Pygarctia sp.
Larva and Adults  Otero County, New Mexico
Eric Metzler points out: "...it looks a lot like Pygarctia murina, but once spread, the differences become apparent. The color of the hindwing is different as is the shape of the hindwing. It appears to be undescribed, genus either Pygarctia or Eucheates." Thus it is likely that we are dealing here with a species complex to be elaborated by further investigation. This applies to the specimen photographed by Bob Barber and perhaps to others.

Mature larva on Kallstroemia parviflora in the caltrop family, Zygophyllaceae.
P. murina larva feed on Euphorbia sp. and have been reared on Funastrum sp.
Adults
images copyright Bob Barber