The Grimm Family Center for Organic Production and Research at California Polytechnic State University will host its Fourth Annual Organic Field Day on Thursday, July 23, 2026, at Cal Poly’s Organic Sandbox on Highland Ave. The free event is open to the public and designed for farmers, agricultural professionals, students, and anyone interested in organic agriculture.
The Organic Field Day offers attendees hands-on access to ongoing student-led research in organic nutrient and pest management, a workshop with the Coalition for Food Safety and Sustainability, and a discussion of trap crops for flea beetles and cucumber beetles. Participants can expect guided field tours, live demonstrations, and direct conversations with Cal Poly researchers and faculty working on practical solutions for organic producers.
“The Grimm Organic Center Field Day is an opportunity to see the next generation of
agricultural innovation in action. Attendees will hear directly from Cal Poly students researching soil health and pest management while engaging with experts on practical topics, including trap cropping, food safety, and sustainability. Whether you’re a grower, advisor, student, or industry professional, you’ll leave with ideas and connections that can be applied immediately.” — Matthew Grieshop, Director of the Grimm Family Center for Organic Production and Research (mgriesho@calpoly.edu)
“The Grimm Organic Center Field Day is a great event with educational sessions on key topics that are critical for organic farming – organic nutrient management, organic pest and disease management, and understanding soil health. These sessions are all presented by Cal Poly students involved in conducting the research. I believe the information presented will be of interest to the whole organic farming community.” — Ramy Colfer, True Organic Products (rcolfer@true.ag)
The event follows the Strawberry Center Field Day, also held on July 23 at Cal Poly. Attendees should register for each event separately.
Registration is free and open to all. Registration and sponsorship links can be found at
Time: 1:00 PM – 4:00 PM, immediately following the Strawberry Center Field Day.
Location: Cal Poly Organic Sandbox, Highland Ave., Cal Poly campus.
Free Event Parking: H1 Lot, Mount Bishop Rd.
Cost: Free and open to the public.
For more information, please email Matthew Grieshop, director of the Grimm Family Center for Organic Production and Research, at mgriesho@calpoly.edu, or visit organic.calpoly.edu/field-day-2026. — Story contributed by the Grimm Family Center for Organic Production and Research
The FDA and CDC, in collaboration with state and local partners, are investigating a multistate outbreak of Cyclospora illnesses linked to shredded iceberg lettuce served at Taco Bell locations in Indiana, Kentucky, Michigan, Ohio and West Virginia. The illnesses included in this outbreak are a subset of the Cyclospora illnesses identified nationwide.
Based on epidemiological information collected by CDC, a total of 1,644 people infected with Cyclospora and reporting exposure to Taco Bell have been reported by five states. Illnesses started on dates ranging from May 13 to July 13. There have been 94 hospitalizations and no deaths have been reported. Michigan analyzed food exposure details from 190 of the cases who reported eating at Taco Bell and shared these findings with CDC. Ingredient level analyses on meals eaten by these cases indicate that 90% of those interviewed reported eating iceberg lettuce.
FDA’s traceback investigation has identified convergence on a single supplier of iceberg lettuce from Mexico used by Taco Bell locations where sick people ate before becoming ill.
FDA is working directly with the identified supplier to determine if potentially contaminated shredded iceberg lettuce remains on the market. As part of this investigation, FDA and state partners have initiated collection of product samples for testing and analysis. Additionally, FDA has increased screening at the border for products implicated in the outbreak.
FDA is also working with Taco Bell and they have committed to stop using any lettuce from the supplier identified by FDA’s traceback investigation.
FDA and state partners are actively investigating the source and scope of the contamination. Because the investigation remains ongoing, additional implicated brands, restaurants, retailers or distribution channels may be identified as the investigation continues. This advisory will be updated promptly as new information becomes available.
FDA is aware that the case counts in this advisory may not match what is being reported by individual states. State data may include both probable and confirmed cases, while CDC and FDA include confirmed cases only. State case counts may also include initial case reports that have not yet been reported to CDC. As cases are confirmed, these numbers will continue to update.
Additionally, 2026 national surveillance numbers reported by the CDC track laboratory-confirmed cases in the U.S. overall, which include this outbreak as well as illnesses that are not a part of this outbreak. — Story contributed by the U.S. Food and Drug Administration
Effective July 8, 2026 the CDFA is removing the MedFly quarantine located in Santa Clara and Alameda counties. Maps of any remaining MedFly quarantine boundaries can be found at www.cdfa.ca.gov/plant/medfly/regulation.html.
Regulated articles and conditions for intrastate movement under the quarantine can be found at Title 3 California Code of Regulations (CCR) section 3406. Pursuant to Title 3 CCR section 3406 any interested party or local entity may appeal a quarantine area designation.
Process to Appeal the Area Boundaries
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 – Pest Exclusion
1220 N St., Room 221
Sacramento, CA95814
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 list at: https://public.govdelivery.com/accounts/CADFA/subscriber/new
For questions regarding the regulations or map, please email Vince Arellano at vince.arellano@cdfa.ca.gov or call 916-654-0312.
Effective June 18, the CDFA is expanding the sweet orange scab (SOS) quarantine in the Burbank, Los Angeles and Long Beach areas of Los Angeles County and the Anaheim and Garden Grove areas of Orange County (grids 438, 439, 455, 456, 457, 470, and 471). A map of the new boundary can be found at https://www.cdfa.ca.gov/citrus/pests_diseases/sos/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 3443. Pursuant to 3 CCR §3443, 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, Calif. 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, email Raymond Niem (Raymond.Niem@CDFA.ca.gov) or call (916) 274-6300. — Story contributed by the California Department of Food and Agriculture
A portion of San Diego County has been placed under quarantine for the Mexican fruit fly following the detection of one mated female fly in and around the unincorporated community of Spring Valley. This new quarantine will overlap a portion of the existing La Mesa Mexican Fruit Fly quarantine by 19 square miles. The USDA, the San Diego County Agricultural Commissioner and the CDFA are working collaboratively on this project.
The new quarantine area in San Diego County measures 76 square miles, bordered on the north by El Cajon; on the south by Proctor Valley; on the west by Lemon Grove; and on the east by McGinty Mountain. A link to the quarantine map may be found here: www.cdfa.ca.gov/plant/mexfly/regulation.html.
Sterile male Mexican fruit flies will be released in the area as part of the eradication effort. The release rate will be up to approximately 250,000 males per square mile per week in an area up to 50 square miles around the infestation.
The quarantine will affect growers, wholesalers and retailers of susceptible fruit in the area as well as nurseries that grow and sell Mexican fruit fly host plants. The quarantine will also affect local residents; home gardeners are urged to consume homegrown produce on site and not move it from their property.These actions protect against the spread of the infestation to nearby regions where it could affect California’s food supply and backyard gardens and landscapes.
The Mexican fruit fly can lay its eggs in and infest more than 50 types of fruits and vegetables, severely impacting California agricultural exports and backyard gardens alike. For more information on the pest, please see the pest profile at: www.cdfa.ca.gov/plant/go/MexFly. Residents who believe their fruits and vegetables may be infested with fruit fly larvae are encouraged to call the state’s toll-free Pest Hotline at 1-800-491-1899.
The eradication approach used in the Spring Valley area of San Diego County is the standard program used by CDFA and it is the safest and most effective and efficient response program available.
While fruit flies and other invasive species that threaten California’s crops and natural environment are sometimes detected in agricultural areas, the vast majority are found in urban and suburban communities. The most common pathway for these invasive species to enter our state is by “hitchhiking” in fruits and vegetables brought back illegally by travelers as they return from infested regions of the world. To help protect California’s agriculture and natural resources, CDFA urges travelers to follow the Don’t Pack a Pest program guidelines (www.dontpackapest.com). — Story Contributed by the California Department of Food and Agriculture
Effective June, the CDFA is expanding the sweet orange scab (SOS) quarantine boundary in the Artesia area of Los Angeles County and Buena Park area of Orange County (grids 470 and 471). A map of the new boundary can be found at https://www.cdfa.ca.gov/citrus/pests_diseases/sos/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 3443. Pursuant to 3 CCR §3443, 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 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, email Raymond Niem (Raymond.Niem@cdfa.ca.gov) or call 916.274.6300. — Story contributed by the California Department of Food and Ag
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.
In 2022, Jeannine Lowrimore Onstott, technical sales representative for Pacific Biocontrol, got a call from independent PCA Paul Precissi, asking if she had any mating disruption (MD) pheromones for lilac borer, Podosesia syringae, a clearwing moth that was infesting olive trees under his watch.
In 2022, PCA Paul Precissi started finding lilac borers in olive trees he advised for. Photo credit: Precissi Ag Services
Does the Peachtree Borer Pheromone Work for Lilac Borer?
Pacific Biocontrol did not have a lilac borer pheromone, but they did have a pheromone called Isomate P for another clearwing moth, the greater peachtree borer, Synanthedon exitiosa. The pheromone is a synthetic version of what greater peachtree borer females release from their abdomen to attract male moths for mating. Usually, moth pheromones are species-specific, but Onstott decided to test Isomate P on the lilac borer anyway.
For monitoring, two delta traps with peachtree borer lures from Alpha Scents were hung in both the control block and the MD block on April 26, 2022. On April 29, Isomate P-containing twist-ties were deployed at the rate of 134 per acre — one for every fifth olive tree — in the MD block. The traps were checked the same day, and six more times through June 17.
Twist-ties containing pheromone are used for mating disruption of the lilac borer. Photo credit: Pacific Biocontrol.
The twist-ties released pheromone at a consistent rate for 170 days — way more than was needed to cover the mid-March to early-June flight time of the lilac borer. Each twist-tie released a higher concentration of pheromone than did the traps.
The pheromone-treatment “shut down” the traps for the duration of the flight due to the pheromone load from the MD twist-ties being stronger and more numerous than the pheromone lures in the traps.
Achieving “trap shut down” (few or zero moths caught) was the first measure that the pheromone was effectively disrupting mating.By the end of the test, only five moths had been caught in the MD block (all on April 29), whereas 415 were caught in the control group.
Since the male moths could not find the traps, presumably they also could not find the female moths to mate with them. The moths remained in the orchard until early June, but presumably most failed to reproduce and create the next year’s population.
Once the effectiveness was confirmed, Pacific Biocontrol applied for approval to use Isomate P to control the lilac borer. Even though growers were waiting to use it, and it was registered in other states for organic use, not to mention that pheromones have zero toxicity, the application sat on DPR’s (California Department of Pesticide Regulation’s) desk for 18 months before they finally approved it in 2025.
What Is the Lilac Borer?
Native to North America east of the Rockies, the lilac borer, or ash borer, was first noticed in California in the 1970s.
A clearwing moth that flies in the daytime, it resembles a large paper wasp — as a way of defending itself.
It should not be confused with the emerald ash borer, a beetle native to Asia that has decimated North American ash tree populations.The lilac borer does infest ash trees, though, and other trees in the same plant family, Oleaceae, including lilac, privet and olive.
What Is the Lilac Borer’s Life Cycle?
The adults emerge early to mid-March and immediately start mating.Each mated female lays about 400 eggs in crevices in the bark within 7-14 days of emerging.
The eggs hatch in another 14 days and then burrow into the wood, leaving sawdust protruding from the hole.The following March, the larvae pupate and the cycle starts over.The pupal case often is left hanging at the entrance hole.
Where Is the Lilac Borer Found?
No one knows why the lilac borer is now infesting olives, nor the exact range of where they are a problem.San Joaquin County extension specialist Jhalendra Rijal reported the borer in olive trees in the northern San Joaquin Valley in May of 2020.It has also been reported as far south as Modesto and as far north as Corning, 100 miles northwest of Sacramento — overall, in Stanislaus, San Joaquin, Yolo and Tehama counties.
Matt Morelli, a Nutrien PCA based in Woodland, finds the borer infestation to be most severe in the Picual cultivar of oil olives. Photo credit: Nutrien Ag Solutions.
Precissi says he would love to see most California olive growers put at least one trap in each olive orchard to get an idea of how widespread the borers are.(California is the only US state that produces olive oil on a large, commercial scale.)
Onstott concurs with him.The moths are very sensitive to the pheromone and “super easy to trap,” whereas “the sawdust and tunnels are easy to miss,” she notes.
Precissi finds the lilac borer to be more common in riparian areas and near ornamental olives.He says the borers can kill trees aged 1- 4 years and damage stressed trees, whereas mature, healthy trees seem to weather the infestation.
He mainly consults for oil olives, but people have called him about ornamental olives, and the borer was present in those, too.
Matt Morelli, a Nutrien PCA based in Woodland, finds the borer infestation to be most severe in the Picual cultivar of oil olives.
He recalls pulling out a block of 15 or 20 acres in an orchard west of Yolo after about 12th leaf. The moth was boring into the base of the tree even though it usually likes smaller diameter wood, girdling half the tree.
Morelli thinks Picual may be more susceptible because it has softer wood. For the most part, though, he agrees with Precissi.
“It’s not common to see a mature orchard go out like that — it usually affects young trees more,” Morelli says.
What Are the Signs & Symptoms of Lilac Borer?
The best way to detect lilac borer is to set up pheromone traps in the orchard, by March 1 if possible. One visible sign is 3 mm diameter holes in pruning cuts. Digging into such holes reveals the larvae. Adults can be seen from March through early June.
Some of the entry holes will have a pupal case hanging out, left behind by the emerging adult. The holes tend to have frass around them, too.
The bark was cut away to reveal a lilac borer larva in a young olive tree. Photo credit: Randy Post.One sign of lilac borer infestation is a pupal case protruding from the 3 mm entry hole. Photo credit: Matt Morelli.
How to Prevent and Manage Lilac Borer
“It’s easier to prevent rather than battle your way out — especially since it is a borer, so hard to control,” says Onstott.
Randy Post of Agricultural Advisors recommends using the pheromone lures plus insecticides plus pruning out dead limbs and burning them before March 1. Photo credit: Agricultural Advisors.
According to Precissi, prevention includes avoiding suckering or pruning soon before or during the lilac borer’s flight, because wounds tend to be the entry point. Olive knot infections, frost damage, wet feet — anything that weakens the tree makes it more enticing to the opportunistic lilac borer.
Management of the borer is three-fold, according to Randy Post of Agricultural Advisors.First, use the pheromone.
Onstott says the 2026 price for Isomate P is about $45/acre for 100 dispensers/acre and about $60/acre for 134 dispensers/acre, the rate used in the study.
To give an idea of the labor involved, the test run required six people 1.5 hours to cover 13 acres, hanging 134 dispensers/acre at five to six feet in the canopy.
Second, use insecticides.Not many are registered for oil olives, but the ones registered are effective in combination with the pheromone. Altichor or Danitol attacks the egg and larval stages. If sprayed on the tree, and the female lays her eggs on it, the eggs should not hatch.
Carbaryl, in turn, attacks the adult stage of the borer, and has the side benefit of controlling olive scale as well.
Third — according to Post — is to cut out dead limbs and burn them before March 1 when the overwintered generation starts emerging as adults.“It’s very labor intensive but it’s the life of your orchard,” he asserts.
Lilac borers infest and girdle the branches of young olive trees. Photo credit: Randy Post.
Since olive trees do not age out at 20 years like almond trees, he sees it as a big hit to the grower if a tree dies or is impaired. “With a pest like this that is detrimental to the tree, you want to throw the kitchen sink at it to eradicate it, not manage it,” he proffers.
Biocontrol of Lilac Borer
So far, biocontrol is not being used in commercial olive orchards in California to combat the lilac borer, but some options may be developed in the future from the borers’ natural enemies. One such enemy is ichneumonid wasps that parasitize the borers within their tree galleries.
The University of Massachusetts recommends the fungus Beauveria bassiana, which is commercially available for organic use for borers in some states.
The Missouri Botanical Garden recommends spraying gallery entrances with Steinernema carpocapsae nematodes on ornamental trees infected with lilac borer.
Finally, woodpeckers are important predators of lilac borers.
Even without commercial biocontrol options, growers can prune before March and use pheromone lures, insecticides and sanitation to prevent this new pest from causing major disruption to California olive growing.
The California Department of Food and Agriculture (CDFA) announced it is expanding its sweet orange scab (SOS) quarantine in the La Puente area of Los Angeles County (grids 456 and 457). The quarantine is effective as of April 8.
SOS is believed to be caused by Elsinöe australis, a fungal pathogen. The disease results in the formation of pustules and lesions on the skin of the citrus.
Regulated articles and conditions for intrastate movement under the quarantine can be found at Title 3 of the California Code of Regulations section 3443. Interested parties and local entities may request to lift the quarantine area designations by submitting a written appeal supported by convincing evidence. Appeals must be filed within 10 working days of the notification. Quarantines will remain in effect during the appeal’s pending. Appeals can be mailed to: CDFA – Citrus Division 1220 N. St. Sacramento, CA 95814.
Soil sampling is the first step toward effective control of plant-parasitic nematodes. These underground, microscopic worms, especially root-knot species, develop and feed on the root systems of young fruiting vegetables. Their feeding leaves visible galls on roots, which disrupt the plant’s ability to efficiently take up water and essential nutrients needed for healthy plant development.
A single acre of ground can harbor several hundred million nematodes. Because nematodes reproduce quickly, making control applications early in the cropping cycle is critical to protecting developing roots.
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Salibro CA nematicide is in a unique chemical group, making it a strong tool for resistance management and helping prolong the efficacy of all nematicides. It offers excellent compatibility with soil health, including with beneficial nematodes, soil fungi and soil bacteria. Let Salibro CA nematicide protect the roots of tomatoes and other fruits and vegetables for increased yield potential and more marketable crops at harvest.
