Small Beetle, Big Problem

Two closely related species of small, non-native beetles and the fungi they carry pose an imminent threat to millions of trees in Southern California. Invasive shot hole borers (ISHB) attack a wide variety of tree species including commercial avocado groves, common landscape trees and native species in urban and wildland environments.

These beetles tunnel into tree trunks and branches creating channels called galleries. In the process, they introduce fungi that grow in the galleries and later serve as the food source for ISHB larva. The fungi also destroy the food and water conducting systems of the tree, eventually causing stress, dieback and ultimately death of the tree.

For more information about invasive shot hole borers, view the video* below and explore this website.

* This is a shortened version of a video produced by California Releaf, a nonprofit organization that works to empower grassroots efforts and build strategic partnerships that preserve, protect, and enhance California’s urban and community forests.

  • May 7, 2020

    As part of the UC Ag Experts Talk series, on May 20 from 3 pm to 4 pm, Dr. Akif Eskalen, Plant Pathology Specialist in UCCE, will host a webinar discussing the shot hole borers attacking avocado trees and their management. Click here to register.

    shot hole damage avocado


Online Training

ISHB eXtension Training! The course is served by the eXtension national online learning platform.

ISHB Detection & Management Assessment

Before reporting infestations, take the ISHB Detection Assessment to see if your tree is suffering from ISHB damage.