- Author: Kathy Keatley Garvey
Ah, Saturday, April 17. It's the 107th Annual UC Davis Picnic Day! What's a picnic without bugs?
This year's event, all virtual, is themed "Discovering Silver Linings," and you can do just that by watching the pre-recorded videos and by participating in the Zoom sessions. Check out the Picnic Day schedule of events which include entomological exhibits and talks from the UC Davis Department of Entomology and Nematology, Bohart Museum of Entomology and the UC Davis Graduate Student Association.
New additions to the line-up (featured on the Bohart Museum of Entomology website), involve what you could call "The good, the bad and the bugly." Blue orchard bees, tsetse flies and mosquitoes are spotlighted in UC Davis research-based videos created by KQED's Deep Look series and presented by PBS Digital Studios. Each runs about four minutes.
Here are the KQED productions:
- Watch this Bee Build Her Bee-Jeweled Nest, featuring blue orchard bees, the project of UC Davis doctoral student Clara Stuligross.
- A Tsetse Fly Births One Enormous Milk-Fed Baby, showcasing the work of medical entomologist Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology.
- This Dangerous Mosquito Lays Her Armored Eggs--in Your House, involving the Aedes aegypti mosquitoes that the Attardo lab studies.
Clara Stuligross, Doctoral Student
They exposed the bees to the neonicotinoid insecticide imidacloprid, widely used in agriculture, and found that the combined threats—imidacloprid exposure and the loss of flowering plants—reduced the bee's reproduction by 57 percent, resulting in fewer female offspring.
Other scientists have conducted similar research on honey bees, but this is the first comparable research on wild bees in field or semi-field conditions. The blue orchard bee, nicknamed BOB, is a dark metallic mason bee, smaller than a honey bee. It is prized for pollinating almond, apple, plum, pear, and peach trees. California almond growers often set up bee boxes or "bee condos" for blue orchard bees to aid in honey bee pollination. In the wild, the bees nest in reeds or natural holes.
Update? "We are currently working on a follow-up study to investigate potential carryover effects of past insecticide exposure on the same bee population, as well as how repeated pesticide exposure over multiple years impacts bee population growth," Stuligross said today.
Geoffrey Attardo, Medical Entomologist-Geneticist 
What many people do not know: "Female tsetse flies carry their young in an adapted uterus for the entirety of their immature development and provide their complete nutritional requirements via the synthesis and secretion of a milk like substance," Attardo says.
Attardo led landmark research published Sept. 2, 2019 in the journal Genome Biology that provides new insight into the genomics of the tsetse fly. The researchers compared and analyzed the genomes of six species of tsetse flies. Their research could lead to better insights into disease prevention and control.
The Deep Look episode on mosquitoes, "This Dangerous Mosquito Lays Her Armored Eggs-- in Your House," deals with the ability of Aedes aegypti eggs to survive out of water. Wrote the producers: "The Aedes aegypti mosquito, which can transmit dengue fever and Zika, makes a meal of us around our homes. And her eggs are hardy. They can dry out, but remain alive for months, waiting for a little water so they can hatch into squiggly larvae."
- Author: Kathy Keatley Garvey
You should also think about "pollination journeys."
On Wednesday, March 10, community ecologist Romina Rader from the University of New England's School of Environmental and Rural Science will speak on "The Journey to Effective Pollination" at the UC Davis Department of Entomology and Nematology's virtual seminar.
Professor and pollination ecologist Neal Williams is the host. Click here to register to attend the 4:10 p.m. seminar. This is the last of the winter seminars.
Rader, an associate professor, says she is broadly interested in pollination ecology, landscape ecology and plant–animal interactions in natural and human-modified landscapes. She is currently working on projects that investigate the ways in which plant and animal biodiversity respond to global change and the performance of wild and managed insect pollinators in horticultural crops.
She writes on her website: "I am a community ecologist and my research focuses on plant–animal interactions in natural and human-modified landscapes. I am interested generally in the ecology of plants and animals in different types of habitats and landscapes and how they respond to differing management practices and global change. My current projects relate to wild and managed insect pollinators, their efficiency at pollinating horticultural crops and finding ways to improve fruit yield and quality by understanding their life history needs."
Rader holds a bachelor of environmental science (1998) from the University of New South Wales, Sydney, Australia. She obtained both her master's degree (2005) and doctorate (2011) from James Cook University, Cairns, Australia. Her master's thesis: "Vertical Distribution, Resource and Space Use in a Tropical Rainforest Small Mammal Community." For her doctorate: "The Provision of Pollination Ecosystem Services to Agro-Ecosystems by a Diverse Assemblage of Wild, Unmanaged Insect Taxa." She won a 2017- 2020 Australian Research Council Discovery Early Career Researcher Award.
Among her most recent journal publications:
- S.A.E.C. Wijesinghe, L.J. Evans, L. Kirkland & R. Rader 2020, ‘A global review of watermelon pollination biology and ecology: The increasing importance of seedless cultivars,' Scientia Horticulturae, vol. 271, pp. 109493,
https://doi.org/10.1016/j.scienta.2020.109493 - Heidi Kolkert, Rhiannon Smith, Romina Rader & Nick Reid 2020, ‘Insectivorous bats foraging in cotton crop interiors is driven by moon illumination and insect abundance, but diversity benefits from woody vegetation cover,' Agriculture, Ecosystems & Environment, vol. 302, pp. 107068,
https://www.sciencedirect.com/science/article/abs/pii/S0167880920302541 - Jamie R. Stavert, Charlie Bailey, Lindsey Kirkland & Romina Rader 2020, ‘Pollen tube growth from multiple pollinator visits more accurately quantifies pollinator performance and plant reproduction,' Scientific Reports, vol. 10, no. 1,
https://www.nature.com/articles/s41598-020-73637-5 - Liam K. Kendall, Vesna Gagic, Lisa J. Evans, Brian T. Cutting & Jessica Scalzo, Romina Rader. 2020, ‘Self-compatible blueberry cultivars require fewer floral visits to maximize fruit production than a partially self-incompatible cultivar,' Journal of Applied Ecology,
https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2664.13751 - Vesna Gagic, Lindsey Kirkland, Liam K. Kendall, Jeremy Jones & Jeffrey Kirkland Romina Rader 2020, ‘Understanding pollinator foraging behaviour and transition rates between flowers is important to maximize seed set in hybrid crops,' Apidologie,
https://link.springer.com/article/10.1007/s13592-020-00800-2
Agricultural Extension specialist Ian Grettenberger coordinates the seminars. For technical issues, contact him at imgrettenberger@ucdavis.edu.
- Author: Kathy Keatley Garvey
Lead author and doctoral student Clara Stuligross teamed with her major professor, pollination ecologist Neal Williams of the UC Davis Department of Entomology and Nematology, to publish Pesticide and Resource Stressors Additively Impair Wild Bee Reproduction, in the journal Proceedings of the Royal Society B.
They exposed the bees to the neonicotinoid insecticide imidacloprid, widely used in agriculture, and found that the combined threats—imidacloprid exposure and the loss of flowering plants—reduced the bee's reproduction by 57 percent, resulting in fewer female offspring.
Of the two stressors—food scarcity and pesticide exposure—pesticide exposure showed the great impact on nesting activity and the number of offspring produced, they said.
Other scientists have conducted similar research on honey bees, but this is the first comparable research on wild bees in field or semi-field conditions.
The blue orchard bee, nicknamed BOB, is a dark metallic mason bee, smaller than a honey bee. It is prized for pollinating almond, apple, plum, pear, and peach trees. California almond growers often set up bee boxes or "bee condos" for blue orchard bees to aid in honey bee pollination. In the wild, the bees nest in reeds or natural holes.
“Bees and other beneficial insects experience multiple stressors within agricultural landscapes that act together to impact their health and diminish their ability to deliver the ecosystem services on which human food supplies depend,” Stuligross and Williams wrote in their abstract. “Disentangling the effects of coupled stressors is a primary challenge for understanding how to promote their populations and ensure robust pollination and other ecosystem services.”
To study the survival, nesting and reproduction of the blue orchard bee, they set up nesting females in large flight cages, some with high densities of wildflowers and others with low densities that were treated “with or without the common insecticide, imidacloprid.” Bees are commonly exposed to insecticides when they forage on treated flowers.
“Pesticides and resource limitation acted additively to dramatically reduce reproduction in free-flying bees,” they wrote in their abstract. “Our results emphasize the importance of considering multiple drivers to inform population persistence, management, and risk assessment for the long-term sustainability of food production and natural ecosystems.”
Key factors in affecting bee reproduction are the probability that females will nest and the total number of offspring they have. The UC Davis research found that pesticide-exposed and resource-deprived female bees delayed the onset of nesting by 3.6 days and spent five fewer days nesting than unexposed bees.
They found that only 62 percent of pesticide-exposed bees produced at least one daughter compared to 92 percent of bees not exposed to pesticides.
The research, accomplished in the spring of 2018 on the grounds of the Harry H. Laidlaw Jr. Facility west of the campus, drew support from a UC Davis Jastro Research Award, a UC Davis Ecology Graduate Research Fellowship, a National Science Foundation Graduate Research Fellowship, and the UC Davis bee biology facility
The blue orchard bee bee is one of the few native pollinators that is managed in agriculture. North America has 140 species of Osmia, according to a Pollinator Partnership (PP) article in a U. S. Forest Service publication, authored by entomologist and PP member Beatriz Moisset and PP director Vicki Wojcik. “Mason bees use clay to make partitions and to seal the entrance,” they wrote. “This unique mud-building behavior leads to their common designation as mason bees. Honey bees are very important to commercial agriculture, but native bees like the blue orchard bees are better and more efficient pollinators of native crops.”
Imidacloprid, a systemic insecticide that acts as an insect neurotoxin, is used to control sucking insects, termites, some soil insects and fleas on pets, according to National Pesticide Information Center. It mimics nicotine, toxic to insects, which is naturally found in many plants, including tobacco. More than 400 products for sale in the United States contain imidacloprid.
- Author: Kathy Keatley Garvey
The event, sponsored by UC Davis Environmental Law Society (ELS) and scheduled from 8:30 to 6:30 p.m., Friday, March 6 in Room 1001 of the School of Law, 400 Mrak Ave., is free and open to the public. It will include lunch and an evening cocktail reception. Registration is under way on this Facebook page.
Four UC Davis entomologists will be among the speakers. They are:
- Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology, UC Davis Department of Entomology and Nematology, whose expertise includes wasps. Kimsey is the "go-to" person in the department when the public requests general insect information.
- Neal Williams, professor and pollination ecologist, UC Davis Department of Entomology and Nematology, who focuses on native bees.
- Art Shapiro, distinguished professor of evolution and ecology, who has been monitoring the butterfly population of central California since 1972; and
- Brendon Boudinot, doctoral candidate and ant specialist, Phil Ward lab, UC Davis Department of Entomology and Nematology.
Experts in the field of entomology and agricultural sciences will converse with leaders in government, legal scholars and practitioners about the current threat to insect populations "and how we can use legal tools, policy and management practices to combat the sixth mass extinction," according to co-chairs Kelly Beskin (kvbeskin@ucdavis.ed) and Peter Jansen (pcjansen@ucdavis.edu).
Four separate panels will center on protecting insects and biodiversity. Some of the major topics will be about "listing insects under the Endangered Species Act and the tensions within agriculture between the need for pollinators and pesticide use," Beskin said.
- Franklin's bumble bee, Bombus franklini
- Suckley cuckoo bumble bee, Bombus suckleyi
- Western bumble bee, Bombus occidentalis
- Crotch bumble bee, Bombus crotchi
An insect fair will take place during lunch time. The Bohart Museum of Entomology will showcase insect specimens as well as a live "petting zoo," including Madagascar hissing cockroaches, walking sticks, and tarantulas. Graduate students will display their research projects, and the Entomology Graduate Student Association will be offering insect-themed t-shirts for sale. Cricket protein bars will be handed out to all those interested. Also planned is honey tasting from the UC Davis Honey and Pollination Center.
"It should be a lot of fun for everybody," Beskin said.
Sponsors, in addition to ELS, include the California Environmental Law and Policy Center; UC Davis John Muir Institute of the Environment and the UC Davis School of Law.
See agenda on the Facebook page.
- Author: Kathy Keatley Garvey
Ever seen a bumble bee nest?
We remember when insect enthusiast Rita LeRoy of the Loma Vista Farm, part of the Vallejo City Unified School District, found the nest of the yellow-faced bumble bee, Bombus vosnesenkii, in May of 2015. They were buzzing in and out, providing nectar and pollen for the growing colony.
However, as we all know, overwintering bumble bee nests are even more difficult to find. The queen is hibernating, getting ready to emerge next spring to start a new colony.
And now comes newly published research led by the Neal Williams lab, UC Davis Department of Entomology and Nematology, on Fantastic Bees and Where to Find Them: Locating the Cryptic Overwintering Queens of a Western Bumble Bee.
Published Nov. 20, 2019 in Ecosphere, an open access journal of the Entomolgoical Society of America, it is drawing the attention it should.
The abstract:
"Bumble bees are among the best‐studied bee groups worldwide, yet surprisingly we know almost nothing about their overwintering habitats nor the microsite characteristics that govern selection of these sites. This gap represents a critical barrier for their conservation, especially if preferred overwintering habitats differ from foraging and nesting habitats. Current conservation plans focus on foraging habitat, potentially creating a problem of partial habitats where improved forage might fail to prevent population declines due to limited overwintering sites. We provide the first data on the overwintering habitat for any western North American bumble bee. Our data suggest that overwintering and foraging habitats are likely distinct, and queens' selection of overwintering sites may be shaped by environmental stressors of the year. In our study area, queens overwintered in litter beneath cypress trees, where no floral resources exist. Whether this separation of overwintering and foraging habitat holds for other bumble bee species remains to be discovered. Our data highlight the need to consider the whole life cycle for understanding population dynamics and conservation planning. This need is underscored by growing evidence for the decline of multiple North American bumble bee species."
They detailed how they "looked for overwintering queens on California's central coast. We spent ~80 person‐hours searching different ground covers around abandoned military barracks at former Fort Ord Military Base where we previously observed large numbers of nest‐searching queen Bombus vosnesenskii Radoszkowski and B. melanopygus Nylander."
"Ground cover at Fort Ord is typical of the central California coast: a patchwork of grassy meadow, mats of non‐native ice plant (Carpobrotus edulis), and small stands of Monterey cypress (Cupressus macrocarpa) and Monterey pine (Pinus radiata). In December 2018, we searched for bumble bee queens by carefully digging the vegetative, litter, and soil strata of grassy meadow, ice plant mat, and the needle litter under two cypress and two pine tree."
What did they find and learn? It's well worth the read: https://doi.org/10.1002/ecs2.2949
