It is a Nearctic genus distributed throughout Canada and much of the United States.

In 2007 it was revised using evidence from studies of morphology, mitochondrial DNA, and development.

These studies suggested that all the moths in the genus are actually members of a single species, Probole amicaria, making the genus monotypic.

It is simply a variable species, with sexual dimorphism as well as variability across its geographical range, within a single population, and even within a single brood.

[2] Other moths of the genus, which have included Probole alienaria and P. nepiasaria, are now treated as variations within the species.