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Balsam Woolly Adelgid

Photo by Robert L. Anderson, USDA Forest Service,

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Common Name: Balsam woolly adelgid
Scientific Name: Adelges piceae
Origin: Europe


Adults are tiny (about 1 mm long) and appear dark purple to black in color. They produce a thick layer of light-colored, waxy, wool-like material that covers their body.


This insect infests and kills fir trees. North American species are the most sensitive to their attack.


As the adelgids feed on the bark of stems, they release toxins contained in their saliva. These toxins severely weaken the tree, affecting development and growth. Extensive tree mortality has occurred in the Southeast and Northwest U.S.


Several species of predatory insects have been introduced into North America, but they are ineffective on a large scale. Applying insecticides by aerial spraying over large areas is not possible, but spraying individual trees has proven effective.


Gouting occurs with distinct swellings around the buds and branch nodes as terminal growth is stunted. The foliage in a dying tree generally turns yellow, then deep red or brown before the needles fall off and the tree dies.

Regional Distribution

Early Detection

WNY PRISM Priority

Tier 2 – Eradication

Invasive Species Priorities – Tier Chart


This map shows confirmed observations (green points) submitted to the NYS Invasive Species Database. Absence of data does not necessarily mean absence of the species at that site, but that it has not been reported there. For more information, please visit iMapInvasives.