Utah State University Extension
This fact sheet describes three common caterpillar species that are pests to cabbage and mustard plants in Utah, including their life history, type if injury they cause, and management options.
Cannon, Cami; Bunn, Bonnie; Alston, Diane; and Murray, Marion, "Caterpillar Pests of Brassica Vegetables" (2016). All Current Publications. Paper 1595.