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Polyphagous and Kuroshio Shot Hole Borers

Infested tree, infested trunk, adult beetles in galleries

The Polyphagous Shot Hole Borer (PSHB) is an invasive wood-boring beetle that attacks dozens of tree species in Southern California, including commercial avocado groves, common landscape trees, and native species in urban and wildland environments.

PSHB spreads a disease called Fusarium Dieback (FD), which is caused by pathogenic fungi. Trees that are FD-susceptible may experience branch dieback, canopy loss, and, in some cases, tree mortality.

Like PSHB, Kuroshio Shot Hole Borer (KSHB) is an exotic Euwallacea species that also vectors Fusarium Dieback. Both beetles are present in Southern California but are concentrated in different regions. See their known distribution here.


  • New Online Training

    Invasive shot hole borers (ISHB) are a pest and disease complex potentially affecting over 200 tree species, but posing a strong risk to box elders, sycamores, and other riparian and urban trees, as well as being a nuisance pest for avocado. The beetles...

    By Sabrina L. Drill
    Author - Natural Resources Advisor

Latest News

A Tiny Beetle has Decimated Hundreds of SoCal Trees. Now experts are worried about Sacramento

Sacramento Bee

Michael Finch II, 09/19/2019


So Many Shot Hole Borers: New research charts four nearly identical species

Entomology Today

Jiri Hulcr & Jackson Landers, 01/07/2019


Reducing the Spread of Invasive Pests in Cut Wood/Managing ISHB in Southern California (2 articles)

UC IPM Green Bulletin

California Firewood Task Force/Beatriz Nobua-Behrmann, Fall 2018


Beetle Mania: The Nasty Insect that is Killing the Trees of Johannesburg

Yale Environment 360

Adam Welz, 10/16/18


Tiny Beetle Killing Trees, Ups Fire Risk in San Diego

NBC 7 News

May Tjoa 7/6/18


Tree Will Need Replacing with More Resilient Species

NPR - Market Place

Aaron Schrank 6/7/17


Southern California Trees Threatened by Borer Beetles

California Audubon

Sandy DeSimone 6/6/17


Find out more by following this link: 

ISHB in the News

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Online Training

ISHB on-line training!  The course is  served by the eXtension national online learning platform (and users will need to create a free account). 

ISHB Detection & Management Assessment

Before reporting infestations, take this online assessment to see if your tree is suffering from ISHB damage.

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