Bronze Birch Borer

A native insect pest of birch trees throughout the US and Canada, BBB attacks several varieties of birch. Birches that are already weakened are particularly susceptible to attack. We can help your birch tree maintain resistance to BBB, and apply a pesticide to protect it when necessary.

What is Bronze Birch Borer (BBB)?

(Agrilus anxius)

Bronze Birch Borer is a native insect pest of birch trees throughout the US and Canada. The adult beetle is about ½  inch long, black in color and has bronzy iridescence on its back. The adult beetles may be found crawling on tree trunks during late May and early June on sunny days. BBB attacks several varieties of birch, but paper and yellow birch are the preferred hosts. Landscape birches and trees that are already in a weakened or stressed condition are particularly susceptible to attack by the insect.

What to look for? – i.e. Signs and Symptoms

BBB tunnels beneath bark layers, causing damage to the tree’s vascular tissues.This damage can cause leaf yellowing and branch dieback. Dieback is often seen in the upper canopy of the tree first. Raised welts can be seen on the stems and branches where tunneling has occurred, and if bark is removed in these areas, the tunnels can be observed.

How does Teacher’s Tree Service manage BBB?

A healthy, happy birch is a more BBB resistant birch. However, if a tree does appear to be infested, there are ways to help it out. 

Maintaining and Improving Tree Vigor

Keep a landscaped birch tree appropriately watered and ensure it has the nutrients it needs to thrive. Teacher’s conducts fertilization services to maintain the overall health and wellness of your trees. Call us to set up a fertilization. 

Regular Pruning

Part of maintaining your tree’s health is a regular pruning schedule. Keeping dead and dying branches pruned off before adults beetles emerge in early spring can help reduce dieback in the rest of the tree and reduce spread to other trees in the area. Teacher’s Tree Service has all the tools and experience to help you keep your tree in tip top health.

Resistant Varieties and Planting Location

When considering planting a birch tree, select well-drained, sandy, or loamy soil. Birches struggle in clay soils. Additionally, less susceptible varieties can be planted to prevent BBB attack. Our team can help you select a tree and plant it in the perfect location. 

Insecticide Treatments

If your birch tree is already infested with Bronze Birch Borer, an insecticide treatment may be necessary to ensure the recovery and longevity of your tree. Our plant healthcare team can complete a soil application in early spring that will kill the BBB present in the tree. Treatment may be required yearly until the tree has recovered. 

I think I have a birch tree, what do I do?

We can help you by assessing the overall current health of your birch tree(s) and discussing your management options. Our staff of ISA Certified Arborists and ecologists have the knowledge and experience to help you make the best choice for your trees, your woodlot, and your community.

Citations/Resources

Gibb, Timothy J. , and Clifford S. Sadof. 2017. “Bronze Birch Borer.” Extension.entm.purdue.edu. Purdue University Extension – Department of Entomology. November 2017. https://extension.entm.purdue.edu/publications/E-50/E-50.html.

Hanson, T., and E. B. Walker. n.d. “Bronze Birch Borer, Agrilus Anxius Gory – Field Guide to Common Insect Pests of Urban Trees in the Northeast.” Www.forestpests.org. Accessed December 11, 2023. https://www.forestpests.org/vermont/bronzebirchborer.html.

Katovich, S.A., A.S. Munson, J. Ball, and D. McCullough. n.d. “Bronze Birch Borer – Forest Insect & Disease Leaflet 111.” Accessed December 11, 2023. https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043665.pdf.

Swier, Dr. Stanley R. 2018. “Bronze Birch Borer [Fact Sheet].” University of New Hampshire Extension. University of New Hampshire. April 16, 2018. https://extension.unh.edu/resource/bronze-birch-borer-fact-sheet.

The Morton Arboretum. n.d. “Bronze Birch Borer.” The Morton Arboretum. Accessed December 11, 2023. https://mortonarb.org/plant-and-protect/tree-plant-care/plant-care-resources/bronze-birch-borer/.