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Manitoba Museum

Butterflies and Moths (Lepidoptera)

Milkweed Butterflies

Nymphalidae (Subfamily Danaiinae)

The only Milkweed Butterfly in the Canadian prairies is the Monarch. It undertakes an annual two-way migration, flying thousands of kilometres from Canada, to over-winter in Mexico and California. Monarchs store toxins from the milkweed plants they eat, and their bright coloration warns predators that they are poisonous. Because of this, other butterflies like the Viceroy, mimic them. Environmental conditions and loss of breeding habitat pose threats to this species.

Representative Genera and Species:

Danaus plexippus

Pollinator Life Cycle:

In the spring, adults migrate north from Mexico and coastal California, laying eggs exclusively on milkweed plants. Larvae feed then form a green and gold chrysalis. The next-generation adults emerge and migrate to Canada. These adults lay eggs in June; new adults emerge in late summer/early fall. This generation migrates back south in the fall, and will move north again in the spring.

Rarity Status:

They are federally protected under Canada’s Species at Risk Act and in some parks under the Canada National Parks Act. Provincial status ranges from “secure” in Manitoba and Ontario to “may be at risk” in Saskatchewan.

Physical Appearance:

Their orange wings (up to 10 cm across) have distinctive black veins, wing tips, and outer edges with double rows of white spots. Their chest is also spotted white. Males have dark patches of scent scales on each hind wing. Larvae have yellow, black, and white banding.

Pollinator Habitat:

Found in abandoned farmlands, roadsides, fields/meadows, prairies, wetlands and urban areas (e.g. city gardens, along highways), where milkweed grows. They overwinter in remnant Oyamel fir forest in Mexico, and isolated groves of Monterey pine, Monterey cypress, and eucalyptus in coastal California.

Canadian Distribution:

  • Alberta
  • British Columbia
  • Manitoba
  • New Brunswick
  • Newfoundland/Labrador
  • Northwest Territories
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Saskatchewan

Prairie Types:

  • Mixed Grass Prairie
  • Tall Grass Prairie
Milkweed Butterflies