Adults find nectar from a great variety of flowers including dogbane, swamp milkweed, shepherd's needle, asters, and winter cress.

The eggs are laid in small batches on the underside of host plant leaves of aster species (family Asteraceae).

Furthermore, these specific butterflies were chosen because in the case of P. campestris montana and P. tharos, they share common larval food plants and habitat.

The reason for these studies is to investigate the effects of incompatible genomes and how they affect offspring viability and variation between species.

As P. tharos span across the Americas and Canada,[6] hybridization and interspecies breeding is a phenomenon that could lead to variety among species or infertility within offspring.

[10] In Wingert et al.'s study on the differentiation between the Phyciodes butterflies, they found that the genome sequence of all of these Lepidoptera was different because of the low levels of gene flow and hybridization.