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

  • ACP Scouting and Monitoring Workshop for Growers in Riverside County

    Added September 21, 2018
    ACP 1

    The University of California Cooperative Extension is hosting free workshops for citrus grove owners, managers and farmers. The workshop will provide an overview of proper Asian citrus psyllid (ACP) scouting techniques from University of California...

  • Avocado Annual Meeting - October 4/5

    Added September 21, 2018
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    BIG Things are happening in the avocado world!!! Come find out at the Annual Avocado Meeting to be held in two weeks.  Yes, it's coming up fast. And it's going to be in the Temecula area.  New growers need to come to learn from the...

  • New News Letter on Subtropics

    Added September 21, 2018
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    The latest Topics in Subtropics quarterly is out.  Check it out. And subscribe for further editions.  And check out the archive of past editions. Topics in Subtropics The U.C....

  • Grower Meetings are Good

    Added September 19, 2018
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    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
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    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
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    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...

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.

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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.

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