- Author: Kathy Keatley Garvey
Vannette, an assistant professor, seeks to unlock the mysteries of flower microbes: how do plants protect against them, and can bees benefit from them?
“I am interested in understanding and predicting how microbial communities influence interactions between plants and insects,” she says. Her lab uses "tools and concepts from microbial ecology, chemical ecology, and community ecology to better understand the ecology and evolution of interactions among plants, microbes and insects."
Vannette recently received a five-year Faculty Early Career Development (CAREER) Program award, titled “Nectar Chemistry and Ecological and Evolutionary Tradeoffs in Plant Adaptation to Microbes and Pollinators. NSF grants CAREER awards to early career faculty “who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization,” a NSF spokesman said.
The other grant is a three-year grant, “The Brood Cell Microbiome of Solitary Bees: Origin, Diversity, Function, and Vulnerability.” Vannette serves as a co-principal investigator with professor Bryan Danforth, Cornell University; research entomologist Shawn Steffan of the USDA's Agricultural and Research Service, University of Wisconsin; and assistant professor Quinn McFrederick, UC Riverside.
Of the CAREER grant, Vannette explained in her abstract:
“Plants interact with a variety of organisms. The flowers and the nectar plants produce are adapted to attract beneficial organisms like bees or hummingbirds. However, microbes like bacteria and fungi also inhabit flowers and can reduce plant reproduction. Plant traits can reduce microbial growth in nectar, but this may also reduce pollinator visitation. This project will investigate if plants that are pollinated by different organisms (e.g. birds vs bees vs flies) differ in their ability to reduce microbial growth and if nectar chemistry is associated with microbial growth. This project will examine if nectar traits can be used to breed plants to be more resistant to harmful microbes without reducing attraction to pollinators. Resistance to microbes is beneficial in agricultural contexts where floral pathogens can limit food production but crops still rely on pollination.
“This research will link variation in plant phenotype to microbial abundance and species composition, and microbial effects on plant-animal interactions,” she noted. “This project will use a tractable system: the microorganisms growing in floral nectar, which can influence floral visitors and plant reproduction. The underlying hypothesis tested is that plant traits can facilitate or reduce microbial growth, and the community context (e.g., presence of pollinators) influence ecological and evolutionary outcomes.”
Vannette will perform the research activities using 1) a community of co-flowering plant species and 2) genotypes within California fuchsia (Epilobium canum). “Experiments will characterize variation in microbial growth, nectar chemistry, and microbial effects on plant reproduction and floral visitor behavior and the interactions of these factors,” she related in her abstract. “ Experiments and analysis will reveal how variation in nectar chemistry is associated with microbial growth and species composition in nectar, and subsequent effects on plant-pollinator interactions including plant reproduction. Experiments across Epilobium genotypes will elucidate how microbes affect microevolution of floral traits in a community context.”
The project “will engage students from a large undergraduate class to participate in practitioner-motivated research projects,” she wrote. “Students from the Animal Biology major, including in the class ABI 50A will participate in outreach on pollinator-friendly plantings for horticultural and landscaping. The project will support students recruited from diverse and underrepresented backgrounds to participate in independent projects related to project objectives, including hosting students through the Evolution and Ecology Graduate Admissions Pathway (EEGAP), a UC-HCBU program." The program connects faculty and undergraduate scholars at both UC (University of California) and HBCU (Historically Black Colleges and Universities) campuses
Collaborative Grant
The collaborative grant will enable the researchers to do cutting-edge research as they investigate the diverse community of bacteria and yeasts in the pollen and nectar diet of bees.
“Bees are the single most important pollinators of flowering plants worldwide,” the co-investigators wrote in their abstract. “Over 85% of the 325,000 flowering plant species on earth depend on animals for pollination, and the vast majority of pollination is carried out by bees. Annually, bees are estimated to contribute $15 billion to US crop production and $170 billion to global crop production. High-value bee-pollinated crops include apple and other early spring tree fruits, strawberries, blueberries, cherries, cranberries, squash and pumpkins, tomatoes, almonds, and many others. The economic viability of US agricultural production is dependent on stable and healthy wild and domesticated bee populations.”
“However, bee populations are threatened by a variety of factors, including habitat loss, pathogen spillover, invasive plants and animals, and pesticide use, which can disrupt the normal microbial symbionts essential for bee larval development (the ‘brood cell' microbiome),” they pointed out in their abstract. “This research project focuses on understanding what role microbes play in the larval nutrition in a wide variety of bee species. Previous research has documented a diverse community of bacteria and yeasts in the pollen and nectar diet of bees. As larvae consume these pollen/nectar provisions they are ingesting microbes, and our preliminary results indicate that these microbes form an essential component of the larval diet. This project has the potential to significantly modify how we view the 120 million-year-old partnership between bees and flowering plants, and will provide essential information for developing long-term bee conservation efforts. Project outreach efforts include educational activities on solitary bees for K-12 students and interactive demonstrations of bee-microbe-flower interactions for broad audiences.
The co-principal investigators said that the project will use cutting-edge methods to (1) document the microbial diversity in flowers and pollen provisions, (2) determine the nutritional role of microbes in larval development and health, and (3) understand how alterations in microbial community impact larval development.
To document microbial diversity in both host-plant flowers and pollen provisions, the research team will use amplicon sequencing and microbial metagenomics. These methods will document the microbial species present in pollen provisions as well as the metabolic activities these microbes perform during pollen maturation. Screening the pollen and nectar of host-plant species will provide key insights into the source of the brood cell microbiome. To determine the nutritional role of the microbial community the research team will use two methods from trophic ecology: compound specific isotope analysis and neutral lipid fatty acid analysis. These analyses will permit the research team to track the origin (floral or microbial) of amino acids and fatty acids in the larval diet of 15 focal bee species.
Finally, through manipulative laboratory experiments, the research team will determine how modifications of the microbial communities impact larval development. They hope by combining the results of these studies, the researchers will provide a comprehensive understanding of how bees and flowering plants interact via their shared microbial partners.
The collaborative project is funded jointly by the Systematics and Biodiversity Sciences Cluster (Division of Environmental Biology) and the Symbiosis, Defense and Self-recognition Program (Division of Integrative Organismal Systems).
Vannette, a Hellman Fellow, joined the UC Davis Department of Entomology and Nematology in 2015 after serving as a postdoctoral fellow at Stanford University's biology department. As a Gordon and Betty Moore Foundation Postdoctoral Fellow from 2011 to 2015, she examined the role of nectar chemistry in community assembly of yeasts and plant-pollinator interactions.
A native of Hudsonville, Mich., Vannette received her doctorate in ecology and evolutionary biology from the University of Michigan, in 2011. Her dissertation was entitled “Whose Phenotype Is It Anyway? The Complex Role of Species Interactions and Resource Availability in Determining the Expression of Plant Defense Phenotype and Community Consequences.”
- Author: Kathy Keatley Garvey
If you're thinking of apiculture, you might be thinking of drones (male bees).
But if you're thinking of agriculture--more specifically sustainable agriculture practices in the 21st century--you ought to be thinking of the importance of unmanned aerial robots.
These drones promise to have a huge impact on 21st century sustainable agriculture.
Indeed, a newly published review paper, “Drones: Innovative Technology for Use in Precision Pest Management,” appearing in the Journal of Economic Entomology, should be required reading. The work of a four-member international team of scientists, including UC Davis entomologist Elvira de Lange, it's one of the first of its kind to summarize scientific literature on the use of agricultural drones for pest management.
De Lange, who assembled the team of authors, says that sustainable agricultural practices in the 21st century should increasingly depend on drones and other innovative technologies.
In advocating the need for more research, the authors say that drones are becoming an important part of precision pest management, from detecting pests to controlling them.
In their review, they emphasize "how sustainable pest management in 21st-century agriculture will depend heavily on novel technologies, and how this trend will lead to a growing need for multi-disciplinary research collaborations between agronomists, ecologists, software programmers, and engineers."
“We propose extensive communication and collaboration between scientists from various disciplines, extension agents, industry professionals, and commercial growers to reach drones' optimal potential to help with pest management and control,” said De Lange, the corresponding author and a postdoctoral fellow in the Christian Nansen lab, UC Davis Department of Entomology and Nematology.
The paper covers the use of drones with remote sensing equipment, to detect pest problems from the air. It calls for the increased use of actuation drones, to provide solutions such as spraying pesticides and releasing biocontrol organisms. “Most literature concerns remote sensing,” said de Lange.
Filho just completed his master's degree on drones and remote sensing in Brazil and is currently a doctoral student. Co-authors, in addition to De Lange, are engineer and drone communication expert Zhaodan Kong, assistant professor, UC Davis Department of Mechanical and Aerospace Engineering; and remote sensing expert Wieke Heldens of the German Aerospace Center, Earth Observation Center, Germany.
“Early outbreak detection and treatment application are inherent to effective pest management, allowing management decisions to be implemented before pests are well-established and crop losses accrue,” the authors wrote in their abstract. “Pest monitoring is time-consuming and may be hampered by lack of reliable or cost-effective sampling techniques. Thus, we argue that an important research challenge associated with enhanced sustainability of pest management in modern agriculture is developing and promoting improved crop monitoring procedures.”
Drones can target pest outbreaks or hot spots in field crops and orchards, such as Colorado potato beetle in potato fields or sugarcane aphid in sorghum, the scientists pointed out. “Pests are unpredictable and not uniformly distributed. Precision agricultural technologies, like the use of drones, can offer important opportunities for integrated pest management (IPM).”
De Lange, noting that drones are increasingly used in agriculture for various purposes, commented: “They are often equipped with remote sensing technology, for yield predictions, evaluation of crop phenology, or characterization of soil properties.”
“There are myriad possibilities for use of drones in pest management,” she said. “Sensing drones, equipped with remote sensing technology, could help detect pest hotspots. Pests are often small and hard to find, so indirect detection, through changes in how plants reflect light, has the potential to find the pest earlier, treat earlier, and keep damage in check.”
“Furthermore, actuation drones, equipped with precision spray rigs or dispensers of biocontrol organisms, could apply localized solutions. Pesticide sprays exactly where needed would reduce the needs to spray an entire field. More efficient distribution of biocontrol organisms would make them a more competitive alternative to pesticides.”
“Remote sensing equipment,” De Lange added, “can also be placed on manned aircraft and satellites. However, drones fly lower, increasing images' spatial resolution, and making clouds less of an issue. They are generally cheaper and can be flown more frequently. Compared to ground-based devices, drones can cover much more ground in a shorter period of time.”
The authors said that drones could also be used to distribute sterile insects and mating disruption, and contribute to pest outbreak prevention, rather than provide only solutions to existing problems.
De Lange, who holds a doctorate in chemical ecology from the University of Neuchâtel, Switzerland, joined the Nansen lab in 2016. Her research interests include plant-insect interactions, integrated pest management, chemical ecology and precision agriculture. She does much of her research on California strawberries.
- Author: Kathy Keatley Garvey
It was a great day to get acquainted with insects and arachnids and learn how to raise them.
And the nearly 300 visitors did just that at the recent UC Davis Bohart Museum of Entomology open house, "Arthropod Husbandry: Raising Insects for Research and Fun." The guests held the critters, photographed them, and asked questions of the scientists.
At first they didn't see the praying mantids reared by entomologist and UC Davis alumnus Lohit Garikipati. They were there, all right, but camouflaged amid the leaves and branches.
The five species of mantids Garikipati displayed included a tropical shield praying mantis, Choeradodis stalii, also known as a hooded mantis or leaf mantis, and a spiny flower praying mantis, Pseudocreobotra wahlbergii.
UC Davis entomology student Andrew Goffinet, a former UC Davis Bio Boot Camper, discussed rearing butterflies and moths. He showed the visitors a display of Gulf Fritillaries, caterpillars and a chrysalis.
Entomology alumnus Nicole Tam, showed her beetle-mimicking roaches and talked about rearing insects in the Geoffrey Attardo lab. Doctoral student and Bohart associate Ziad Khouri explained how to rear tarantulas and millipedes. Entomology student Ben Maples kept the crowd interested with the "hissers"--Madagascar hissing cockroaches.
Jeff Smith, who curates the Lepidoptera section, and naturalist Greg Kareofelas, opened the drawers of butterflies and moths. Entomology student Ian Clark staffed the family crafts activity, assisting youngsters in making decorated finger puppets from Seker-donated silkworm cocoons.
Entomologist Ann Kao, a 2019 UC Davis graduate and newly employed by the California Department of Food and Agriculture, crafted and displayed her insect jewelry.
Tabatha Yang, educational and outreach coordinator, coordinated the open house. The Bohart crew also included Bohart associates Emma Cluff, James Heydon, Brennen Dyer and Xiaofan Yang.
Special guests included 40 students from the Samuel Jackson Middle School and the James Rutter Middle School, Elk Grove Unified School District, in a program offering special educational opportunities and mentoring. The youths wore t-shirts lettered with "The Power of Us" on the front, and "Resilient, Authentic, Passionate" on the back.
The Bohart Museum, directed by Lynn Kimsey, UC Davis professor of entomology, houses a global collection of nearly eight million specimens. It is also the home of the seventh largest insect collection in North America, and the California Insect Survey, a storehouse of the insect biodiversity. Noted entomologist Richard M. Bohart (1913-2007) founded the museum.
In addition to the specimens, the Bohart Museum maintains a live "petting zoo," featuring Madagascar hissing cockroaches, walking sticks or stick insects and tarantulas. The museum's gift shop, open year around, is stocked with T-shirts, sweatshirts, books, jewelry, posters, insect-collecting equipment and insect-themed candy.
More information on the Bohart Museum is available on the website at http://bohart.ucdavis.edu or by contacting (530) 752-0493 or bmuseum@ucdavis.edu.
- Author: Kathy Keatley Garvey
Silkworm moth expert İsmail Şeker, a Turkish medical doctor and author of a book showcasing his hobby, displayed the eggs, larvae, pupae, adults, as well as silk fabric, and fielded questions from the audience.
Seker showed his newly produced 13-minute video detailing the history of the silkworm moth and its life cycle. The crowd marveled at his macro photography and exquisite videography. Assisting him at the presentation were his grandson, Emre, 7, and granddaughter, Ruya, 4. Their father, Erkin Seker, is an associate professor in the UC Davis Department of Electrical and Computer Engineering.
The silkmoth, Bombyx mori, domesticated in China more than 5,000 years ago, belongs to the family Bombycidae, The life cycle: egg, larva, pupa and adult. Their food: mulberry leaves.
The caterpillars are celebrated for spinning silk; each cocoon is comprised of a single strand of raw silk from 1000 to 3000 feet long. It takes about 2000 to 3000 cocoons to make a pound of silk. Worldwide, silkworms produce some 70 million pounds of raw silk, requiring nearly 10 billion cocoons.
The adults cannot fly, and neither eat nor drink. They mate, lay eggs, and the cycle continues.
Seker donated cocoons for the Bohart Museum's family craft activity and watched visitors gleefully turn the cocoons into decorated finger puppets.
Among the visitors: 40 students from the Samuel Jackson Middle School and the James Rutter Middle School, Elk Grove Unified School District, in a program offering special educational opportunities and mentoring. The youths wore t-shirts lettered with "The Power of Us" on the front, and "Resilient, Authentic, Passionate" on the back. Academic mentor Keishawn Turner said the group toured the campus, had lunch, and ended the day by attending a UC Davis football game.
(More photos of the open house pending in the next Bug Squad)
The Bohart Museum is located in Room 1124 of the Academic Surge Building on Crocker Lane. It houses a global collection of nearly eight million specimens. It is also the home of the seventh largest insect collection in North America, and the California Insect Survey, a storehouse of the insect biodiversity. The Bohart Museum maintains a live "petting zoo," featuring Madagascar hissing cockroaches, walking sticks or stick insects, tarantulas, and praying mantids. The museum's gift shop, open year around, includes T-shirts, sweatshirts, books, jewelry, posters, insect-collecting equipment and insect-themed candy.
Director of the museum is Lynn Kimsey, professor of entomology at UC Davis. The staff includes Steve Heydon, senior museum scientist; Tabatha Yang, education and outreach coordinator; and Jeff Smith, who curates the Lepidoptera (butterflies and moths) section.
More information on the Bohart Museum is available on the website at http://bohart.ucdavis.edu or by contacting (530) 752-0493 or bmuseum@ucdavis.edu.
- Author: Kathy Keatley Garvey
The beetle? The walnut twig beetle, Pityophthorus juglandis.
In association with the fungus, Geosmithia morbida,it causes the insect-pathogen complex known as "thousand cankers disease," which wreaks havoc on walnut trees.
Audley will share his research at his exit seminar, "Semiochemical Interruption of Host Selection Behavior of the Invasive Walnut Twig Beetle, Pityophthorus juglandis," set for 4:10 p.m., Wednesday, Dec. 4 in 122 Briggs Hall, UC Davis campus. It's open to all interested persons.
Jackson, who joined the UC Davis doctoral program in September 2015, investigates behavioral chemicals that repel the walnut twig beetle from landing on English walnut trees. He conducts his research in a commercial orchard near Winters.
Audley says in his abstract: "The walnut twig beetle (WTB) is an invasive bark beetle pest of walnut trees in California and throughout much of its recently expanded range across the North American continent. Feeding by the beetle and canker development by the associated fungal pathogen, Geosmithia morbida, constitute the progressive and often fatal, thousand cankers disease. Management efforts to protect walnut trees are currently lacking. Here I present work related to understanding and manipulating WTB chemical ecology. First, we investigate the beetle's host-searching behavior in the context of a dense, native riparian forest habitat. The goal was to establish WTB's inflight sensitivity to host and non-host cues. Next, I present the results of flight-intercept behavioral assays of four potentially repellent volatile compounds: limonene, chalcogran, concophthorin and verbenone, first individually and then in compounds in reducing trap captures in the context of WTB aggregation phermone.
"Finally, we tested the most effective combination on whole walnut trees in a commercial, English walnut orchard. We compared beetle landing rates on treated and untreated trees as a correlate for WTB attacks. I report that we effectively reduced the number of WTB landing on treated trees; however, the repellent effect was spatially limited. Thus, further testing is required prior to recommending a management schedule. This work did provide proof of concept of semiochemical interruption in a hardwood attacking bark beetle system."
Audley, on a path to receive his doctorate in entomology this month, studied with Steve Seybold, who tragically died Nov. 15 of heart disease. Seybold was a lecturer and faculty affiliate with the UC Davis Department of Entomology and Nematology and a forest entomologist and chemical ecologist with the Pacific Southwest Research Station, USDA Forest Service, Davis.
Louie Yang, associate professor, UC Davis Department of Entomology and Nematology and Professor Richard “Rick” Bostock of the UC Davis Department of Plant Pathology serve as mentors. The Bostock lab is heavily involved with the chemistry side of Audley's repellent research.
A native of Washington, D.C., Jackson spent most of his childhood in Atlanta, Ga. He was first introduced to forest entomology while studying at the University of Georgia, Athens, where he received his bachelor of science in wildlife biology and natural resource recreation and tourism in 2009. He went on to receive his master's degree in forestry in 2015 from the University of Tennessee, Knoxville, where he focused his thesis on managing the walnut twig beetle in cut black walnut logs, live edged boards, and nursery stock.
He recently received the 2019 Western Forest Insect Work Conference Memorial Scholarship Award for his research on the chemical ecology of the walnut twig beetle.
His career plans? “I plan to devote my career to conducting chemical ecology-based research of bark and wood boring beetles that threaten trees in forest landscapes in the western U.S.,” Audley said. “In this capacity, I plan to continue adding to the scientific understanding of bark beetle ecology and management.”
Audley aims to engage with the scientific community and public alike in the arena of forest health issues and sound forest management practices. “Our western forests are in dire need of sound forest management to return them to a healthier state, and I plan to conduct and disseminate research to help achieve that goal.”
Community ecologist Rachel Vannette, assistant professor, is coordinating the weekly seminars. (See list of seminars)
