How to Identify Spruce Beetle Infestation in Your Trees

Spruce Beetle occurrences are becoming more common. If you've noticed deficiencies or death in your large trees, Spruce Beetles may be the cause. 

Some of the signs of Spruce Beetle infestation include:

• Small, pencil-sized holes, with white or reddish-brown pitch tubes.
• Small amounts of sawdust along the trunk.
• Fan-shaped galleries with frass (larvae droppings) under the bark.
• Flaking from woodpeckers.
• Entrance holes on lower stem, late May to June

Spruce Beetles do not attack young trees and usually kill larger trees, starting from the top and working down, over a period of 2-3 years. In some cases only one side of a tree will be successfully attacked (strip attack); this tree will survive unless living portions are re-attacked in subsequent years. An easy step to stop the spread of beetles is to remove all dead trees in the area.

Adult beetles are hard, stout-bodied cylindrical insects, with black-brown or black reddish wing covers. They are tiny, averaging four to seven mm in length (about half a cm). They primarily attack hybrid white spruce, but have also been found in White Spruce, Engelmann Spruce, Sitka Spruce, and Black Spruce. Adults bore approximately 12cm long galleries under the bark, and lays about 100 eggs per gallery. 

Spruce beetles normally infest downed trees or logging debris, but when beetle populations are large, they will attack and kill living trees, causing widespread damage.