The Hemlock Looper is a pale yellowish geometrid moth that can cause devastating defoliation to hemlock trees during population irruptions in boreal forests. Outbreaks occur periodically and can kill vast expanses of hemlock and balsam fir, dramatically altering forest structure. The inchworm caterpillar is pale greenish-yellow and hard to spot among needles.
Habitat
Boreal and mixed forests with hemlock and fir
Diet
Larvae: hemlock, balsam fir, and spruce needles. Adults: do not feed
How common
Common
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