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Mourning Cloak Butterfly

Characteristics:

  • Eggs: Females lay 300 – 450 orange eggs in galleries located on branches and twigs in late spring.
  • Larvae: Larvae are black with long spines. They have white speckles and a red line which runs down their backs. When full grown, larvae may reach 50 millimetres in length.
  • Adults: Mourning cloak butterflies are usually the first butterflies to appear each spring as they overwinter in sheltered areas. Adult mourning cloak butterflies have dark maroon or purple brown wings edged with yellow. Iridescent blue spots border the yellow bands. Their wings’ undersides are brown with wavy thin black lines. Their wingspan is over 45 millimetres wide.

Identifying infestations:

  • Eaten leaves: Larvae can defoliate tree branches if they are present in large enough numbers.

IPM Toolkit:

  • Preventive tools: Not applicable
  • Physical tools:
    • Remove eggs and larvae by hand from heavily infested branches.
  • Biological tools:
    • Birds and numerous wasp parasites prey on mourning cloak butterflies.
  • Least toxic chemical tools: Not applicable