Community ecologist Rachel Vannette, assistant professor and coordinator of the Department of Entomology and Nematology's winter quarter seminars, has announced the schedule.

All seminars will take place on Wednesdays from 4:10 to 5 p.m. in 122 Briggs Hall.

Wednesday, Jan. 8
Karen Menuz, University of Connecticut, Storrs
Topic: "Molecular Basis of Insect Olfaction"
Host: Walter Leal, distinguished professor, Department of Molecular and Cellular Biology and a former chair of the entomology department

Wednesday, Jan. 15
Corrie Moreau, Cornell University, Ithaca, N.Y.
Topic: "Piecing Together the Puzzle to Understand the Evolution of the Ants"
Host: Marshall McMunn, graduate student

Wednesday, Jan. 22
Sebastian Eves-van den Akker, University of Cambridge, UK
Topic: Nematology (to be announced)
Host: Shahid Siddique, assistant professor

Wednesday, Jan. 29
Elizabeth Crone, Tufts University, Medford, Mass.
Topic: "Why Are Monarch Butterflies Declining in the West?"
Hosts: Neal Williams, professor; Rachel Vannette, assistant professor

Wednesday, Feb. 5
Andrew Young, postdoctoral scholar at California Department of Food and Agriculture, Pest Diagnostic
Topic: Syrphids
Host: Lynn Kimsey, professor and director of the Bohart Museum of Entomology

Wednesday, Feb. 12
Kevin Rice, University of Missouri, Columbia
Topic: "Lasers, Drones, and Growth Promoting Fungus: New Technologies for IPM"
Host: Ian Grettenberger, assistant professor

Wednesday, Feb. 19
Mercedes Burns, University of Maryland, Baltimore County
Topic: (pending) She studies evolutionary ecology of reproductive traits and behaviors, sexual conflict, reproductive polymorphism, arthropod biology
Host: Jason Bond, professor and Schlinger Chair in Insect Systematics

Wednesday, Feb. 26:
Faculty Flash Talks (featuring series of faculty members, including Rachel Vannette, Ian Grettenberger, Shahid Siddique, Geoffrey Attardo, Jason Bond)

Wednesday, March 4
Brendon Boudinot, doctoral candidate, Phil Ward lab, exit seminar
Topic: "Morphology and Evolution of the Insects, and the Ancestors of the Ants"
Host: Phil Ward, professor

For more information, contact Vannette at rlvannette@ucdavis.edu.

Who won the Department of Entomology and Nematology's cookie contest?

A nematologist, an aquatic entomologist and a community ecologist.

The event, which took place at the department's recent holiday luncheon in the International House, drew nine contestants. They competed in one of three categories: best chocolate cookie, best non-chocolate cookie and best decorated cookie, announced coordinator William "Bill" Tuck, academic personnel specialist in the Phoenix Cluster, serving the Department of Entomology and Nematology and the Department of Plant Pathology.

And the winners...drum roll...are:

• Best chocolate cookie: Aquatic entomologist Sharon Lawler, professor, UC Davis Department of Entomology and Nematology, for her recipe, "Dirty Drunk Snowballs"
• Best non-chocolate cookie: Nematologist Steve Nadler, professor and chair, UC Davis Department of Entomology and Nematology, for his Internet-modified recipe, "Cranberry Orange Cookies"
• Best decorated cookie: Community ecologist Rachel Vannette, assistant professor, UC Davis Department of Entomology and Nematology, for her "Stamped Citrus Shortbread" recipe from the New York Times

Each of the winners, determined by popular vote, received a $25 Amazon gift card.

Dirty Drunk Snowballs
By Sharon Lawler

Ingredients:

1 box Trader Joe's Mini Dark Chocolate Mint Stars
1/4 cup dark rum (white rum or bourbon will also work)
1/4 cup confectioner's sugar

Method:

Grind up the cookies in a food processor or blender until pretty fine but with some texture left. Stir enough dark rum so that the crumbs hold together well, but stop before it gets soggy. Let the mix sit for 15 minutes or so. Sift the confectioner's sugar into a bowl. Roll the mix into small balls, and then roll them in the confectioner's sugar.

Cranberry Orange Cookies
By Steve Nadler
Internet-modified recipe

Ingredients:

1 cup unsalted butter, softened
1 cup granular white sugar
1/2 cup brown sugar (packed)
1 egg
1-1/2 teaspoons grated orange zest
5 tablespoons orange juice
2-1/2 cups all-purpose flour
1/2 teaspoon baking soda
1/2 teaspoon salt
2 cups orange-flavored dried cranberries (Trader Joe's)
1-1/2 cups confectioner's sugar

 Method:

1. Use a food processor to chop the dried cranberries
2. Preheat oven to 375 degrees F.
3. In a large bowl, blend together the butter, white granular sugar, and brown sugar until smooth.
4. Whisk the egg in a small bowl, then mix into the large bowl.
5. Add 1 teaspoon of orange zest and 2 tablespoons of orange juice into the large bowl and mix.
6. In a separate bowl, mix together the flour, baking soda, and salt.
7. Stir the flour mixture from step 6 into the large bowl.
8. Mix in the chopped cranberries, working to distribute them evenly.
9. Drop cookie dough mixture (rounded tablespoon) on ungreased cookie sheets. Space them 2 inches apart.
10. Bake for about 12 minutes in the preheated oven (375 F). The edges will begin to turn golden brown when ready.
11. Remove cookies from sheets and cool on wire racks.
12. In bowl, mix 1/2 teaspoon orange zest, 3 tablespoons of orange juice, and the confectioner's sugar until smooth. Brush on the tops of the cooled cookies. Let dry.

Stamped Citrus Shortbread
By Rachel Vannette
Recipe from New York Times

For the Cookies

• 2 cups/255 grams all-purpose flour, plus more as needed
• ⅓ cup/45 grams cornstarch
• ½ teaspoon kosher salt
• 1 cup/225 grams unsalted butter (2 sticks), softened
• ½ cup/100 grams granulated sugar
• 1 orange (preferably tangelo)
• 1 lemon
• ½ teaspoon vanilla extract
• ½ teaspoon lemon extract
• ¾ cup/75 grams sifted confectioners' sugar
• 1 tablespoon melted butter
• 1 tablespoon fresh orange juice, plus more as needed

For the Glaze:

• 3/4 cup/75 grams sifted confectioners' sugar
• 1 tablespoon melted butter
• 1 tablespoon fresh orange juice, plus more as needed

Preparation

1. Prepare the cookies: Add flour, cornstarch and salt to a medium bowl, and whisk to combine. Set aside.
2. Combine butter and granulated sugar in the bowl of a stand mixer fitted with the paddle attachment. Zest half the orange and half the lemon directly into the bowl. Reserve the lemon and orange for the glaze. Cream the butter mixture on medium-high speed until light and fluffy, 2 to 3 minutes. Add vanilla and lemon extracts and beat on medium speed until well combined, scraping the bowl a few times as needed.
3. Add the flour mixture to the butter mixture and beat on low speed just until combined. Scrape the bowl and fold a few times to make sure everything is well combined. Wrap dough in plastic wrap, flatten into a disk, and chill until firm, at least 1 hour, and up to 3 days.
4. Heat oven to 350 degrees. Cut dough in half and let one piece warm up for 30 minutes if it has chilled longer than an hour. Return the other half to the refrigerator. Portion the dough into pieces roughly the size of walnuts (a scant 2 tablespoons/about 35 grams), then roll each piece into a ball between your hands. One at a time, dip a ball of dough into flour and set on work surface. If dough balls soften too much, return them to the refrigerator to firm up for a few minutes. You want it cool, but malleable. Dip cookie stamp in flour, and press down on the ball of dough until it is about 1/4-inch thick. Remove stamp. (If dough sticks to stamp, carefully peel it off. Don't worry about excess flour as you will brush it off after chilling.) Trim the edges using a 2-inch cookie cutter, and transfer dough rounds to 2 parchment- or silicone mat-lined baking sheets, arranging them about 1 1/2 inches apart. Repeat with remaining dough.
5. Once you have stamped out all the cookies, knead together the scraps to make a few more. Chill in the freezer until very firm, about 10 minutes. When cold, brush off any excess flour with a dry pastry brush.
6. Bake until cookies just start to turn golden underneath, 12 to 14 minutes, switching the baking sheets from front to back and top to bottom halfway through baking time.
7. Make the glaze while the cookies bake: Zest the remaining skin from the reserved lemon and orange into a small bowl. Add the confectioners' sugar, butter and orange juice and whisk until smooth. If glaze is too thick, add more orange juice. If it is too thin, add more confectioners' sugar. It should be the consistency of thin custard.
8. Let the cookies cool for a few minutes on the baking sheets, and transfer to a wire rack set over a parchment- or wax paper-lined baking sheet. Pick up a cookie, and using the back of a small spoon, spread a generous teaspoon of glaze on a cookie, letting any excess drip onto the next cookie. Repeat until all the cookies are glazed. Cool completely. Cookies will keep in an airtight container at room temperature for up to 1 week.

 Proof of how delicious the winning cookies were? Empty containers.

Community ecologist Rachel Vannette of the UC Davis Department of Entomology and Nematology 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. The Vannette 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."

Now the UC Davis assistant professor has two more opportunities that will enable her to pursue her research: she recently received two National Science Federation (NSF) grants.

One is 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 is a three-year collaborative 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.”

Bee scientist James Nieh, a UC San Diego professor in the Section of Ecology, Behavior and Evolution, Division of Biological Sciences, will present the first fall quarter seminar hosted by UC Davis Department of Entomology and Nematology.

Nieh will speak on "Animal Information Warfare: How Sophisticated Communications May Arise from the Race to Find an Advantage in a Deadly Game Between Honey Bees and Their Predators" at 4:10 p.m., Wednesday, Sept. 25 in 122 Briggs Hall. Brian Johnson, associate professor of entomology, is the host.

"In addition to the classical arm race that has evolved between predators and prey, information races also occur, which can lead to the evolution of sophisticated animal communication," Nieh says in his abstract. "Such information can shape the food web and contribute to the evolution of remarkable communication strategies, including eavesdropping, referential signaling and communication within and between species, including between predators and prey."

"I focus on the world of information exchange (acoustic, olfactory and visual) that has co-evolved between Asian honey bees (Apis cerana, A. florea, and A. dorsata) and their predators, the Asian hornets (Vespa velutina and V. mandarinia)," Nieh says. "I will explore how and why such information races occur through the remarkable examples provided by these high social insects."

He presented a TED talk on "Bees and Us: an Ancient and Future Symbiosis" in July 2019.

A native of Taiwan, Nieh grew up in Southern California and received his bachelor's degree in organismic and evolutionary biology in 1991 from Harvard University, Cambridge, and his doctorate in neurobiology and behavior from Cornell University, Ithaca, N.Y., in 1997. He subsequently received an NSF-NATO postdoctoral fellowship to study at the University of Würzburg in German. A Harvard junior fellowship followed.

Nieh joined the faculty of the Section of Ecology, Behavior and Evolution in 1997 as an assistant professor, advancing to associate professor in 2007 and professor in 2009. He served as vice chair of the section from 2009 to 2014, and as chair from 2014 to 2017.

His latest co-authored research, published in the journal Chemosphere in 2019, is titled Combined Nutritional Stress and a New Systemic Pesticide (flupyradifurone, Sivanto^®) Reduce Bee Survival, Food Consumption, Flight Success, and Thermoregulation.

 Assistant professor Rachel Vannette is coordinating the fall quarter seminars. (See list of seminars.)She may be reached at rlvannette@ucdavis.edu.