The Mediterranean Oak Beetle or MOB is responsible for the deaths of several Valley Oak trees recently in the western area of Santa Rosa. While most oak trees killed by the beetles that we are aware of are Valley Oaks or Blue Oaks, the beetles can infest eight species of native oak trees according to the University of California Cooperative Extension in Sonoma County.
The Mediterranean Oak Beetle is a type of Ambrosia Beetle that attacks declining or dead trees. The beetles kill the trees by chewing through the trees’ vascular system which reduces the flow of water and nutrients that the tree needs to survive. The beetles may also cultivate a fungus within the trees’ branches for a food source. This fungus may also affect the trees vascular system which could contribute to the eventual death of the tree.
Signs of Mediterranean Oak Beetle Infestation:
- One large dead branch in the top of the tree. The beetles attack the tree from the top down and may at first affect only one branch before spreading to other branches.
- Small holes in branches or trunks of the trees.
- Galleries with an overlapping pattern when the bark is removed or affected branches are cut. (Galleries are the tunnels formed by the beetles as they feed on the tree.)
How to Prevent Mediterranean Oak Beetle Infestation:
- Currently, beetles appear to affect trees that are in poor health or dead trees, so keeping your trees healthy and removing dead branches or dead trees is important. Chipping wood material to kill any potential beetles or covering firewood with clear plastic sheeting to trap and kill beetles will prevent spreading the beetles to other locations.
- Monitoring your home landscape and trees for beetles with specialized traps may identify a potential threat that can be treated proactively. TreePro can install and monitor traps in your home landscape.
- Promote optimal tree health by scheduling an inspection by an ISA Certified Arborist from TreePro. One of our Certified Arborists will make recommendations on pruning and suitable Plant Health Care treatments for oak trees.
