Forest & Grassland Health

Urban Tree/Plant Pests

Dendroctonus rufipennis (Kirby)  
Adelges piceae (Ratzeburg) 
Pineus coloradensis (Gillette) 


Click on the image for a larger version.

Spruce beetle killed trees along Campbell Creek Trail

Spruce beetle killed trees along Campbell Creek Trail in Anchorage.


white woolly tufts of balsam woolly adeglids on subapline fir

White woolly tufts of balsam woolly adeglids on subapline fir.

Multi-agency effort to survey balsam woolly adelgid

A multi-agency effort began in 2019 to survey for balsam woolly adelgid following the initial detection.

woolly adelgid on spruce

Woolly adelgids on spruce.


Current Status (2020 Update)

Spruce beetle (D. rufipennis) continues to be a top damage causing agent in urban and community trees in Southcentral Alaska and particularly in Anchorage. Requests for identification, general information, and information regarding removal and processing of spruce beetle infested material continue to be high. 

Balsam woolly adelgid (A. piceae) was found infesting ornamental true fir in Juneau, AK in 2019, the vast majority of which were in Dimond Park. The City and Borough of Juneau moved quickly to remove all 36 true fir on city property and destroy the infested material in 2020. Several infested trees remain on private properties in Juneau. The Alaska Division of Forestry is developing a cost-share program to assist Juneau home and business owners with removal of infested trees.  

In 2020, the University of Fairbanks Cooperative Extension Service and the Alaska Division of Forestry investigated a report of suspected woolly adelgids on several long-established lodgepole pines in the Big Lake area. Since lodgepole pine are not native to the region, these adelgids are of particular interest. During a site visit, specimens were collected from infested trees and sent to a specialist for DNA-based identification. The species was confirmed as Pineus coloradensis. The adelgids were most prevalent on numerous potted lodgepole pine seedlings described by the landowner as being the natural regeneration of several long-established larger lodgepole pines. It is unclear whether this adelgid species occurs naturally in the state or if it may have been introduced. Further investigation is needed. 

If you have an urban pest problem report your findings at the Cooperative Extension Service Pest Reporter, available here.

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