Daniel Perry places western drywood termites into the groove of blocks, then seals sides. Some blocks were then treated with wintergreen oil. Photos by Evett Kilmartin

Termites can eat you out of house and home by chewing through wood and weakening the structure. The results of a new termite study led by entomologists at UC Riverside may enable homeowners to rid their homes of termites with a safer, effective pest control approach.  

“Combining a volatile essential oil with heat might reduce callbacks for pest management professionals and potentially lead to lower risk of heat damage to things in the homes,” said Dong-Hwan Choe, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside.

The conventional method of exterminating termites requires residents to vacate the house while pest control professionals tent the structure then pump in toxic chemicals to kill the termites. While insecticides are effective at killing termites, urban pest managers are under pressure from regulators and residents to find alternatives that won't harm people, pets or the environment. 

Perry and Michael Linford, CEO of GreenTech Heat Solutions, discuss strategy for heating the structure to kill termites.

To rid structures of termites without using chemicals, pest control professionals heat the air inside structures to lethal temperatures. However, termites can survive in hard-to-heat areas such as in wood positioned against concrete foundation walls. In a recent study, Choe found adding essential oils to heat treatments can kill termites insulated from the heat.

“You need some kind of insecticide to kill the termites in those locations that are hard to heat,” said Daniel Perry, who conducted the study as a UC Riverside graduate student with Choe.

“By using an essential oil, which is toxic to termites, we can kill them without really any risk to humans or other animals that live in the house.”

Kathleen Campbell, a research staff associate in the Choe laboratory at UC Riverside, selects pseudergates, the pale, wingless, worker stage of the western drywood termites that damages wood structures.

The western drywood termite, Incisitermes minor (Hagen), is a common structural pest in the United States native to California, from the border with Mexico to Central California and inland to the Sierra Nevada Mountains.

“We tested several insecticidal essential oils on individual western drywood termites and found that methyl salicylate, or wintergreen oil, killed them the fastest,” said Choe.

Wintergreen oil kills termites, but it doesn't hurt people or their pets. Although pest control professionals commonly use orange oil for localized drywood termite treatments, wintergreen oil has about twice the flash point so it's safer to use with the heat treatment, Perry said.

Blocks containing termites, some treated with wintergreen oil, were placed in uninsulated wall voids prior to heating the house.

To test the synergy of the volatile essential oil and heat, the research team placed wood blocks infested with 20 drywood termites each in Villa Termiti, a small wooden structure built for pest management research at the UC Berkeley Richmond Field Station. They applied 160microliters (about 16 drops) of wintergreen oil to some infested wood blocks (the treatment) and no wintergreen oil to other infested blocks (the untreated control), then used propane heaters to heat the house to between 134 degrees and 146 degrees Fahrenheit for 140 minutes. After seven days, they found that 92% to 100% of the drywood termites were dead when treated. In contrast, in blocks without the wintergreen oil, only 36% to 44% of the termites died in the same time period when treated within areas near the concrete foundation wall. Incorporation of the essential oil substantially increased the control efficacy for this area near the foundation, resulting in more than 90% mortality.

Pseudergate termites were place in wood blocks, which were sealed before being placed in the walls of the house.

Lethal temperatures and essential oils will kill termites at all life stages, but the scientists used immature termites at the pseudergate (worker) stage. The wingless, pale pseudergates do most of the work for the colony, excavating tunnels and chewing up food for the other termites to eat.

“If you can kill all of the pseudergates, then the rest of the colony will likely collapse,” said Perry, who went to work for Procter & Gamble after finishing this project and his master's degree at UC Riverside.

“The most common treatment is fumigation and that requires three or four days during which the structure has to be vacated,” said Perry. "With the heat treatments, all you have to do is heat up the structure until the wood inside gets to the temperature that will kill the termites, hold the lethal temperature for a few hours, and then let the house cool off. You only have to be out of the house for maybe six hours, so it's a lot more convenient.”

Andrew Sutherland, UC Cooperative Extension integrated pest management advisor for the Bay Area, offers training for pest management professionals. He is encouraged by the results.

Sutherland said, “It means that folks will be able to heat effectively at lower target temperatures and lower durations, so it's less cost for everybody, and probably less time for everybody. It's a way to really synergize the heat treatment and no fumigant gas is released to the atmosphere.”

“Volatile Essential Oils Can Be Used to Improve the Efficacy of Heat Treatments Targeting the Western Drywood Termite: Evidence from Simulated Whole House Heat Treatment Trials” was published in the October 2020 edition of Journal of Economic Entomology.

Vernard Lewis, emeritus UC Cooperative Extension entomology specialist at UC Berkeley, and Andrew Sutherland, UCCE integrated pest management advisor, assisted in the experiment at Villa Termiti.

Sarah Keiser of Wild Oat Hollow in Sonoma County moves sheep for the Penngrove Grazing Project to graze her neighbors’ pastures.

Improved soil health, increased profitability, and reduced spread of wildfire are among the many benefits that arise from keeping livestock on the landscape. Efforts are underway in California and South Dakota to connect landowners with livestock managers for their mutual benefit.

Farmers can increase the organic matter in their soil and reduce their fertilizer costs by allowing livestock to graze crop residue or cover crops on their land.

Nick Jorgensen, CEO of Jorgensen Land and Cattle in Ideal, SD, said that grazing every acre allows his operation to increase soil organic matter by up to 0.75% per year and cut fertilizer costs by $50 per acre with no yield loss.

Livestock managers can rest their pastures and reduce their feed costs by seeking out crop residue, cover crops and additional pasture or rangeland for their livestock to graze.

Jorgensen said that grazing cattle on all crop and cover crop acres cuts his feed and manure management costs by up to $2 per head per day.

Grazing livestock is also a cost-effective way to reduce the accumulation of fire fuels on the landscape, helping to slow the spread of wildfires. This can be especially important for land that is too steep, rocky or remote for mowing or chemical treatment.

“I've noticed on several fires, including extreme fires, the fence lines where the fire just stopped. And the one variable, the one difference, was grazing,” CAL FIRE Battalion Chief Marshall Turbeville said.

As this year has proven, fire is a serious risk to California landowners. That's one reason University of California Cooperative Extension has launched Match.Graze. It's a map-based website designed to help livestock owners find pasture, rangeland, cover crops or crop residue available for grazing and help landowners find cattle, sheep, goats and other livestock to graze their land.

“Every property is different and requires thoughtful consideration of how it should best be grazed,” said Stephanie Larson, director of UCCE in Sonoma County, UCCE livestock and range management advisor and co-creator of the livestock-land matchmaking service.  “UC Cooperative Extension is here to serve. Put Match.Graze to work, and let's prevent catastrophic fire while helping landowners and agriculture.”

California landowners and livestock managers can visit MatchGraze.com, set up a free account, create a pin on the map and find a grazing partner.

The California website is based on the South Dakota Grazing Exchange, the original site launched by the South Dakota Soil Health Coalition with work supported by Natural Resources Conservation Service, U.S. Department of Agriculture.

Cattle graze cover crops near Roscoe, South Dakota.

Many farms in South Dakota have moved away from livestock to focus on row crops. However, increased diversity and incorporating livestock are two key principles for good soil health management.

At www.sdgrazingexchange.com farmers can find livestock to graze their crop residue or cover crops in order to capture the soil health benefits for their cropland without having to own livestock. Similarly, ranchers can give their pastures and rangeland a rest and reduce their feed costs by finding farmers with cropland to graze.

The Match.Graze and SD Grazing Exchange websites are not limited to California and South Dakota. Users from anywhere in the nation can create accounts on either website and advertise their land and livestock. The more people who use the websites, the better resources they will become.

When landowners partner with ranchers to keep livestock on the landscape, everyone wins, so the SDSHC will work to help other states create Grazing Exchange websites and connect to the maps and users of Match.Graze and SD Grazing Exchange. For more information, contact Cindy Zenk, SDSHC coordinator, at (605) 280-4190 or sdsoilhealth@gmail.com.

What do 4-Hers do during a pandemic? California 4-H youth members decided to learn about disease outbreaks and transmission, public health investigations, personal practices to stay healthy, and much more. 

During June and July 2020, the 4-H youth joined the Healthy Living Team to become “Disease Detectives,” participating in the virtual UC 4-H Statewide Epidemiology Project.

With the emergence of the coronavirus, 4-H in-person meetings had to be canceled, along with schools, sports and other youth development programs. Emerging research shows this gap of in-person socializing, disruption to routines, fear of the virus, and the loss of a sense of personal autonomy has led to an increase in social, emotional and mental health issues for teens. Over half of teens in a National 4-H Council/ Harris Poll stated that the pandemic has increased their feelings of loneliness, and 7 in 10 teens report struggling with their mental health. 

Additionally, the team witnessed that Californians were navigating confusing information about the best way to reduce the spread of the disease, with much misinformation being circulated. So the University of California 4-H Healthy Living Team decided to address these issues the best way they knew how, through education. 

Dorina Espinoza and Anne Iaccopucci trained the “Disease Detectives.”

Anne Iaccopucci, California 4-H Healthy Living coordinator; Dorina Espinoza, UC Cooperative Extension youth, families and communities advisor in Humboldt and Del Norte counties; and Marcel Horowitz,UCCE healthy youth, families and communities advisor inYolo County, adapted the CDC/4-H Junior Disease Detective: Operation Outbreak project for remote instruction.

The project focused on concepts of epidemiology and included eight sessions covering public health professions, disease investigation, virus transmission, disease outbreaks, vaccines, immunity, prevention (such as how protective actions like handwashing and wearing masks reduce spread) and education. Project sessions were adapted to be as interactive as possible using virtual delivery. 

Eighty-nine youth indicated an interest in participating, with more than 45 4-H members from 15 counties across the state enrolling and completing the Virtual UC 4-H Epidemiology Project. Project meeting materials were coordinated online at https://ucanr.edu/sites/DiseaseDetectives. 

True to the 4-H experiential learning framework, and to address the research showing that teens are currently experiencing high levels of loneliness, the Project Leaders intentionally created a learning environment that included interactive, fun, challenging and social activities to foster a sense of connection. At the beginning of each project session, youth worked on team-building activities. For example, youth participated in a mapping activity where they “pinned” their desired vacation destination and attempted to guess each other's location with a selected prop as a hint. This activity culminated with a discussion on how we serve as potential vectors of disease transmission. Also, youth learned about the benefits of wearing face masks with an activity where youth were challenged to blow a rolled up tissue from one to six feet away without a mask and then while wearing a mask. Their giggles did not mask the direct learning of how well a mask can contain one's breath.

Youth were challenged to blow a rolled-up tissue from 1 to 6 feet away without a mask and again while wearing a mask.

When youth were asked “What part of this project was fun and engaging?” several responded, “When we did the activities in breakout rooms,” and “The activities at the beginning of the meetings.” This indicates that this dedicated time for talking with peers was a motivator and benefit of continued participation.

To foster healthy youth, families and communities, this project contributed to the UC ANR Condition Change of improved health for all. Specifically, youth adopted healthy lifestyles and decision-making practices and changed attitudes toward, and gained knowledge about, healthy practices.

After completing the UC 4-H Epidemiology Project, youth reported that they were more likely to wash their hands before food preparation (78.1%), after sneezing or coughing (56.2%), and after shopping in a public space (87.5%). The majority (84.4%) of youth also reported that they were more likely to wear a face mask when out in public, compared to before the project. When youth were asked what they learned from the project, one youth stated, “I learned why masks work, I learned how hand sanitizer works, and I learned how I can help my community.” 

Youth reported not only improved health behaviors for themselves, but also reported being leaders in the health of their communities. Many of the young participants (62.5%) reported that they can definitely help control the spread of diseases and 71.9% could envision themselves getting involved in their local community to help slow the spread of disease. Following project participation, over half of all participants picture themselves choosing a career in medicine, public health, veterinary sciences or epidemiology.

This poster is one of the health education materials developed by the 4-H youth as part of the UC 4-H Epidemiology Project.

Participants of the UC 4-H Epidemiology Project have become advocates for health, with 75% reporting that they are discussing disease transmission and prevention with others. When asked what the best part of the project was, a participant stated, “The best part of the project was learning about how to protect myself and keep my family safe in these troubled times." Other youth stated that their favorite parts were “the interactive activities” and “making new friends.” Others responded to the question “What part of this project was fun and engaging?” with, “I enjoyed interacting with others and getting to collaborate on the final project,” and “discussing ideas with the group.” These indicate that learning reached beyond knowledge, skills, attitudes and behaviors and into youth development domains as well.

Interested in leading this project for youth 12 years and older in your community? Sixty leaders from throughout America have already been trained and 93% reported they would recommend it. 

Contact Anne Iaccopucci at amiaccopucci@ucanr.edu for information on how to get started. 

Participants drew super heroes during the ice breaker socializing and grounding activity.

In breakout rooms, participants discussed careers in public health.

Hispanic Heritage Month begins on September 15 and continues until October 15. The purpose of the celebration is to recognize the contributions and vital presence of Hispanics and Latin Americans in the United States.

President Lyndon Johnson first approved Hispanic Heritage Week in 1968 and expanded to a full month by President Ronald Reagan in 1988. Finally, Hispanic Heritage Month was officially enacted as a law on August 17, 1988.

UC ANR joins in the celebration of Hispanic Heritage Month 2020. (Photo: Pixabay)

Why is Hispanic Heritage Month held from mid-September to mid-October? It was chosen in this way to reserve two significant dates for Spanish-speaking countries. On the one hand, Independence Day is celebrated in countries such as Mexico, Chile, and five Central American nations (Guatemala, Honduras, Nicaragua, El Salvador, and Costa Rica).

Also, Columbus Day or Día de la Raza was commemorated, a date celebrated more by Italian-Americans than Spanish-speaking immigrants.

Hispanics and Latinos in the United States are getting stronger every day; it is undeniable. But they are more recognized for their culinary richness and the attractiveness of their rhythms, such as Mariachi, salsa, cumbia, mambo, and merengue, than for their essential contributions the professional level. Although, at the national level, there are all kinds of professionals who, with their work, have contributed to the cultural, social, and economic wealth of this country. 

Hispanics who have helped improve our lives range from an astronaut to a winner of the Nobel Prize in Physics.

Luis Walter Alvarez, born in Mexico and naturalized American, was an experimental physicist, inventor, and professor who was awarded the Nobel Prize in Physics in 1968.

Franklin Ramón Chang Díaz is a Costa Rican mechanical engineer, naturalized American, physicist, and former NASA astronaut.

Ellen O. Ochoa is an engineer born in Los Angeles, CA, to Mexican parents, who became the first Hispanic woman to travel to space and was a former director of the Johnson Space Center.

Did you know that, according to the Census Bureau, there are 60 million Hispanics in the country? And that more than half live in three states: California, Texas and Florida? Two-thirds of Hispanics in the United States have their origins in Mexico, followed by Puerto Rico (9.5%) San Salvador (3.8%), and Cuba (3.6%). The rest come from the twelve countries where Spanish is the official language.

According to the Census Bureau, college enrollment has increased over the past decade, and 49% of Hispanic high school graduates enrolled in a university. The U.S. Department of Education recognizes six University of California campuses as institutions serving Hispanic students, including UC Irvine, while UC Merced is one of the universities in the country with the highest percentage of Hispanic students.

UC Agriculture and Natural Resources joins the celebration

This year UC ANR the celebration by recognizing three Latino professionals who serve their communities while always upholding UC ANR's public values of academic excellence, honesty, integrity, and community service.

Claudia Diaz - 4-H youth development advisor for Riverside and San Bernardino counties. Claudia has received numerous awards and recognitions for her work with underprivileged youths in urban areas. She has been with UC ANR for five years.

Sonia Ríos - Subtropical horticulture advisor for Riverside and San Diego counties. Since an early age, Sonia knew her future was in agriculture, her grandfather and her father worked in agriculture and taught her the love for nature and the fields. She has been with UC ANR for almost nine years.

Javier Miramontes - Nutrition program supervisor for Fresno County. Javier enjoys the opportunity his work gives him to serve the community where he grew up. He finds it very rewarding to teach parents, senior citizens, and Highschool students about the importance of a healthy diet and how to create a sustainable environment. He has been with UCANR for over five years.