Key to species of Anthidianum

1 Metasoma with light yellow bands interrupted medially on T1–T3. Male: clypeus with median projection; T7 with three fingerlike, flattened lobes ........................................................................................................ A . caroliameghinoi

- Metasoma with two or three complete light yellow bands. Male: clypeus with apical margin concave; T7 with four acute apical projections ................................................................................................................................................. 2

2 Metasoma with three light yellow bands ...................................................................................................... A. andicola

- Metasoma with two light yellow bands ........................................................................................................................ 3

3 Mesoscutum with two yellow bands. Males: head entirely black, sometimes with two tiny yellow spots above eyes

............................................................................................................................................................. A . subpetiolatum - Mesoscutum entirely black. Males: always with yellow maculations on head ................ A . chilense and A. bizonatum Type material examined. Anthidianum andicola — Holotype male (DZUP). ARGENTINA: ‘R A. Jujuy\Tilcara-Toma\de Água 2900m \J. L. Neff 25-I-77 ’. Paratype: one female (DZUP) also was examined, from same location of holotype.