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Pero moth

Pero moth -
  • Latin name: Pero morrisonaria (Hy. Edwards)
  • French name: Arpenteuse cornue piquetée
  • Order: Lepidoptera
  • Family: Geometridae


Quebec, Newfoundland, Nova Scotia, Ontario, British Columbia

This species is generally distributed throughout British Columbia south of the Skeena and Fraser drainages; it also occurs east to Newfoundland.


Leaf, Needle

Damage, symptoms and biology

Pero morrisonaria is a relatively uncommon innocuous solitary defoliator.

Mature larva up to 32 mm long. Head, grey with rust markings, frontal triangle black, vertex cleft. Body, elongate, tan to rusty brown; dorsum marked with parallel dark streaks on abdominal segments 3 and 4.

This species overwinters in the pupal stage. Adults emerge in July; larvae are present from July to September and pupation occurs in September.

Canadian Forest Service Publications

Pero moth

Diet and feeding behaviour

  • Phyllophagous : Feeds on the leaves of plants.
    • Free-living defoliator: Feeds on and moves about freely on foliage.
Information on host(s)

The principal hosts of Pero morrisonaria are Douglas-fir and western hemlock; other hosts include Engelmann spruce, white spruce, Sitka spruce, grand fir, amabilis fir and subalpine fir. Non-coniferous hosts include willow and alder.

Main host(s)

Amabilis fir, balsam fir, balsam willow, Bebb willow, black willow, Douglas-fir, Engelmann spruce, European black alder, feltleaf willow, golden weeping willow, grand fir, green alder, hazel alder, heartleaf willow, hooker willow, hybrid white willow, laurel willow, littletree willow, Mackenzie willow, meadow willow, mountain alder, Pacific willow, peachleaf willow, pussy willow, red alder, red spruce, Rocky Mountain Douglas-fir, sandbar willow, satiny willow, Scouler willow, shining willow, Siberian alder, Sitka alder, Sitka spruce, Sitka willow, speckled alder, subalpine fir, tamarack, violet willow, western hemlock, western redcedar, white spruce, willow

Secondary host(s)

Bigleaf maple, black spruce, Douglas maple, dwarf birch, eastern white-cedar, eastern white pine, Garry oak, red maple, silver maple, western hemlock, white birch


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