California Ag Network

Tag: Vineyard Pest Management

  • Funding Committed to Fight Pierce’s Disease

    The Consolidated Central Valley Table Grape Pest and Disease Control District Board of Directors authorized the use of up to $1.7 million in district reactionary funds, generated through the California table grape industry, to support CDFA activities related to the prevention and control of Pierce’s Disease (PD) and the Glassy-Winged Sharpshooter (GWSS).

    The action was taken during the district’s board of directors meeting on Friday, August 21, 2026, in response to an approximately $1.7 million funding shortfall associated with current PD/GWSS program activities.

    The district recognizes continued GWSS surveillance, treatment, and suppression as critical to limiting the spread of Pierce’s Disease and protecting California’s table grape, wine grape and raisin industries. Since there is currently no cure for Pierce’s disease, preventing the movement of the disease and controlling populations of GWSS remain essential to protecting California vineyards.

    Background

    The Consolidated Central Valley Table Grape Pest and Disease Control District was formed pursuant to Article 8.7 of Chapter 9 of Division 4 of the California Food and Agricultural Code.

    Under California Food and Agricultural Code Section 6047.87, the district is authorized to take actions necessary to control, eradicate, remove, or prevent the spread of GWSS, Pierce’s Disease and other designated pests and diseases injurious to table grapes. GWSS presents a significant threat because it can spread the bacterium that causes Pierce’s disease as it feeds on grapevines.

    Historically, USDA and CDFA have provided funding for the GWSS Area-Wide Treatment Program. Due to federal and state funding shortfalls, the funding toward the GWSS program has been cut year-over-year. The district’s board of directors is providing emergency industry funding to prevent disruption of the program while longer-term state and federal funding solutions are pursued.

    Protecting Kern and Tulare Counties

    GWSS and Pierce’s Disease do not recognize county, crop, or district boundaries. A

    coordinated, area-wide approach to surveillance and treatment is critical to reducing GWSS populations and limiting the potential movement of the pest into vineyards and other agricultural areas.

    Citrus plays a particularly important role in GWSS management because citrus trees serve as a primary year-round host for the pest. Area-wide programs use trapping and monitoring to identify areas with elevated GWSS populations and coordinate treatments in citrus and other host areas when necessary.

    The funding commitment from the district will help support continued CDFA-coordinated PD/GWSS activities, including area-wide efforts that provide resources for eligible citrus growers to conduct approved treatments designed to suppress GWSS populations. These activities complement trapping, monitoring, and other preventative measures intended to reduce the movement of GWSS and protect nearby vineyards.

    By committing up to $1.7 million from accumulated district reactionary funds, the board is

    investing industry-generated funds directly into efforts intended to protect table grape

    growers. For growers in Kern and Tulare counties, there will be no assessment change.

    The district remains committed to working collaboratively with CDFA, county agricultural

    commissioners, growers and other agricultural partners to protect California’s grape industry from Pierce’s Disease and Glassy-Winged Sharpshooter.

    For additional information, please contact the Consolidated Central Valley Table Grape Pest and Disease Control District at 559-210-0118. — Story contributed by the Consolidated Central Valley Table Grape Pest and Disease Control District

  • How to Control Vineyard Ants and Vine Mealybug

    George Zhuang, UC Cooperative Extension Specialist, and Manuel Marin Jr, PCA and California Raisin Grower, discuss some of the best practices for controlling ants and vine mealybug in your vineyard. Key takeaways include improved vineyard monitoring practices, specific methods of ant and Vine Mealybug control, and new ideas to bring home to your farm.

    Special thanks to Bayer Movento Insecticide for making this episode possible.

  • Vine Mealybug Control in California Vineyards

    Vine mealybug (Planococcus ficus) has become one of the most economically damaging pests in California vineyards. Left unmanaged, infestations can reduce yield, weaken vines, lower sugar content and spread viruses like leafroll, which contribute to sudden grapevine collapse.

    The good news is effective control is possible with the right timing and integrated approach.

    In this guide, we break down proven strategies used by California growers to control vine mealybug based on field insights and expert interviews featured on the California Ag Network channel.

    What is Vine Mealybug?

    Vine mealybug is a small, sap-feeding insect that:

    ·      Hides under bark, in clusters and on roots

    ·      Produces sticky honeydew that attracts ants and encourages sooty mold

    ·      Reproduces rapidly in warm climates like California’s Central Valley

    Why it’s so dangerous?

    ·      Multiple generations per year.

    ·      Protected hiding spots make detection more difficult and contact sprays less effective.

    ·      Can vector or spread various vineyard diseases like grapevine leafroll disease and others.

    Signs of Vine Mealybug infestation

    ·      White, cottony masses under bark or on clusters

    ·      Sticky residue (honeydew) on leaves and fruit

    ·      Black sooty mold developing on vines

    ·      Increased ant activity (ants protect mealybugs)

    Ant presence is often your first indicator of vine mealybug. If you have ants in your vineyard, you probably have vine mealybug.

    So, you’ve scouted your vineyard and found vine mealybug: what next?

    Integrated Vine Mealybug Control Strategy

    The most effective approach combines timing, chemistry, biology and monitoring.

    ·      Dormant and early season control

    ·      Growth stage foliar sprays

    ·      Biological control (natural enemies)

    ·      Ant control

    ·      Monitoring and timing

    Dormant & Early Season Control

    Prevention is the best medicine. An insecticide spray during late dormancy or at bloom is usually enough to control their population all season long for milder infestations. There is a lot that goes into determining which chemistries to use such as soil conditions and specific regional climates. The UC Cooperative extension also recommends considering other pests in your treatment in strictly preventative situations. Broad spectrum pesticides can take care of more problems than just vine mealybug and reduce the number of passes through the vineyard. Be aware, however, that broad spectrum insecticides can also reduce beneficial insect populations so be sure to consult your Pest Control Advisor for the best dormancy and bloom treatments.

    Other helpful strategies include:

    ·      Remove loose bark to expose hiding populations

    ·      Apply delayed dormant insecticides if the pressure is high

    This stage is critical because you’re targeting populations before they explode

    In-Season Chemical Control

    While the vine mealybugs are developing, it’s essential to use systemic insecticides applied through drip irrigation where possible for the deepest control. Contact insecticides and foliar systemic sprays can contribute to control as well. The crawler stage is when they are most vulnerable so be sure to target early season.

    Biological Control

    Beneficial insects play a critical role in long -term suppression

    ·      Parasitic wasps

    ·      Mealybug destroyer

    It’s important to avoid broad spectrum sprays that kill beneficials, so be sure to consult your pest control adviser for the best in-season treatments.

    Ant Control

    Ant control is critical in managing growing vine mealybug infestations as ants will protect them in exchange for their honeydew. Without controlling ants, your biological control strategy becomes less effective, and infestations can spread more quickly. To control ants, you can:

    ·      Setup bait stations

    ·      Apply sticky trunk barriers

    ·      Apply targeted insecticides

    Monitoring and Timing

    Monitoring populations is essential as it allows you to time sprays effectively and reduce unnecessary applications thus improving ROI on inputs. Understanding the movements and stages of the infestation is essential for effective control. Growers often use a combination of pheromone traps and visual scouting under the bark to detect and track vine-mealybugs.

    Key Takeaways for Growers

    ·      Vine mealybug requires year-round management.

    ·      Timing of control methods is everything.

    ·      Combine chemical control, biological control, and ant management strategies.

    ·      Monitoring tools dramatically improve effectiveness.

    Vine mealybug is not a one-time fix; it’s a management system. Growers seeing the best results stay proactive, use integrated strategies and adjust based on monitoring data.

    Check out this video on control of Vine Mealybug HERE

    Check out our webcast on scouting for Vine Mealybug HERE

    —   By Hyrum Malcolm, Publisher

  • New Vineyard Advisor App for American Grape Growers – FREE

    Looking for instant pest, disease and nutritional recommendations in the palm of your hand?  Download the new Vineyard Advisor app, free and applicable to grape growers nationwide.  The app was developed by viticulture experts at Texas Tech University, as represented by Ed Hellman in this video interview.  Watch the brief interview as professor Hellman as he shares more details about this new app.