Zimmerman Pine Moth

The Zimmerman pine moth is one of the most important economic pests of ornamental and commercial pine trees in the Midwest. The larva is capable of attacking and severely damaging most pine species in the north central part of the U.S. and poses a real threat to Christmas tree plantations. In Wisconsin, the insect causes greatest injury to Austrian pines.

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The larvae move into the trunk and branch wood where they tunnel into the wood, weakening the wood and compromising the structural integrity of portions of the tree. While tunneling in the wood, large globs of sticky resins mixed with sawdust are present on the trunk and branches. These weakened areas of the tree often break during wind storms and heavy snow loads. Damage can be significant, sometimes necessitating tree removal.

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The Zimmerman pine moth was first found in the U.S. in 1879. Since then, it has been reported in 23 states, primarily in the northern part of the country, east of the Rocky Mountains.