Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology, and professor Sharon Lawler with their empty containers. (Photo by Kathy Keatley Garvey)

Sounds like a great story, right?

Make that great cookies.

They weren't there to present their research on nematodes, aquatic insects or pollinators. They were there to enjoy some camaraderie at the UC Davis Department of Entomology and Nematology's holiday party, and...drum roll...they won the top prizes in the cookie contest.

• 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

William Tuck, academic personnel specialist in the Phoenix Cluster, which serves the Department of Entomology and Nematology and the Department of Plant Pathology, coordinated the event and awarded $25 Amazon gift cards to the winners.

The proof of the pudding? Empty containers.

Want to make the recipes? They shared!

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.

Rachel Vannette, community ecologist and assistant professor (Photo by Kathy Keatley Garvey)

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.

Community ecologist Rachel Vannette. (Photo by 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.”

Takato Imaizumi

The exciting research of Professor Takato Imaizumi of the University of Washington.

If you read Scientific Reports, you probably remember the piece he co-authored: "Circadian Clocks of Both Plants and Pollinators Influence Flower-Seeking Behavior of the Pollinator Hawkmoth Manduca sexta," published Feb. 12, 2018.

The abstract:
"Most plant-pollinator interactions occur during specific periods during the day. To facilitate these interactions, many flowers are known to display their attractive qualities, such as scent emission and petal opening, in a daily rhythmic fashion. However, less is known about how the internal timing mechanisms (the circadian clocks) of plants and animals influence their daily interactions. We examine the role of the circadian clock in modulating the interaction between Petunia and one of its pollinators, the hawk moth Manduca sexta. We find that desynchronization of the Petunia circadian clock affects moth visitation preference for Petunia flowers. Similarly, moths with circadian time aligned to plants show stronger flower-foraging activities than moths that lack this alignment."

"Moth locomotor activity is circadian clock-regulated, although it is also strongly repressed by light. Moths show a time-dependent burst increase in flight activity during subjective night. In addition, moth antennal responsiveness to the floral scent compounds exhibits a 24-hour rhythm in both continuous light and dark conditions. This study highlights the importance of the circadian clocks in both plants and animals as a crucial factor in initiating specialized plant-pollinator relationships."

And now, Takato Imaizumi will head to the University of California, Davis to present a seminar hosted by the UC Davis Department of Entomology and Nematology.  His seminar, titled "Circadian Timing Mechanisms in Plant-Pollinator Interaction," is scheduled for 4:10 p.m., Wednesday, Oct. 30 in 122 Briggs Hall, off Kleiber Hall Drive.

"He will be speaking about his work on circadian clocks of plants and pollinators, and how circadian timing can shape plant-pollinator relationships," said molecular geneticist and physiologist Joanna Chiu, associate professor and vice chair of the UC Davis Department of Entomology and Nematology. Chiu, a UC Davis Chancellor Fellow, will introduce him.

Julián Hillyer

Wait, there's more! "Not So Heartless: Functional Integration of the Immune and Circulatory Systems of Mosquitoes."

This may not be the proverbial heart-stopping seminar, but it promises to be an eye opener by a medical entomologist and captivating speaker.

Julián Hillyer, associate professor of biological sciences, Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, Tenn., will deliver that seminar at 4:10 p.m., Wednesday, Oct. 23, in 122 Briggs Hall, as part of the weekly UC Davis Department of Entomology and Nematology seminars. 

"Mosquitoes--like all other animals--live under constant threat of infection," Hillyer says in his abstract. "Viral, bacterial, fungal, protozoan and metazoan pathogens infect mosquitoes through breaches in their exoskeleton and following ingestion. Because these pathogens pose a threat to their survival, mosquitoes have evolved a powerful immune system."

In his seminar, Hillyer will present his laboratory's work characterizing the circulatory and immune systems of the African malaria mosquito, Anopheles gambiae.  "Specifically," he says. "the talk will describe the structural mechanism of hemolymph (insect blood), circulation in different mosquito life stages, and the role that immune cells, called hemocytes play in the killing of pathogens by phagocytosis, melanization and lysis. Then I will describe the functional integration of the circulatory and immune systems a process that is manifested differently in larvae and adults. Specifically, the infection of an adult mosquito induces the aggregation of hemocytes at the abdominal ostia (valves) of the heart--where they sequester and kill pathogens in areas of high hemolymph flow--whereas the hemocytes of larvae aggregate instead on respiratory structures that flank the posterior in current openings of the heart."

"This research," Hillyer explains, "informs on the physiological interaction between two major organ systems and uncovers parallels between how the organ systems of invertebrate and vertebrate animals interact during the course of an infection."

What does the mosquito heart look like? Check out former Vanderbilt graduate student Jonas King's prize-winning image--a fluorescent image of the heart of a mosquito. It won first place in Nikon's "Small World'" photomicrography competition in 2010.  King's image shows a section of the tube-like mosquito heart magnified 100 times.  At the time he was a member of Hillyer's research group and is now an assistant professor at Mississippi State University.

In a piece by David Salisbury of Vanderbilt News, Hillyer related that "Surprisingly little is known about the mosquito's circulatory system despite the key role that it plays in spreading the malaria parasite. Because of the importance of this system, we expect better understanding of its biology will contribute to the development of novel pest- and disease-control strategies.”

"The mosquito's heart and circulatory system is dramatically different from that of mammals and humans," wrote Salisbury in the Oct. 15, 2010 piece. "A long tube extends from the insect's head to tail and is hung just under the cuticle shell that forms the mosquito's back. The heart makes up the rear two-thirds of the tube and consists of a series of valves within the tube and helical coils of muscle that surround the tube. These muscles cause the tube to expand and contract, producing a worm-like peristaltic pumping action. Most of the time, the heart pumps the mosquito's blood—a clear liquid called hemolymph—toward the mosquito's head, but occasionally it reverses direction. The mosquito doesn't have arteries and veins like mammals. Instead, the blood flows from the heart into the abdominal cavity and eventually cycles back through the heart."

“The mosquito's heart works something like the pump in a garden fountain,” Hillyer told Salisbury.

Hillyer was a Vanderbilt Chancellor Faculty Fellow (2016-2018) and was awarded the 2015 Henry Baldwin Ward Medal by the America Society of Parasitologists. He was elected to the Council of the American Society of Parasitologists, serving from 2012-2016. Other recent awards: the 2011 Jeffrey Nordhous Award for Excellence in Undergraduate Teaching and the 2012 Recognition Award in Insect Physiology, Biochemistry and Toxicology from the Southeastern Branch of the Entomological Society of America.

Hillyer received his master's degree and doctorate from the University of Wisconsin-Madison under the mentorship of Ralph Albrecht and Bruce Christensen, respectively. He completed a postdoctoral fellowship under the mentorship of Kenneth Vernick at the University of Minnesota, now with Institut Pasteur. In 2007, Hillyer moved to Nashville, Tenn. to establish Vanderbilt University's mosquito immunology and physiology laboratory.  (See more.)

The Hillyer Lab is interested in basic aspects of mosquito immunology and physiology, focusing on the mechanical and molecular bases of hemolymph (blood) propulsion, and the immunological interaction between mosquitoes and pathogens in the hemocoel (body cavity)," according to his website. "Given that chemical and biological insecticides function in the mosquito hemocoel, and that disease-causing pathogens traverse this compartment prior to being transmitted, we expect that our research will contribute to the development of novel pest and disease control strategies."

Host is Olivia Winokur, doctoral student in the Chris Barker lab. Community ecologist Rachel Vannette, assistant professor, Department of Entomology and Nematology, coordinates the weekly seminars. (See list of seminars)