Revision of the genus Heteranassa Smith, 1899 (Lepidoptera, Erebidae, Omopterini)

Heteranassa Smith (Erebidae, Omopterini), native to the southwestern United States and Mexico, includes two recognized species, namely Heteranassa mima (Harvey) and Heteranassa fraterna Smith. These are separated mainly by subtle differences in wing color and pattern, leading to speculation about the validity of the described species. This study examines variation in external and internal morphology across the geographic range of the genus, aiming to clarify species limits, describe morphology, and provide a comprehensive assessment of variation within the genus. Results indicate that Heteranassa fraterna syn. n., is a junior synonym of Heteranassa mima.