One of Art Shapiro's monitoring sites is Gates Canyon, Vacaville. Here he looks for butterflies in this image taken on Jan. 25, 2014. (Photo by Kathy Keatley Garvey)
One of Art Shapiro's monitoring sites is Gates Canyon, Vacaville. Here he looks for butterflies in this image taken on Jan. 25, 2014. (Photo by Kathy Keatley Garvey)
UC Davis distinguished professor Art Shapiro estimates he wears out three or four pairs of a shoes a year. (Photo by Kathy Keatley Garvey)
UC Davis distinguished professor Art Shapiro estimates he wears out three or four pairs of a shoes a year. (Photo by Kathy Keatley Garvey)
Larvae of the western grapeleaf skeletonizer feeding on a grape leaf. (Photo by Surendra Dara)
The western grapeleaf skeletonizer (WGLS), Harrisina metallica, is a pest of vineyards in some parts of California. Larval feeding skeletonizes grape leaves and uncontrolled populations can lead to a complete loss of foliage, fruit damage, and yield reduction. WGLS populations are usually suppressed with standard pest management practices used against it or other pests. However, considering regular WGLS infestations in the past few years especially in organic vineyards in warmer parts of the state warrant development of a good monitoring and integrated pest management strategy to improve the pest control efficacy and to minimize the risk of resistance development from potential overuse of limited organic pesticides. An earlier bioassay with biologicals showed azadirachtin, spinosad, Bacillus thuringiensis subsp. aizawai, and entomopathogenic fungi Beauveria bassiana and Metarhizium sp. as potential control options (Dara et al., 2019). The potential of Harrisina brillians granulovirus, a naturally occurring virus that previously suppressed WGLS populations a few decades ago is also explored as a natural solution (Federici and Stern, 1990).
WGLS has 2-3 generations per year with late spring-early summer and mid-late summer infestations in the coastal regions (Fig. 1). Based on the detection of shiny black moths and growing degree-day calculations, pesticide applications can be timed to target hatching larvae. Growing degree-day calculations were made using a model provided by Pest Prophet and temperature data from GreenCast. Good monitoring tools such as traps equipped with lures can be useful to improve the monitoring accuracy especially when the adult activity spreads over multiple weeks for each generation. A study was conducted to assist with the development of new lures for WGLS.
Fig. 1. Growing degree-days indicating WGLS sping and summer generations and thresholds for larvae and adults
Methodology
An organic Cabernet Sauvignon vineyard (San Juan North) in Shandon was used for the study conducted between May and July 2021. Treatments included a blank lure, Pherocon WGLS, TRE 2500, and TRE 2501. The last two are developmental formulations. The pheromone components of the lures are different combinations of 2S-butyl Z7-tetradecenoate, 2-butyl decanoate, 2-butyl dodecanoate, and isopropyl Z7-tetradecenoate to attract male moths and the latter two are new combinations of active ingredients. Each treatment was replicated six times in a randomized complete block design. Within each treatment, a lure was placed in Pherocon VI Delta trap with an adhesive, replaceable liner and tied in the top part of the canopy. A 30 m distance was maintained between the traps with and between replications. Traps were first set up with new lures and liners on 8 May 2021. Adhesive liners were observed every week between 15 May and 3 July 2021 on eight observation dates to count the number of moths. Lures were replaced on 5 June 2021 and adhesive liners were replaced every week or every other week as needed. Data were analyzed using Statistix software and Tukey's HSD test was used to separate significant means.
Pheromone infused lure surrounded by the western grapeleaf sekeltonizer male moths (Above photo by Surendra Dara and below photo by Carson DiCicco)
Results
Moth counts significantly (P < 0.0005) varied among the lures on all observation dates (Table 1 and Fig. 2). In general, TRE 2501 lure attracted significantly higher number of moths for most of the observation period. Due to a logistics issue, adhesive liners were not replaced after the moth counts were made on 12 June and those numbers were detected from the next count to derive 19 June moth counts. A lack of space on the liner was probably the reason for having lower moth numbers on 19 June 2021 in TRE 2501. Pherocon WGLS, which is commercially available in the market, was generally less attractive than the developmental formulations. Pheromone combination in the TRE 2501 can be considered for the new formulation for improved monitoring efficacy. Compared to visual monitoring of moth activity, using lures appeared to be an effective strategy for monitoring WGLS, which helped the grower to make effective treatment decisions. On average, 287 moths were captured per each TRE 2501 lure during the 8-week observation period. Considering that each moth can deposit 300 eggs in its lifetime, trapping adults during monitoring can also contribute to reduction in their offspring. In addition to serving as a monitoring tool, lures can also be a control option, if economical.
Acknowledgments: Thanks to Trece for providing lures and traps for the study.
References
Dara, S. K., S. S. Dara, and S. Jaronski. 2019. Biorational control options for the western grapeleaf skeletonizer, a re-emerging pest in California. eJournal of Entomology and Biologicals. https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=29081
Federici, B. A. and V. M. Stern. 1990. Replication and occlusion of a granulosis virus in larval and adult midgut epithelium of the western grapeleaf skeletonizer, Harrisina brillians. J. Invertebr. Pathol. 56: 401-414.
Coyote conflicts with Californians are on the rise, with reports of urban coyotes biting people and killing pets. In July, two people were bitten by a coyote in separate attacks on a trail in Mission Viejo. Recently one elusive coyote has been linked by DNA tests to biting attacks on two children and three adults in the East Bay Area. To better understand coyote behavior, University of California Cooperative Extension advisor Niamh Quinn has been collaring and tracking coyotes in the Los Angeles area.
In urban areas, hazing is often used to frighten coyotes and deter them from approaching people. Although waving arms and shouting at urban coyotes are commonly thought to drive the animals away, no research has been done to determine whether hazing truly changes coyote behavior. Human and wildlife interactions expert Quinn is studying the movement of urban coyotes to find out how effective hazing is.
With funding from the Los Angeles County Quality and Productivity Commission and the Los Angeles County Agricultural Commissioner/Weights & Measures Project, Quinn bought GPS tracking collars and pays for game cameras to find the coyotes.
“Without the support of the county we wouldn't have a project,” said Quinn, who is based at the UC South Coast Research and Extension Center in Irvine.
UC Agriculture and Natural Resources and LA County Agricultural Commissioner/Weights & Measures share the goal of learning how to more effectively manage coyotes. Because so little information is available, this project is expected to help both county and municipal managers who have found themselves involved more frequently in the management of wildlife over the last decade.
A documentary by Benjamin Fargen describes Quinn's research. In “Coyote Conflict in Los Angeles - The UCANR Hazing Study,” Fernando Barrera of Los Angeles County Agricultural Commissioner/Weights & Measures says about 60 pets were taken from people's homes in a three-month period near a park in the county. LA County Agricultural Commissioner/Weights & Measures sets out humane traps that are designed specifically to catch coyotes and for quick release of other species.
“They help set and unset traps, scout for new trapping sites and are there in the middle of the night to help me handle the coyote when we trap them,” Quinn said.
Although they know where coyotes are, catching them to put collars on isn't easy. In the documentary, Quinn describes watching via game camera monitor as coyotes approach traps, but not close enough to get caught.
“We wouldn't be able to do this research without a team,” Quinn said. “For scientific research, we need different ideas to come from people with different expertise. It can be a frustrating mix of trying to get all the team together, our veterinarian Curtis Eng of Western University of Health Sciences has to be available, the trappers have to be available and I have to be available.”
Quinn monitors her phone for alerts constantly. “I'm listening for the buzz of my phone to tell me there's something there.”
To date, Quinn's team has collared 19 coyotes. One coyote she has dubbed “Lazy Legs” has a range of about a half-mile, partly in natural habitat, but often in neighborhoods. In contrast, a female collared coyote has ranged 7 to 10 miles.
“You can see that she hangs out in the natural areas, but also dips in and out of the neighborhoods,” Quinn said. “She's probably choosing to go into the neighborhoods to find maybe some trash, maybe cats, or maybe even some rats because we know they eat rats. We know they eat a lot of cats and they eat a lot of bunnies.”
After a coyote killed her cat in 2011, Debora Martin launched Coyotes of Orange County to educate pet owners how to keep their pets safe from coyotes. She praises Quinn's Coyote Cacher website https://ucanr.edu/coyotecacher for the map showing where community members have reported coyotes have been sighted. “Based on that information, things can be done,” she said.
Torrance Police Department has also partnered with Quinn to learn about wildlife management and to educate the public about coyotes. Residents may unintentionally attract coyotes by leaving pets and pet food outside or fruit that falls from trees in their yards.
UC Agriculture and Natural Resources brings the power of UC to all 58 California counties. The coyote conflict project and other UC ANR programs rely on donor contributions. To learn more about how to support human and wildlife interactions research, visit https://donate.ucanr.edu/?fund_id=1145.
A robot that tells growers when to water crops is on the way
Every backyard gardener knows how hard it can be to tell when to water the plants. Multiply that by tens or hundreds of acres and it's easy to see the challenges growers face keeping their crops healthy while managing water resources wisely.
To determine water needs accurately, growers hand-pluck individual leaves from plants, put them in pressure chambers, and apply air pressure to see when water begins to leak from the leaf stems. That kind of testing is time consuming and means growers can only reach so many areas of a field each day and cannot test as frequently as needed to accurately determine optimal irrigation scheduling patterns.
A group of researchers from UC Riverside and UC Merced have received a grant for more than $1 million from the U.S. Department of Agriculture through the National Science Foundation's National Robotics Initiative to address these challenges. From UC Riverside are Assistant Professor Konstantinos Karydis and Professor Amit K. Roy-Chowdhury, both from the Department of Electrical and Computer Engineering. UC Merced, which leads the effort, is represented by Stefano Carpin, professor of computer science; and Joshua Viers, professor of environmental engineering.
As part of the project, the group is developing a robotic pressure chamber that can autonomously sample leaves and immediately test them on site to provide the freshest data. The system will work to gather data even in large fields, and over a period of time, rather than just providing a snapshot.
The base robot for the new plant-moisture-measuring system researchers are developing will navigate rows of crops to reach individual leaves and stems.
Frequently updated data can help growers better plan irrigation schedules to conserve water, optimize the time and effort spent by crop specialists tasked with determining and analyzing lead water potential, and help decrease some of the costs in the food-production chain.
Current measuring techniques involve collecting leaf samples and transporting them to an off-site location, where testers can use very accurate, expensive pressure chambers; or sampling and analyzing leaf samples in the field using hand-held pressure chambers.
“In the first category, leaf samples can get mixed up, making it impossible to track them back to the specific areas of the field they came from, Karydis said. “In addition, the properties of the leaf might vary given the time elapsed between being sampled and being analyzed, which in turn may yield misleading results.”
Hand-held instruments in the field can be less accurate, but testing can be done multiple times with different leaves from the same plants. This method is time- and labor-intensive, and must be undertaken by specially trained personnel.
Carpin has already worked with colleagues at UC Davis and UC Berkeley to create the Robot-Assisted Precision Irrigation Delivery, or RAPID, system, which travels along rows of crops adjusting irrigation flows according to sensor data that tells the robot precisely what's needed for each plant.
The project will use the same mobile base robot as in RAPID but equip it with a custom-made robotic leaf sampler and pressure chamber being designed by the researchers at UC Riverside, and pair it with drones that can survey the fields and direct the robot to areas of interest.
“Using this process, growers could survey plants all day long, even in large fields,” Carpin said.
The four-year project will support graduate students as well as summer research opportunities for undergraduates. The project has four phases: development of the chamber; developing machine vision so the robot can “see” the water coming from the leaf stems; coordinating multiple robots — in the air and on the ground; and evaluation.
The researchers plan to have the first set of automated pressure chamber prototypes fabricated by spring 2021, and to evaluate their performance and refine designs in controlled settings over spring and summer 2021. They expect to have a completed setup by winter 2022, so they can begin controlled field testing.
“We have to be quick about it because if we miss a peak growing season, we have to wait another nine months for the next one,” Carpin said. “We'd like to be able to start testing next summer and test every summer, and we need to be able to maximize the tests.”
When all of the components have been designed, the designs and code will be made open source, and all the data collected during the project will be made available to the scientific community, the researchers wrote in their proposal.
The project came about after Carpin and Viers, director of the Center for Information Technology Research in the Interest of Society, or CITRIS, at UC Merced, had been talking with area farmers about the challenges of growing almonds and grapes. Karydis and Roy-Chowdhury had been hearing the same challenges from citrus and avocado growers in the Riverside area, so the four partnered up.
“California agriculture presents a challenge in terms of scalability,” Carpin said. “But this an exciting collaboration because we'll get to develop a system that will work on different kinds of crops.”
Every backyard gardener knows how hard it can be to tell when to water the plants. Multiply that by tens or hundreds of acres and it's easy to see the challenges growers face keeping their crops healthy while managing water resources wisely.
To determine water needs accurately, growers hand-pluck individual leaves from plants, put them in pressure chambers, and apply air pressure to see when water begins to leak from the leaf stems. That kind of testing is time consuming and means growers can only reach so many areas of a field each day and cannot test as frequently as needed to accurately determine optimal irrigation scheduling patterns.
A group of researchers from UC Riverside and UC Merced have received a grant for more than $1 million from the U.S. Department of Agriculture through the National Science Foundation's National Robotics Initiative to address these challenges. From UC Riverside are Assistant Professor Konstantinos Karydis and Professor Amit K. Roy-Chowdhury, both from the Department of Electrical and Computer Engineering. UC Merced, which leads the effort, is represented by Stefano Carpin, professor of computer science; and Joshua Viers, professor of environmental engineering.
As part of the project, the group is developing a robotic pressure chamber that can autonomously sample leaves and immediately test them on site to provide the freshest data. The system will work to gather data even in large fields, and over a period of time, rather than just providing a snapshot.
The base robot for the new plant-moisture-measuring system researchers are developing will navigate rows of crops to reach individual leaves and stems.
Frequently updated data can help growers better plan irrigation schedules to conserve water, optimize the time and effort spent by crop specialists tasked with determining and analyzing lead water potential, and help decrease some of the costs in the food-production chain.
Current measuring techniques involve collecting leaf samples and transporting them to an off-site location, where testers can use very accurate, expensive pressure chambers; or sampling and analyzing leaf samples in the field using hand-held pressure chambers.
“In the first category, leaf samples can get mixed up, making it impossible to track them back to the specific areas of the field they came from, Karydis said. “In addition, the properties of the leaf might vary given the time elapsed between being sampled and being analyzed, which in turn may yield misleading results.”
Hand-held instruments in the field can be less accurate, but testing can be done multiple times with different leaves from the same plants. This method is time- and labor-intensive, and must be undertaken by specially trained personnel.
Carpin has already worked with colleagues at UC Davis and UC Berkeley to create the Robot-Assisted Precision Irrigation Delivery, or RAPID, system, which travels along rows of crops adjusting irrigation flows according to sensor data that tells the robot precisely what's needed for each plant.
The project will use the same mobile base robot as in RAPID but equip it with a custom-made robotic leaf sampler and pressure chamber being designed by the researchers at UC Riverside, and pair it with drones that can survey the fields and direct the robot to areas of interest.
“Using this process, growers could survey plants all day long, even in large fields,” Carpin said.
The four-year project will support graduate students as well as summer research opportunities for undergraduates. The project has four phases: development of the chamber; developing machine vision so the robot can “see” the water coming from the leaf stems; coordinating multiple robots — in the air and on the ground; and evaluation.
The researchers plan to have the first set of automated pressure chamber prototypes fabricated by spring 2021, and to evaluate their performance and refine designs in controlled settings over spring and summer 2021. They expect to have a completed setup by winter 2022, so they can begin controlled field testing.
“We have to be quick about it because if we miss a peak growing season, we have to wait another nine months for the next one,” Carpin said. “We'd like to be able to start testing next summer and test every summer, and we need to be able to maximize the tests.”
When all of the components have been designed, the designs and code will be made open source, and all the data collected during the project will be made available to the scientific community, the researchers wrote in their proposal.
The project came about after Carpin and Viers, director of the Center for Information Technology Research in the Interest of Society, or CITRIS, at UC Merced, had been talking with area farmers about the challenges of growing almonds and grapes. Karydis and Roy-Chowdhury had been hearing the same challenges from citrus and avocado growers in the Riverside area, so the four partnered up.
“California agriculture presents a challenge in terms of scalability,” Carpin said. “But this an exciting collaboration because we'll get to develop a system that will work on different kinds of crops.”