Subtropical Fruit Crops Research & Education
University of California
Subtropical Fruit Crops Research & Education

We are San Diego & Riverside County Farm Advisors

HLB - Potential Threat Near San Diego County

HLB detected in Riverside County: 

The Asian citrus psyllid is a tiny, mottled brown insect about the size of an aphid that poses a serious threat to all of California's varieties of citrus (e.g., oranges, grapefruit, lemons, and mandarins).


The insect is associated with the fatal citrus disease Huanglongbing (HLB), also called citrus greening disease. The psyllid takes the bacteria into its body when it feeds on bacteria-infected plants and spreads when a bacteria-carrying psyllid flies to a healthy plant and injects bacteria into it as it feeds.

HLB can kill a citrus tree in as little as five years, and there is no known cure. All commonly grown citrus varieties are susceptible to the disease.

The only way to protect trees is to prevent spread of the HLB pathogen in the first place, by controlling psyllid populations and removing and destroying any infected trees.

Learn more about HLB and how to protect your crops from it by following these links. 


News Stories: 

Distribution & Management: 

IPM Blog: 

IPM Pest Notes 

California Citrus Pest & Disease Prevention Committee: 

Topics in Subtropics Blog

  • Grower Meetings are Good

    Added September 19, 2018
    grower meeting

    One good idea from a meeting can make all the difference of whether that was a meeting worth going to or not. One idea, that's all it takes to make a big difference back at the ranch.  A lot of times the good idea comes from the people you meet...

  • Weather Tracker

    Added September 17, 2018
    rainfall forecast CA

    Reno, NV (Sept 10, 2018): Scientists from the Western Regional Climate Center (WRCC) at the Desert Research Institute (DRI) in Reno, Nev. are pleased to announce the release of a long-awaited update to a climate mapping tool called the California...

  • Wild Fire Effect on Soils?

    Added September 14, 2018
    firefighters in avocado grove

    Low-severity wildland fires and prescribed burns have long been presumed by scientists and resource managers to be harmless to soils, but this may not be the case, new research shows. According to two new studies by a team from the University of...

  • New Class of Herbicides?

    Added September 12, 2018
    weeds bordering avocado orchard

    A garden can be a competitive environment. Plants and unseen microorganisms in the soil all need precious space to grow. And to gain that space, a microbe might produce and use chemicals that kill its plant competitors. But the microbe also needs...

  • STINK Bugs

    Added September 10, 2018
    stink bugs mating

    Stink bugs of various species have been an issue on avocado and citrus for many years. Not always an issue, but occasionally they can reach damaging proportions. For stink bugs to...

  • Say it Ain't So, But Yes, It's True. Watch Out Blueberries !

    Added September 7, 2018
    shot hole borer cake

    Akif Eskalen, the Subtropical Crops Plant Pathology Extension Specialist at UC Riverside has accepted a new position at UC Davis. He will be filling the position of his mentor, Doug Gubler. From now on, he will work on grapes, strawberries, caneberries,...

Avocado Production in California Books

Book 1: Background Information

In Book 1, Gary S. Bender, Farm Advisor, takes you through the history of the avocado industry in California and teaches you about grove development.

Browse by Chapter

Book 2: Cultural Care

Book 2 focuses on cultural care and includes articles on irrigation, fertilization, disease and insect control, vertebrate pest management, pruning and frost management. The author for most of the articles is Gary S. Bender, Farm Advisor for Subtropical Horticulture in San Diego County.

Browse by Chapter

Webmaster Email: