Small bugs eating magnolia tree

Asked September 18, 2019, 4:57 PM EDT

Hello, I have a 30 year old magnolia tree in my backyard that did not bloom for the first time ever this year. I recently noticed what seemed like a powdery white substance on the trunk. On closer inspection I found these insects and an almost sandy powder I am assuming is wood. Any ideas on what these are?

Howard County Maryland

1 Response

Hi - These are called Barklice or Tree Cattle (Cerastipsocus sp.). Barklice are often found on smooth-barked trees and shrubs including crape myrtles and magnolias. Barklice do not feed on living plants. They feed on lichens, decaying organic matter, dead insects, molds, fungi, and pollen. They are not harmful to trees and shrubs. No control is necessary. There is more information about them in this article.

Check further up on the tree above where you see the powdery material and see if there are any small holes in the trunk. This type of damage can be caused by beetles. It would not be caused by the Barklice.

The horizontal lines of holes are from old sapsucker damage. They would not cause this powdery substance either.