West Virginia White Government Response Statement

The West Virginia White (Pieris virginiensis) is a medium-sized, all-white butterfly that does not stray far from the forest interior. It emerges during the mid-spring months (April-May) when mature hardwood forests are beginning to leaf-out. Closely linked to spring-flowering (ephemeral) host plants belonging to the Mustard family (Brassicaceae), it most commonly selects Two-leaved Toothwort (Cardamine diphylla) upon which it lays single eggs on a leaf. The West Virginia White has a patchy distribution in southern Ontario and sites of known occurrence are separated from each other by significant distances. It is found exclusively in mesic hardwood and mixed forests with rich soils and hardwood swamps. Host plant populations are typically abundant and distributed across the sites in which the butterfly occurs. It is currently found in five main areas (i) Halton region; (ii) Manitoulin Island; (iii) the Frontenac axis of eastern Ontario; (iv) central Peterborough County; and (v) southeastern shoreline of Lake Superior/St. Joseph Island. Despite the existence of apparently suitable habitat elsewhere, it is found in very few locations outside of these sites.

Special concern in Ontario

The protection and management of species of special concern is a key part of protecting Ontario’s biodiversity. Biodiversity—the variety of life on Earth— provides us with clean air and water, food, fibre, medicine and other resources that we need to survive.

The Endangered Species Act, 2007 (ESA) is the Government of Ontario’s legislative commitment to protecting and managing species of special concern and their habitats. A species is classified as special concern if it lives in the wild in Ontario, is not endangered or threatened, but may become threatened or endangered due to a combination of biological characteristics and identified threats.

Government response statements

The management plan for West Virginia White was completed on June 28, 2013. Management plans are prepared for the Government of Ontario based on the current scientific knowledge for each species and identify approaches for the management of species of special concern.

This response statement is the government’s policy response (subsection 12 (5) of the ESA) to the possible actions identified in the management plan. The response statement summarizes the actions that the Government of Ontario intends to take in response to the management plan and the government priorities in taking those actions. The response also reflects the best available knowledge at this time and may be modified if new information becomes available.

Moving forward to protect and manage West Virginia White

West Virginia White is listed as a species of special concern under the ESA. Along with its small population in the province, the species faces uncertainty due to the combined threats of habitat fragmentation, invasive species, human population growth and climate change. Garlic Mustard (Alliaria petiolata), an invasive biennial plant that is difficult to control through manual and/or chemical removal, is currently spreading throughout the Ontario range of the butterfly and has been identified as the most serious threat. Though the effects on the Ontario population have yet to be studied, Garlic Mustard is a leading cause of declines and extirpation of West Virginia White over much of its US range. Other potential issues relate to spraying of non-specific insecticides (Btk or Carbaryl) and the rapid spread of Beech Bark Disease. The West Virginia White faces increasing pressure on its habitat from human recreational activities, aggregate resource extraction, and climate change which could affect the timing of butterfly and host-plant life cycles.

Management goal

The Government of Ontario’s goal for the management of West Virginia White is to maintain or improve its distribution and abundance.

Management objectives and actions

Protecting and recovering species at risk is a shared responsibility. No single agency or organization has the knowledge, authority or financial resources to protect and recover all of Ontario’s species at risk. Successful recovery requires inter-governmental co-operation and the involvement of many individuals, organizations and communities.

In developing the government response statement, the Ministry considered what actions are feasible for the government to lead directly and what actions are feasible for the government to support its conservation partners to undertake. Government-led actions are those that the government will directly undertake to protect and manage the species. Governmentsupported actions are those that are endorsed by the government as being necessary for the protection and management of the species. Support for conservation agencies, municipalities, industry partners and Aboriginal communities to undertake actions will be provided where appropriate through funding, and advisory services.

Government-led management actions

• Encourage the submission of Shumard Oak data to the Ministry’s central repository at the Natural Heritage Information Centre.

Government-supported management actions

1. Develop a standardized survey and monitoring protocol and implement the protocol to:
   • Identify West Virginia White occurrences in Ontario; and,
   • Assess population size and health, reproduction, habitat quality threats and limiting factors at occupied sites.
   Priority: High

Government-led management actions

• Continue to implement the Ontario Invasive Species Strategic Plan to address the invasive species threat to West Virginia White.
• Continue to implement protection for species of special concern and their habitat through management planning processes, including planning for provincial parks and forest management on Crown land.
• Encourage Municipalities to consider the habitat of West Virginia White as significant wildlife habitat and/or significant woodland under the Provincial Policy Statement.
• Encourage planning and environmental authorities to consider the conservation of West Virginia White in management planning and decision making. (e.g., road and corridor planning).

Government-supported management actions

2. Develop effective management techniques for invasive species (especially Garlic Mustard) at priority sites to improve/maintain habitat.
   Priority: Medium
3. Identify and protect key sites across a representative range through stewardship and land securement in connection with existing initiatives and partners.
   Priority: High

Government-led management actions

• Continue forest pest monitoring programs in Southern Ontario (example: gypsy moth population monitoring and outbreak prediction).

Government-supported management actions

4. Conduct research to identify and prioritize potential West Virginia White habitat for inventory efforts.
   Priority: High
5. Conduct research examining the impacts of Garlic Mustard on West Virginia White in Ontario and its adaptations to this invasive host
   Priority: High
6. Conduct research to evaluate the effects of forest management operations on host plant (Two-leaved Toothwort) abundance and overall habitat suitability.
   Priority: High

Government-led management actions

• Undertake communications and outreach to increase public awareness of species at risk in Ontario.

Government-supported management actions

7. Develop and distribute educational material to inform land managers and land owners about the significance, biological needs and stewardship of West Virginia White. For example; identification, impacts of fragmentation, invasive species and pesticides.
   Priority: Medium
8. Collaborate among relevant agencies and the scientific community to develop and implement conservation actions. These actions include encouraging the use of best management practices for mature mixed forests, and retaining continuous forest cover.
   Priority: Medium

Implementing actions

Financial support for the implementation of actions may be available through the Species at Risk Stewardship Fund, Species at Risk Research Fund for Ontario, and the Species at Risk Farm Incentive Program. Conservation partners are encouraged to discuss project proposals related to the actions in this response statement with the Ministry of Natural Resources.

Implementation of the actions may be subject to changing priorities across the multitude of species at risk, available resources and the capacity of partners to undertake recovery activities. Where appropriate, the implementation of actions for multiple species will be co-ordinated across government response statements.

Acknowledgement

We would like to thank all those who participated in the development of the “Management Plan for West Virginia White (Pieris virginiensis) in Ontario” for their dedication to protecting and managing species of Special Concern.

For additional information:

Visit the Species at Risk website
Contact your MNR district office
Contact the Natural Resources Information Centre
1-800-667-1940
TTY: 1-866-686-6072
Email: NRISC@ontario.ca
Website: Ministry of Natural Resources and Forestry