California Ag Network

Category: Pest/Disease Management

  • New World Screwworm Detected in Texas

    The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) confirmed the detection of a New World screwworm (NWS) in a bovine in Zavala County, Texas. NWS is a serious pest that affects livestock, pets, wildlife, and less commonly, people and birds. NWS larvae (maggots) burrow into the flesh of living animals, causing serious damage to livestock and economic losses.

    The affected animal is a 3-week-old calf and larvae were identified in its umbilical area. To date, there have been no further detections.

    “All models showed New World Screwworm entering the country in 2025; however, thanks to the hard work across the entire Trump administration and our industry, state, and local partners, we were able to buy time for this moment. Protecting our livestock industry is a national security issue of the utmost importance, and USDA is wasting no time in taking action,” said Dudley Hoskins, Under Secretary for Marketing and Regulatory Programs. “USDA invested heavily in the tools needed to eliminate NWS ever since cases started increasing in Central America and Mexico. The United States has defeated this pest before, and we will do it again.”

    USDA and Texas officials are taking immediate action to contain and eradicate NWS from the United States, following the strategies and actions outlined in the NWS Response Playbook (884.59 KB). This includes:

    • Forming a unified Incident Command Team with the Texas Animal Health Commission and deploying response personnel to the area;
    • Establishing a 20 km infested zone around the detection and implementing quarantines, movement controls and surveillance in this area;
    • Expediting targeted release of sterile NWS flies (423.58 KB) by immediately deploying ground release chambers in the area, in addition to the 4 million sterile flies per week already being released aerially in the area;
    • Increasing trapping for NWS flies along the border and just outside of the dispersal area;
    • Implementing NWS surveillance and management strategies in wildlife; and
    • Conducting targeted outreach in the local area.

    Additionally, USDA’s National Veterinary Stockpile stands ready to assist and will provide resources including treatments, equipment and logistics support the response as needed.

    USDA will continue to work with state departments of agriculture, animal health officials, industry and producers to mitigate economic impacts of restrictions as much as possible, including negotiating with our trading partners to regionalize any trade restrictions on live animals, limiting them to defined geographic areas.

    NWS maggots can infest livestock and other warm-blooded animals, including in rare cases people. They most often enter an animal through an open wound and feed on the animal’s living flesh.

    USDA urges residents in the area to check their pets and livestock for signs of NWS. Look for draining or enlarging wounds and signs of discomfort. Also look for screwworm larvae (maggots) and eggs in or around body openings, such as the nose, ears, and genitalia or the navel of newborn animals. If you suspect your animal is infected with screwworm, contact your state animal health official or USDA area veterinarian in charge immediately.

    While not common in people, if you notice a suspicious lesion on your body or suspect you may have contracted screwworm, seek immediate medical attention.

    The U.S. food supply is safe. Screwworms do not infest meat, fruits, vegetables, or other food sources. USDA’s Food Safety and Inspection Service (FSIS) ensures that the nation’s commercial supply of meat, poultry, and egg products is safe and properly labeled. Under the Federal Meat Inspection Act (FMIA), FSIS inspection personnel must inspect all eligible animal species unless they are exempt or covered by a state inspection program.

    Any evidence of screwworm infestation in an animal would be identified during these inspections, and any contaminated product from an affected animal would not be allowed to enter the food supply.

    For more than a year, USDA has led a unified response to NWS. As the lead coordinating agency, USDA has deployed advanced surveillance systems and supported robust cross-border response efforts in Mexico and Central America to combat the pest and push NWS away from the United States. These efforts have bought time for USDA to increase domestic preparedness efforts.

    Learn more about New World screwworm at Screwworm.gov. — Story contributed by the USDA Animal and Plant Health Inspection Service

  • CDFA Urges Immediate Reporting of Grapevines Purchased at Costco

    The CDFA is urging anyone who purchased grapevines from Costco stores in Northern California between April 21 and May 21 to contact their local agricultural commissioner after an invasive pest was discovered among the 13,000 vines shipped during that period.

    Grapevines from a Fresno nursery shipped to California Costco stores in April and May were found to be carrying the glassy-winged sharpshooter (GWSS), an insect capable of spreading a potentially lethal vine disease.

    On May 19, the first glassy-winged sharpshooter was detected on vines sold at the warehouse retailer, triggering an immediate and widespread containment effort by CDFA, agricultural commissioners and winegrape growers throughout Northern California. Officials are responding to public reports, conducting inspections and public outreach and trapping near stores and locations where purchased vines were taken. They are also ensuring that potentially infested plants are safely contained and disposed of.

    In addition to destroying infested stock still in Costco warehouses, CDFA is working with agricultural commissioners and conducting public outreach to locate vines sold to consumers across 24 counties, as well as neighboring at-risk counties.

    “While many vines have been intercepted and destroyed, locating the thousands that may still be in customers’ hands remains our top priority,” said California Ag Secretary Karen Ross. “Anyone who purchased these vines should contact their local agricultural commissioner immediately.”

    Costco is offering a full refund to anyone who purchased these vines. Customers do not need to return the vines to receive a refund.

    To prevent the potential spread of the pest, CDFA officials urge customers to:

    •Immediately contact your county agricultural commissioner

    •Keep the plant in its original pot or container and away from other plants

    •If possible, place the plant inside two trash bags, one inside the other, and seal them closed

    •Do not place the plant in the trash or compost bin

    •An agricultural inspector will come, inspect the vine for GWSS and — if necessary — remove and dispose of the vine

    Winegrapes are one of California’s largest cash crops, generating approximately $73 billion annually in economic activity and supporting more than 422,000 jobs statewide. A 2025 economic study estimated that Pierce’s disease, which is spread by the glassy-winged sharpshooter, could cost California approximately $166 million annually if left unchecked.

    California first recognized the full threat of the glassy-winged sharpshooter in 1999, when a major Pierce’s disease outbreak in the Temecula Valley led to the destruction of more than 300 acres of vineyards. Winegrape growers quickly responded by working with the CDFA to create the Pierce’s Disease Glassy-Winged Sharpshooter Board to control the pest and find solutions to the disease it carries. The program has successfully contained GWSS for over 25 years. Visit cdfa.ca.gov/pdcp/PD_GWSS_Board.html. — Story Contributed by the California PD/GWSS Board

  • CDFA Accepting Proposals for Biologically Integrated Farming Systems Program

    The CDFA’s Office of Pesticide Consultation and Analysis (OPCA) is now accepting concept proposals for its Biologically Integrated Farming Systems Grant Program (BIFS). The BIFS grant program funds on-farm demonstration and evaluation of innovative, biologically based farming systems that employ sustainable pest management (SPM) strategies. These practices aim to reduce reliance on biologically disruptive pesticides while allowing growers to maintain yields and economic sustainability.

    Past BIFS projects have refined and promoted SPM practices such as areawide mating disruption, biological control via natural enemy releases and habitat planting, non-fumigant soil disinfestation, removing diseased plants, bio-pesticides and more across cropping systems.    

    The 2026-2027 Request for Proposals (RFP) identifies five priority funding areas based on recent or proposed regulatory actions and grower needs:

    • Areawide management
    • Monitoring that informs pest management
    • Post-harvest disease control
    • Neonicotinoid alternatives in tomato
    • Paraquat alternatives

    OPCA does not require BIFS project proposals to address one of the priority topics.

    This funding cycle includes $2 million in available grant funding, with up to $1 million per project. A portion of OPCA’s allocation of the pesticide mill assessment funds this solicitation.

    Following review of concept proposals, OPCA will notify applicants in late July 2026 and invite selected applicants to develop and submit a full proposal. Full proposals are due at the end of August 2026.

    Concept proposals are due by June 30 at 5 p.m. Public or private colleges and universities, local, state, and federal government entities including tribal governments, non-profit organizations, and commodity groups are eligible to apply. The project lead(s) and their institutions must be based in California.

    Detailed information, including the application process and requirements, is available at https://www.cdfa.ca.gov/oars/opca/bifs.html. — Story contributed by the California Department of Food and Ag

  • When to Spray for Navel Orangeworm

    Navel orangeworm can be devastating for almond and pistachio growers and knowing when and where to spray can often depend on weather. Researchers have been working with state weather services to collect data and determine the best spraying times. Washington State entomologist Dave Crowder discussed these efforts recently with Matthew Malcolm from California Ag Network. Watch this quick video and read more in Pacific Nut Producer Magazine.

  • DPR Releases Summary of Convening on Post-Harvest Commodity Fumigation

    The California Department of Pesticide Regulation (DPR) recently released the post-harvest commodity fumigation component of an independent study evaluating alternatives to fumigant pesticides. Prepared by the California Council on Science and Technology (CCST), the convening report summarizes key themes and discussion points from a convening assembled by CCST to discuss fumigants that are used to protect stored food products after harvest, potential alternatives, and opportunities to reduce exposure for workers and nearby communities.

    CCST’s convening included academic, industry, public health, environmental justice and regulatory experts who met for a series of discussions on post-harvest commodity fumigation in November 2025. The discussion specifically focused on four fumigant pesticides: methyl bromide, sulfuryl fluoride, phosphine, and propylene oxide. All four fumigants are restricted material pesticides primarily used on produce after harvesting to protect food from fungal disease and insect pests while in storage. The report synthesizes findings from those discussions to summarize and reflect participants’ perspectives on the state of post-harvest commodity fumigation in California.

    The convening report includes discussion summaries related to:

    • How and why post‑harvest fumigants are used today, including factors that drive fumigation for stored commodities.
    • Community exposure and emission concerns, along with current mitigation practices and opportunities to strengthen protections for nearby residents and workers.
    • Available and emerging alternatives to traditional fumigants, such as controlled atmospheres, irradiation, pheromone‑based tools, and multi‑pronged Integrated Pest Management approaches.
    • Barriers that limit the adoption of alternatives, including international and national regulatory requirements, cost and the need for additional research and training.
    • Key research gaps where further scientific study is needed to support a transition to safer, effective pest management tools.

  • How to Annihilate Nematodes

    Farmer John Chandler lamented the loss of methyl bromide for replanting an orchard or vineyard. Photo credit: Diana Gutierrez

    Andreas Westphal, scientist at Kearney Agricultural Research and Extension Center in the San Joaquin Valley, organized a soil plant pathology conference that was held late last month. Growers from as far away as Virginia came to learn about the latest research findings.

    Chandler Farms

    The first day of the conference was a field tour to three sites and then Kearney itself. After meeting at Kearney, the participants rode on a tour bus to Chandler Farms in Selma. John Chandler, his brother Tom and their father, Bill operate a diversified farm that includes almonds, grapes and citrus.

    Soil Fumigants

    The Chandlers typically change out one field per year. John lamented the loss of methyl bromide for replanting an orchard or vineyard. He now uses Telone, which he finds “has less effect but still works.”

    He always contracts out his Telone application because it requires special training. He has the contractor put tarps over it, beyond the usual seal — to prevent off-gassing — but he says, “It’s not worth it to get acres of plastic.” The tarps add about $1000/acre to the cost.

    Westphal explained, though, that Telone is becoming more difficult to use because of a new restriction in the amount of Telone allowed plus a requirement that the fumigant be applied with lots of water. The new regulations say that the soil has to be wet to 2 feet depth. If the soil is bone dry, three inches of water must be added within 72 hours before applying the fumigant.

    However, the excess water makes it hard to get a tractor through the field. Also, the fumigant does not move well through water, as it is made to move through air. Lastly, the Telone stays in wet soil longer before vaporizing off, which may make it toxic to plants.

    Nematodes     

    Chandler said that his farm has nematodes — the microscopic roundworms that feed on plant roots. His soil has root-knot, lesion, ring and citrus types of nematodes.

    When he can afford it, he fallows the land for a year or two instead of fumigating, but he says that fumigation gives the plants the best chance to get started. Once the crop is established, he notes, there are few tools for nematode adjustment.

    In his Ruby Red grape concentrate vineyard, Chandler finds that ring nematodes like the wettest part, whereas other types of nematodes prefer the edges, where they feed on the fresh, new roots.  Ring nematodes, he finds, like pure sand, but root knot nematodes thrive most in clay soil with good secondary structure.

    The tour participants had many more questions for Chandler, but to stay on schedule, Westphal guided everyone back onto the tour bus.

    Burchell Nursery

    The second stop was Burchell Nursery in Fowler, where Mauricio De Almeida led the group around the almond, stone fruit, citrus, pomegranate, and retail table grape plants.

    What Is Eating the Plant Roots?

    Almeida said that, as in all greenhouses, the water, heat and humidity may induce root rot and fungus gnats. The fungus gnat larvae eat soft tissue of the plant roots. The adults do not feed on plants.

    Another larva that needs to be managed is that of the European pepper moth. The caterpillars girdle the plant stem below the soil line.

    The root rot and insect pests occur even though the potting media — made of peat, bark, wood fiber and sometimes Perlite — comes pasteurized. The nursery uses Nemasys® beneficial nematodes to manage the larval insect pests.

    Citrus

    Almeida explained that Burchell Nursery started growing citrus in 2010. They grew the citrus indoors to protect the trees from the Asian citrus psyllid. Westphal remarked that if you grow bareroot trees in the field, the soil must be certified nematode-free or else the trees themselves must get tested for nematodes. He also said that you cannot fumigate after pulling up the plants because the fumigant would kill the tree.

    Among other species, Burchell Nursery sells commercial almond trees, including some cultivars they developed themselves. Photo credit: Tiffany Baiocchi

    Almonds

    In almonds, Bright’s Hybrid 5, Hansen and Viking rootstocks and Shasta scions resist root-knot nematode. Viking and Shasta also tolerate ring nematodes. Bright’s Hybrid also has low susceptibility to root lesion nematodes. In susceptible varieties, root-lesion nematodes create lesions that can lead to secondary infections like bacterial canker.

    The visitors got to see the Cornerstone cultivar of Prunus rootstock, developed by Burchell Nursery to resist the root knot nematodes Meloidogyne javanica and M. incognita. Used as rootstock for almond and stone fruits, Cornerstone is also less sensitive to crown gall, caused by Agrobacterium tumefaciens.

    Developed by Burchell Nursery, the Cornerstone cultivar of Prunus rootstock is resistant to the root knot nematodes Meloidogyne javanica and M. incognita and less sensitive than other rootstocks to crown gall, caused by Agrobacterium tumefaciens. Cornerstone can be used as rootstock for almond and stone fruits. Photo credit: Tiffany Baiocchi

    Unfortunately, in both Kern and Merced counties (but not Fresno County where the tour took place), in 2018 a root-knot nematode from Florida, Meloidogyne floridensis, was found in almond trees on Hansen 536 and Bright’s Hybrid 5 rootstocks, where they caused growth decline of the trees. Now considered an A-rated (“highest concern”), quarantined pest in California, it has since been found in South Carolina and Georgia, after being endemic to Florida before 2018.

    Levels of Plant Response to Pathogens

    Plants can be divided into three groups of responses to nematodes and other pathogens: sensitive, tolerant and resistant. Tolerance allows for high nematode populations, which gives the nematodes more opportunity to have genetic mutations that enable them to overcome the plants’ resistance. Therefore, nematicides should be used in tolerant cultivars to limit the pest population.

    Grapevines  

    In a vineyard section of the research fields, Westphal showed a poster of nematodes in the soil profile. Of the three types of nematodes represented, ring nematodes were found only in the top foot of soil.

    By contrast, citrus and pin nematodes were found in each one-foot segment down to 4-5 feet, the deepest tested. The citrus nematode population peaked at 2-3’ depth and pin nematodes peaked at 3-4’ depth. The population of pin nematodes far exceeded those of ring and citrus nematodes at all depths. Fortunately, pin nematodes do not cause much economic damage in grapes.

    Westphal also showed a poster of total sugar yield in 2025 of Pinot Gris cultivated on different rootstocks planted in 2023 in nematode-infested soil. The negative impact of nematodes was measured as sugar content of the fruit.

    Of the seven commercial grapevine rootstocks tested, Freedom had the highest sugar content. An experimental rootstock had even higher sugar content. Serving as control groups, Chardonnay and Zinfandel rootstock had the lowest sugar content.

    “On sensitive rootstock, even a few nematodes are bad,” Westphal remarked. About 85% of all new grapevine plantings are on Freedom rootstock. Freedom’s downside is susceptibility to quick decline, so the search continues for an even better rootstock.

    In sugar beets, the exudate from plant roots helps nematodes find the roots. Westphal and colleagues are looking into the possibility of manipulating plants to exude different chemicals that do not attract nematodes.

    Walnuts and Almonds

    Walnuts are sensitive to some nematodes and resistant to others, but “every plant has its limits,” Westphal said. Walnut soil is treated pre-plant and at-plant at the planting site.  Tank water is used to settle the tree in. Salibro® is added to the tank water to form a concentration that kills the nematodes but not the trees. Westphal cautioned growers to not overwater walnuts.

    Among other things, Westphal is testing juice from walnut hulls to see if they inhibit nematodes.  He noted that ASD (anaerobic soil disinfestation), created by applying nine tons of rice bran per acre, inhibited nematodes somewhat. However, it would not be worth the $6,000/acre price tag for growers.

    Westphal is testing whether juice from walnut hulls can inhibit nematodes in almond orchards.

    Highly resistant rootstocks can grow without fumigation, with less toxic, affordable nematicides applied.  As with citrus, nursery trees must be grown in nematode-free soil, or the trees must be certified before leaving the premises.

    Westphal showed the tour participants an almond rootstock test orchard, in which nematode resistance is compared among various commercial and experimental rootstocks.  Only the most successful experimental rootstocks make it to the next round of trials, along with the commercial ones for comparison.

    Westphal then concluded the field tour.  The conference continued in an indoor classroom on the following two days.  

    – By Nancy Power, Assistant Editor

  • Leveraging Nature’s Secret Weapon Against Ticks

    Tick populations are increasing, especially in warm, humid areas of the United States. This puts both livestock and people at greater risk for serious tick-borne diseases. Traditional tick control methods are often costly and rely heavily on chemical treatments, which are facing growing resistance in different tick species. Scientists at the USDA’s Agricultural Research Service (ARS) are working on new, safer and practical solutions for controlling tick populations and protecting humans and animals from tick bites.

    At the ARS’s National Center for Agricultural Utilization Research  in Peoria, IL, Entomologist Lina Flor-Weiler, Plant Physiologist Will Hay, and their colleagues are testing the acaricidal effects — substances that are effective at killing ticks and mites — of different defatted seed meals from the mustard plant family against different tick species.

    After mustard seed crops are pressed to extract oils for food and biofuel applications, the remaining seed material is often considered a byproduct of little value. Yet, recent research shows this byproduct can be highly effective against dangerous pests.

    “The defatted seed meal retains a diverse array of compounds —one of which is glucosinolates,” said Flor-Weiler. “When defatted seed meals are hydrated, an enzyme is activated that converts glucosinolates into isothiocyanates, a gaseous compound we know to be responsible for the pungent taste of mustard and horseradish. Research has shown that these isothiocyanates have potent pesticidal properties, making them effective against certain soil insects, nematodes, and disease-causing fungi.”

    The study, published in Experimental and Applied Acarology, measured the bio-fumigation effect of three defatted seed meals from the mustard family and its effectiveness in killing three different tick species. They tested the defatted seed meals of brown mustard(Brassica juncea), garden cress (Lepidium sativum), and pennycress (Thlaspi arvense) against the Lone Star tick, the American dog tick, and the blacklegged tick.

    Defatted seed meals from all three plants killed the ticks under laboratory conditions, though their effectiveness varied by tick species. Since the three mustard species differed in the type and amount of gaseous compounds they produced, the amount of seed meal needed to kill ticks also varies among the species. This suggests that certain plants may be more effective against certain tick species than others.

    “Ticks spend most of their lives on the ground or in vegetation, which are ideal conditions for this plant-based method,” said Flor‑Weiler. “Understanding the levels of effectiveness of each defatted seed meals, along with understanding the tick life cycles, will help us determine the best application strategies useful in real-world conditions.”

    “For example, this method can serve as an effective pest control strategy in areas known to be favorable tick habitats such as around structures, edge habitats, and livestock areas. If successful, this approach could offer a practical, eco-friendly alternative to reduce tick populations and protect public health,” added Flor-Weiler.

    This is particularly significant in the Midwest and Northeast regions of the United States, where ticks transmit a wide array of pathogens that cause serious diseases such as Lyme disease, ehrlichiosis, Rocky Mountain spotted fever, babesiosis (affecting both humans and animals) and the Powassan virus.

    The researchers are eager to expand their studies to include cattle ticks through new collaborative efforts. By targeting cattle ticks in these high-risk areas, the team hopes to further demonstrate the effectiveness of mustard seed meals as a natural tool for controlling tick populations and reducing the spread of tick-borne illnesses.

    In addition to helping control ticks, this research also benefits mustard seed producers in the United States by creating new market opportunities for defatted seed meals, which can be used as a natural tick biofumigant.

    Read about previous ARS studies, showing promising results against biting insects like mosquitoes and in reducing fungal contamination in grains. — Story contributed by Maribel Alonso, ARS Office of Communications

  • Citrus Greening Quarantine Expands in Southern California

    Effective immediately, the Animal and Plant Health Inspection Service (APHIS), in cooperation with the California Department of Food and Agriculture (CDFA), is expanding the area quarantined for citrus greening (Huanglongbing), caused by the Asian citrus psyllid, in California. APHIS is establishing a new quarantined area in the Ramona area of San Diego County of 93 square miles and is expanding the quarantined area in the Loma Linda area of San Bernardino and Riverside Counties by 26 square miles. These measures parallel the intrastate quarantines that CDFA established on March 2, and March 6, 2026, respectively. APHIS is taking this action because of citrus greening detections in plant tissue samples collected from residential properties. There are 25.16 acres of commercial citrus impacted by the new Ramona quarantine and 411.47 acres of commercial citrus impacted by the Loma Linda area expansion.

    APHIS is applying safeguarding measures outlined in 7 CFR 301.76 and Federal Orders pertaining to the interstate movement of regulated articles from the quarantined areas in California. This action is necessary to prevent the spread of citrus greening to non-infested areas of the United States.

    The APHIS Citrus Greening webpage contains specific changes to the quarantined areas in California. APHIS will publish a notice of this change in the Federal Register.

  • How to Protect Your Almonds from Navel Orangeworm and Other Pests

    With spring weather arriving earlier, almond growers in California can expect an earlier influx of pests in their orchards — and to get started sooner on preventing them from harming their nut crops. According to UCCE Sacramento Valley Integrated Pest Management Supervisor Sudan Gyawaly, now is the time to watch out for things like navel orangeworm (NOW), peach twig borers, leaf-footed bugs and spider mites.

    Navel Orangeworm (NOW)

    Navel orangeworms (Amyelois transitella) are the most prominent pests in almond orchards. These moths lay their eggs on the shells after hull split, and the larvae burrow inside the shell, eating the nuts and sheltering inside. Signs of a NOW infestation in an orchard include:

    ·      Small, flat, oval-shaped eggs outside of almond hulls

    ·      Pinhole-sized holes in almond hulls

    ·      Hulls that are oily in appearance

    ·      Fungal infections of nuts

    ·      Extensive webbing inside the hulls

    ·      Partially eaten nuts

    ·      Larvae that are white to pink in color, with crescent marks behind the head

    Navel orangeworm damage to an almond. Photo by Matthew Malcolm

    To manage NOW in your orchards, be sure to continuously monitor male flight activity by using pheromone traps. Also continue to monitor NOW egg traps to establish a spring biofix (the first spring flight, which acts as the starting date for calculating growing degree days), to help you predict the timing of their later flights. The first flight usually occurs from late March through April, but earlier times are possible, depending on the weather.

    According to UC IPM, prevention is key to avoiding infestation. This includes removing all mummy nuts by the start of February. To eliminate existing NOW populations:

    ·      Establish a biofix

    ·      Hang pheromone dispensers in the trees to disrupt mating

    ·      Assess trap activity and begin spraying at hull split.  Apply pesticides at night and early morning for optimal results

    ·      Harvest and clean up as early as possible

    ·      Remove mummy nuts by March 15 of the next year.  Mow or disk mummies on the ground.

    Peach Twig Borer

    While less of a concern in mature orchards, peach twig borer — also a moth — can still be a menace for almond growers in younger fields by causing primary scaffold damage. Begin monitoring pheromone traps in April to establish a biofix and decide if a spray is necessary in May.  Consult with your pest control adviser if you are unsure.

    Leaf-Footed Bugs

    Stink bugs and leaf-footed bugs are especially troublesome after a warm winter. Leaf-footed bugs can be trickier to spot.  UC IPM lists the tell-tale signs of an infestation in your orchard as:

    ·      Gummy nuts — nuts with exudates on the outside of the hull — a signature warning

    ·      Nuts that have dropped prematurely

    ·      Black spots on kernels and wrinkled, misshapen nutmeat from adult feeding

    ·      Withered and aborted shells from bugs feeding on premature nuts

    Leaf-footed bug

    Stink bugs cause similar damage, but this is usually around May or June. Leaf-footed bug management can vary from orchard to orchard, depending on history and severity. Gyawaly advises basing spray decisions on this history plus on damage risk associated with seasonal conditions. Consult with your pest control adviser if you are unsure.

    Spider Mites

    Typically found in the lower parts of the canopy, spider mites may also come out earlier and in greater numbers with warmer weather. Their presence should be monitored once every two weeks.  For this pest, beneficial arthropods that prey on spider mites may be one of your orchard’s best friends. These species include:

    ·      Western predatory mites

    ·      Spider mite destroyers

    ·      Sixspotted thrips

    ·      Pirate bugs

    By monitoring and addressing mite and insect pests in the spring, the pest populations can be kept under control to ensure a large, high-quality almond harvest.

  • Syngenta Voluntarily Cancels CA Paraquat Registration

    Pesticide registrant Syngenta voluntarily cancelled registration of Gramoxone SL 3.0 — a product containing paraquat-dichloride — in California.

    The California Department of Pesticide Regulation (DPR) and U.S. Environmental Protection Agency (EPA) have both designated paraquat as a restricted material, meaning only licensed dealers can sell it and only professionally licensed applicators can use it. Paraquat is under DPR reevaluation.

    Products containing paraquat that are registered by other companies are not affected by Syngenta’s voluntary cancellation. Gramoxone SL 3.0 may continue to be possessed and sold by DPR-licensed dealers for up to two years following the following effective date (April 1, 2028) of the company’s voluntary cancellation under California law. Growers using these products must do so in accordance with all applicable label directions, as well as state and federal regulations. Syngenta indicated that it will continue stewardship practices like training and safety resources while remaining stocks are distributed and sold.

    The DPR is continuing to move through the process of reevaluation of paraquat products registered in California, in alignment with AB 1963. The Department has released two preliminary assessments and will continue to require data and additional information from remaining registrants. The reevaluations is expected to be completed by January 2029.