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 have also been shown to attack a wide variety of common and less common ornamental species. (For a complete host list, visit https:// ucanr.edu/sites/pshb/overview/SHB_Reproductive_Hosts/). The tiny beetles burrow into the trunks and branches of trees, and create galleries where they cultivate a fungus that utilizes the tree's own circulatory system, harming and in some cases killing the tree. We know the beetle can reproduce in over 60 species of trees, and they have devasted natural riparian areas, though we are beginning to see recovery of some infestations. Currently, the most effective management method is to remove infested wood, sometimes entire trees, and chip what is removed to smaller than 1 inch.
Now there is a new resource for getting up to speed on ISHB, an on-line training! Available through our website, www.pshb.org, the course is actually served by the eXtension national online learning platform (and users will need to create a free account). The course consists of four chapters, including history and impacts, biology, symptoms and look-alike pests, and monitoring and management. While it can't fully replace field training, it can be a good way to get familiar with the issues.
We're moving north, and holding a training workshop with CalFire ongoldspotted oak borer and invasive shot hole borers May 9th, 2019 in San Luis Obispo! This workshop will address biology, identification, surveillance, and management of infested trees, downed wood. and firewood. We'll cover these topics in the classroom, then have a hands-on lab to learn how to identify signs of shot hole borer damage, set up a monitoring program, and sample trees.
$30.00 Registration fee includes lunch, a ISHB Field Guide, and ISHB Demonstration Kit. Pre-registration is required. Click here to register.
We have applied for CEU's from the Department of Pesticide Regulation and the International Society for Arboriculture.
Speakers include Bea Nobua-Behrmann, UCCE Urban Forestry Advisor; John Kabashima, UCCE Environmental Horticulture Advisor (Emeritus); Kim Corella, Forest Pest Specialist, CalFire; and Kevin Turner, Southern California Invasive Pest Coordinator, CalFire
Thanks to The Britton Fund, CalFire, and US Forest Service - State and Private Forestry for supporting these workshops.
Invasive shot hole borers are in the news again. Our collaborator, Greg McPherson with the US Forest Service, has just released a new estimate of the potential damage polyphagous and Kuroshio shot hole borers may cause as the spread across the landscape. As quoted in this recent LA Times article by Louis Sahagun:
His initial estimate is that just one particularly dangerous menace — the polyphagous shot hole borer beetle — could kill as many as 27 million trees in Los Angeles, Orange, Riverside and San Bernardino counties, including parts of the desert.
That's roughly 38% of the 71 million trees in the 4,244 square mile urban region with a population of about 20 million people.
UCCE Plant Pathology Specialist Akif Eskalen added:
“Here's the sad news about sycamores....If we cannot control the shot hole borer, it will kill all the sycamores in California. And when they're done with sycamores, they'll move to other trees.”
And emeritus Environmental Horticulture Advisor John Kabashima was also featured.
You can read the whole story at http://www.latimes.com/local/california/la-me-dying-urban-trees-20170403-story.html