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Saddleback looper

Saddleback looper - Dorsal view of mature larva on western hemlock
  • Latin name: Ectropis crepuscularia (Denis and Schiffermuller)
  • French name: Arpenteuse bossue de la pruche
  • Order: Lepidoptera
  • Family: Geometridae




Leaf, Needle

Damage, symptoms and biology

The saddleback looper is a common and occasionally destructive solitary defoliator.

Mature larva to 35 mm long. Head, pale mottled with rust, vertex moderately cleft. Body, grey to brown marked with black, brown and pale areas. Dorsum of second thoracic segment slightly raised. Faint broken cream colored middorsal line; broken subdorsal double black lines; prominent dark chevron on dorsum of second abdominal segment and dark U marking on dorsum of eighth abdominal segment.

This species overwinters as a pupa buried in the duff. Adults emerge in May, mate and lay eggs in groups of 10 to 20 in bark crevices and under moss on tree boles. Larvae are present from June to August; pupation occurs from August to September.

Life cycle (East of the Rockies)

Life cycle (East of the Rockies)
Stage/Month J F M A M J J A S O N D

Canadian Forest Service Publications

Saddleback looper

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)

Main host(s)

Alders, amabilis fir, balsam fir, Douglas-fir, Engelmann spruce, Sitka spruce, subalpine fir, tamarack, western hemlock, western larch, western redcedar, white birch, white spruce, willow


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