Wood-Boring Insects

Wood-boring insects are incredibly destructive pests of trees and shrubs. These borers are typically the larval stage of certain adult beetles and moths. Living up to their name, they ‘bore’ in trees, feeding inside roots and branches and tunneling beneath the bark. Their movement and feeding activity results in internal damage, restricting the tree’s ability to transport water and nutrients.   

While some borers will attack healthy trees, most attack those that have already been stressed and weakened. Common stressors including improper irrigation, soil compaction and extreme weather such as drought. Recently transplanted trees are also likely targets for these insect invaders.  

Loss of leaves and wilting or dieback in the crown are signs of an infestation. You may also notice exit holes in the trunk or branches as well as sawdust like debris or ‘frass’ near the tree.  

Keeping trees healthy through proper care, fertilization and adequate irrigation is the best way to prevent infestation.  You should also be careful not to wound the bark when doing lawn care and plant maintenance as this can attract beetles and borers.