University of California
Cooperative Extension Fresno County

A Lineup of Some of the Most Unwanted!

Latest Pests on the Radar in California:

Asian Citrus Psyllid

State of CA Overview Quarantine Map 9/7/2017

CDFA  PLANT QUARANTINE MANUAL - State Interior Quarantine list of quarantined counties and description of boundaries.


Brown Marmorated Stink Bug

Click here for Pest Alert fact sheet.


Polyphagous Shot Hole Borer

(Previously misidentified as the Tea Shot Hole Borer.) 

UC IPM Invasive and Exotic Pests: Polyphagous Shothole Borer

An ambrosia beetle named Polyphagous Shot Hole Borer is an invasive pest that attacks oak and avocado trees, causing branch dieback and eventually death.  The beetle bores into the trees and spreads a fungus that, in turn, attacks the vascular tissue of the tree and disrupts water and nutrient flow. The beetle also attacks Coast Live Oak, Box Elders and other trees.Both the fungus and the beetle were discovered on several backyard avocado trees in residential neighborhoods and a commercial avocado grove in Los Angeles County in February and March 2012. (The beetle was previously misidentified as the Tea Shot Hole Borer.  But subsequent DNA sequencing at the University of California, Riverside revealed the beetle to be different from the Tea Shot Hole Borer. The name Polyphagous Shot Hole Borer has been suggested for the beetle.)  No effective solutions for eradicating the beetle have been found.Ambrosia beetles typically live symbiotically with one or more fungi, which they spread into trees when they bore into the tree’s  tissue.  When dieback begins, its symptoms include a white powdery exudate (either dry or surrounded by wet discoloration of the outer bark) around beetle entry holes in the bark.


(Photos from USDA Animal and Plant Health Inspection Service)
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