KEY TO ADULTS OF US SPECIES OF SPINTHEROPHYTA (modified from Schultz 1976)

1. Pronotum and elytra of same color, or only slightly different in color from each other... ......................................................... 2

1´. Pronotum metallic blue, elytra metallic red or violet with bronze luster; Arizona, California and Mexico .......... S. violaceipennis (Horn)

2. Pronotum strongly alutaceous, densely punctate ..................... S. punctum Gilbert and Clark, new species

2´. Pronotum shining or only vaguely punctate .... .............................................................. 3

3. Anterior margin of prosternum recurved ventrally; Arizona, California and New Mexico ................. S. arizonensis Schultz

3´. Anterior edge of prosternum level with rest of prosternum, without anterior lip; US east of Rocky Mountains ................................ 4

4. Color shining green; shape elongate oval; New Mexico and Texas ........... S. exigua Schultz

4´. Color shining brown to black; shape globular; Colorado, New Mexico, South Dakota and eastward (Riley et al. 2003) ..................... ............................... S. globosa (Olivier)