- Author: Christine Casey
I've written previously about the Haven's research on bees and gardens. This work included a look at bee preferences for common California landscape plants and work to help growers and landscapers provide the healthiest plants for bees.
Studies on bee plant preferences were described in this blog post, and the first year's results (2022) of our current project developing bee sampling methods for growers and landscapers was described in this post.
The current project is an evaluation of a common insect sampling method, timed counts, with a novel method called snapshot counts. As the name suggests, the snapshot methods uses several quick counts rather than one longer timed count to assess the number of bees choosing a plant. Our goal was to see if the faster snapshot method could provide bee counts with accuracy similar to the widely used timed count method.
The speed of the snapshot method could allow it to be included with other routine insect sampling done by growers and landscapers. This would provide a way to assess the relative attractiveness of a nursery or landscape plant mix to bees, allowing for both accurate plant recommendations and targeting of bee-compatible pest management.
Trials took place at locations in San Diego County, the center of California's nursery industry.
While the average number of bees observed per plant differs between the two methods, the pattern of preference is the same for both (Fig. 2). This is confirmed by regression analysis (Fig. 3), which found a strong correlation between the two methods
Our goal was not to determine the absolute number of bees expected on a plant, as that will vary with location, season, and weather. Rather, we wanted to understand which plants are more likely to be chosen within a plant mix. Growers can then compare new plant varieties to those with known attractiveness to determine how they'll fit into a bee garden.
- Author: Dong Hwan Choe
- Author: Chow-Yang Lee
- Author: Michael K Rust
Ants are one of the major seasonal pests around structures in California's urban environments. Pest management companies throughout the state report that ants are responsible for a significant proportion of their pest control services. In urban residential areas of California, the Argentine ant, Linepithema humile, is the most common nuisance ant species treated by pest management professionals (PMPs) as well as the public themselves (Figure 1).
While contact insecticides are frequently used to control Argentine ants, they also contribute to environmental contamination via drift and runoff. However, insecticide applications following California's recent regulatory changes and label updates may fail to control target pest ants consistently potentially resulting in repeated insecticide applications (Choe et al. 2021).
Baiting for ant control
Baiting (Figure 2) can reduce the need for insecticide spray applications. Active incorporation of baits in a management program may help to lower the risk of environmental contamination caused by insecticide drift and run-off. For Argentine ants, which often form large colonies with multiple nest sites and reproducing queens, the initial application of perimeter spray would still be needed to provide a quick knockdown of foraging ant populations during peak season (June or July). However, baits are particularly useful for subsequent maintenance visits (monthly or bimonthly). In fact, baiting has been demonstrated to be an effective tool for maintenance services for Argentine ants (see References).
Many bait products are available for professional use, and when strategically used, they can be effective at keeping ant numbers low (at acceptable levels) following the initial spray treatment. Gel / liquid / granular bait products containing boric acid, indoxacarb, and thiamethoxam are effective for Argentine ant control.
Importance of bait placement
If PMPs choose to incorporate baits as a main tool for maintenance visits, there is an important question to be answered: Where to place the bait? Unless bait stations are already installed in specific locations and periodically serviced (e.g., cleaning and refilling), PMPs must determine where the baits need to be applied during their visit.
Unlike insecticide sprays, the ants must consume the bait to be effective. Baits placed in just any location cannot be expected to work. Strategic placement of baits is critical to maximize the bait consumption by foraging ants and control of the pest ant populations. In fact, baits start losing their palatability (attractiveness as food) from the moment they are applied in the environment.
Since all ant foragers are liquid feeders, keeping the bait hydrated (minimal water loss) is vital to maximize bait consumption. Contamination and degradation might also impact bait palatability over time. Placing baits in the areas where the ants are currently traveling or foraging will ensure maximum bait consumption. Baits are typically more expensive than insecticide sprays (based on the product cost to treat a unit area), so strategic placement of baits is also crucial from an economic standpoint.
Label information on bait products usually includes specific tips regarding bait placement. For example, one commercial ant bait product label states, “place bait on, into, or adjacent to structures where ants are observed, adjacent to ant trails and to areas suspected of ant activity.” Another product's label instruction states, “locate areas around the building where ants are seen trailing. Apply [the bait] in areas inaccessible to children and pets. For a perimeter defense system, place bait stations near the foundation or where ant trails are found.” In essence, these instructions require knowledge of the locations where the ants are currently active or likely will be within a day or two.
Finding ant trails might be easy if customers have already observed or reported the ant infestation. However, finding active ant trails could be time-consuming, and time for careful inspection to discover active ant trails around the structure during a service visit is often limited.
Ant trail location study
Is there a quick and reliable way to identify the most likely places where Argentine ants would trail and forage in residential outdoor settings? Knowing this would make it possible to quickly determine the best sites for bait placement without looking for ant trails. Argentine ants are known to rely on chemical signals (trail pheromone) as well as structural features (structural guidelines) when maneuvering in the environment (Klotz et al. 1997). Many residential settings share some common structural features such as concrete, lawn, mulch, plant, and soil. If common features can be used to reliably locate the foraging ant trails, that could reduce the time needed to look for ant trails during bait applications.
Site types | Surface/characteristics |
---|---|
L | Lawn |
C | Concrete |
D | Dumpster/trashcan |
T | Tree |
V | Vegetation/bush |
LC | Lawn – concrete interface |
SC | Soil – concrete interface |
MC | Mulch – concrete interface |
BS | Building (vertical surface) – soil interface |
BC | Building (vertical surface) – concrete interface |
A simple field experiment was designed to identify the best sites for bait placement. The study was conducted in October on the University of California, Riverside campus. Several site types were identified based on structural characteristics. Five of these site types were characterized by the presence of a single surface type or a single characteristic item—lawn (L), concrete (C), dumpster or trashcan (D), tree (T), vegetation/bush (short plant without trunk, V). Five other site types were characterized by the presence of two surface types and the interface between them – lawn and concrete (LC), soil and concrete (SC), mulch and concrete (MC), building and soil (BS), and building and concrete (BC). The list of site types is provided in Table 1.
The experiment was replicated 5-13 times for each of the site types. Small squares of cotton (monitoring squares) soaked in 25% (wt:wt) sucrose solution were placed in these sites. The monitoring squares were collected after one hour, and Argentine ants on the cotton squares were counted. The number of ants on the monitoring square was used as the quantitative indicator for ant foraging activity.
The overall data suggest the interface between lawn and concrete (LC) was the location with the highest level of Argentine ant foraging activity (Figure 3). The interface between lawn and concrete (LC) had a much higher number of ants than its single-surface counterparts (L, lawn only or C, concrete only). Bases of the tree (T) and dumpster site (D) also had a good amount of ant activity, but there can be significant amounts of variation in ant activity, especially for dumpster sites (i.e., hit-or-miss). Open concrete surface (C) had the lowest level of foraging activity. Lawn (L), vegetation/bush (V), and four other interface types (SC, MC, BS, and BC) showed intermediate levels of ant activity.
Certain structural and landscape features can be used to quickly determine the best locations for inspection and bait (liquid or gel) placement against Argentine ants. Interfaces between lawns and concrete are among the most common structural features of residential outdoor settings. For example, they are found between lawns and various concrete surfaces, such as driveways, sidewalks, patios, and landscape curbing (Figure 4).
There are possible reasons why the Argentine ants prefer to trail along the interface between lawn and concrete. Preferred microclimate conditions (moisture, temperature) may exist in that location. The absence of heavy vegetation along the lawn and concrete interface (ease of travel), but still with some level of protection (partially shaded), may also be preferred by trailing ants. Environmental factors such as relatively high humidity and partial protection from direct sunlight would also be advantageous in keeping the liquid or gel bait palatable for extended periods.
Take-home message
It is vital to effectively manage pest ants in urban environments with minimal impacts on human health and the environment. To help reduce our reliance on repeated application of insecticide spray products, baiting should be considered for maintenance service visits for pest ants. To maximize the impact of baiting, the baits should be placed along lawn and concrete surfaces. Of course, a control program should not rely only on baiting but also be supplemented with non-chemical techniques such as exclusion, sanitation, removal of honeydew sources, and water management.
It is important to note that the information and data discussed in this article are focused on Argentine ants and sugar-based bait products targeting this species. Thus, the information may or may not directly apply to other ant species with different feeding habits, foraging strategies, or population structures.
For more information about ant management, see the UC IPM Ant page https://ipm.ucanr.edu/PMG/invertebrates/links.ants.html.
References cited
Choe D-H, Paysen, E, Greenberg L, Campbell K, Rust MK. 2019. A closer look: Argentine ant control. Pest Control Technology. GIE Media, Inc. p. 130-135. Vol. 47. No. 10.
Choe D-H, Tay J-W, Campbell K, Park H, Greenberg L, Rust MK. 2021. Development and demonstration of low-impact IPM strategy to control Argentine ants (Hymenoptera: Formicidae) in urban residential settings. J. Econ. Entomol. 114: 1752–1757.
Klotz JH, Greenberg L, Shorey HH, Williams DF. 1997. Alternative control strategies for ants around homes. J. Agric. Entomol. 14: 249-257.
[Originally featured in the Spring 2024 edition of the Green Bulletin Newsletter for structural and landscape pest professionals.]
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- Author: Saoimanu Sope
Agriculture generates $59 billion and employs nearly 400,000 individuals in California. The industry, however, is often threatened by challenges like climate change, land conversion and water scarcity. Motivated to act, Sustain Southern California – an organization associated with UC Irvine Beall Applied Innovation – hosted a roundtable discussion on Feb. 20 featuring subject matter experts including Darren Haver, director of UC Agriculture and Natural Resources' Research and Extension Center System.
During his keynote address, Jose Arriaga, Orange County Agricultural Commissioner, defined sustainability as food and fiber production that does not compromise the ability for future generations to meet their needs. In doing so, he acknowledged the benefit of discussing such timely topics with key players, especially for places where agriculture is not as prevalent as it used to be.
“Many people don't think of Orange County as a place for agriculture. It's probably because less land is being reserved for agriculture, not like back in the day. And that worries me,” said Arriaga.
The first roundtable discussion centered on sustainable agriculture, with Haver participating alongside other industry leaders based in Southern California, including A.G. Kawamura of Orange County Produce, Steve Brazeel of Sunterra Produce and Elevated Foods, Anthony Curci of Buttonwood Ranch and Parker Cohn from Performance Resource Management.
In discussing today's generation, Haver said that he has seen a shift over the last few decades away from yield alone, which used to be the most important aspect of production in agriculture. Today, much more attention is dedicated to sustainability – a change that Haver attributes to the younger generation of researchers and plant scientists working in agriculture.
There has also been an emphasis on sustaining the environment while maintaining economic progress. Haver recognized these important elements, but highlighted the social impact of sustainability, too.
“I don't have all the answers, but I do believe that addressing the environmental, economic and social aspects of agriculture is important. I also think that these factors should be addressed systemically rather than in silos,” said Haver.
Southern California agricultural producers, in particular, are responsible for $7.8 billion in gross receipts and nearly 100,000 jobs directly related to agriculture. In Orange County alone, where Haver is based at the South Coast Research and Extension Center, agriculture makes up $86 million of total economic output, with nurseries leading as a top commodity followed by fruit trees, vegetable production and livestock and apiary.
- Author: Saoimanu Sope
In celebration of Black History Month
When she was younger, Tamekia Wilkins believed that becoming a movie star was her calling. “Then reality sank in, and I knew that wasn't going to happen,” said Wilkins, an evaluation coordinator based at UC Agriculture and Natural Resources headquarters in Davis.
Her path forward focused on becoming a psychologist instead.
“I had this vision of helping people, but doing it while they were sitting on my couch, telling me about their troubles,” she said. Originally from Tuscaloosa, Alabama, Wilkins earned a bachelor's degree in psychology from the University of Alabama. Although she was set on psychology, Wilkins experienced a shift along the way – most of which was shaped by questions of identity and race.
Thinking back to the place and people that raised her, Wilkins said she had a good childhood. “I spent my days outside playing with friends. We'd play freeze tag, hide and seek… you know, normal stuff,” she said.
Wilkins grew up in Alabama during the 1980s and '90s. Her parents, however, endured the racial discrimination and segregation that catapulted the civil rights movement during the mid 1950s to late 1960s. Alabama has and always will be home for Wilkins and her family, especially her parents who live in the same house she grew up in, to this day.
For Wilkins and her three older siblings – two sisters and a brother – conversation about race and identity was a regular topic in their home. “My parents did not shy away from talking about our Blackness and race relations in this country,” said Wilkins. “It was a good thing, because it prepared us to have these conversations outside of the home, too.”
Despite only having high school diplomas due to circumstances, Wilkins' parents advocated for higher education. “They told us that if we went to college, life would be easier; they wanted us to do better than they were able to,” Wilkins said.
After completing her bachelor's degree, Wilkins packed up her stuff and left the only place she had ever known. She moved to Illinois to pursue a doctorate, getting her master's degree along the way.
As a master's student at the University of Illinois at Urbana-Champaign, Wilkins studied human and community development. She was primarily interested in understanding the influence parents have on elementary school children's behavior in the classroom, based on their level of involvement. Her interests led to opportunities to learn how to conduct quantitative research, design surveys and use software for statistical analysis.
With her new skills and research-focused mindset, Wilkins completed her dissertation on the influence of racial socialization on children's academic performance and behavior during the early school years. “I wanted to understand internalized behavior, and investigate the how and what parents say about race and its effects on their children in different areas of life,” Wilkins said.
The data collected revealed that Black parents living in predominantly white neighborhoods were more likely to engage in racial socialization compared to those living in neighborhoods where the racial makeup was more diverse or predominantly Black.
“What I learned is that when you live in a community with others who look like you, you don't have to be as intentional all the time,” said Wilkins. “The racial makeup of elementary schools tends to resemble the communities they are located in. So, Black parents are more likely to have conversations about identity when their children are going to predominantly White schools.”
Wilkins surprised herself throughout her educational journey. Earning a Ph.D. was not a solid part of her life plan, but she is grateful that it all happened the way it did, noting some influential mentors along the way. “I had a mentor during grad school, Christy Lleras, whose research, even today, is based on social justice issues and inequity within education. She was my cheerleader and was always on board with everything I wanted to do,” said Wilkins.
Robin Jarrett, another mentor, was the only Black professor in Wilkins' department during the time she was a student. “Even though she wasn't my advisor, she was certainly a mentor with so much wisdom. We keep in touch to this day and sometimes I'll call her up and let her know what's going on in my life,” she added.
Today, Wilkins applies her research skills to her current role as an evaluation coordinator analyzing data for three UC ANR statewide programs: 4-H, UC Master Gardeners, and the Expanded Food and Nutrition Education Program (EFNEP).
“I never thought I would find myself in California,” said Wilkins. “Coming from Alabama, California always seemed like this ‘other place' that was way too expensive to live in.”
Fast forward to 2016, shortly after graduating with her Ph.D., Wilkins moved to Sacramento to begin working for UC ANR and has been supporting the same programs for eight years now. Despite living in California and being a lot closer to Hollywood, Wilkins admits that her dream of becoming a movie star remains in the past.
These days, she is more eager to take advantage of California's natural beauty and landscapes. “In the eight years that I've lived here, I have not done enough things. I need to do more exploration,” she said.
When asked about her success and the trajectory of her journey thus far, Wilkins said that having a growth mindset is number one. “I've always believed that I could accomplish whatever I set my mind to because I have a growth mindset. After that? You've just got to do the best you can. Always do the best you can!”
/h3>- Author: Kathy Keatley Garvey
Congratulations to UC Davis distinguished professor Walter Leal, the recipient of the Academic Senate's highly competitive 2024 Distinguished Faculty Research Award.
That makes three. Good things come in threes.
Leal is the first UC Davis faculty member to win all three of the Academic Senate's most coveted awards: in research, teaching, and public service. In 2020, the Academic Senate awarded him the Distinguished Teaching Award for Undergraduate Teaching, and in 2022 Distinguished Scholarly Public Service Award.
Leal, a member of the Department of Molecular and Cellular Biology since 2013 and former professor and chair of the Department of Entomology, commented: "Faculty at land-grant universities, like the University of California, have three hats labeled Teaching, Service, and Research. A significant challenge is to budget time to wear them equally and avoid the temptation to emphasize one part of the job over others. It is gratifying to be recognized by my peers as excelling in all areas. The Academic Senate Faculty Distinguished Research Award is particularly humbling because more than 3000 eligible faculty excel in all research areas on this campus. Why me? Because of my students, postdoctoral scholars, visiting scholars, collaborators, and colleagues. They deserve most of the credit for this honor. I accept it on their behalf. It is a team effort, like in a honey bee colony.”
"Walter is truly a renaissance man," wrote Hammock. "He chaired our entomology department from 2006 to 2008, and under his tenure, our department was ranked No. 1 in the country. I've long admired (1) his rigorous fundamental research programs supported by National Science Foundation, National Institutes of Health, and the U.S. Department of Food and Agriculture, and other agencies, (2) how he tackles and solves multiple challenging problems in insect olfaction and chemical ecology, (3) his grasp of how to organize and moderate highly successful worldwide research webinars (4) his generosity in helping other succeed and (4) his finely honed sense of humor."
“Walter has been exceptionally conscientious, active, and generous in professional service at UC Davis,” Hammock pointed out. “In August of 2021, he achieved a ‘first' for international science communication when he organized and led the extraordinary virtual conference ‘Insect Olfaction and Taste in 24 Hours Around the Globe.' I especially applaud him for elucidating the mode of action of the insect repellent DEET, developed in 1946 and known as ‘the gold standard of
repellents.' Its mode of action remained an enigma for six decades until Walter's discovery. Inresearching the neurons in mosquito antennae sensitive to DEET, he isolated the first DEET-sensitive odorant receptor, paving the way for the development of better repellents.”
Leal is a newly elected trustee of the Royal Entomological Society, the 13-member council that governs the 190-year-old international organization. He is the first UC Davis scientist to be elected a trustee. And he's chair of the Council of the International Congresses of Entomology, the body that ensures the continuity of the international congresses of entomology. He co-chaired the 2016 International Congress of Entomology, which drew 6,682 registrants from 102 countries to Orlando, Fla.
Among Leal's many honors: Fellow of the Entomological Society of America (2009), American Association for the Advancement of Science (2005), and the National Academy of Inventors (2019).
A native of Brazil, Leal joined the UC Davis entomology faculty in 2000, after serving as the head of the Laboratory of Chemical Prospecting, National Institute of Sericultural and Entomological Science (NISES), Ministry of Agriculture, Forestry, and Fisheries, Japan. In 2013, he accepted a position as professor of biochemistry, Department of Molecular and Cellular Biology. (See news story)
Frankly, we don't know how Leal does it all. He not only excels at research, teaching and public service, but he is widely known as "The UC Davis Ambassador," organizing campus-wide celebrations for faculty transitioning to emeriti.
As an aside, two UC Davis entomology faculty members scored two, but not three, of the Academic Senate's coveted awards. Bruce Hammock received the Distinguished Faculty Research Award in 2001, and the Distinguished Teaching Award (graduate student/professional category) in 2008. UC distinguished professor of entomology, James R. Carey, took home the Academic Senate's Distinguished Teaching Award (undergraduate student category) in 2014 and the Distinguished Scholarly Public Service Award in 2015.
Six other entomology faculty members have received Academic Senate awards:
- UC Davis distinguished professor Jay Rosenheim, Distinguished Teaching Award (undergraduate student category) in 2011
- UC Davis distinguished professor Lynn Kimsey (now emerita), Distinguished Scholarly Public Service Award in 2016
- UC Davis distinguished professor Frank Zalom, Distinguished Scholarly Public Service in 2017
- UC Davis professor and now department chair Joanna Chiu, Distinguished Teaching Award (graduate/professional category) in 2022
- UC Davis distinguished professor Diane Ullman, Distinguished Teaching Award (undergraduate category) in 2022
And the latest to join the winner's circle: Professor Louie Yang won the Distinguished Teaching Award (undergraduate category), announced today. More on this amazing teacher and mentor is pending.