Species At Risk

West Virginia White

(Pieris virginiensis)

Special Concern

West Virginia White


The West Virginia White is a small – three to four centimetre wingspan – dingy white butterfly. Its wings appear translucent and on the underside of the hind wing, the veins have grey-brown scaling. As a caterpillar, it is yellow-green with a green stripe along each side.

Action we are taking:


The West Virginia White is found from Quebec and Ontario south through New England and the Appalachian region to Georgia. Although common in parts of the United States, this butterfly is rare in Ontario, where it has been seen at about 50 sites.

The majority of sites in the province are in central and southern Ontario, but it also extends north to Manitoulin and St. Joseph islands. The largest populations are in the western Lake Ontario region.


The West Virginia White lives in moist, deciduous woodlots. This butterfly requires a supply of toothwort, a small, spring-blooming plant that is a member of the mustard family, since it is the only food source for larvae.


The West Virginia White was probably never common in Ontario. Habitat fragmentation has been responsible for the loss of some sites.

This butterfly is also threatened by garlic mustard, an invasive species in Ontario. Garlic mustard is related to toothwort, so butterflies may lay eggs on it, but the resulting larvae do not feed on the mustard and die.


TThe West Virginia White is listed as a species of Special Concern under Ontario’s Endangered Species Act. Although species of Special Concern do not receive legal protection under this act, this species has been designated as a Specially Protected Invertebrate under the Ontario Fish and Wildlife Conservation Act.

What You Can Do to the West Virginia White

  • The Ministry of Natural Resources tracks species at risk such as the West Virginia White. You can use a handy online form to report your sightings to the Natural Heritage Information Centre. Photographs with specific locations or mapping coordinates are always helpful. nhic.mnr.gov.on.ca
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Private land owners have a very important role to play in species recovery. You may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • Pollinators, such as butterflies, are in steep decline across the globe and they play a key role in the survival of many of Ontario’s rare plants. For information on how you can help monitor pollinator populations in Ontario, visit: www.seeds.ca/proj/poll.
  • Invasive species seriously threaten many of Ontario’s species at risk. To learn what you can do to help reduce the threat of invasive species, visit: ontario.ca/invasivespecies; www.invadingspecies.com; www.ontarioinvasiveplants.ca; and, www.invasivespecies.gc.ca.
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.

Did you know?

The West Virginia White is one of the first native butterflies to emerge in spring.

Did you know?

This butterfly was officially listed as endangered by Ontario in 1977, but in 1990, after a review of its distribution and abundance, its status was changed to vulnerable (now “special concern”).

Did you know?

West Virginia White butterflies fly largely within their woodland habitat and are hesitant to cross open fields or any unshaded habitat.

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.