California Ag Network

Category: Pest/Disease Management

  • Huanglongbing Quarantine Boundary Expands in Riverside, SD Counties

    Effective September 11, 2026, the Department is expanding the citrus greening disease boundary in the Murrieta area of Riverside County and into San Diego County (grids 484, 499, and 510). A map of the expanded boundary can be found at https://www.cdfa.ca.gov/citrus/pests_diseases/hlb/regulation.html. 

    Also effective September 11, 2026, the Department is expanding the Asian Citrus Psyllid Bulk Citrus Regional Quarantine Zone 6 in these areas to reflect the HLB quarantine boundary expansion. A map of the expanded boundary can be found at https://www.cdfa.ca.gov/citrus/pests_diseases/acp/regulation.html.

    Regulated articles and conditions for intrastate movement under the quarantine can be found at Title 3 of the California Code of Regulations (CCR) section 3435 & 3439. Pursuant to 3 CCR § 3435 & 3439, any interested party or local entity may appeal a quarantine area designation. 

    Process to Appeal the Expanded Boundary 

    The appeal must be submitted to the Department in writing and supported by clear and convincing evidence. The appeal must be filed no later than ten (10) working days from the date of this notification. During the pending of the appeal, the designated quarantine boundary under appeal shall remain in effect. 

    Mail Appeals to: CDFA – Citrus Division 1220 N Street Sacramento, CA 95814 

    Electronic Notification of Boundary Changes 

    California Code of Regulation allows interested parties to be notified of quarantine area boundary changes, as well as the opportunity to submit quarantine boundary appeals. If interested in receiving notifications, please sign up for regulatory updates through the email notification at: https://public.govdelivery.com/accounts/CADFA/subscriber/new 

    For questions regarding the regulations or map, please email Raymond Niem (Raymond.Niem@cdfa.ca.gov) or call 916-274-6300. — Story contributed by the California Department of Food and Ag

  • Almond Market Looks Strong Going Into 2027

    The almond industry is entering the new crop year from a solid position according to a recent market update from Blue Diamond Growers. This is thanks in no small part to exports to India.

    The 470.7-million-pound carry-in (of which only 447.1 million pounds is estimated as edible) is down from prior year and confirms the tightness in supply from one crop to the next. Downward pressure on crop potential and overall supply and demand fundamentals continue to support a stable-to-firm market outlook. Export demand remains healthy with the coming weeks expected to provide clarity on crop size, kernel sizing, and the degree to which rapidly appreciated pricing can be absorbed by end markets.

    The 2026 crop year started on a positive note, meeting strong industry expectations. August shipments totaled 190 million pounds. Exports reached 143.2 million pounds, an increase of 31%, while the domestic market shipped 46.8 million pounds at a modest -3.3% decrease versus last year. With six of the last seven last months’ total shipments outpacing previous year, the industry continues to experience strength in global demand.

    India was the clear standout in August, receiving 44.3 million pounds, up approximately 170% from 16.4 million pounds last year. The increase reflects stronger replenishment ahead of the festival season and a normalization from the unusually low August 2025 shipment level. The magnitude of the increase is notable given elevated pricing and confirms India’s continued importance as the primary outlet for California inshell almonds. Local consumption will become increasingly important ahead of festival season as buyers will begin to replenish stocks that dwindled at the end of the 2025 crop year.

    August domestic shipments totaled 46.8 million pounds, down 3.3% year over year. While this may not have been the start to the year the industry had hoped for, the improvement in shipment performance over the last six months provides optimism that the market has stabilized. As prices rose over the last month, purchasing activity slowed and shifted to closer, strategic locations. This cautious approach is expected to continue. Looking ahead, domestic demand is expected to remain steady, with a pipeline of commitments providing support for shipments in the next few months.

    The 2026 crop is progressing rapidly with current receipts for August coming in at 401.9 million pounds. The pacing of receipts is 55% above August 2025 due to harvest beginning approximately 2 weeks earlier than prior year. The increase in receipts over last year is not a reflection of projected crop receipts for 2026.
    Nonpareil and Independence varieties are largely harvested with pollinizer varieties following closely behind. In some of the most advanced areas, growers have completed orchard harvest activities and are focusing on post-harvest practices and minimizing water stress to support next season’s crop.

    Current Nonpareil reject levels are the lowest in several years, though ticking up slightly, driven by a third flight of navel orangeworm. Independence rejects are trending higher than last year, mainly due to brown spot from leaf-footed plant bugs.

    Yields are variable in Nonpareil and Independence depending on the region. Speculation on smaller kernel sizes coming into harvest are beginning to be realized. Yields in Nonpareil and Independence receipts are signaling a lower 2026 crop than 2025, as forecasted. There is continued downward pressure on crop potential, which will be informed by pollinizer varieties that hullers are beginning to process. Next month’s report may reflect further shifts to the forecast as pollinizer volume comes in and is accounted for.

  • APHIS Expands the Citrus Greening (Huanglongbing) Quarantined Area in California

    The Animal and Plant Health Inspection Service (APHIS), in cooperation with the California Department of Food and Agriculture (CDFA), is expanding the citrus greening (Huanglongbing; HLB) quarantined area in California. APHIS is adding one square mile to the Santa Paula quarantined area in Ventura County, which impacts 151.7 acres of commercial citrus. APHIS is adding 10 square miles to the quarantined area in Riverside and San Diego Counties, which impacts 121.5 acres of commercial citrus. This measure parallels the intrastate quarantine that CDFA established on July 15, 2026. APHIS is taking this action because plant tissue samples from residential properties tested positive for Candidatus Liberibacter asiaticus, the causal agent of HLB.

    APHIS is applying safeguarding measures outlined in 7 Code of Federal Regulations (CFR) 301.76 through 301.76-11 and associated Federal Orders that govern interstate movement of regulated articles from the quarantined areas. This action helps prevent HLB from spreading to areas that are not currently infested.

    For updated maps and details, visit the APHIS Citrus Greening and Asian Citrus Psyllid webpage. APHIS will also publish a notice of this change in the “Federal Register.”

    For additional information contact Abby R. Stilwell at 919-323-6296 or abby.r.stilwell@usda.gov

    — Story contributed by the USDA Animal and Plant Health Inspection Service

  • 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

  • FDA Issues Emergency Use Authorization for Generic Drug to Prevent New World Screwworm in Cattle

    FDA’s 14th EUA against NWS

    The U.S. Food and Drug Administration issued an Emergency Use Authorization (EUA) for Bimectin (ivermectin) injection for the prevention of New World screwworm (NWS) infestations in cattle when administered within 24 hours of birth, at the time of castration or at the appearance of a wound Bimectin injection is not authorized for use in lactating dairy cows or in calves that will be processed for veal.

    Based on the available evidence, the FDA has concluded it is reasonable to believe that Bimectin injection may be effective for the prevention of Screwworm infections in certain cattle when used as authorized, and the known and potential benefits of the product outweigh its known and potential risks.

    “This authorization reflects the FDA’s commitment to expanding generic drug options against New World screwworm,” said Timothy Schell, Ph.D., director of the FDA’s Center for Veterinary Medicine. “By authorizing both generic and pioneer products, the Agency is ensuring producers aren’t dependent on a single manufacturer or product to protect their herds.”

    To maintain the continued safety of the food supply and avoid drug residues, it is critical that cattle producers carefully follow the 35-day slaughter withdrawal time and not administer this drug in lactating dairy cows and calves that will be processed for veal.

    Bimectin injection is a generic version of Ivomec, which was authorized in February 2026 for the prevention of NWS myiasis in cattle. The FDA previously approved Bimectin injection for the treatment and control of various parasites in cattle. This EUA is only for the Bimectin injection and does not authorize other dosage forms of Bimectin.

    Bimectin injection is available over the counter without a prescription. Cattle producers are responsible for using Bimectin injection in accordance with the product labeling and fact sheet.

    This EUA will be effective until it is revoked or the HHS Secretary terminates the declaration that the potential public health emergency presented by NWS justifies the emergency use authorization of animal drugs for NWS.

    Bimectin injection is sponsored by Bimeda Animal Health Ltd. based in Ireland.

  • Screwworm Strain Readied for Active Duty

    American scientific ingenuity in the form of sterile fly releases helped eliminate New World screwworm from the country in the 1960s. Now, ARS researchers are combining that ingenuity with next-generation tools to counter new resurgences of the pest threatening livestock and wildlife in New Mexico and Texas.

    “Releasing sterile screwworm flies is a proven, decades-old approach to eliminating populations of this pest and preventing the harm it inflicts—physically to livestock animals and wildlife and financially to the producers who raise livestock for our milk, meat, hide and other products,” said Kim Lohmeyer, Director of ARS’s Knipling-Bushland U.S. Livestock Insects Research Laboratory in Kerrville, TX. “Advances in genetics have now given us better tools to understand the screwworm’s population dynamics and leverage that knowledge for improved control methods, including sterile fly releases.”

    The latest example is NovoFly™, an all-male strain of screwworm developed by Lohmeyer’s team and university collaborators. With full regulatory approval of NovoFly™, critical resources can be redirected towards producing only males, essentially doubling the number available for SIT releases to eradicate established populations of the pest or isolate outbreaks of it.     

    Central to screwworm eradication is the Sterile Insect Technique (SIT). SIT is a biologically based approach to pest control that originated with the pioneering studies of ARS entomologists Edward B. Knipling and Raymond C. Bushland. That research began in the mid-1930s and continues today at the  Kerrville lab, which was posthumously named after these two entomologists.

    In January 2026, USDA Secretary Brooke Rollins and Deputy Secretary Stephen Vaden highlighted  SIT as part of a New World Screwworm Grand Challenge to counter recent U.S. incursions of the pest up through Central America.

    The SIT calls for releasing sterilized male flies near infestation areas where they can mate with wild female flies. The resulting eggs fail to hatch into flesh-eating larvae, which typically burrow into wounds or mucus-lined openings of livestock animals such as cattle—but also wildlife and, less often, pets and people.  Without larval offspring, the screwworm population eventually collapses, sparing animals further harm and reducing producers’ costs for insecticides, veterinary services, and medications.

    Despite SIT’s success in eradicating America’s indigenous screwworm population by 1966 (and eliminating subsequent resurgences of it), researchers saw room for improvement. “A sterile male can prevent a lot of wild females from reproducing, but a sterile female fly that mates only once doesn’t help with SIT,” explained Alex Arp, an ARS Research Geneticist who co-developed the all-male NovoFly™ strain.  While only sterile males are desirable, until now there has been no good way to separate them from females prior to SIT release, he added.

    Producing only male flies would increase production efficiency by doubling the number of male larvae that can be reared and male pupae that can be sterilized without major changes to production facilities. Without sterile females being released, sterile males have increased opportunities to mate with wild females, resulting in a more effective, efficient SIT program.

    Toward that goal, Arp and collaborators engineered Novofly™ with a genetic “switch” that kills female larvae during early rearing stages but doesn’t function in males. This allows for a doubling in the number of males that can be brought to maturity for release using the same amount of artificial diet and equipment.

    NovoFly™ is currently undergoing regulatory approval before the Environmental Protection Agency. Once approved, NovoFly™ will be mobilized for “active duty” at designated screwworm rearing facilities. USDA’s Animal and Plant Health Inspection Service coordinates SIT efforts in the U.S, Mexico, and Central America.

    “The research that went into creating NovoFly™ will provide the basis for the Grand Challenge project led by Max Scott of North Carolina State University together with Arp and many other collaborators,” Lohmeyer added—an effort that will set the stage for the next generation of this screwworm strain.

    To learn more about USDA’s whole-of-government approach to combatting NWS, visit “Stop Screwworm: Unified Government Response to Protect the United States”

  • APHIS Expands Sweet Orange Scab Quarantine

    Effective Aug. 19, USDA’s Animal and Plant Health Inspection Service (APHIS), in cooperation with the California Department of Food and Agriculture (CDFA), expanded the area quarantined for sweet orange scab (SOS) in the Burbank, Los Angeles and Long Beach areas of Los Angeles County and the Anaheim and Garden Grove areas of Orange County. SOS is a disease caused by the fungus Elsinöe australis. APHIS is expanding the quarantined area by 110 square miles in Los Angeles County and 67 square miles in Orange County. APHIS is taking this action because of SOS detections in plant tissue samples collected from residential properties in Los Angeles and Orange Counties. There are 2.5 acres of commercial citrus impacted by the Anaheim and Garden Grove area expansion

    APHIS is applying safeguarding measures outlined in Federal Order DA-2024-34 pertaining to the interstate movement of regulated articles from the quarantined areas in California. This measure parallels the intrastate quarantine that CDFA established on June 18, 2026. This action is necessary to prevent the spread of SOS to non-infested areas of the United States

    The APHIS Sweet Orange Scab webpage has information on this disease, Federal Orders, APHIS approved packinghouse procedures, and a description of current Federal SOS quarantined areas.

    For additional information growers may contact:

    Abby R. Stilwell
    Agriculturalist
    919-323-6296
    abby.r.stilwell@usda.gov

    — Story contributed by USDA APHIS

  • New Fusarium Disease Resistant Wheats

    ARS researchers are helping wheat farmers deal with a devastating crop disease. ARS scientists in Lincoln, Neb. released new lines of common and durum wheat with resistance to Fusarium Head Blight (FHB). FHB, commonly known as scab, significantly affects wheat and barley, resulting in approximately $1B in yield losses annually in the U.S. and worldwide.

    ARS scientists used modern and conventional breeding technologies to transfer a new FHB-resistance gene [Fhb7The2] from wild grass to wheat and developed a new germplasm named ‘WGC002’ and many other wheat breeding lines.  These new wheat lines derived from WGC002 have exhibited desirable agronomic traits in addition to FHB resistance across different locations and seasons. They will be released as varieties or germplasm following further development and evaluation. Scientists expect a substantial reduction in U.S. economic losses from wheat crops affected by FHB within a few years if farmers adopt new varieties with this resistance gene. — Story contributed the USDA Ag Research Service

  • Wine Grape Industry Commits Additional Funding to Stop GWSS

    To stop the glassy-winged sharpshooter from spreading a fatal grapevine disease into Northern California, the Pierce’s Disease and Glassy-Winged Sharpshooter (PD/GWSS) Board at the California Department of Food and Agriculture committed $820,000 to the ongoing emergency response.

    Preventing the glassy-winged sharpshooter from becoming established in new areas protects winegrapes and other agricultural and landscape plants. California’s wine industry generates about $73 billion in annual economic activity and supports more than 422,000 jobs statewide. A 2025 economic study estimated that if glassy-winged sharpshooters spread unchecked, outbreaks of Pierce’s disease could cost winegrape growers an additional $56 million a year in lost production and vine replacement.

    Since May, county agriculture officials have been tracking down nearly 10,000 grapevines from a Fresno nursery that may have carried the invasive pest into 40 counties. The Board’s special emergency funding is intended to support those efforts. Officials have contacted more than 3,100 customers who purchased the grapevines, inspected and/or destroyed more than 2,900 plants and set more than 2,700 additional insect traps.

    Glassy-winged sharpshooters have been found on customer plants in 23 counties. Inspections and trapping must continue for at least three years to track if the pest spreads beyond customers’ properties.

    “California’s winegrape industry is facing some of the hardest economic times in a generation, but we recognize what is at stake if this destructive pest becomes established in Northern California,” said Board chair Trey Irwin. “Putting $820,000 from the Board’s limited reserves toward this effort is a major commitment for our industry and shows how seriously we’re taking this threat.”

    The funding comes from assessments paid by California winegrape growers to support pest and disease research and prevention. Since 2001, the Board has invested $99 million in research, outreach, prevention and control for Pierce’s disease, grapevine viruses and the insects that spread them.

    “It is important that we continue with inspections and trapping to closely monitor the situation,” said Michelle Pham, response lead with the CDFA Pierce’s Disease Control Program. “This effort depends on close coordination among growers and county, state and federal agencies. For 25 years, that partnership has helped keep the glassy-winged sharpshooter from spreading throughout California.”

    People who suspect they have found a glassy-winged sharpshooter should contact their local agricultural commissioner’s office (bit.ly/CountyAg). For pictures of the pest and for more information, visit bit.ly/GWSS-Costco.

  • New Investment Aims to Give Growers Another Tool for NOW

    California almond growers know the challenge navel orangeworm brings every season. The pest can reduce crop quality, increase production costs and raise concerns around aflatoxin and marketability. Now, new additional funding is helping continue an industry-backed research effort to advance another tool growers may one day be able to use as part of an integrated pest management program.

    The Foundation for Food & Agriculture Research, the Almond Board of California and Flyttr™ partnered on a nearly $5 million grant to advance development of a biological approach targeting navel orangeworm in almonds and pistachios. ABC is helping fund a portion of the project, reflecting the almond industry’s continued investment in research that supports long-term orchard productivity, crop quality and grower profitability.

    The project centers on Flyttr’s Friendly™ navel orangeworm technology. The concept is simple: release Friendly™ male moths into areas with pest pressure. When those males mate with wild females, no surviving offspring are produced. With continued releases over time, the goal is to reduce the pest population and lower damage pressure in orchards.

    For growers, the significance is not that this replaces today’s best practices. Sanitation, monitoring, mating disruption, timely harvest and well-timed treatments remain important parts of navel orangeworm management. Instead, this research is focused on developing a targeted biological tool that could complement existing programs and help reduce reliance on conventional insecticides over time.

    Navel orangeworm remains one of the costliest pests facing California tree nuts, with industry losses estimated at more than $800 million each year. Damage can affect yield, quality and food safety, which is why the pest continues to be a priority for research, industry collaboration and new technology development.

    Funding from FFAR and industry partners will support the continued work needed to move the technology closer to practical use, including large-scale production systems and field studies. That means the effort is still in development, but it represents an important step toward expanding the number of durable tools available to growers managing navel orangeworm pressure.

    ABC’s role in helping fund this work is part of a broader commitment to support practical, science-based solutions for almond growers. By investing alongside partners, the almond industry is helping advance research that could protect crop value, strengthen pest management options and support the long-term competitiveness of California almonds.