Laboratory hybridization experiments using Phyciodes batesii anasazi and P. batesii lakota show genetic incompatibility expressed as a reduction in F1 viability and disturbance in development rate and adult eclosion pattern comparable to those between P. b. batesii and P. tharos or P. cocyta. When P. b. anasazi was hybridized with P. tharos or with P. cocyta there was less but still significant genetic incompatibility. Hybrid inviability arises from regulatory differences in metabolic pathways during development. Disturbance in adult eclosion patterns seems to be related to differences in larval diapause regulation. The results indicate that P. b. anasazi is not conspecific with P. batesii, but is a separate species more closely related to P. cocyta and P. tharos.