California Ag Network

Tag: USDA Agricultural Research Service

  • 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”

  • 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

  • Mysterious Virus Affects Melons

    ARS researchers have found a new virus playing hide and seek with the melon industry. In 2023, unusual symptoms of infection were observed in melon and watermelon plants from Arizona and California. ARS scientists in Salinas sampled infected plants and used gene sequencing technology to identify the culprit as watermelon chlorotic stunt virus (WmCSV).

    This virus is transmitted by whiteflies and can cause significant yield loss — particularly in watermelon —but it also infects all types of cucurbit (melon, pumpkin, squash and cucumber) crops. WmCSV joins an existing virus complex causing yield impacts for production of melon and watermelon in the southwestern United States. This is the first time WmCSV has been identified in cucurbit plants in the Western Hemisphere. As a result, the cucurbit industry was notified of the threat posed by this virus, and they are taking efforts to keep it from being transported to other regions of the United States. — Story contributed by the USDA Ag Research Service

  • Participants Wanted for Wine Industry Survey

    The wine market is changing as consumers reconsider what they drink, how they make purchasing decisions and the role wine plays in their lives. UC Davis is inviting those in the wine industry to participate in a survey examining industry perspectives on current and emerging wine-consumer behavior.

    This survey is part of a research collaboration involving by Drs. Arran Rumbaugh (USDA Ag Research Service), Ha Nguyen (UC Davis), and Carola Grebitus (Arizona State University).

    The survey focuses on factors that may influence wine consumption and purchasing. The goal is to identify unmet consumer-insight needs and use the findings to inform future consumer research, applied projects, and decision-support tools that address practical industry priorities.

    About the Survey:

    •The survey takes approximately 10–15 minutes to complete.

    •Participants must be at least 21 years old.

    •Participation is voluntary.

    •Responses are anonymous, handled confidentially and reported only in aggregate.

    •Aggregated findings will be shared with participants so they can see perspectives from across the industry.

    Industry professional experience can help ensure that future consumer-behavior research reflects industry realities rather than assumptions.

    Complete the survey

    — Story contributed by UC Davis

  • Honey Bees Can Detect Viruses in Food

    Honey bees encounter viruses in their environments, especially when they forage on flowers and other food sources. Being able to detect viruses is important for reducing infection and the spread of disease. Many insects, including honey bees, can detect viruses indirectly with sick nestmates, but it has been unclear if honey bees can directly detect viruses in food sources.

    To help beekeepers protect their colonies by reducing viral spread, ARS researchers from the Honey Bee Breeding, Genetics, and Physiology Research Unit in Baton Rouge, LA, studied if honey bees could sense viruses such as deformed wing virus, black queen cell virus, and chronic bee paralysis virus in contaminated food sources.

    In an experimental study, the researchers found that when honey bees were presented with the choice between a spiked sugar solution with viruses and a plain sugar solution, the honey bees preferred the virus-spiked solution.

    “These findings demonstrate that honey bees can directly detect the presence of viruses in contaminated food sources, which has important implications for pathogen transmission within pollinator communities and disease management strategies aimed at improving honey bee health,” said Michael Simone-Finstrom, ARS Research Molecular Biologist.

    According to Simone-Finstrom and ARS Research Entomologist Elizabeth Walsh, both co-lead authors of the study, the results highlight the need to control viral infections and spread in bee colonies.

    One major concern is viral spread from Varroa mites, parasitic pests that feed on honey bees. Currently, controlling Varroa mite populations is one of the most effective ways to protect honey bee colonies. Beekeepers can consider changing how they feed honey bees to limit outside insects from getting access to their food, according to Simone-Finstrom and Walsh.

    “Open feeding scenarios where bees from different colonies and other insects, who may carry viruses, get food from the same source may not be in the honey bees’ best interest,” said Walsh. “Beekeepers can consider an alternative like an individual colony feeder where only honey bees from one colony have access to the food.”

    It is unknown what mechanisms cause bees to gravitate towards the contaminated food sources. More research is underway to better understand honey bees’ foraging behaviors and how the viral presence affects their behaviors.

    “The study’s findings will help us with providing data-driven decisions in honey bee management and ecological decisions,” said Walsh. – By Jessica Ryan, ARS Office of Communications

  • 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

  • ARS Research May Help Save Grapes from Smoke Damage

    The USDA Ag Research Service is helping grape growers and winemakers save wine grapes impacted by wildfires by finding a natural solution to remove the unpleasant flavors caused by smoke taint — which costs billions of dollars in the U.S. wine industry.

    Smoke taint occurs when wine grapes are exposed to high levels of smoke in a vineyard and absorb volatile compounds. The leaves and grapes attach sugars to the smoke compounds and store them, which results in unpleasant flavors in the wine, often described as tasting “smoky” or “ashy.” Consequently, most grapes exposed to wildfire smoke are considered unsuitable for making wine.

    In a research study, researchers from the ARS Plant Gene Expression Center in Albany, CA, and their collaborators found that Gordonia alkanivorans, a bacterium that can occur naturally on grape leaves, is able to break down guaiacol, one of the main phenols responsible for smoke taint in wine. Phenols are naturally occurring chemical compounds that are responsible for much of the flavor and color in wine.

    “We found two strains of the same species of Gordonia alkanivorans that can use guaiacol as their only food source,” said Devin Coleman-Derr, ARS Research Molecular Biologist.

    The researchers sequenced the strains’ genomes and studied which genes were active when Gordonia alkanivorans were given access to guaiacol. They found that a gene called guaA produced an enzyme that was key to breaking down guaiacol into a harmless compound. Furthermore, the guaA enzyme broke down only guaiacol and not the other phenols.

    Though guaiacol is just one of several phenols potentially responsible for smoke taint,  Coleman-Derr says the findings show that using bacteria as a biotechnological tool in treating smoke taint is a potential solution.

    “This research provides a roadmap for finding bacteria and other microbes that can target other problematic chemicals in or on plants,” said Coleman-Derr.

    The research was done in collaboration with University of California, Merced’s Department of Molecular and Cell Biology, Oak Ridge National Laboratory’s Biosciences Division, and Washington State University’s Viticulture and Enology Program. – By Jessica Ryan, ARS Office of Communications

  • New Pesticides Could Better Control Mite Disease in Honey Bees

    The Varroa mite (Varroa destructor) is a parasite of the honey bee (Apis mellifera L.) and is considered one of the species’ most serious threats, inflicting more damage and higher economic costs than all other bee keeping diseases. Varroa mites harbor numerous viruses and feed on honey bee adults and pupae, causing weakened immune systems, decreased body weight, and a shortened lifespan. The external wounds caused by repeated feeding can become infected with bacteria, fungi, and viruses.

    ARS researchers at the Bee Research Lab tested numerous pesticides for the chemical control of Varroa mites, and screened 40 compounds of samples in the lab (and three in the field). They documented how the viruses, carried by the mites, move within honey bee colonies and play key roles in bee-to-bee transmission. Through this research, two promising miticides were identified to manage the Varroa mite. This ARS research could lead to new management techniques that can minimize bee losses, reduce bee keeper and crop pollination costs, and ensure food security for all Americans. —By USDA Ag Research Service

  • Taking the Bite Out of Cattle Fever Tick Disease

    ARS researchers identified innovative ways to prevent the potential spread of the cattle fever tick, a known carrier of babesiosis, into the U.S. Babesiosis is a disease caused by a protozoan parasite that infects red blood cells. It was eradicated in the U.S. decades ago, but it continues to be a significant problem in Mexico, which raises concerns about its potential return to the U.S. The cattle fever tick is the most economically important pest of cattle worldwide. Pesticides have been shown to be effective in managing this tick, but pesticide resistance has become an emerging issue.

    ARS researchers in Edinburg, TX, in collaboration with university partners, evaluated the efficacy of different organic compounds for controlling this tick, including NootkaShield™, Stop the Bites®, and BioUD®. The results indicated that NootkaShield™, Stop the Bites®, and BioUD® led to significant mortality in cattle fever ticks when dosed at low concentrations. They also demonstrated strong repellent properties and a significant reduction in the tick’s fecundity (ability to produce an abundance of offspring). These compounds show promise for controlling cattle fever ticks, and scientists plan to further test them in the field.   

    Related links:

    Project: USDA ARS

    Cattle Fever Tick Research Unit: Kerrville, TX

    —By USDA Ag Research Service

  • An Indoor Air Scrubber for Removing Ammonia in Poultry Houses

    Researchers from the USDA’s Ag Research Service (ARS) are helping poultry farmers protect their flocks and their employees, while improving poultry production. ARS researchers recently developed an indoor air scrubber that purifies the air in chicken houses and reduces ammonia levels by 87% to 99%.

    High levels of ammonia pose problems for poultry and agricultural workers. Ammonia, which is released from litter in poultry houses, reduces birds’ body weight gain, causes poor feed conversion, and makes birds more susceptible to viral diseases. In addition, ammonia exposure can pose health risks to agricultural workers.

    Poultry manure accounts for 27% of atmospheric ammonia emissions in the United States, representing a significant loss of nitrogen that could otherwise be used as fertilizer for crop production.

    Currently, farmers use poultry litter acidifying amendments such as adding aluminum sulfate, known as alum, to litter to reduce ammonia levels in poultry houses. However, the amendments only last up to three to four weeks. Ammonia scrubbers offer an alternative solution; however, current systems only treat exhaust air. As a result, they provide no direct benefits to poultry production and are not cost-effective.

    To find a more economical solution for farmers, researchers from the ARS Poultry Production and Product Safety Research Unit in Fayetteville, AR, designed and patented a full-scale prototype of an indoor air scrubber that can be easily installed in a poultry house to purify the air and save valuable nitrogen. The scrubber has a fast sand filter that removes particulate matter from the scrubbing solution to prevent the nozzles from clogging – a problem that existing air scrubbers have in animal facilities with heavy dust.

    “In study trials at our testing facility, our scrubber purified the amount of air in a 40 foot by 400-foot chicken house every 30 minutes and reduced ammonia levels by 87% to 99%, depending on the ammonia concentration and the air flow rate at which it is operated,” said ARS Research Soil Scientist Philip Moore.

    Moore and his research partners are planning to test the air scrubber in commercial poultry houses in the near future.

    In addition to measuring ammonia levels, the researchers will look at how effectively the air scrubber can remove dust and pathogens from the air, such as viruses responsible for avian influenza and other pathogens that cause foodborne illnesses.

    “This innovative technology could transform livestock production in poultry and potentially swine housing operations by improving animal welfare and worker safety, reducing disease transmission risks, and increasing farm profitability and environmental sustainability,” said Moore.

    The study was published in the Journal of Applied Poultry Research and done in collaboration with the ARS Poultry Research Unit at Mississippi State University, MS, and the University of Delaware’s Department of Animal and Food Sciences.

    Abou USDA Ag Research Service

    The Ag Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.