Posts Tagged: IPM

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.

UC Cooperative Extension advisor helps property managers prevent pests in the home

Living with pests, or “unwanted guests” as some put it, can take a physical, mental and economic toll. For people living in multi-family unit housing, like an apartment complex where everyone lives under one roof, a single infestation of insects or rodents can expose all residents.

Using integrated pest management, or IPM, residents and property managers can detect infestations early and control severe ones and protect people. IPM programs can also save money. IPM saved a 75-unit complex in Contra Costa County $11,121 annually. Similarly, in Santa Clara County, a 59-unit complex saved $1,321 on pest control annually after implementing a proactive IPM program.

This summer, regional directors, property managers, residential service coordinators, maintenance managers and groundskeepers of Mercy Housing – a nonprofit organization that provides affordable, low-income housing – gathered in Long Beach to learn about in-home IPM. The session was led by Siavash Taravati, University of California Cooperative Extension area IPM advisor for Los Angeles, Orange, Riverside and San Bernardino Counties, and

Josh Shoemaker, an entomologist and private consultant.

Taravati and Shoemaker collaborated with StopPests in Housing, a national program out of Cornell University's Northeastern IPM Center, which seeks to improve pest control in affordable housing and teach management practices for cockroaches, bed bugs and rodents within and around the home.

During their presentation, Taravati introduced participants to the IPM principles and emphasized the importance of monitoring pests.

“IPM is all about making informed decisions which requires knowing the latest status of an infestation,” explained Taravati. “That's where monitoring comes into play. It can help us to identify the exact species we are dealing with as well as telling us if an infestation is growing or shrinking.”

“Monitoring is foundational,” agreed Shoemaker. “If a program does not include monitoring, it's not an IPM program.” 

According to Shoemaker, the benefit of partnering with UC IPM is their sharp focus on general IPM, which includes monitoring. “It's real IPM, that prioritizes the well-being of the public,” said Shoemaker, who's eager to continue working with Cooperative Extension and Taravati to ensure that children are growing up in safe environments.

Pest control treatments commonly take place following a serious infestation or several complaints, but IPM promotes constant monitoring to prevent heavy infestations from ever happening. It's a proactive approach rather than a reactive or emergency-response. For many attendees, the training revealed a need to engage with pest management operators more closely. 

Training prompts changes that improve safety for residents

Pest management operators commonly use pesticide sprays to control pests. Besides inconveniencing residents, forcing them to do extensive preparations and evacuate their unit until it's safe to return, sprays increase exposure risk to pesticides since the aerosols can linger and land on surfaces. 

Instead, Taravati and Shoemaker recommend using gel baits, which are much safer to apply and can target a specific area of a home, including crevices, instead of along all the walls.

“Now that I'm more informed, I'll be speaking to my contractor to discuss how we can switch their approach from a bug spray to a gel,” said Leonardo Pinuelas, a maintenance manager for Mercy Housing.

Pinuelas is not the only one wanting to modify their program, however. According to feedback from staff members at the Housing Authority of the City of Los Angeles who experienced the same training earlier this year, they prompted their team to amend their pest extermination to include dusting, or applying insecticidal dusts, against roaches, and to review and update their existing IPM plan and practices where appropriate.

Cindy Wise, area director of operations for Mercy Housing, said that in her 35 years, this was one of the few trainings that engaged her staff so actively. “I couldn't help but text my regional vice president to say that our managers were actively participating and asking questions. That doesn't happen often, not even in our own meetings,” said Wise.

Many of the attendees, with their new understanding of how cockroaches move through a structure, shared that they are eager to return to work to meet with residents and support them.

“If you've got roaches in one unit, you've got them in the entire building,” Wise said.

Shoemaker recalls the words of Judy Black, senior technical entomologist for Orkin, and Dini Miller, entomologist at Virginia Tech, who urge the importance of inspections and documentation as IPM best practices.

Although reporting pests in the home can make one feel embarrassed, Wise said she is more interested in making residents feel empowered to not only report signs of infestation to the staff, but to their neighbors.

Training residents is certainly beneficial, but as experts such as Black and Miller have pointed out, housing managers must do their part, instead of scapegoating tenants for their cleaning habits.

StopPests provides free IPM training and technical assistance to Housing and Urban Development assisted properties. If you are interested in the training provided by Taravati and Shoemaker, in collaboration with StopPests, visit StopPests.org for more information.

Cooperative Extension advisor, UC experts tackle ‘nightmare’ termite

During summer swarming season, homeowners urged to check for signs of Formosan subterranean termite

In the lottery of troublesome termite infestations, “Roger,” a Rancho Santa Fe homeowner, hit the jackpot (a pseudonym is used to protect his privacy). In 2021, his house in San Diego County was identified as home to only the fourth documented colony of the Formosan subterranean termite (Coptotermes formosanus) in California.

“FST is one of the most destructive urban pests in the world,” said University of California, Riverside entomologist Chow-Yang Lee, affiliated with UC Agriculture and Natural Resources through the campus' Agricultural Experiment Station. “It's also the only termite species listed in the ‘100 of the World's Worst Invasive Alien Species.'”

Endemic to East Asia, this termite is now established in many tropical and subtropical regions, including across the American South. Annually, its infestation costs more than $4 billion in control measures and damage repairs of structures in the U.S.

FST was first discovered in California in La Mesa (San Diego County) in 1992, and it was rediscovered in that city in 2018. Another infestation was reported in Canyon Lake (Riverside County) in 2020. And then, the following year, Roger received his surprise.

“Imagine being in your kitchen looking at your drywall and it's totally normal and then the next day there's a four-inch hole there and you're like ‘What the heck is that? Who put their elbow into the drywall?'” he recalled.

FST colonies can reach millions of individuals

Roger hired a pest control company, Green Flash Pest Control, which sprayed a powerful liquid termiticide in the soil around the house. But the termites – workers, soldiers and winged “alates” – continued to appear. The company tried a second application of soil treatment. But, again, the termites kept popping up.

“We were deeply concerned about the potential damage these termites could cause to the home since these invasive termites are extremely destructive,” said Eric Veronick, director of operations at Green Flash. “Unfortunately, there isn't a whole lot of information available on the behavior and management of this termite in California.” 

The company called upon Siavash Taravati, a UC Cooperative Extension urban Integrated Pest Management (IPM) advisor based in Riverside.

“Some colonies are aerial, meaning that they are formed above the ground with limited or no connection to the soil – in such cases, soil treatment using contact insecticides may not be very effective in managing these termites,” Taravati said. “Furthermore, contact insecticides usually kill a much smaller portion of the colony when compared to termite baits.”

To make matters worse, once FST is established in an area, there have been no records of successful eradication anywhere in the world, according to Taravati. He added that a major reason why the Formosan subterranean termite is so destructive is the enormous size of their colonies.

“Their colonies can reach millions of individuals, versus most native subterranean species that reach a few hundred thousand individual termites per colony,” Taravati explained.

This termite, through its sheer numbers, can turn the wood in a structure into a “spongy kind of cake,” in Taravati's words. More than 10 pounds of wood in a house can be eaten by a mature colony each month. The financial hit for a homeowner can be substantial, up to tens of thousands of dollars – not to mention the increased risks to safety.

“Anything from studs to rafters to door frames and window frames – everything is going to be compromised, if the termites are left unchecked. And then, as soon as we have a major stress on the building, let's say there's a big storm or an earthquake – there's a high risk of at least part of the building collapsing,” said Taravati, who also noted that, unlike California native subterranean termite species, FST can attack and kill live trees and plants.

“These termites can be a nightmare,” he said.

Summer is ‘swarming season' for FST

Since the Rancho Santa Fe case in 2021, four more colonies have been documented, in La Mesa again and also in Highland Park, Hollywood Hills and La Verne (the latter three in Los Angeles County). Taravati said it's possible that FST has been spreading via structural lumber or potted plants and soil.

And even if a colony appears to be eliminated at a certain locale, Taravati noted, there is always the chance that part of the colony survives or more colonies of termites already have been established in nearby locations, as a result of swarming termites from the originally infested property.

Although nominally “subterranean,” certain members of an FST colony grow wings and fly to nearby locations to establish new colonies. These winged alates are also called swarmers because of their behavior during the “swarming” season, when termites mate and reproduce.

For the Formosan subterranean termite, that swarming season in California is late May through early August, so now is the time for homeowners and building managers in southern and central California to keep an eye out for those winged termites.

“If you experience a termite swarm in your house, contact a pest management professional and keep some termite samples in a Ziploc bag in the event you need to send the samples to UC Riverside for morphological and DNA-based identifications,” said Lee, who added that it's a good idea to periodically check your structure for signs of infestation, such as wood damage or shelter tubes (mud tubes).

Lee said FST swarmers have a lighter colored body compared to the dark color of native subterranean termites and the orange-brown body of drywood termite swarmers (see this flyer for additional identification information).

Following an especially wet winter, there's a chance California could see more FST infestations, as this termite generally requires moist environments to thrive, Lee added. He recommends that concerned community members seek professional advice.

“Do not attempt to control an FST infestation by yourself,” Lee said. “This is not your typical native Californian subterranean termite species; they are highly destructive, and you want to intercept the problem with the right strategy before it's too late.”

Homeowner: ‘I owe them my house'

In Roger's case, Taravati enlisted the help of Lee and his UC colleague, Greg Kund. They made multiple visits to inspect the home and analyze the situation – going “above and beyond,” according to Roger.

At Lee's suggestion, they used a caulk gun to insert a gel-like experimental bait into the wall where the termites were coming out. Once spread and passed on to the other nestmates, the product – which contains a chitin synthesis inhibitor (a type of insect growth regulator) – interrupts the termites' development so they are unable to properly molt and replace the short-lived “workforce” of foragers and soldiers. The colony eventually collapses and is eliminated.

“Generally speaking, IGRs are much more effective, but they require more patience,” Taravati explained. “You're not going to see the results the next day, or two-three days. You're going to see the results in a few weeks – but when you see the results, it's massive.” 

And that's exactly what Roger and Green Flash Pest Control saw.

“Soon after their bait application, the termites stopped emerging from the walls and that gave us and the homeowner a big sigh of relief,” Veronick said. “I appreciate their expertise and dedication in helping us get rid of this destructive pest."

Roger said he is immensely grateful to the UC team.

“They were fantastic; I owe them my house,” he said. “They were super gracious and helpful and responsive and – ultimately, the thing I care most about – they were effective; they fixed the problem. Here we are two years later and – knock on wood, or maybe I should knock on something else! – everything is good.”

Lee also credited Taravati for bringing his knowledge and “can-do” attitude to communities across Southern California.

“He is highly knowledgeable and always able to come up with feasible solutions,” Lee said. “We need good Cooperative Extension urban IPM advisors like Siavash who could provide good advice and bring solutions to the stakeholders, be they homeowners or pest management professionals.” 

Taravati said community members need to maintain their vigilance and urges them to download and share the FST flyer that includes identification tips and contact information. He said they are always free to e-mail him with their concerns and photos of suspected FST – not only to help stop the spread of the pest but to expand scientific understanding.

“This termite is so new to California – even for us, as researchers. Despite being in La Mesa since the 1990s, it wasn't until 2020 when these termites were detected in other places, including Riverside and Los Angeles counties,” Taravati explained. “All of us need to learn more about this pest and closely monitor the behavior of this pest.”

Invasive pests kill thousands of trees, but scientists see some successes

 

Early detection increases the chances of eradicating pests

Trees provide shade to keep us cool, produce oxygen for us to breathe and calm our nerves. Numerous studies have demonstrated that even brief contact with trees and green spaces can provide significant human health benefits such as reductions in blood pressure and stress-related hormones. Trees also reduce noise and visual pollution, help manage storm water runoff, reduce erosion and provide habitat for birds and wildlife. Trees naturally capture carbon, helping to offset the forces of climate change. They also increase the value of our properties and communities. In short, trees are essential to our well-being.

Unfortunately, invasive pests pose an ongoing threat to California's forests in both urban and wildland settings. Invasive insects such as goldspotted oak borer and invasive shothole borers have killed hundreds of thousands of trees in Southern California and are continuing to spread. Meanwhile, other pests and diseases such as Mediterranean oak borer and sudden oak death are killing trees in Northern California.

While the situation may sound dire, it is not hopeless. Of course, the best way to stop invasive pests is to prevent them from entering the state, as the California Department of Food and Agriculture has done on many occasions. For example, several months ago, CDFA border inspectors seized a load of firewood containing spotted lanternfly eggs (a pest that is causing extensive damage on the East Coast). When pests do sneak in, the next defense is to catch them early before they become established. Finally, even if pests do become established, they can be managed if not completely eradicated.

A few examples may help to illustrate why invasive tree pests deserve action, but not panic.

Red striped palm weevil eradicated in Laguna Beach

When red striped palm weevil, a highly destructive palm pest native to Indonesia, was discovered in Laguna Beach in October 2010, a working group was quickly formed to develop a management plan. The small but diverse group included international palm weevil experts, research scientists from University of California Riverside, CDFA and U.S. Department of Agriculture, UC Cooperative Extension personnel from San Diego, Orange and Los Angeles counties and county entomologists from the agricultural commissioner's offices in Orange and San Diego counties.

The resulting response included a pheromone-based trapping program, public advisory and targeted insecticide treatments. Within two years, additional trapping and inspections could not find any signs of continued infestations. Early detection was key to the success: the infestation in Laguna Beach was identified early, so the weevil population was still relatively small. In addition, Laguna Beach is geographically isolated, the local climate is much cooler than the weevil's place of origin, and the eradication effort was well funded by state and federal agencies. Eliminating invasive pests where such conditions are not present may prove more difficult.

Invasive shothole borers attack Disneyland

The Disneyland Resort in Anaheim contains 16,000 trees and over 680 different tree species. When park officials identified an infestation by invasive shothole borers in 2016, their initial attempts at vanquishing the insects with pesticides produced mixed results. Then, they consulted with experts from UC Riverside and UC Cooperative Extension and together designed and followed an integrated pest management program that included monthly ground surveys, a trapping program that helped to detect infestation hot spots and find and remove the source of beetles, and occasional pesticide treatments on selected trees. The park went from a large number of beetles in 2017 to very low levels today. There are still some beetles, but resulting damage is extremely low, and although monitoring programs continue, the park's landscape team has been able to turn its focus elsewhere.

Goldspotted oak borer spotted in Weir Canyon

When goldspotted oak borer was confirmed in Orange County's Weir Canyon in 2014, a team from Irvine Ranch Conservancy, the organization that manages the area on behalf of Orange County Parks, sprang into action. UC Cooperative Extension and the US Forest Service assisted IRC in developing a management program, and over the ensuing years, IRC has actively collaborated with OC Parks, The Nature Conservancy, OC Fire Authority, and CAL FIRE to control the existing infestation and stop its spread. IRC has surveyed the oaks in the area yearly to monitor the infestation and guide each year's management actions.

To reduce the spread of the infestation, IRC removed more than 100 severely infested oaks in the first few years of management (no severely infested oaks have been found in the last few years of surveys). Additionally, more than 3,000 tree trunks have been sprayed annually in the late spring to kill emerging adult beetles and newly hatched offspring.

In the most recent survey of the oaks in Weir Canyon, the IRC team found only 12 trees with new exit holes, and most of those had just one to two exit holes per tree, which is an extremely low number. With the situation well under control, IRC is now considering modifying its annual spraying program and adapting other less aggressive treatment options. Finally, IRC has been actively planting acorns to mitigate losses due to the removals as well as the Canyon 2 Fire of 2016.

As these brief examples demonstrate, insect pest infestations can be managed or even eradicated if caught early enough. Early detection not only increases the chances of success, but also minimizes the cost of pest management efforts.

What you can do to prevent infestation

While management actions will vary depending on the insect or disease, species of tree and location, there are a few steps that will lead to greater success in fighting tree pests and diseases.

• Keep your trees healthy. Proper irrigation and maintenance go a long way toward keeping trees strong and resistant to pests and diseases.
• Check your trees early and often for signs and symptoms of tree pests and diseases. These may include entry/exit holes, staining, gumming, sugary build-ups, sawdust-like excretions, and branch or canopy dieback. Use available tools like the UC IPM website to determine probable causes of the problems.
• Talk with experts (arborists, pest control advisers, researchers and advisors from the University of California and other institutions), and report pest findings to your county Agricultural Commissioner.
• Evaluate the extent of tree damage and determine a management plan. Remove severely infested branches and trees that may be a source of insect pests that can attack other trees.
• Properly manage infested wood and green waste. Chip wood and other plant materials as small as possible. Solarization or composting can further increase the effectiveness of chipping. It is generally best to keep those materials close to where they originated, but if you absolutely need to move them, first make sure the facility where they will be sent is equipped to process them. Always tightly cover materials while in transit. If working with a tree care professional, insist that proper disposal is part of the job requirements.
• Many invasive tree pests can survive in down wood for long periods. When buying or collecting firewood, always obtain it as close as possible to where you are going to burn it and leave leftover firewood in place.

Pitahaya/dragon fruit growers gather to learn from UCCE research and each other

Once you know what a dragon fruit looks like, you will never forget it. The bright red, sometimes yellow or purple, scaly skin makes for a dramatic appearance. One that will surely leave an impression. The flesh ranges from white to a deep pink and the flavor is often described as having hints of kiwi, watermelon, or pear.

Since 2007, the Pitahaya/Dragon Fruit Production Tour, has united dragon fruit growers of all levels and backgrounds. After a two-year hiatus due to the pandemic, registration for the 2022 tour filled up in less than 24 hours.

A group of 60 participants gathered Sept. 8 at the Wallace Ranch Dragon Fruit Farm in Bonsall to learn the latest research on growing the drought-tolerant specialty crop. Ramiro Lobo, a small farms and agricultural economics advisor for UC Cooperative Extension in San Diego County, introduced dragon fruit growers and other UC scientists. 

“I can't remember a year where this event was not sold out. So, the need and demand is there,” said Eyal Givon, a long-time participant and dragon fruit grower.

The tour not only demonstrates how to grow the fruit, but it also grants participants access to plant material for varieties that are unavailable elsewhere.

“We have given out about 50,000 cuttings through our festival and some varieties were unique to us because we introduced them to the U.S.,” said Lobo. 

During their time at Wallace Ranch, participants heard from the farm's owner, Neva Day, regarding the growing practices that have shaped her success today. Day has been growing organic dragon fruit since 2013 and has well over 5,000 plants on the ground and more than 20 varieties.

Eric Middleton, UCCE integrated pest management area advisor for San Diego County, talked about managing insects and pests that growers are likely to encounter such as Argentine ants. 

According to Middleton, Pecan Sandies are a balanced source of fat, protein, and sugar, making them excellent bait for the sugar-loving insects. 

Participants eventually made their way to Dragon Delights Farm located in Ramona. Kevin Brixey, the farm's owner, has been growing organic dragon fruit for six years.

Although Brixey was hosting this year's tour participants, he used to be one of them.

“I attended the Pitahaya Festival in 2014 and that's where I realized dragon fruit was something I could grow. There was a lot of good information being shared and a connection to other growers, so it was a major steppingstone for me,” he says.

Unlike traditional dragon fruit growers, Brixey uses shade to grow his dragon fruit after learning about the method from another grower. 

“I was impressed. I liked how the fruit performed under shade and now I use it as a management tool,” Brixey explained. In Inland Valleys, shade can shield fruit from intense sunlight and protect them from unwanted guests that eat the fruit, such as birds. 

At the Farm Bureau of San Diego County offices, participants learned about the history of dragon fruit growing in California, food safety, pest management, best production practices and much more.

The presenters included experts like Paul Erickson from Rare Dragon Fruit, Lobo, Middleton, Johanna del Castillo from UC Davis Department of Plant Pathology and Ariana Reyes, a community education specialist from UCCE San Diego.

When reflecting on his time participating in the production tour, Givon, who has been growing dragon fruit for about 20 years and manages a 20-acre farm in Moorpark, said he enjoys reconnecting with other growers the most.

“What others are doing, might be better than what I'm doing,” Givon said. “Or what I'm doing, could be better than what someone else is doing. This time together is good for us to learn from each other.”

Lobo agreed with Givon and added, “I hope that these tours become self-sustained, and that we go back to a research field day at Southcoast REC with regional tours in San Diego and Ventura as we did before, or any other counties.”

The Pitahaya/Dragon Fruit Production Tour is an annual event hosted by UCCE San Diego. To learn more about UCCE San Diego events, visit https://cesandiego.ucanr.edu.

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