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LinkedInPosts Tagged: E. O. Wilson
Visual ID guide from UC aids in managing new almond pest
Nut orchard hygiene key to control carpophilus beetle, say UCCE, UC Integrated Pest Management experts
Since the first reports of a new almond pest – the carpophilus beetle (Carpophilus truncatus) – came in during fall 2023, it has become clear that the beetle is widely dispersed across the San Joaquin Valley.
“My lab has identified infestations from every county in the San Joaquin Valley; we have found infestations in both almonds and pistachios, and we will likely find infestations in walnuts this fall,” said Houston Wilson, a University of California Cooperative Extension entomology specialist at UC Riverside. The California Department of Food and Agriculture has confirmed the beetle's presence in Stanislaus, Merced, Madera and Kings counties.
Historically a major threat to almond production in Australia, the beetle – as larvae and adults – feeds directly on the nut kernel. In California, some almond growers have lost 10 to 15% of their yield – a “significant economic loss,” according to Jhalendra Rijal, University of California integrated pest management (IPM) advisor for the region. Given the prominence of almonds as a commodity, even a 1% overall reduction statewide represents an approximately $70 million loss.
“This year there has been a lot more reports from PCAs [pest control advisers]; they're sending me the pictures of the damage and beetles,” said Rijal, noting that the increase is likely due to greater awareness of the pest.
To help almond growers identify the carpophilus beetle and develop management plans, Rijal, Wilson and their IPM colleagues have put together a visual ID guide for the beetle and the damage it causes, as well as telltale signs of navel orangeworm (Amyelois transitella) and ant damage. In particular, the experts would like PCAs and growers to differentiate between the carpophilus beetle and navel orangeworm, another key pest in almonds.
“Even though their way of causing damage looks more or less similar, we're dealing with two different types of insects,” Rijal explained. “One is a Lepidoptera moth [navel orangeworm], and the other one is a beetle – many of the management practices and biological controls would be different for these two different things.”
To control carpophilus beetle, ‘sanitize, sanitize, sanitize'
One crucial cultural practice for managing both pests, however, is destroying the remnant “mummy” nuts – the nuts that remain in the orchard postharvest. They serve as overwintering habitat for the carpophilus beetle, as well as its sustenance for the next generation of beetles in spring.
“The best way to manage this pest is to do the orchard hygiene – continuing the winter sanitation, destroying the nuts that are on the ground and on the tree and on the berms,” Rijal said.
Based on observations in Australia and locally, carpophilus beetles tend to rely more on mummies on the ground, whereas navel orangeworm generally favors mummies in the tree canopy. Correctly identifying the pest – with help from the new ID guide – enables growers to better target and prioritize their management efforts, Rijal said.
“What we are strongly emphasizing is that growers need to sanitize, sanitize, sanitize to control both pests,” Wilson added.
Correct identification of the pest would also prevent unnecessary application of insecticides, as those used for controlling Lepidoptera such as navel orangeworm would be largely ineffective on the beetle.
Indeed, another insight shared by Australian experts is that the carpophilus beetle cannot be controlled just by insecticide.
“Insecticides are not very efficient, given the cryptic nature of these beetles; exposing these beetles to the insecticide is very hard,” said Rijal, noting that the beetle spends most of its life cycle protected inside the nut.
Reporting carpophilus beetle infestation helps researchers
This harvest season, Rijal advises almond growers to harvest as efficiently as possible, to minimize the number of mummies that need to be cleaned up. And because signs of damage (like damaged hulls and frass) are most obvious during harvest time, Rijal said growers should review the new guide, using the photos and other resources to help identify potential pests.
If the grower or PCA suspects a carpophilus beetle infestation, they should contact the UCCE farm advisor in their area.
Scientists are looking to expand their knowledge about this relatively new pest to California. In the coming weeks, for example, researchers are planning to survey for the carpophilus beetle in the Sacramento Valley.
“Technically it has not been found there, but we suspect that we'll find it this fall when we go looking for it,” Wilson said.
Researchers are also collecting samples from infested orchards to better understand the biology of the species, as well as how it progresses through and responds to seasonal and climactic changes. In addition, they are analyzing data from a trial study of an insecticide that might be used as a supplemental control measure.
“This is our first full season dealing with this insect, and there are still many things we need to understand,” Rijal said. “We are continuing our research efforts on all fronts.”
Grasshoppers gobble crops, farm profits
UCCE advisors share control, abatement strategies across Northern California
That buzzing noise in Northern California is the sound of grasshoppers chewing a path of destruction through crops and pollinator-friendly plants as they hop across an expanding area.
This is the fifth year in a row that massive numbers of grasshoppers have overrun Modoc County and “probably the worst I've seen yet,” said Laura Snell, a University of California Cooperative Extension livestock and natural resource advisor in Modoc County, located in the northeastern corner of the state.
In past years, Snell has heard from farmers who have lost up to 70% of their hay crop. This year, she is hearing of grasshopper damage from farmers who grow a wider array of crops, including onions and garlic – crops that the pests eschewed in past years.
“I've had an even broader group of producers contact me about damage,” Snell said. “Our local vegetable producers are being affected, decreasing farmers market and food hub products. Bee producers are not seeing good honey yields due to grasshoppers eating huge amounts of pollinator plants.”
Modoc County isn't alone. Lassen, Sierra, Plumas, Siskiyou, Tehama, Butte, Placer and Nevada counties are being invaded by grasshoppers.
“The county ag commissioners are circulating a survey to get an idea of other counties that may be affected,” Snell said. “Things like droughts and – I suppose, fires as well – would affect grasshopper migrations.”
While scientists don't know what's causing the explosive growth of grasshopper populations, there are some contributing factors, according to Tom Getts, UC Cooperative Extension weed ecology and cropping systems advisor for Lassen, Modoc, Plumas and Sierra counties.
In the past, grasshopper outbreaks seemed to be more isolated, and the populations tended to crash after a year or two. Getts said, “For whatever reason, the population cycle does not appear to have been broken, and they continue to have high numbers.”
Grasshoppers can consume 30% to 250% of their body weight per day, according to a fact sheet about grasshoppers, co-authored by Getts. While grasshopper nymphs walk, adults can fly 15 miles or more.
Getts and UC Cooperative Extension farm advisors have been giving presentations throughout the intermountain region on grasshoppers and the various control methods.
“The difficulty to controlling them is the scale and their ability to move,” Getts said. “The insects need to be targeted at a small growth stage for the tactics to be most efficacious. Once they are adults, it doesn't matter what one grower does to control them if their neighbor doesn't do anything.”
UCCE farm advisors in multiple counties are working on abatement options.
They recommend monitoring in April–May to control grasshoppers while they are still nymphs and susceptible to insecticides. Birds, spiders, rodents and fungi also can help keep the insects in check, but years of drought have reduced the fungi.
“The population of grasshoppers in the region have increased in size, scope and density in recent years,” said Rob Wilson, a UC Cooperative Extension agronomy and pest management advisor and director of the Intermountain Research and Extension Center in Tulelake.
The massive growth and spread of the pests is a problem because 30 pounds of grasshoppers can eat as much forage as a 600-pound cow can eat per day, he explained.
Part of the challenge of controlling grasshoppers is their changing behavior. In the past, grasshoppers would go away after a couple of years, now they persist. They used to thrive in dry fields, but last year, grasshoppers migrated 10 to 20 miles into irrigated fields, Wilson said.
Wilson, who has been monitoring grasshoppers near Tule Lake since early April, said that In some fields, there were 20 to 30 nymphs per square yard. More than eight nymphs per square yard can cause economic damage.
As if the grasshoppers themselves weren't enough of a nuisance, they attract other pests, including blister beetles.
“As the grasshopper population increases, you are bound to see an increase in all of the species that eat them over time,” Getts said. “Blister beetles cause terrible blisters when they get on your skin, hence the name, but they can also be problematic for livestock if they contaminate bales of hay.”
Getts recommends that growers take steps to prevent grasshopper populations from building over successive years. Growers should coordinate with neighboring growers to treat their fields due to the limited longevity and efficacy of treatments on individual fields.
[Editor's note: The sentence comparing the appetite of grasshoppers to that of cows was revised to clarify that grasshoppers aren't eating cows.]
Report outlines top concerns in California organic agriculture
Organic Agriculture Institute needs assessment refines how it can address pressing challenges
The explosive growth of organic agriculture in the U.S. – reflected in a 90% increase in organic farms from 2011 to 2021, according to U.S. Department of Agriculture statistics – has come at a cost for some farmers. With new farming operations increasing the supply of organic commodities, along with consolidation of buyers, growers report that their profit margins are not what they used to be.
Those market size considerations are among the challenges highlighted in a new report detailing the initial findings by the University of California Organic Agriculture Institute on the most pressing needs of the state's organic sector. OAI gathered and analyzed data from 423 responses to an online grower survey, over 60 interviews with stakeholders across the organic community, and additional observations from farm visits and workshops.
The report describes other frequently mentioned systemic priorities, such as maintaining integrity of the term “organic,” developing a market for organic seeds, spreading consumer awareness, and alleviating the burdens of organic certification and reporting.
Shriya Rangarajan, the postdoctoral researcher with OAI leading this statewide needs assessment, said that the reported challenges varied by organic status (fully certified, transitioning to organic, or a mixed farm with some conventional), type of crop, as well as size of the operation. She noted survey respondents were roughly representative of the sector overall – 70% small-scale growers and 30% medium and large.
“Organic is not a homogenous industry, to say the least – small growers and large growers are very different; for small growers, their challenges tend to be financial and regulatory, especially relating to certification requirements and labor,” said Rangarajan. She added that larger growers mentioned different types of challenges, weeds and pest pressures for instance, given the difficulty in controlling managing these at scale without the use or availability of organic inputs.
Organic Agriculture Institute key to sharing resources across state
Another common theme from the assessment is that the organic sector needs more accessible resources to address those myriad concerns. For OAI, established in 2020 under UC Agriculture and Natural Resources, the initial findings validated and refined the direction of its research and extension programs.
“As a new organization, we've been trying to figure out where we fit into this ecosystem and how we can support it,” said Houston Wilson, a UC Cooperative Extension entomology specialist who has served as OAI's director since its founding.
Because OAI was envisioned as a hub of resources and connections for California's organic community, Wilson and his colleagues are especially interested in understanding how its constituent members obtain information – and how OAI can improve their access.
“Growers are finding it difficult to navigate the resources that exist for organic agriculture, like technical information, financial support, compliance and certification support,” Wilson said. "While we'd like to see more resources for organic in general, those that currently exist can sometimes be hard to navigate or it can be hard to know where to go for the right thing – that became really apparent early on.”
While some producers are contacting OAI directly with their questions, Wilson is eager to develop tools and systems that can serve the community more broadly. For example, Wilson and Krista Marshall – OAI's policy and partnerships coordinator – are currently beta-testing a new map tool, built in conjunction with UC ANR's Informatics and GIS (IGIS) team. The map, expected to be ready in fall 2024, will enable users to click on their county and see all available resources related to organic agriculture.
Wilson added that OAI will have four full-time staffers by fall, further expanding its research, extension, and education efforts. After holding four field events this past year, OAI aims to increase activities in the coming year, including not just field events but also online resources, webinars and more. Also, a new training and technical assistance coordinator will be tasked with bringing Cooperative Extension advisors and other technical assistance personnel across the state up to speed on a range of organic topics, so they can more effectively answer questions from clientele in their region.
New survey aims to trace crucial organic knowledge networks
Although the OAI team has gained a sense of how information is shared across the organic community (and started to formalize those interconnections through a California Organic Agriculture Knowledge Network), they are now developing a survey to study those relationships more systematically.
“We're trying to understand what kind of knowledge resources people tap into, which is something that has come up repeatedly in our needs assessment,” Rangarajan said. “We're trying to understand who people are speaking to because, at the end of the day, organic is still a relatively small part of agriculture in California, and that makes it more fragmented. So trying to connect those different parts becomes important.”
Once Wilson has a more nuanced understanding of organic knowledge networks, he will be able to strategize and position OAI – and the UC – as a more effective partner and contributor in the sector.
“Given the history of organic, growers have had to rely on each other a lot,” Wilson explained. “We understand that the university has unique expertise to bring to the table, but we also acknowledge that there's all these other knowledge holders out there, so one of the roles that we see ourselves having is helping to facilitate those connections, strengthen them and increase the frequency of interaction.”
That may include further supporting efforts that connect transitioning organic farmers with experienced growers (a mentorship program led by Certified California Organic Farmers, or CCOF), or giving more structure to grower-researcher partnerships that can help address a host of production challenges. In OAI's grower survey, weed management topped the list, followed by water and disease issues, all exacerbated by climate variability.
“I think a lot of the real innovation changes are coming through growers experimenting with their own practice,” Rangarajan explained. “From a research perspective, one of the best ways to take this forward would be to formalize those experiments in some way so that knowledge becomes more reportable.”
And collaboration on “organic topics,” such as finding alternatives to synthetic pesticides, are a boon to the entire agricultural sector – conventional growers included.
“Everyone is trying to reduce pesticide use; everyone is trying to reduce environmental impacts,” Wilson said. “You don't have to be certified organic to benefit from organic research; these practices can be used by anyone.”
The report with OAI's initial findings on organic needs can be found at: https://ucanr.edu/sites/organic/files/396228.pdf.
New pest infesting almonds and pistachios in the San Joaquin Valley
Crop sanitation will be key to controlling the invasive carpophilus beetle
Growers and pest control advisers (PCAs) should be on the lookout for a new pest called carpophilus beetle (Carpophilus truncatus). This pest was recently found infesting almonds and pistachios in the San Joaquin Valley, and is recognized as one of the top two pests of almond production in Australia. Damage occurs when adults and larvae feed directly on the kernel, causing reductions in both yield and quality.
Populations of carpophilus beetle were first detected in September in almond and pistachio orchards by University of California Cooperative Extension Specialist Houston Wilson of UC Riverside's Department of Entomology. Pest identification was subsequently confirmed by the California Department of Food and Agriculture.
Wilson is now working with Jhalendra Rijal, UC integrated pest management advisor, North San Joaquin Valley; David Haviland, UCCE farm advisor, Kern County; and other UCCE farm advisors to conduct a broader survey of orchards throughout the San Joaquin Valley to determine the extent of the outbreak.
To date, almond or pistachio orchards infested by carpophilus beetle have been confirmed in Stanislaus, Merced, Madera and Kings counties, suggesting that the establishment of this new pest is already widespread. In fact, some specimens from Merced County were from collections that were made in 2022, suggesting that the pest has been present in the San Joaquin Valley for at least a year already.
“It has likely been here for a few years based on the damage we've seen," Rijal said.
This invasive beetle overwinters in remnant nuts (i.e. mummy nuts) that are left in the tree or on the ground following the previous year's harvest. Adults move onto new crop nuts around hull-split, where they deposit their eggs directly onto the nut. The larvae that emerge feed on the developing kernels, leaving the almond kernel packed with a fine powdery mix of nutmeat and frass that is sometimes accompanied by an oval-shaped tunnel.
Carpophilus beetle has been well-established in Australia for over 10 years, where it is considered a key pest of almonds. More recently, the beetle was reported from walnuts in Argentina and Italy as well. Carpophilus truncatus is a close relative to other beetles in the genus Carpophilus, such as the driedfruit beetle (C. hemipterus) that is known primarily as a postharvest pest of figs and raisins in California.
Monitoring for carpophilus beetle is currently limited to direct inspection of hull split nuts for the presence of feeding holes and/or larvae or adult beetles. A new pheromone lure that is being developed in Australia may soon provide a better monitoring tool for growers, PCAs and researchers.
“We're lucky to have colleagues abroad that have already been hammering away at this pest for almost a decade,” said Haviland. “Hopefully we can learn from their experiences and quickly get this new beetle under control.”
The ability to use insecticides to control carpophilus beetle remains unclear. The majority of the beetle's life cycle is spent protected inside the nut, with relatively short windows of opportunity available to attack the adults while they are exposed. The location of the beetles within the nut throughout most of their life cycle also allows them to avoid meaningful levels of biological control.
In the absence of clear chemical or biological control strategies, the most important tool for managing this beetle is crop sanitation.
“Given that this pest overwinters on remnant nuts, similar to navel orangeworm, crop sanitation will be fundamental to controlling it,” Wilson said. “If you needed another reason to clean up and destroy mummy nuts – this is it.”
In Australia, sanitation is currently the primary method for managing this pest. And here in California, new research and extension activities focused on carpophilus beetle are currently in the works.
“It's important that we get on top of this immediately,” said Wilson. “We're already starting to put together a game plan for research and extension in 2024 and beyond.”
If you suspect that you have this beetle in your orchard, please contact your local UC Cooperative Extension farm advisor (https://ucanr.edu/About/Locations/), County Agricultural Commissioner (https://cacasa.org/county/) and/or the CDFA Pest Hotline (https://www.cdfa.ca.gov/plant/reportapest/) at 1-800-491-1899.
USDA awards $2 million to study livestock grazing in organic orchards
UC, The Organic Center, University of Rhode Island partner on $3.5m food-safety study for organic produce growers
Grazing sheep and other livestock can help convert cover crops to fertilizer for orchard crops. To develop best management practices, the University of California and The Organic Center are collaborating on research to help organic orchard growers safely incorporate livestock grazing into their farming practices. The project is funded by a $2 million grant recently awarded through the U.S. Department of Agriculture's Organic Agriculture Research and Extension Initiative research program.
Interest in grazing livestock on cover crops in nut orchards has increased in recent years. However, research is needed to determine the best way to improve soil health and pest suppression, and to address concerns about food-borne pathogens and food safety.
“Organic farmers typically follow the USDA National Organic Program standards for raw animal manure, waiting 90 to 120 days between incorporating raw manure into the soil and harvesting the crop,” said Alda Pires, UC Cooperative Extension urban agriculture and food safety specialist in the School of Veterinary Medicine at UC Davis.
“Little research has been conducted to verify adequate waiting periods to reduce contamination risks in integrated crop-livestock production systems,” she said. “This research will fill the knowledge gap and facilitate the development of science-based food safety guidelines for grazing small ruminants in orchards.”
For this four-year project, “Influence of Orchard Grazing on Soil Health and Pest Control While Mitigating Food Safety Risk,” the scientists will study organic almond, walnut and pistachio orchards in two distinct nut-growing regions in California – the Sacramento Valley and San Joaquin Valley. The scientists will assess the effects of livestock grazing of cover crops on bacteria populations, soil health, pest control and economics.
Building soil health
“Growers have consistently raised the need for more information on grazing impacts on nutrient availability during tree growth, as well as potential to build up the biological, physical and chemical pillars of soil health,” said Amelie Gaudin, associate professor and endowed chair of agroecology in the UC Davis Department of Plant Sciences.
Livestock grazing may provide an opportunity to quickly enhance the amount of nitrogen that can be used by plants and microbes when the cover crop is terminated. “This project will help growers develop nitrogen budgets for these more diversified systems and quantify additional benefits and potential tradeoffs for soil health – such as compaction and salinity – to guide the development of place-based best management practices,” Gaudin said.
Pest management
Houston Wilson, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside, will be studying the effects of livestock grazing on orchard pests.
“Navel orangeworm, or NOW, is by far the most destructive pest of almonds and pistachios,” Wilson said. “These moths overwinter in unharvested nuts in the orchard, and so removal and destruction of remnant nuts over the winter is the foundation of NOW control. While farmers typically use machinery to do this, grazing with animals may present a unique alternative that is more cost-effective and provides additional ecosystem benefits, such as soil health and weed control.”
Outreach to farmers
As part of the project, The Organic Center was awarded $75,000 to work with UC Agriculture and Natural Resources to direct national extension and education outreach activities. These will include a social media campaign, webinars and educational sessions and a technical report for growers.
“There is an increasing interest from organic farmers to learn how to incorporate livestock into their operations to gain better soil health and fertility,” said Amber Sciligo, director of science programs at The Organic Center.
“This research is very exciting because it will holistically explore the potential risks and benefits of livestock not just to soil health, but also pest control – a truly interdisciplinary project that matches the whole system of the organic farm.”
Produce food-safety management tools
For another organic food-safety project, Pires and Sciligo will be working with Patrick Baur, professor of Sustainable Agriculture and Food Systems at the University of Rhode Island.
The University of Rhode Island and The Organic Center received $3.5 million from USDA's Organic Agriculture Research and Extension Initiative research program for the new organic food-safety education project.
“We're going to develop a new food safety management tool designed specifically for organic soil amendments,” said Baur, who is leading the project. “We're also going to develop a suite of new communication and training tools aimed at the entire fruit and vegetable sector to build a shared language between organic agriculture and the food safety community and help them work better together.”
As part of the produce project, Pires of UC Davis was awarded $1.16 million to conduct a risk assessment and create a publicly accessible dashboard to meet the specific needs of organic growers operating at different scales, under different cropping systems, in different regions.
Also participating in this project will be Beatriz Martinez Lopez, professor in the School of Veterinary Medicine at UC Davis, and Abhinav Mishra and Govindaraj Dev Kumar of the University of Georgia.
