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May 2025Archived

 

Field picture submitted by Elizabeth Fichtner

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Mediterranean Oak Borer: Page

About the Disease

All ambrosia beetles (like MOB) grow fungi inside their galleries and use it as food for larvae and adults. Some of these fungi can be pathogenic and cause tree diseases that may lead to tree decline and, sometimes, tree death.
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Mediterranean Oak Borer: Page

Host Trees

MOB attacks at least 12 species of oaks. In California, it has been found infesting two species of white oak: most commonly valley oak and, to a lesser extent, blue oak. A single, very limited attack was found in a severely distressed California black oak. Valley Oak Valley Oak in Calistoga.
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Mediterranean Oak Borer: Page

Impact

MOB creates tunnels (or galleries) in the trunks and branches of host trees. It initially attacks the crown of the tree, where it will kill individual limbs. Infestation can continue over several growing seasons, eventually invading the main trunk and killing the entire tree.
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Mediterranean Oak Borer: Page

Identifying Signs & Symptoms

Oak trees infested with MOB are most easily identified by damage caused by the beetles tunneling activity (galleries) in the xylem. MOB galleries are often: Trellis-like Very crowded and intersecting Fanning out in a single plane 1.2-1.
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Mediterranean Oak Borer: Page

Look-alikes

In Northern California, two native ambrosia beetles in the genus Monarthrum also create black-colored galleries in oaks. Monarthrum galleries branch from a single point like a palm leaf and do not cross over neighboring galleries.
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Mediterranean Oak Borer: Page

Infested Material Disposal

Take the following steps to limit the spread of MOB: Moving infested wood artificially spreads pests to other areas. Buy It Where You Burn IT, Dont Move Firewood. firewood.ca.gov Cut stumps as low to the ground as practical and cover with soil if possible.
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Mediterranean Oak Borer: Page

Reporting Infestations

Under a collaborative program, agencies and organizations are working together to determine the distribution, impact and possible prevention methods of tree mortality caused by Mediterranean Oak Borers/Pathogen Complex Disease (MOB/PC).
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Mediterranean Oak Borer: Page

Distribution in California

MOB has been found in Amador, El Dorado, Lake, Napa, Marin, Mendocino, Napa, Sacramento, Sonoma and Yolo Counties. .
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Communications Toolkit: Page

Lower Thirds Text

Sometimes it is necessary to add text to a video, particularly when you want to call out a speaker's name. Text information is usually presented in the lower third of the screen. Here are some examples: Some video, especially news content, relies heavily on lower thirds text.
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Communications Toolkit: Page

Copyrights and Permissions

This page covers copyright basics as they apply to UC ANR video production, including how to handle still images, music, filming locations, and model releases. The information here is intended as a guide and should not be taken as legal advice.
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