Pests and Diseases

Massive Ant Hunt Launches Across 7 O.C. Cities

Source: Scott Martindale; Orange County Register

Susie Federico peered through her glasses at the dozens of ants swarming a tiny plastic trap she’d staked in the ground.

Federico, an agricultural technician for the state Department of Food and Agriculture, used a pair of tweezers to inspect all sides of the plastic basket, filled with one of ants’ favorite foods – Spam canned meat.

Unless they were big-headed ants, Federico let them go free.

“I’m looking for the larger head,” Federico said as she flicked off ants that had crawled up her hand and arm.

“There is not a sample as of now.”

Assigned to a residential neighborhood in northwestern Santa Ana, Federico was part of a team of state agricultural technicians that began setting ant traps Monday across a 79-square-mile swath of Orange County.

State officials are looking for the aggressive Pheidole megacephala species of big-headed ants, which were discovered last month in the front yard of a Costa Mesa home near the Santa Ana River.

“Knowing the extent of the infestation is an important consideration,” said Steve Lyle, a spokesman for the state Department of Food and Agriculture. “We’re still evaluating what this means. Is it something that needs to be taken care of? Is it something we can take care of?”

Named after their disproportionately large heads, big-headed ants are considered an agricultural pest and one of the world’s most invasive insects. They aren’t dangerous to humans.

In all, state officials plan to place Spam traps at 1,570 locations in seven Orange County cities in the coming days – the equivalent of 20 per square mile.

A team of up to eight state workers will spend at least a week systematically placing traps in neighborhoods up to 5 miles from where the original colony was discovered, Lyle said.

The study area encompasses all of Costa Mesa and parts of Huntington Beach, Fountain Valley, Westminster, Santa Ana, Irvine and Newport Beach.

Once officials know how far the ants have spread, they can decide whether to move forward with extermination, Lyle said.

Although California is home to native varieties of big-headed ants, the species discovered in mid April in Costa Mesa was the first documented sighting of the aggressive Pheidole megacephala species in its natural environment in California. It can displace other ants and eat beneficial insects, authorities say.

The Costa Mesa colony was first spotted by amateur entomologist Gordon C. Snelling of Apple Valley, who was visiting a friend in mid April.

The friend had been complaining about aggressive ants invading his house and winding up dead in his swimming pool, Snelling said.

Snelling said the big-headed ants had likely traveled to his friend’s home inside potted plants or sod, and that they had probably been there at least a year.

“I knew the state and the county would get in an uproar as soon as I let them know,” Snelling, 55, told the Register last week.

“It’s one of those things that gets the adrenaline pumping and your brain churning,” added Snelling, who runs the website armyants.org and has published scientific papers on ants. “It’s certainly caused more response than anything else I’ve done.”

Patrick Cavanaugh2016-05-31T19:37:59-07:00May 6th, 2014|

ALERT: Immediate Action Needed for Thrips/TSWR

Source: Neil McRoberts

For those who have water and tomatoes:

Thrips numbers have increased rapidly in the southern arm of the Central Valley and Tomato spotted wilt virus (TSWV) has been reported in all of the areas we monitor,” according to Neil McRoberts, Assistant Professor, Plant Pathology Department, UC Davis.

There are numerous reports of TSWV symptoms in crops from Stanislaus County down to Fresno and Kings County particularly around the Huron area.

The current risk in Fresno County is high and we are recommending that growers who plan to use an insecticide program against thrips/TSWV take immediate action. The current mini heat wave will accelerate thrips development slightly and further bump up thrips numbers.

If you are planning to use an insecticide program against thrips/TSWV this season, you should target the next generation of thrips (generation 3). If it is not possible to arrange for treatment in time to catch generation 3, target generation 4. Delaying treatment until later in the season will be much less effective at preventing damage from TSWV. Coordinated spraying across large areas has an additional effect on thrips populations because it makes it difficult for them to avoid treatment by migrating.

Generation 3 adults are projected to peak on May 17th. Sprays applied in the 14-day period before this peak date will check generation 3 and delay further population build-up and TSWV spread. This means you need to take immediate action.

Generation 4 adults are projected to peak on June 11th. Sprays applied in the 14-day period before this peak date will check generation 4 and delay further population build up and TSWV spread. Treatment in the 14 days immediately following the generation 3 peak date will also be effective.

The current risk in the Merced area is high and we are recommending that growers who plan to use an insecticide program against thrips/TSWV take immediate action. The current mini heat wave will accelerate thrips development slightly and further bump up thrips numbers.

Generation 3 adults are projected to peak on May 22nd. Sprays applied in the 14-day period before this peak date will check generation 3 and delay further population build-up and TSWV spread.

Generation 4 adults are projected to peak on June 16th. Sprays applied in the 14-day period before this peak date will check generation 4 and delay further population build up and TSWV spread. Treatment in the 14 days immediately following the generation 3 peak date will also be effective.

The current risk in eastern San Joaquin County is lower than in other southern Counties, but we think a precautionary approach is best. The current mini heat wave will accelerate thrips development slightly and further bump up thrips numbers.

Generation 3 adults are projected to peak on May 28th. Sprays applied in the 14-day period before this peak date will check generation 3 and delay further population build-up and TSWV spread.

Generation 4 adults are projected to peak on June 22nd. Sprays applied in the 14-day period before this peak date will check generation 4 and delay further population build up and TSWV spread.

The current risk in Kings County is high and we are recommending that growers who plan to use an insecticide program against thrips/TSWV take immediate action. The current mini heat wave will accelerate thrips development slightly and further bump up thrips numbers.

Generation 3 adults are projected to peak on May 22nd. Sprays applied in the 14-day period before this peak date will check generation 3 and delay further population build-up and TSWV spread. This means you need to take immediate action.

Generation 4 adults are projected to peak on June 14th. Sprays applied in the 14-day period before this peak date will check generation 4 and delay further population build up and TSWV spread. Treatment in the 14 days immediately following the generation 3 peak date will also be effective.

The current risk in western San Joaquin County is lower than in other southern counties, but we think a precautionary approach is best. The current mini heat wave will accelerate thrips development slightly and further bump up thrips numbers.

Delaying treatment until later in the season will be much less effective at preventing damage from TSWV. Coordinated spraying across large areas has an additional effect on thrips populations because it makes it difficult for them to avoid treatment by migrating.

Generation 3 adults are projected to peak on May 28th. Sprays applied in the 14-day period before this peak date will check generation 3 and delay further population build-up and TSWV spread.

Generation 4 adults are projected to peak on June 22nd. Sprays applied in the 14-day period before this peak date will check generation 4 and delay further population build up and TSWV spread.

The web resource for integrated management of Western Flower Thrips and Tomato Spotted Wilt Virus in the California Central Valley contains two tools to help in disease risk management:

A Field Risk Index tool uses simple information about field locations, land use, and agronomy to calculate a risk category for tomato crops. This tool can be used before planting or early in the season to get a heads up about the general risk to a crop from TSWV.

A thrips population projection model, driven by degree-day accumulation at several Central Valley locations, aids in projecting when thrips generations are hatching, developing, and adult numbers are peaking. This information is used to issue regular updates and provide broad guidelines for timing insecticide sprays to keep thrips numbers low enough to prevent TSWV from spreading.

The research behind these tools was supported by the California Tomato Research Institute (CTRI)

The model was developed in Collaboration with Dr. Len Coop of Oregon State University’s Integrated Plant Protection Center (IPPC). The IPPC developed and hosts the USPEST web service which is a multi pest multi model tool that provides information on pest development and disease risk for the Contiguous 48 US states using a network of weather stations.

Patrick Cavanaugh2021-05-12T11:03:06-07:00May 4th, 2014|

Know Dibble’s Law For Best Orchard Spraying

Remember Dibble’s Law in Orchard Sprayings

Keep this in mind: < 2 mph!

Jack Dibble is credited with Dibble’s Law.

It’s called Dibble’s Law and it’s named after Dr. Jack Dibble, a retired UC Berkeley and UC Kearney Agricultural and Extension Center Research Entomologist.

He has worked primarily in tree crops and a big part of his career was on spray techniques and he is well known for Dibbles Law, which states the best spray coverage is when the driver goes less than two miles per hour down the row.

“We found out right from the outset and continued to prove this with growers and commercial spray applicator companies that speed of travel is very important,” said Dibble, in an exclusive interview with California Ag Today.

“The faster you go, the whippier the spray gets, and the spray that is released must be pushed up into the tree by the spray behind it,” said Dibble. “If the driver is going too fast, there is no spray pushing the spray you just released. Therefore, you lose control of the spray project because you are not getting coverage in the centers at the top of the tree.”

“By going two miles per hour or less, the spray released will be pushed up into the tree by the spray behind it. It just pushes it up,” said Dibble.

Patrick Cavanaugh2016-05-31T19:38:02-07:00April 17th, 2014|

Beet Curly Top Virus ALERT

A small population of Beet Leafhoppers (BLH) was found in the Tumey Hills area. Counts were on average, 7-9 2^nd and 3^rd instar nymphs and 1-3 adult BLH, per 10 sweeps.

Another small population of BLH was found in the Coalinga “Big C” area last week. Counts were on average, 2-3 adult BLH and 5-10 2nd and 3rd instar nymphs, per 10 sweeps.

The Beet Curly Top Virus Control Program is currently planning treatment in the Tumey Hills area for this week. Treatment plans and waivers are being prepared for the Coalinga area.

Email jennifer.willems@cdfa.ca.gov if you suspect curly top virus in your fields, so that the BCTV program can monitor and collect samples for testing. Thank you!

Patrick Cavanaugh2016-05-31T19:38:02-07:00April 14th, 2014|

Pistachio Growers: Beware of Gill’s Mealybug

David Haviland says pistachio growers should be aware of the damage caused by Gill’s Mealybug.

Gill’s Mealybug May Appear in Orchards Over the Next Few Weeks

By Patrick Cavanaugh, Editor

As Gill’s Mealybug overwinters, a new generation will appear in May, and growers should treat the first generation around June 1.

Gill’s mealybug is a relatively new pest of pistachios in California. “It was first recognized in the late 1990s in a an orchard near Tulare. It has now spread up to Colusa County and has move down to Kern County,” said David Haviland, UC Cooperative Extension Kern County, who organized the field day with Elizabeth Fichtner, UC Cooperative Extension Tulare County.

Tulare County is a hot spot with most pistachio orchards having the bug, which has three generations per year. “Right about harvest time there are a whole bunch of mealybug crawlers hatching, and then they overwinter and become adults in May. These adults will produce an enormous amount of new crawlers the first week of June, which is an important treatment time, right when those crawlers come out,” said Haviland. “The ones that are born the first week of June will become adults in about mid-to-late July, which is the second generation. The mealybugs that are in the tree now are the start of the third generation when they become adults then hatch more young bugs at harvest.”

“Population-wise, growers will get millions of crawlers at harvest, but if you come back to the tree in the spring, you will see maybe one or two per pistachio cluster, so there is a huge winter mortality,” said Haviland.

Haviland stood by a tree that had only about one mealybug per 10 clusters in the May, but now the untreated trees in the trial have clusters that are covered with honeydew, and now blackened with sooty mold, with 30 or 40 adults on the clusters. The lower leaves on the trees were turning black from the sooty mold.

“Typically growers go out in their orchards April and May and see about one mealybug for every 10 clusters. In fact they might not even notice it. But that mealy bug produces about 20 live young, which increases the count to about one per cluster, but now those adults give rise to 15 or 20 crawlers per cluster which causes clusters to be moist and black,” said Haviland. “So the point is that one or two per cluster can cause many more per cluster near harvest time, so May is the time to be thinking about spraying the first of June.”

Haviland looked back at the tree he was standing next to, and said: “If you have tree that looks like this, with a lot of mealybugs and sooty mold, let it go; you can’t do anything about it. Come back the first week of June 2014 and treat it with an insecticide and you should be clean at harvest next year. It’s really that simple.

Insecticide timing is important, but there is a widow. Of all the products registered, they are most effective on crawlers. “So you really want to get them the first week of June when the crawlers are out regardless of which product your using,” Haviland said.

During the upcoming harvest season, Haviland warn growers to ask the harvest crew to wash down the harvesting equipment and make sure no tree debris from another orchard is on the equipment. “And if growers have an orchard with mealybug, please inform the harvest crews so that they clean the equipment before moving to another site, which may not have mealybug.

“The harvest crew should blow off all leaf trash and hose the equipment down before it goes from property to property. Growers should insist upon this,” Haviland said.

Patrick Cavanaugh2016-05-31T19:38:02-07:00April 13th, 2014|

Training on Cucumber Green Mottle Mosaic Virus

The California Department of Food and Agriculture (CDFA) will be providing one-day training in cucumber green mottle mosaic virus (CGMMV) and bacterial fruit blotch (BFB) of cucurbits 8:30 a.m. to 2:30 p.m. on May 1 and on May 2, 2014, at the CDFA Plant Pest Diagnostics Branch, 3294 Meadowview Road, Sacramento, CA 95832.

The training is geared toward county agricultural commissioners’ staff and cucurbit seed and transplant growers of Yolo, Sutter and Colusa counties. This training will be provided in collaboration with members from the seed industry and the United States Department of Agriculture, Animal and Plant Health Inspection Service.

Topics covered will include:

CGMMV/BFB 2013 detections, subsequent actions taken, current status and future perspectives;
Impact on California seed industry;
Biological perspectives – symptoms, biology, management;
Field detection protocols and bio-security measures;
Sterile seed sampling and seed law considerations;
Federal perspectives on CGMMV and other invasive species.

Training to other counties will be provided on later dates.

Seating is limited and early registration via RSVP is mandatory by April 24, 2014 to the California Seed Association (CSA). Register by email: betsy@agamsi.com or fax: 916-446-1063. See attached flyer for registration and more information. Parking is free and lunch will be provided by CSA.

Featured Photo by Dennis H. Hall. (UC Davis IPM): Cantaloupe leaves infected with Cucumber Mosaic Virus showing vein clearing, mosaic and necrosis.

Patrick Cavanaugh2016-05-31T19:38:03-07:00April 9th, 2014|

ACP QUARANTINE IN SAN LUIS OBISPO COUNTY DEFINED

TODAY, the California Department of Food and Agriculture (CDFA) defined the borders of the 84 square mile-quarantine zone, following the detection of one Asian citrus psyllid (ACP) in the Arroyo Grande area of San Luis Obispo County.

The zone is bordered on the north by Corbett Canyon Road; on the south by Oso Flaco Lake Road; on the east by Mehlscau Creek; and on the west by the coast of California. The quarantine map is below.

The quarantine prohibits the movement of citrus and curry tree nursery stock out of the quarantine area and requires that all citrus fruit be cleaned of leaves and stems prior to moving out of the area. An exception may be made for nursery stock and budwood grown in USDA-approved structures designed to keep ACP out. Residents with backyard citrus trees in the quarantine area are asked not to transport fruit, citrus or curry leaves, or potted trees from the quarantine area.

ACP quarantines, in addition to San Luis Obispo County, are now in place in Imperial, Los Angeles, Orange, Riverside, San Bernardino, San Diego, Santa Barbara, Ventura and portions of Fresno, Kern and Tulare Counties. A total of more than 46,420 square miles are under quarantine.

Residents in the area who think they may have seen the Asian citrus psyllid are urged to call CDFA’s Pest Hotline at 1-800-491-1899. For more information on the Asian citrus psyllid and huanglongbing disease please visit: www.cdfa.ca.gov/go/acp

Contact: Steve Lyle, Director of Public Affairs, CDFA, 916-654-0462

Patrick Cavanaugh2016-05-31T19:38:04-07:00April 8th, 2014|

USDA Provides Farm Bill Funding for Pest and Disease Management Programs

U.S. Department of Agriculture (USDA) Secretary Tom Vilsack announced today the allocation of $48.1 million, provided by the Agricultural Act of 2014 (the 2014 Farm Bill), to projects across the country that will help to prevent the introduction or spread of plant pests and diseases that threaten America’s agriculture economy and the environment.

The economic stakes for stopping invasive species are high, with scientists estimating the total economic cost of all invasive species to be approximately $120 billion annually.

“Invasive pests cause billions of dollars in damage each year and endanger our nation’s food security,” said Vilsack. “The funds USDA is making available today will help partners and stakeholders develop strategies, products and treatments to safeguard our farms and natural resources from invasive threats.”

USDA’s Animal and Plant Health Inspection Service (APHIS) sought project suggestions from states and U.S. territories, universities, federal agencies, nongovernmental organizations, private companies and tribal organizations that would provide a direct impact in managing pests and diseases, as well as disaster prevention.

A list of selected projects and the FY 2014 funding plan are posted at http://www.aphis.usda.gov/newsroom/2014/04/pdf/fy14_farm_bill_spending_plan.pdf

Funded initiatives include $2 million for protection against exotic fruit flies in California.

Prospective projects were evaluated by teams comprised of USDA experts and industry representatives and were selected based on criteria that supported six goals:

enhancing plant pest/disease analysis and survey
targeting domestic inspection activities at vulnerable points in the safeguarding continuum
enhancing and strengthening pest identification and technology
safeguarding nursery production; enhancing mitigation capabilities
conducting outreach and education about these issues.

The teams also evaluated submissions based on expected impacts of the project, the technical approach, and how submissions would complement ongoing USDA programs and other previously funded projects funded under the 2008 Farm Bill (Section 10201).

The 2008 Farm Bill has provided funding for more than 1500 projects over the last five years and has played a significant role in protecting American agriculture and educating the public about the threat of invasive species.

Visit www.Hungrypests.com during April, which APHIS has proclaimed Invasive Plant Pest and Disease Awareness Month, to learn more about invasive plant pest and diseases impacting your area and how you can help. And, join the discussion about invasive plant pests via the HungryPests Facebook page.

Patrick Cavanaugh2016-05-31T19:38:04-07:00April 3rd, 2014|

Asian Citrus Psyllid Quarantine Established in San Luis Obispo County

Breaking News: NEW ACP Discovery

Victoria Hornbaker, APHIS Citrus Program Manager, announced TODAY the first confirmed Asian citrus psyllid find in San Luis Obispo County as reported in a San Luis Obispo County Ag Commissioner’s press release.

Hornbaker also announced a Science Advisory Panel Report Stakeholder meeting will be held on April 16, 2014 at 9 am at CDFA headquarters, 1220 N Street, Room 220, Sacramento, CA 95814. To participate via conference call, please call 866-692-3158 and use participant code 87947483.

The meeting agenda follows this article.

Martin Settevendemie, Agricultural Commissioner/Sealer, County of San Luis Obispo announced detection of an adult Asian Citrus Psyllid in an insect trap on March 26^th in a residential landscape near Arroyo Grande. The discovery prompted a high-density trapping delimitation survey of the immediate and adjacent area – about a nine square mile area – and no other ACPs were found.

A quarantine restricting the movement of citrus nursery stock and citrus fruit within a five-mile radius around the detection site has already been established by the California Department of Food and Agriculture to prevent the spread of this serious plant pest. “We are working with growers to get everyone in compliance with the regulation. This will help them understand what the requirements are to move any product outside of the quarantine area,” said Settevendemie.

CDFA announced that they will be conducting spray eradication treatments approximately 800 meters around the detection to eradicate this pest.

The first detection of the Asian Citrus Psyllid in California occurred in San Diego County in 2008. Since then, it has been found throughout southern California.

“This insect pest is of serious concern to California’s commercial citrus because it is responsible for spreading Huanglongbing, also called citrus greening disease, a plant disease that is fatal to all types of citrus trees. This includes citrus trees in countless landscapes across the county as well as local commercial citrus orchards valued at over $13 million in 2013,” according to Settevendemie.

Over the past ten years nearly 50% of the commercial citrus groves in Florida have been killed by this disease. The University of Florida estimates the disease has tallied more than 6,600 lost jobs, $1.3 billion in lost revenue to growers and $3.6 billion in lost economic activity for the state. The disease does not affect human health.

A single orange tree infected with Huanglongbing was found in a Los Angeles County backyard in 2012. To date no additional detections of the disease in California have occurred.

Staff from the San Luis Obispo County Agricultural Commissioner’s office and officials from the California Department of Food and Agriculture continue to search for this pest by monitoring hundreds of insect traps placed in urban neighborhoods and commercial orchards throughout the county.

“It is difficult to close off all potential pest pathways into the county. An engaged community of all county residents is critical in successfully excluding pests such as Asian Citrus Psyllid,” said Settevendemie.

Community members can do the following to protect backyard citrus trees and the local citrus industry:

        Buy Local! Purchase citrus trees from reputable local sources selling plants that have been routinely inspected by the Agricultural Commissioner’s staff.
        Do not transport citrus plants or plant parts into the county from quarantine areas. Call 805- 781-5910 for information about quarantine areas.
        Check residential landscaping often for signs of unusual symptoms or strange insects. Contact the local University of California Cooperative Extension’s Master Gardener Program at 805-781-5939 for help in identification of unusual plant symptoms or pests.
        If asked, allow the Agricultural Commissioner’s staff to place an insect trap in your yard and cooperate with officials if it becomes necessary to exclude or eliminate Asian Citrus Psyllid from San Luis Obispo County.

For more information about the Asian Citrus Psyllid visit the California Department of Food and Agriculture website or the San Luis Obispo County Agricultural Commissioner/Sealer’s website.

AGENDA FOR: ACP/HLB Ad Hoc Science Advisory Panel Report

Stakeholder Review/Conference Call

April 16, 2014, 9:00 a.m.

Call-in number: 866-692-3158

Passcode: 87947483

– This meeting is open to the General Public –

AGENDA

1. Call to order, introductions – Jason Leathers

2. Review of Science Advisory Panel Questions and Answers

3. Review of Science Advisory Panel Report

a. Rapid Detection of HLB Infected Trees and/or Psyllids

b. Longitudinal Study being Conducted at the UC Davis Containment Facility

c. Potential for Movement of CLas Infected ACP with Fruit Movement

d. Recommendations Regarding Areawide ACP Treatment Program

e. Recommendations Affecting Quarantine Area

f. Recommendations Affecting Citrus Nurseries

4. Additional Questions/Review Items

Patrick Cavanaugh2016-05-31T19:38:04-07:00April 3rd, 2014|

BREAKING NEWS: Medfly Infestation in Los Angeles

A quarantine has been declared due to a Mediterranean fruit fly (Medfly) infestation detected in the city of Los Angeles. One adult male and five unmated females were detected in five traps between March 3 and 12, 2014, and four larvae were discovered in backyard fruit on March 18.

The Medfly can infest more than 250 types of fruits and vegetables, causing severe impacts on California agricultural exports and backyard gardens alike. Residents who believe their fruits and vegetables are infested with fruit fly larvae are encouraged to call the state’s toll-free Pest Hotline at 1-800-491-1899.

The United States Department of Agriculture (USDA), the Los Angeles County Agricultural Commissioner, and the California Department of Food and Agriculture (CDFA) are working collaboratively on this project.

The 88-square mile quarantine is in central Los Angeles, near the University of Southern California. Additional information, including a map of the 88-square mile quarantine zone, is available at: http://www.cdfa.ca.gov/plant/medfly/regulation.html#index.

To eradicate the infestation, the increased release of sterile male Medflies began last week, at a rate of 250,000 flies per square mile per week, double the normal rate in that area.

The sterile male Medflies are brought to California by the joint CDFA/USDA sterile insect rearing facility in Los Alamitos, which prepares sterile flies for release everyday over the Los Angeles Basin.

The sterile release program has a proven track record of eradication in southern California. Sterile male flies mate with fertile female flies in the environment but produce no offspring.

The Medfly population decreases as the wild flies reach the end of their natural life span with no offspring to replace them, ultimately resulting in the eradication of the pest.

The enhanced release area is approximately 25 square miles. In addition, properties within 200 meters of detections are being treated with an organic formulation of Spinosad, which originates from naturally-occurring bacteria, in order to eliminate any mated females and reduce the density of the population.

Finally, fruit removal will occur within 100 meters of the larval detection property in order to remove any fruit infested with eggs and larvae.

“Our pest prevention system to detect and respond to invasive species like the Mediterranean fruit fly is working well and according to design,” said CDFA Secretary Karen Ross. “The release of sterile Medflies is a proven method of eradicating an infestation. The key is to move swiftly and take action before the pests can cause widespread damage and become established.”

The quarantine will affect any growers, wholesalers, and retailers of susceptible fruit in the area as well as local residents – home gardeners are urged to consume homegrown produce on site and not move it from their property.

The eradication approach in the Los Angeles area is the standard Medfly program used by CDFA and it’s the safest, most effective and efficient response program available.

Patrick Cavanaugh2016-05-31T19:38:07-07:00March 24th, 2014|

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