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

  • New News for Subtropicals

    Added November 14, 2018
    topics in sub masthead

    TOPICS IN THIS ISSUE   California Citrus Network: an online forum to facilitate communication and information exchange regarding California citrus High Density Planting for Avocado Production: A Chilean Perspective Avocado Brainstorming...

  • Stones in Avocado Fruit

    Added November 9, 2018
    avocado stones

    The English often call a fruit seed other names, like pip. A large pit could be called a stone.  Avocado usually has a seed, and if not it turns out to be a small fruit, called a "cuke".  Well that's a different story.  Sometimes little...

  • Shot Hole Borer Training

    Added November 7, 2018
    field id

    Come Learn About Field Identification of Invasive Shot Hole Borers  We're holding two early December trainings on invasive polyphagous and Kuroshio shot hole borer biology, identification, surveillance, and management of infested...

  • Rootey Tootey - Citrus Fruitey!!!

    Added November 5, 2018
    citrus cornucopia

    Grower and the Public are invited to see, taste and hear about the citrus fruits and trees that make an industry and an iconic fruit in this State.  There are two separate days, One for Growers and One for the general Public.  Note the two...

  • Ready! Set! Split! Navel Orange Time.

    Added November 2, 2018
    navel split

    These are hard days for navel oranges.  Drought stress.  Salt stress due to drought. Then a heat wave in July that messed the trees up.  And now we head into a weird fall with maybe rain. Maybe no rain. Maybe a little rain. This is...

  • Which Avocado Tree Is It?

    Added October 31, 2018
    avocado varieites

    Of the many known varieties, they fall into three broad categories based on whether they are of the Mexican, Guatemalan or West Indian races of Persea americana, the avocado specie and the crosses that occur between these races. For example, ‘Hass'...

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: