Pieris oleracea, or more commonly known as the mustard white, is a butterfly in the family Pieridae native to a large part of Canada and the northeastern United States.

[3][4] As indicated by the common name, P. oleracea adults and larvae primarily feed on plants in the mustard family, Brassicaceae.

However, it may not be a fast enough process to ensure its survival, due to the high level of aggression on the part of the plant and the continuing encroachment of human development.

[2] Larvae that are mature have many black spots with a green body, dark dorsal stripe, and short, dense hairs.

[3] There has been a steady decline in the populations of P. oleracea, which is being attributed to either climate change, the expansion of the toxic garlic mustard plant, human development, or, most likely, a combination of these factors.

A. petiolate is an extremely invasive species in much of the United States and is becoming increasingly common in areas with P. oleracea populations.

[7] The slow nature of this potential evolution (preliminarily estimated to be as high as 100 generations for it to possibly be occurring), coupled with the dominance of Alliaria petiolata as an invasive species, where it often creates dense herb layer monocultures on the forest floor, at forest edges, along streams, and in other habitats — and the smallness of the populations of P. oleracea, make passively waiting for this adaption to save the species questionable, particularly in light of the repeated blockage of biological control weevil species by the USDA's TAG group, despite multiple petitions from scientists for approval of even the monophagous weevil C.

[10] Researchers have said that the univoltine nature of Pieris virginiensis, coupled with its rarity, makes A. petiolata potentially an even greater threat to its survival, due to a reduced ability to adapt.

In similar Pieridae species, sinigrin was found to negatively impact larval survival by affecting a pathway that transforms harmful substances into harmless ones.

[7] With the increasing abundance of A. petiolata, there is concern about the potential adaption rate to what appears to be an incompatible, yet attractive to females, host plant.

The larvae in this group on the mustard plants had reduced survival rates than those on their normal native hosts.

Females in the group with the newly introduced garlic mustard had a wide range in their selection of host plants, and the larval survival rates were also higher in general.

Garlic mustard, however, creates monocultures due to its extreme success as an invasive species in the United States, where it lacks over seventy predators that occur in its native areas.

[7][11] Alliaria petiolata is a toxic invasive species that is causing decreased survival in larval populations.

[12][13] Even though sinigrin is an oviposition stimulant for adult females, it has shown to be detrimental to larvae because it delays growth.

Sinigrin is not found in normal host plants, and even though butterflies of the Pierid family have a detoxification system to remove the toxic chemical, it is not effective when large amounts are consumed.