually metallic blue or dark green .......I

- Head and mesosoma different in coloration from that of metasoma (typically with T1 dark and T2–5 with yellow or golden shining pubescence, sometimes with blue or purple iridescence) ................................................................................................................ 10

9(8) Facial area green and greenish blue like remainder of head and body; pubescence white to off white on gena and mesosomal pleura [México to Honduras] ..................................... .............................................................. E. caerulescens (LEPELETIER DE SAINT FARGEAU)

- Facial area with integument green, bluish green, or greenish blue, contrasting with remain- der of dark blue and purple integument on remainder of head and body; pubescence dark fuscous to black on gena and mesosomal pleura [west-central México] ............................ .......................................................................................................... E. micheneri sp. n.

10(8) Glossa extending beyond S2 ....................................................................................... 11

- Glossa short, not extending to S2 ............................................................................... 13

11(10) Vertex and anterior half of mesoscutum with pale pubescence [southern México] ........... ......................................................................................................... E. pallida (KIMSEY)

- Vertex with black pubescence, contrasting with brown or pale brown setae on anterior half of mesoscutum ........................................................................................................... 12

12(11) Forewing medial cell not darker than remainder of wing; S8 produced into a single, elongate apical point in lateral view [México to northern Costa Rica] ..... E. mexicana (MOCSÁRY)

- Forewing medial cell darker than remainder of wing; S8 produced into two apical points in lateral view [Mexico to Brazil] .......................................... E. surinamensis (LINNAEUS)

13(9) Clypeus with strong sublateral ridges; surface of metatibia black, without metallic iridescence .......................................................................................................................... 14

- Clypeus without sublateral ridges; metatibia with exterior surface reddish brown, remainder of tibia black [México to western Panamá] ......................................... E. rugosa (FRIESE)

14(13) Clypeus without medial ridge, area between sublateral ridges concave and impunctate; mesotibia with setal brush poorly developed [México to southeastern Brazil] .................. ......................................................................................................... E. concava (FRIESE)

- Clypeus with medially punctate, with ridge or welt; mesotibia with setal brush well developed [México to southeastern Brazil] ....................................... E. mussitans (FABRICIUS)