Tiny Holes in a Dying Evergreen Tree

Boring Beetles Within Trunk

• A number of boring pine beetles can infest a tree, producing larvae that feed hungrily on its bark and cause the tree's decline. Many of these insects tunnel to the center of the trunk to lay eggs, leaving tiny holes behind. In the case of the Southern pine beetle, they may leave boring dust on the bark or tree base. The larvae feed on bark and sap, ultimately affecting the tree's nutrient capacity. Southern pine beetles can kill a tree in a matter of days after infestation. Prune regularly and remove weak and diseased parts. Spray a pesticide or remove the tree completely to prevent spread.

Boring Beetles Under Bark

• If you notice small holes about 3/8 inch wide that produce wood shavings, the pine sawyer beetle may be to blame. This beetle often attacks white and Scotch pine trees. Peel back the bark to locate these beetles. Their chewing sound is sometimes discernible beneath the bark in July. The pest may carry pine wilt nematode, a roundworm that can clog the circulatory system of the tree. Apply insecticides to the tree trunk that are labeled for use against this pest. Remove heavily infested trees to prevent spread.

Moths

• Zimmerman pine moths can kill limbs and tree tops of many evergreens including Austrian pines, Scotch pines and Norway spruce trees. Usually they bore into the bark at the apex of branches and main stems. Identify this infestation by the gummy sap and sawdust pellets that are produced and usually appear in summer. After adults lay eggs in the bark, the caterpillars emerge and consume bark and pine gum. Apply appropriate pesticides to the bark in April to kill emerging caterpillars.

Weevils

• Pine weevils often infect pine, fir and spruce trees. Lateral branches may curl in response to the presence of this pest, and entrance and exit holes are often found in the central tree shoot. Grubs are born in summer and live underneath the bark, feeding on the tree's tissues. Control weevils by removing curled branches that are infected and applying borer insecticides to the main leader of the tree in early spring.