Sphaeropthalma imperialis

Boehme, Nicole F., Tanner, David A., Williams, Kevin A. & Pitts, James P., 2012, Faunal study of velvet ants (Hymenoptera: Mutillidae) and their activity patterns and habitat preference at Ash Meadows National Wildlife Refuge, Nye County, Nevada, USA, Zootaxa 3587, pp. 1-45 : 42

Key to the females of the Sphaeropthalma imperialis species-group

1. T2 of metasoma without distinct tubercles located anteriorly just lateral of the midline and pubescence dense on T2 at least along anterior margin................................................................................. 2

- T2 of metasoma with distinct tuberculate sculpturing located anteriorly near margin just lateral of midline and pubescence sparse on T2..................................................................... S. megagnathos Schuster

2. Mesosoma as broad as long; flagellomere 1 less than 2 × length of pedicel, subequal in length to flagellomere 2; pubescence of head, mesosoma and metasoma not concolorous............................................................ 3

- Mesosoma longer than broad; flagellomere 1 more than 2 × length of pedicel, noticeably longer than flagellomere 2; pubescence of head, mesosoma and metasoma reddish to orange or yellow, concolorous except plumose fringes on metasomal tergites whitish.......................................................................... S. edwardsii (Blake)

3. Mesosoma with yellow setae; T2 not concave anteromedially; antennal scrobe having a well-developed dorsal carina............................................................................................ S. marpesia (Blake)

- Mesosoma with black to reddish setae; T2 appearing concave antero-medially; antennal scrobe lacks a well-developed dorsal carina.............................................................................. S. imperialis (Blake)