- (Strategic Initiative) Endemic and Invasive Pests and Diseases
- Author: Beatriz Nobua-Behrmann
UC ANR program trains volunteers to accurately identify and report infested trees, protecting forests and encouraging civic engagement through participatory science.
Invasive pests are one of the main threats to our urban and natural forests. Tiny beetles, like the invasive shothole borers (ISHB), attack trees and cause their decline and death. Even though ISHB can have devastating effects to urban and natural forests throughout Southern California, many trees can still be saved with proper management, allowing infested areas to recover over time. Detecting infestations early is key for successful management of this pest and to prevent spread to new areas.
Participatory science can be a useful tool to identify ISHB-infested trees and help monitor high-risk areas throughout the state. However, accurately identifying the presence of ISHB is challenging because the beetles spend most of their lives within the tree, hence we must rely on signs and symptoms to determine if the tree is infested (to learn more, visit www.ISHB.org)
How UC Delivers
Given these challenges, we wanted to know if participatory science can still be a good tool to monitor for ISHB. We created a training program to teach volunteers how to identify ISHB-infested trees and evaluated how different training modalities can make volunteer's observations more accurate.
UCCE Urban Forestry Advisor, Beatriz Nobua-Behrmann, teamed up with the California Naturalist program to develop a reporting tool in iNaturalist and a six-hour training that included an online course, two workshops, and after-training office hours for follow-up questions. They ran two trainings: one fully online in October 2020, and one that included an in-person component in October 2021. A total of 34 participants were trained, including volunteers from the California Naturalist and the Master Gardeners programs, and other community members.
Each participant reported up to five ISHB-infested trees. Each report included descriptive data of the individual tree, level of infestation, geolocation, and pictures of the signs and symptoms observed. To evaluate the accuracy, first UC experts assessed each report and determined if the tree was probably infested or not based on the submitted pictures. Then, UC experts located and re-assessed the same trees in the field. The data collected by the volunteers was compared side-to-side with the data collected by the experts to evaluate the accuracy of volunteer-collected data.
Participants of this program learned how to identify and report ISHB-infested trees and the importance of early detection to successfully manage invasive pests. Despite the challenges of correctly identifying infested trees, participants applied what they learned by submitting more than 122 reports of suspected infestations. After experts re-assessed the reported trees, we learned that volunteers collected overall high-quality data, but training modality seemed to make a substantial difference in the accuracy of the IDs. Volunteers who received in-person training were significantly more accurate (96% correct ISHB IDs) than the ones who received online training only (85% correct IDs).
Many program participants are now participating in the Master Gardeners Emerging Tree Pests Program and are sharing this information with the public, helping to create awareness in their community, demonstrating how UC ANR's civic engagement helps to protect California's natural resources.
All the incorrect IDs confirmed in the field were also previously flagged as possibly incorrect during the first evaluation of the reports from the pictures. This means that future quality control can safely rely on experts evaluating the pictures in the reports without having to re-evaluate the tree in person. Thanks to this study, we now know that community-based data can reliably contribute to the local and state-wide efforts to monitor the presence of ISHB, especially if in-person components are included in the trainings. Future steps of this program include delivering more trainings and using the data collected by the volunteers to inform the current ISHB distribution map available to the public. Having accurate information on the current distribution of ISHB throughout the state is an important decision-making tool for the agencies working on managing this pest, who need to determine where the infestation focuses are and how far away they are from other high-risk areas./h3>/h3>/h3>/h3>
After attending West Coast Rodent Academy, 75% of participants implemented improved rodent management skills, decreasing negative environmental impacts and demonstrating UC ANR's commitment to protecting California's natural resources.
How UC Delivers
UCCE Advisor Niamh Quinn co-created the Rodent Academy curriculum, informed by research that has determined ways to decrease rodenticide exposure to nontarget wildlife. The goal of commensal rodent management is to reduce the population of rodents quickly so that no further damage or exposure to allergens and pathogens occurs. To achieve this goal, rodent management needs to be quick and efficient and involve a combination of trapping and rodenticides.
The curriculum is being delivered via the three-day West Coast Rodent Academy (WCRA). To date, 307 individuals from 115 pest management companies, as well as city, county, and state agencies have participated. It is projected that the WCRA will continue to grow and reach pest management professionals across California. WCRA has also had attendees from ten other states despite the program being developed for California's pest management professionals. For example, Oregon State University's School of Integrated Pest Management Program attends WCRA trainings to learn more about starting an academy in the Pacific Northwest. Furthermore, funds generated from the West Coast Rodent Academy are applied to research being conducted in three Master of Science projects related to pest management.
To evaluate the impact of WCRA, a follow-up survey was sent to approximately 180 professionals trained through the West Coast Rodent Academy in 2019.
- Author: Siavash Taravati
Red imported fire ant (RIFA) control routine guidelines adopted by Los Angeles County school , protecting 500 school students from stings and contributing to improved community health and wellness.
Red imported fire ant (RIFA, Solenopsis invicta, Fig. 1) is a venomous ant that was accidentally brought into California in 1989. Since its introduction, it has spread to many new territories in Southern California and Central Valley. RIFA infests lawns on parks, cemeteries, schools, houses, farms, etc. RIFA bites and stings people and its venom may cause anaphylactic shock in susceptible individuals. RIFA is currently found in many areas in Orange, Riverside, and San Bernardino counties. It is also becoming increasingly more problematic in the Merced County. In the Los Angeles County, it occurs near the borderline of Orange and San Bernardino counties. In 2017, the California School for the Deaf in Riverside experienced a severe RIFA infestation and school's ground crew had little success in trying to control RIFA on their 70-acres of land.
How UC Delivers
Dr. Siavash Taravati, an IPM advisor at UC Cooperative Extension office in the Los Angeles County was contacted by the California Department of Pesticide Regulation about this infestation. Taravati visited the school, spoke to the grounds crew on the field, inspected infested areas for RIFA mounds, collected some ant samples for identification, and took some pictures for the study. Later, Taravati created a new pest management program to help the school management reduce the level of RIFA infestations. This study was part of a RIFA management research program and was sponsored by the California department of pesticide regulation. Four different active ingredients were used for suppressing RIFA populations. Granular insecticides were distributed using a handheld spreader or manually by hand. Construction flags and marking spray paint were used to mark areas with RIFA activity. The school was visited by Taravati 2-3 times a month for insecticide applications and monitoring the infestation levels. The project duration was one year. RIFA activity was measured prior to and after treatment. RIFA population declined drastically shortly after the onset of UCCE's RIFA management efforts. After a few months, the number of RIFA mounds in many areas was decreased by 50 percent, and ultimately up to 95 percent in some of the athletic fields that used to be one of the most heavily infested spots. Similar results were obtained in other areas with 90 percent or more reduction in the number of mounds. Even when new mounds appeared periodically on the lawn, they were often small in size. Furthermore, unlike mature and large colony mounds, only a small number of ants emerged from these new mounds when they were poked with a rod.
The RIFA control routine guidelines were adopted by the school staff upon finding the best practices from this research. They changed their primary pesticide management method from liquid insecticide applications to using granular baits as much as possible and talked to their supervisors and asked them for more support for their RIFA management efforts. As described above, this research shows that implementing this method decreases RIFA population, thus, protecting 500 school students from stings. Research shows these stings that can cause pain and discomfort and in some cases, life-threatening anaphylactic shock requiring immediate care. In this way, this applied pest management research and extension effort contributed to improved community health and wellness.
School ground crew: I really want to thank you for your great help. It was nice to have help with the fire ants. There aren't many places to get free help for fire ant control. Your work helped us to protect our school kids from being bitten during your reach for sure. We really liked your method of granular bait application and adopted it for better and more efficient fire ant control. Thanks
- Author: Kris E. Tollerup
Because of UC ANR's IPM research on spider mites and almonds, 80,000 acres were not treated with miticide, saving $2.2 million and reducing CO2 greenhouse gas emissions by 880,000 pounds.
The almond industry in California produces approximately 80% of the world's almond supply and currently consists of approximately 1.2 million bearing and non-bearing acres. In an effort to reduce the risk of economic loss from spider mite damage, producers have adopted the strategy of applying a preventative miticide during the month of May – a period when mite populations typically are well below the economic threshold. During the 2017 growing season, approximately 517,000 acres received at least one miticide application during May with a single miticide, abamectin, accounting for 93% of applications. On almond, the strategy runs contrary to sustainable, integrated pest management (IPM) practices. The preventative sprays adversely affect spider mite natural enemies and forgo making a pesticide application based on monitoring and an economic threshold. Finally, the heavy reliance on abamectin has caused some populations in the mid-San Joaquin Valley to become 16-fold more resistant to the miticide than susceptible populations.
How UC Delivers
UC Cooperative Extension Advisor, Kris Tollerup partnered with the Almond Board of California (ABC) and a large-scale almond producer to conduct applied research evaluating the effectiveness of applying a preventative miticide spray. The large-scale field trials provided almond producers with scientific results showing that the strategy does not provide any benefit. To extend the results to his clientele, Tollerup organized field meetings, consulted with growers andpest control advisers, and gave educational presentations stressing sustainable IPM of spider mites on almond. One client attests, "Tollerup has correctly identified the problem and has spoken out both in public and private about not treating unless economic thresholds have been met. Because of Tollerup's role we have been able to collaborate with farmers to hold off on spring treatments at many ranches and only treat when warranted, which has essentially removed a spray treatment on a vast number of our acres."
In formal and informal surveys conducted between Dec 2017 and Nov 2019 pest control advisers reported that approximately 80,000 acres did not receive a preventative miticide application in May of 2018 and 2019 growing season. This represents a reduction in treated acres of approximately 5.5%, a savings of about $2.2 million in miticide and application costs. Moreover, we calculated that eliminating the spray reduced the use of diesel-engine application equipment on approximately 56,000 acres - a reduction in CO2 greenhouse gas emissions of nearly 880,000 pounds. Via this research partnership, UC ANR has begun moving the industry away from preventative miticide applications and toward better IPM practices against spider mites. In the coming growing seasons, we anticipate producers will rapidly adopt better IPM of spider mites. For each 1,000 acres on which preventative sprays are not applied, $27,500 are saved and 15,700 fewer pounds CO2 are emitted. In this way, UC ANR increases agricultural efficiency, profitability, and ecological sustainability, contributing to the public values of promoting economic prosperity in California and protecting California's natural resources./h3>/h3>/h3>/h3>
As a result of UC ANR's Almond Pest Management Alliance Project, use of mating disruption as an ecologically sustainable pest management practice tripled over two years by growers and pest control advisers who influence over 400,000 acres of almonds in the San Joaquin Valley.
Navel orangeworm is the single most important pest of more than 1.3 million acres of almonds in California. It feeds exclusively on almond kernels, rendering them unmarketable. Larvae are also associated with Aspergillus sp. fungi which can produce aflatoxin contamination of kernels at harvest. Control of navel orangeworm is essential to prevent yield losses, off-graded kernels, and kernel contamination.
How UC Delivers
For the past three years, UC ANR Integrated Pest Management (IPM) Advisors David Haviland, Jhalendra Rijal, and Emily Symmes demonstrated an innovative new approach to worm management called mating disruption to more than 16,000 farmers at more than 120 conferences in 36 cities and 20 counties. This technique is done by releasing large quantities of a chemical pheromone used by female moths to attract males. This disorients males and substantially impairs their ability to locate a mate, leading to reduced offspring. Eight demonstration orchards were established across the San Joaquin and Sacramento Valleys as part of an Almond Pest Management Alliance grant in conjunction with the California Department of Pesticide Regulation, almond farmers, pest control advisers, and the Almond Board of California.
More than 93% of participants in the Almond Pest Management Alliance Project stated that information that they received was considered when making pest management decisions, with 81.4% reporting that they changed their practices because of what they learned. In the southern San Joaquin Valley, pest control advisers reported increases in the percentage of their acreage using mating disruption from 16.3% in 2017 to 39.0% in 2019 and, in the northern San Joaquin Valley, from 6.5% in 2017 to 37.7% in 2019. These growers and advisers influence over 400,000 acres of almonds.
Mating disruption is agriculturally efficient and profitable because, at harvest, there was a 47.4% reduction in navel orangeworm damage on average across all participating orchards over two years. This increased crop value by more than $250 per acre, which is more than twice the cost of employing this novel management technique.
In addition, the pheremone-based approach is more sustainable because it reduces reliance on pesticides, reducing groundwater contamination and avoiding resistance problems for pests and diseases, respectively. Recent pesticide use reporting data for Kern County underscored these changes in practice, showing a 26% countywide increase in the adoption of mating disruption from 2017-2018 on the more than 200,000 acres bearing almonds in the county.
In this way, UC ANR increases agricultural efficiency, profitability, and ecological sustainability, contributing to the public values of promoting economic prosperity in California and protecting California's natural resources.