Co-lead author Clara Stuligross collects data at nest blocks for Osmia lignaria. (Photo courtesy of the Neal Williams lab)

In a newly published article titled, “Flower Plantings Support Wild Bee Reproduction and May Also Mitigate Pesticide Exposure Effects,” in the Journal of Applied Ecology, the eight-member team related that "to address the potential of flower plantings to mitigate bee pesticide exposure and effects and support bee reproduction, we established replicated sites where half contained flower plantings. We used sentinel bees to assess nesting and reproduction, quantified local and landscape flower availability, and used bee-collected pollen to quantify bee pesticide exposure and forage resource use. We asked the following questions:

1. To what extent do bees use flower plantings?
2. Do flower plantings promote bee reproduction?
3. Do flower plantings modify bee pesticide exposure and effects on reproduction?"

Professor Neal Williams (Photo by Kathy Keatley Garvey)

The paper is the work of co-lead authors Maj Rundlöf and Clara Stuligross, and co-authors Arvid Lindh, Rosemary Malfi, Katherine Burns, John Mola, Staci Cibotti and Professor Williams.

Their abstract:

1. Sustainable agriculture relies on pollinators, and wild bees benefit yield of multiple crops. However, the combined exposure to pesticides and loss of flower resources, driven by agricultural intensification, contribute to declining diversity and abundance of many bee taxa. Flower plantings along the margins of agricultural fields offer diverse food resources not directly treated with pesticides.
2. To investigate the potential of flower plantings to mitigate bee pesticide exposure effects and support bee reproduction, we selected replicated sites in intensively farmed landscapes where half contained flower plantings. We assessed solitary bee Osmia lignaria and bumble bee Bombus vosnesenskii nesting and reproduction throughout the season in these landscapes. We also quantified local and landscape flower resources and used bee-collected pollen to determine forage resource use and pesticide exposure and risk.
3. Flower plantings, and their local flower resources, increased O. lignaria nesting probability. Bombus vosnesenskii reproduction was more strongly related to landscape than local flower resources.
4. Bees at sites with and without flower plantings experienced similar pesticide risk, and the local flowers, alongside flowers in the landscape, were sources of pesticide exposure particularly for O. lignaria. However, local flower resources mitigated negative pesticide effects on B. vosnesenskii reproduction.
5. Synthesis and applications. Bees in agricultural landscapes are threatened by pesticide exposure and loss of flower resources through agricultural intensification. Therefore, finding solutions to mitigate negative effects of pesticide use and flower deficiency is urgent. Our findings point towards flower plantings as a potential solution to support bee populations by mitigating pesticide exposure effects and providing key forage. Further investigation of the balance between forage benefits and added pesticide risk is needed to reveal contexts where net benefits occur.

 Journal of Applied Ecology, a publication of the British Ecological Society, publishes novel, high-impact papers on the interface between ecological science and the management of biological resources.

Lynn Kimsey, director of the Bohart Museum of Entomology (Photo by Kathy Keatley Garvey)

All are free and family friendly and all--except one--will take place in the Bohart Museum, located in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus.

The schedule: 

Sunday, Sept. 25, 1 to 4 p.m.
Weird and Wonderful Wasps
Visitors will learn about the smallest fairy wasps  to the "murder hornets"; what role wasps play in plant galls and figs; and how to distinguish a parasitoid from a parasite.  Lynn Kimsey, director of the Bohart Museum and a UC Davis distinguished professor of entomology, will discuss the Asian giant hornet, Vespa mandarinia. A single colony of the Asian giant hornet was found and destroyed Sept. 18, 2019 in Nanaimo, Vancouver Island, Canada, and a single dead hornet was found Dec. 8, 2019 in nearby Blaine, Wash. Since then, it also has been sighted-- and destroyed--in both Canada and Washington state

Saturday, Oct. 15, 1 to 4 p.m.
Insects, Art & Culture
Visitors will learn about insects through the lenses of art and culture.   This event is part of Spirit Week (Oct. 10-16) for Aggie students, parents and alumni, but all are welcome. 

Saturday, Oct. 15, 11 a.m. to 11:50 a.m.
Special Talk: Plants, Insects and Art: Mary Foley Benson's Scientific Illustrations
Location: Teaching and Learning Complex (TLC) Building, 482 Hutchison Drive, UC Davis campus
This event is part of Spirit Week for Aggie students, parents and alumni, but all are welcome. Srdan Tunic, a candidate for a master's degree in art history and a Bohart associate, will be highlighting the scientific illustrations of Mary Foley Benson (1905-1992), formerly of the U. S. Department of Agriculture's Bureau of Entomology and the Smithsonian Institution and who later worked for UC Davis entomologists. Much of her work appears on campus. (See research story on the artist by Malcolm Furniss)

Sunday, Nov. 6, 1 to 4 p.m.
Dragonflies Rule!
Dragonflies are described as "the ultimate predator both in the water and the air." Visitors will meet scientists and natural historians who will share information on the world of dragonflies. 

The Bohart Museum is part of the UC Davis Department of Entomology and Nematology. It houses a worldwide collection of eight million insect specimens. It also is the home of a live "petting zoo" (Madagascar hissing cockroaches, stick insects and tarantulas) and an insect-themed gift shop, which includes t-shirts, sweatshirts, jewelry, books, posters and other items. The gift shop is open all year-around and is also online.

The Bohart Museum is open to the public Monday through Thursday for families, friends and individuals, but groups (such as scouts, school groups, homeschool groups)  must make reservations and everyone must follow the UC Davis visitor guidelines: https://campusready.ucdavis.edu/visitors.

Three-dimensional image of the previously unknown extinct ant species. (Photo by Hammel/Lauströer)

Their work, drawing global attention, is newly published in the journal Insects.

The researchers examined 13 individual male fossilized ants that lived during the Miocene epoch and identified them as a new genus of primordial ants. The team used the X-ray light source PETRA III at the German Electron Synchrotron (DESY) in Hamburg, aided by state-of-the-art imaging technology. The name given to the new species and genus: "†Desyopone hereon gen. et sp. nov," to honor the two research institutions involved--DESY and Hereon. 

The males resemble species of the relictual lineage Aneuretinae, "but which effectively belong to the Ponerinae, as revealed by advanced 3D-imaging technology (synchrotron radiation micro-computed tomography, SR-µ-CT)," the authors wrote. "We subsequently propose a revision of ant classification at the subfamily level. We also recognize that the new species belongs to a new genus based on recent phylogenomic results that have clarified the generic boundaries of Ponerini ants. Our work, therefore, represents an example of reciprocal illumination between phenomic and genomic data."

"The study was really pleasing from a scientific perspective, as we were able to pass through the whole cycle of hypothesis induction based on the original light microscopy, then deductive prediction for structures we then tested using synchrotron radiation, which allowed us to reject the initial hypothesis—and to go even further!" said Boudinot, an Alexander von Humboldt Research Fellow at the Institute of Zoology and Evolutionary Research at Friedrich Schiller University Jena.

"There are a couple of important elements to the study," Boudinot said. "Based on this discovery, we had to redefine two ant subfamilies and two tribes, and we demonstrate the value of the oft-neglected male ants for understanding evolution through the comparison of mandibles of male and females across the phylogeny, revealing a major trend in mandible evolution. In the bigger picture, what I think is significant is that this work marks a boundary for ant paleontology, where we will increasingly be able to use x-ray micro-computed tomography (µ-CT) to generate 3D models for study and quantitative analysis. Soon, we will be able to analyze these phenomic data simultaneously with genomic data. The study of ant morphology and paleontology is transforming and becoming 'big data'! There will be lots more work to come."

The team, in addition to researchers from Friedrich Schiller University Jena, included scientists from the University of Rennes in France, the University of Gdansk in Poland, and the Helmholtz-Zentrum Hereon in Geesthacht, Germany.

In a University of Jena news release, Vincent Perrichot from the University of Rennes explained: "The piece with these ants is from the only amber deposit in Africa so far that has featured fossil organisms in inclusions. Altogether, there are only a few fossil insects from this continent. Although amber has long been used as jewelry by locals in the region, its scientific significance has only become clear to researchers in the last 10 years or so. The specimen therefore offers what is currently a unique insight into an ancient forest ecosystem in Africa.”  Its complicated dating was possible only indirectly, by determining the age of the fossil palynomorphs--the spores and pollen--enclosed in the amber, he added.

"Research results such as these are only possible through the use of state-of-the-art technology," according to the University of Jena news release. "As the genetic material of fossils cannot be analyzed, precise data and observations on the morphology of animals are particularly important. Comprehensive data can be obtained using high-resolution imaging techniques, such as micro-computed tomography (CT), in which X-rays are used to look through all layers of the sample."

A quote from Jörg Hammel from the Helmholtz-Zentrum Hereon: “Since the ants enclosed in amber that are to be examined are very small and only show a very weak contrast in classical CT, we carried out the CT at our measuring station, which specializes in such micro-tomography. This provided the researchers with a stack of images that basically showed the sample that was being studied slice by slice.” 

"Put together, these produced detailed three-dimensional images of the internal structure of the animals, which the researchers could use to reconstruct the anatomy with precision," the news release related. "This was the only way to exactly identify the details that ultimately led to the new species and genus being determined."

Boudinot, a two-year Alexander von Humboldt Research Fellow,  recently was awarded a Peter S. Buck Research Fellowship at the Smithsonian Institution, Washington, D.C., and will begin his fellowship there early next year. 

Boudinot received his doctorate in entomology from UC Davis in 2020, working with major professor Phil Ward. During his years at UC Davis, Boudinot received the John Henry Comstock Award from the Pacific Branch, Entomological Society of America, the highest ESA graduate student honor.

UC Davis distinguished professor emeritus Frank Zalom is the editor-in-chief of the Journal of Economic Entomology. (Photo by John Stumbos)

Native to Asia, the agricultural pest is a worldwide threat to the berry production industry, which includes raspberries, blackberries, blueberries, strawberries, and cherries. The tiny insect, about 1/12 to 1/8 inch long, invaded the continental United States in 2008. 

“All of the papers were by invitation of the co-editors of the special collection—Jana Lee, Cesar Rodrigue-Saona, and me,” said journal editor-in-chief Frank Zalom, a UC Davis distinguished professor emeritus and recall professor in the Department of Entomology and Nematology. Zalom's research includes the spotted-wing drosophila.

Lee, formerly with the UC Davis laboratory of the late chemical ecologist Steve Seybold, is a research entomologist with the Horticultural Crops Research Unit,  U. S. Department of Agriculture, Agricultural Research Service, Corvallis. Rodriguez-Saona, who received his doctorate from UC Riverside, is an Extension entomologist with the Department of Entomology, Rutgers University, the State University of New Jersey.

In addition to Zalom and Lee, the UC Davis-linked authors include Joanna Chiu and Antoine Abrieux (Joanna Chiu lab); Zain Syed and Kevin Cloonan (Walter Leal lab); Gregory Loeb (Rick Karban lab); and Kelly Hamby, Hannah Burrack, Fatemeh Ganjisaffar, Brian Gress, Nicole Nicola and Mark Demkovich (Zalom lab).

Overall, the Special Collection includes authors from Austria, Brazil, Canada, Italy, Spain, Sweden, United Kingdom, and the United States that represent perspectives from universities, federal and state laboratories, growers, and pest product companies, according to the editors. 

One of the authors is molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the Department of Entomology and Nematology. (Photo by Kathy Keatley Garvey)

UC Davis Department of Entomology and Nematology communication specialist Kathy Keatley Garvey provided the cover photo of the spotted-wing drosophila feeding on a raspberry.

Since 2008, "D. suzukii has become a key economical pest of raspberries, blackberries, blueberries, strawberries, and cherries in the United States and worldwide," the editors wrote in their introductory remarks. "Not surprisingly, the number of publications has proliferated from 29 publications as of 2010 to 978 additional publications between 2011 and 2021 from a Web of Science search for ‘Drosophila suzukii.' While many publications are available, this special collection will highlight advances in D. suzukii pest management since its U.S. invasion. We solicited papers by open call and received 66 abstracts, and selected 14 papers covering: 1) review, 2) monitoring and risk, 3) behavioral control, 4) biological control, 5) cultural control, and 6) chemical control."

The editors pointed out that “Given that 14 years of research has accumulated since the continental U.S. invasion, it was fitting to include two reviews that provide a different scope than was covered in prior reviews on D. suzukii biological control (Lee et al. 2019, Wang et al. 2020), trapping (Burrack et al. 2020), cultural control (Schöneberg et al. 2021), and chemical ecology (Cloonan et al. 2018). This special collection is anchored by Tait et al. (2021), a review of the most promising methods as part of an Integrated Pest Management (IPM) strategy against D. suzukii across the world since 2008. The effectiveness, impact, sustainability, and present stage of development and implementation are discussed for each of the considered techniques, and insights for continued development are presented.”

“A second review in this special collection by Garcia et al. (2022) summarizes the history and current status of D. suzukii in Latin America. The authors first provide a history of the D. suzukii invasion through Latin American countries, which started in 2011 in Mexico, and is now present in Argentina, Brazil, Chile, and Uruguay. They describe the host plants where D. suzukii has been found as well as advances in monitoring, biological control, chemical control, cultural control, and in the sterile insect technique. The authors posit that this information can serve as the basis for developing sustainable area-wide management programs in Latin America.”

The researchers related that the pest is a significant threat to California's berry production industry, which the California Department of Food and Agriculture (CDFA) valued at more than $2.8 billion in 2019. Caneberries, in particular, "are a preferred host of D. suzukii, and California accounts for 89.4 percent of all production in the United States, with the Monterey Bay region producing about half of the state's raspberries and blackberries (CDFA 2020). This pest has now spread to all major berry and cherry growing areas of the United States."

The collection is meant to serve "as a key reference point for entomologists across many institutions (e.g., academia, government, and industry) on important advances in D. suzukii pest management," according to the Entomological Society of America. "The articles in this collection will also provide scientists information on potential research gaps that will help guide future research directions on this important pest. The goal is to preserve and catalog articles on various aspects of D. suzukii pest management, i.e., monitoring, cultural control, chemical control, behavioral control, and biological control, that will be shared among entomologists."