Western Spruce Budworm vs Black Arches

Side-by-side species comparison

Attribute Western Spruce Budworm Black Arches
Scientific Name Choristoneura occidentalis Lymantria monacha
Order Lepidoptera Lepidoptera
Family Tortricidae Erebidae
Size 22-28 mm wingspan 40-55 mm wingspan
Habitat Mountains Forests
Diet Omnivores Omnivores
Regions North America Europe, temperate Asia, Japan
Conservation Not Evaluated Least Concern

Western Spruce Budworm

A major defoliator of Douglas-fir and true firs in western North America. Repeated defoliation leads to growth loss and tree mortality.

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Did You Know?

Fire suppression has increased susceptibility of western forests to budworm outbreaks.

Black Arches

A striking moth with white wings boldly marked with black zigzag lines and a pink-flushed abdomen. It can occasionally erupt in huge outbreaks that defoliate conifer forests.

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Did You Know?

During outbreaks in central Europe, caterpillar frass falling from trees sounds like rainfall.