Twig Borer

Black Twig Borer is a species of ambrosia beetle that attacks the twiggy branches of magnolias, dogwoods,  and oaks. Though one little twig doesn’t seem like that big of a problem, it can be bad news for a young tree, especially when up to 20 beetles can infest one twig. The female beetle bores into the tree’s wood where she lays her eggs. Typically, wilting will be visible only a week after the attack, followed by the death of foliage. Another tell is the twig forming an unsightly canker from the beetle's activity.  

Inside the twig, the beetle introduces a fungal infection to the tree that the grubs will feed on, along with the soft, spongey center of the twig called the pith. This leads to deformed and underperforming new growth. We recommend a systemic insect control, but improving the trees' overall health is just as important to prevent future infestations. Ensure your tree is being properly watered, fertilized, and mulched.