Bronze Birch Borer - (Agrilus anxius)

If you have Birch trees in your yard, there’s a good chance you’ve heard of the Bronze Birch Borer. It’s a small, bronze-coloured beetle that might not look like much, but it can do serious damage – especially Birch trees that are already stressed or aren’t native to North America. The real trouble comes from the larvae. After hatching, they tunnel under the bark and interfere with how the tree moves water & nutrients. Over time you’ll start to notice the top branches dying back, leaves thinning out, and maybe some activity from woodpeckers. If you look closely, you might see D-shaped holes, this is where the adult Bronze Birch Borer exists.

Some Birch trees are more vulnerable than others. European White Birch (Betula pendula) and Paper Birch (Betula papyrifera) tend to be the hardest hit, while River Birch (Betula nigra) and certain Asian varieties hold up better. If you’re thinking about planting birch trees, it’s best to choose one of the more resilient types. Keeping trees healthy is key – avoiding damage to the roots, regular watering especially in hotter weather & not letting them get too can go a long way. In some cases insecticides can help, especially if used early before damage gets too bad. If a tree is badly infested, it might be better to remove it to keep the beetles from spreading. If you remove an infested birch you have to be sure to dispose of material appropriately. Material should be chipped, burned or exposed to direct sunlight.

In the end, the Bronze Birch Borer is a manageable problem if you can catch it early and you take good care of your trees. A little attention now can save you a lot of trouble down the line.