Bronze Birch Borer


A: Bronze Birch Borer adult beetle | B: Bronze Birch Borer larva

The Bronze Birch Borer is a wood boring beetle, common across the northern half of the United States, which attacks all birch species. The adult is a copper/bronze colored slender beetle. The larvae,
which does the damage, are unseen, feeding on the vascular tissue under the bark. The Bronze Birch Borer typically attacks trees which are already stressed or in decline. A birch infested with Bronze Birch Borer will start showing dieback in the crown, increasing in severity as the infestation continues, often leading to death of the tree. In later stages of infestation, the trunk will show D-shaped, rust-stained exit holes and may also have swollen extrusions under the bark where the tree tried to grow over larval galleries.


Bronze Birch Borer larvae live under the bark and feed on the nutrient and water-conducting vascular tissues. Larvae create meandering galleries through the phloem, vascular cambium and etch the xylem, effectively girdling the tree. Dieback of the canopy is a symptom of Bronze Birch Borer larval infestation; more than one half of the branches may die back as infestation progresses. The tree responds to canopy dieback by sprouting new (epicormic) branches below the disrupted tissues. The bark will split over dead vascular tissues, and trees may die within only two years of the onset of symptoms.

Info Source: Arborjet

Trees will recover from infestation and will be protected from this disease after the application of effective treatments offered by Joe’s Tree Care. We have certified arborists that can help you keep your trees healthy! Call us today! 512-215-1551