oak tree in tacoma

Mediterranean Oak Borer Tree Monitoring Study

Get involved in protecting the PNW’s native Garry oak

What is the Mediterranean Oak Borer (MOB)?

The Mediterranean oak borer (Xyleborus monographus) is an invasive ambrosia beetle originally from the Mediterranean regions of Europe, Africa, and the Middle East. It has recently been found in the Pacific Northwest regions of California and Oregon. Many oak species are susceptible, including the Northwest’s native oak, the Garry oak (Quercus garryana). There is concern regarding the spread of MOB within Washington.

What is the Garry oak tree?

The Garry oak tree also known as Oregon white oak (Quercus garryana) is an oak tree native to the Pacific Northwest spanning from Northern California to British Columbia. The Garry oak is the only native oak in Washington. Historically, the Garry oak tree has been a vital part of the prairie oak woodland ecosystem providing vital nutrients and shelter for insects and animals.

Mediterranean Oak Borer’s Impact on Garry Oak Trees

Introduced species such as the Mediterranean Oak Borer threaten the health of Garry oak trees and their ecosystems. These beetles tunnel into Garry oaks and can spread fungi that infect and damage the tree. The fungi then clog water conducting tissues and lead to wilting. Generations of beetle infestation lead to tree branch and eventual entire tree death.

Diagram of DIY beetle trap. Illustration by Ambrosia Symbiosis.
Diagram of DIY beetle trap. Illustration by Ambrosia Symbiosis.

Study

Community scientists will place DIY beetle traps containing ultra high release (UHR) ethanol lures on Garry oak trees exhibiting signs and symptoms of MOB infestation. Ethanol lures will be provided by the Forest Health Lab at WSU as well as instructions for trap assembly and sample collection. These lures will then be used to capture any beetles residing on the oaks and submitted to the Forest Health Lab for further analysis. Analysis will consist of species identification, through morphology and DNA analyses and identification of fungal colonies present on the beetles. These findings would help us advance research regarding management and conservation efforts.

Mediterranean Oak Borer Tree Monitoring Interest

Please share your contact information if you would like participate in a Mediterranean Oak Borer monitoring study on Gerry Oak trees.
Name(Required)
Please indicate the city that you are closest to.
Please indicate 'public' if interested in participating outside of work
Please use this space to share more about your interests and availability
Please share any other information you would like. We can follow up if requested.

iNaturalist Project

The purpose of this project is to collect observations of healthy and unhealthy oak trees. There are many threats to the health of oak species such as the Mediterranean Oak Borer. Together we can monitor the health of oaks and report concerns.

Oak Health Watch iNaturalist page
You can start getting involved by joining our Oak Health Watch iNaturalist project and recording observations of oaks of all health stages.

Learn More

Mediterranean Oak Borer Flyer

Flyer detailing facts about the Mediterranean Oak Borer

2024 Mediterranean Oak Borer Workshop

MOB Workshop Flyer