- Author: Kathy Keatley Garvey
Bees and blister beetles, yes.
We remember writing about her work in April of 2013 when she addressed the Nor Cal Entomology Society (now folded) about her research on how blister beetle nest parasites cooperate to mimic the sex pheromone of a digger bee. She had just returned from the Mojave National Preserve, tracking the solitary bee Habropoda pallida and its nest parasite, a blister beetle, Meloe franciscanus.
Fascinating research! Saul-Gershenz, who grew up in New York, studies the chemical ecology and parasite-host interactions of solitary native bees and their nest parasites across the western U. S., including the coastal sand dunes of Oregon and the Mojave Desert in south-central California.
"The solitary bee is the first native bee to emerge in the spring on the Kelso Dunes in the Mojave National Preserve," she told us. “The adult beetles emerge on the dunes in the winter months at Kelso Dunes and feed exclusively on the leaves of Astragalus lentiginosus which leafs out in January."
The bee's emergence is generally synchronized with the onset of blooms of the Borrego milkvetch, which is the sole host plant of adults of the blister beetle at Kelso Dunes.
Basically, the larvae of the parasitic blister beetle produce a chemical signal or allomone, similar to that of a female bee's pheromone to lure males to the larval aggregation. The larvae attach to the male bee on contact and then transfer to the female during mating. The end result: the larvae wind up in the nest of a female bee, where they eat the nest provisions and likely the host egg.
Leslie is now Dr. Saul-Gershenz. She received her doctorate in entomology in May 2017. And on Wednesday, Oct. 18, she will share her research at her exit seminar, "Host Range Evolution of the Bee Parasite Meloe franciscanus," set from 4:10 to 5 p.m. in 122 Briggs Hall, Kleiber Hall Drive.
"We report that different populations of M. franciscanus exhibit local adaptations that mimic both the behaviors and the chemical composition of the sex pheromones of locally available bee host species," she writes in her abstract. "We compared a population of M. franciscanus larvae, known as triungulins, parasitizing nests of Habropoda miserabilis (Hymenoptera: Apidae) from the coastal sand dunes of Oregon with a population parasitizing the congener H. pallida in the Mojave Desert in south-central California. We determined that M. franciscanus populations are the same species using molecular analyses.
Working in collaboration with the Neal Williams bee lab and the Steve Nadler molecular lab in the UC Davis Department of Entomology and Nematology, she and chemical ecologist Jocelyn Millar at UC Riverside found that multiple populations of the blister beetle Meloe franciscanus are locally adapted to different bee hosts in different allopatric populations. (Professor Williams is a pollination ecologist, and Nadler is a nematologist and chair of the department.)
The UC Davis evolutionary ecologist also explored which functional traits of hosts are useful for predicting parasite host range. In another study, she brought together a dream team of bee biologists and received funding from the Bureau of Land Management to study the impact of utility-scale solar development on desert bees. This study documented that these landscapes are biologically rich, even in drought years, and contain a minimum of 114 species of bees including six undescribed species of bee.
The significance of her work?
"Our research has added to the understanding of the communication signals of bees in the genus Habropoda," she related. "We now know that they use long-chain hydrocarbons for the female sex attractant and vary the position of the double bounds in different components and vary proportions of these components to avoid cross attraction among closely related species. Parasites co-opt this communication channel to deceive male bees in the Meloe-Habropoda system.
"In our host functional trait research we show that annual host abundance and host abundance from year to year, as well as local temporal overlap are highly predictive of host range."
Results on the impact of utility-scale solar development on desert bees showed high bee species diversity in the Mojave and western Sonoran region. "This suggests the importance of careful regional planning and additional research to protect this area of significant floral and fauna biodiversity," she said.
Future plans? To continue her research.
Leslie Saul-Gershenz, recipient of numerous grants and author of a number of publications ranging from peer-reviewed papers to books, is the co-founder of the Bay Area-based SaveNature.Org and director of Research and Conservation (1988 to present). The international conservation consortium works with partners to protect ecosystems around the world.
She is also a 2004 graduate of The Bee Course, an intensive 10-day workshop sponsored by the American Museum of Natural History at the Southwestern Research Station, Portal, Ariz. One of the instructors is Robbin Thorp, distinguished emeritus professor of entomology at UC Davis, also one of her many collaborators.
Among her other current collaborators: scientists Lynn Kimsey, Neal Williams, Tom Zavortink, Rebecca Hernandez, all of UC Davis; Terry Griswold, USDA-ARS, Bee Biology Lab; Monica Geber, Cornell University; and John Ascher, National University of Singapore.
Her next presentations of her research will be at the Entomological Society of America's annual conference, "Ignite, Inspire, Innovate," scheduled Nov. 5-8 in Denver,Colo., and the California Native Plant Society Conservation Conference, scheduled Feb. 1-3, 2018 in Los Angeles.
- Author: Kathy Keatley Garvey
Margaret “Rei” Scampavia, a doctoral candidate who studies with major professors Neal Williams and Edwin Lewis of the Department of Entomology and Nematology, won first place for her research poster at the recent UC Davis Bee Symposium, held in the Robert Mondavi Center for Wine and Food Science.
Scampavia's poster, “Farming Practices Affect Nest Site Selection of Native Ground Nesting Bees,” won her the $1500 grand prize. The Henry J. Kaiser Family Foundation generously provided the funding.
Two other graduate students in the Neal Williams' lab won second and third place. Jennifer Van Wyk placed second for her poster on “Wet Meadow Restoration Buffers the Impact of Climate Change: Pollinator Resilience During the California Drought” and Leslie Saul-Gershenz, who also studies with professor Steve Nadler, placed third for her poster on “Native Bee Parasite Shows Multitrait, Host Specific Variation and Local Adaptation.” Van Wyk received a $1000 prize and Saul Gershenz, $500.
“Availability of foraging and nesting habitat potentially limits native bee range, which affects where pollinator services occur,” Scampavia wrote in her introduction. “Prior studies focus on how foraging habitat influences bee distribution, but few consider nesting limitations. Understanding how different soil properties affect native bee nest site preference can help predict where these nests will be found in agricultural landscapes, as well as whether particular farming practices could affect the health of nesting bees.”
Her objective: “to determine whether tillage, irrigation and application of pesticides impact nest site selection using a controlled choice assay.”
She examined the nests of bees in four genus categories: Lasioglossum, Halictus, Svastra and Melissodes.
Scampavia concluded “The two soil treatments that positively influenced nest initiation (tillage and irrigation) would be found in actively farmed areas, rather than fallow fields or field margins. If the presence of insecticide residues or tillage affects offspring survival, these results suggest that bees nesting in agricultural areas are faced with an ecological trap that could negatively affect development and overwintering survival. Providing strips of bare, tilled and irrigated soil in early spring in field margins or hedgerows could be one way to create attractive pesticide and late-season tillage-free shelters in which native bees could nest.”
Prior to coming to UC Davis, Scampavia worked for the U.S. Forest service as a biological technician, studying pollinator visitation to rare plants of the Mojave Desert. She also volunteered at Scripps College (Jupiter, Fla.) as a planner and coordinator for large education outreach events.
In addition to her PhD research, she participates in a variety of education outreach and conservation projects. She has presented lectures for the U.S. Fish and Wildlife Service as part of the Schoolyard Habitat Project; worked for the California Native Plant Society, documenting bee diversity in a threatened portion of Knowland Park in Oakland; and co-taught an undergraduate course focusing on current threats to pollinator populations and how to educate the general public to effect positive change.
Scampavia writes a bee blog, “Diadasia, The Lives of Other Bees,” at https://diadasia.wordpress.com/ that she launched in February 2012.
The Bee Symposium, sponsored by the Honey and Pollination Center and the UC Davis Department of Entomology and Nematology, featured keynote speaker Marla Spivak, Distinguished McKnight Professor, University of Minnesota and a 2010 MacArthur Fellow, who discussed "Helping Bees Stand on Their Own Six Feet." The symposium drew 360 people.
Entomology doctoral candidate Matthew Prebus of the Phil Ward lab, UC Davis Department of Entomology and Nematology, video-recorded the presentations and uploaded them today.
They are all on YouTube.
Marla Spivak: Protecting Pollinators
Amy Toth: Combined Effects of Viruses and Nutritional Stress on Honey Bee Health
Elina Niño: Best Management Practices to Support Honey Bee Health
Neal Williams: Enhancing Forage for Bees
Jake Reisdorf: Getting into Beekeeping- Thoughts from a 12-year-old Beekeeper
Katharina Ullmann: Project Integrated Crop Pollination
John Miller: Keeping Bees Healthy with Forage
Benjamin Sallman: Bee Informed Partnership
Gretchen LeBuhn: The Giant Sunflower Project
Christine Casey: Introduction to the Häagen Dazs Honey Bee Haven
- Author: Kathy Keatley Garvey
However, there may be sad ending...more about that later.
Members and their guests will gather Nov. 7 at 9:15 a.m. at their meeting site, the Contra Costa Mosquito and Vector Control District conference room, 155 Mason Circle, Concord. for coffee and registration.
Then, at 9:30 a.m., Saul-Gershenz will discuss “Meloid Parasites of Solitary Bees." A graduate student in the Neal Williams lab, UC Davis Department of Entomology and Nematology, and a co-founder of SaveNature.Org, Saul-Gershenz researches a solitary ground-nesting bee, Habropoda pallida and its nest parasite, a blister beetle, Meloe franciscanus, found in the Mojave National Preserve.
She is the lead author of “Blister Beetle Nest Parasites Cooperate to Mimic the Sex Pheromone of the Solitary Bee Habropoda pallida (Hymenoptera: Apidae)," co-authored by professor Jocelyn G. Millar and staff research associate J. Steven McElfresh, both of UC Riverside. The Mojave National Preserve Science News published the peer-reviewed research in its April 2012 edition.
"The solitary bee is the first native bee to emerge in the spring on the Kelso Dunes in the Mojave National Preserve," said Saul-Gershenz. “The adult beetles emerge on the dunes in the winter months at Kelso Dunes and feed exclusively on the leaves of Astragalus lentiginosus, which leafs out in January."
The bee's emergence is generally synchronized with the onset of blooms of the Borrego milkvetch, which is the sole host plant of adults of the blister beetle at Kelso Dunes.
The UC Davis ecologist said the larvae of the parasitic blister beetle produce a chemical cue or a pheromone similar to that of a female solitary bee to lure males to the larval aggregation. The larvae attach to the male bee and then transfer to the female during mating. The end result: the larvae wind up in the nest of a female bee, where they eat the nest provisions and likely the host egg.
The work of Saul-Gershenz, Millar and McElfresh appears in a newly published academic book, Sensory Ecology, Behaviour, and Evolution (Oxford University Press) by Martin Stevens. Another book, pending publication in December, also will contain their work: the second edition of Pheromones and Animal Behaviour (Cambridge University) by Tristram Wyatt.
Previously, three other books summarized their research:
Keeping the Bees: Why All Bees Are at Risk and What We Can Do to Save Them by Laurence Packer and published in 2011 by HarperCollins Publishers, Ltd.
Cuticular Hydrocarbons: Biology, Biochemistry and Chemical Ecology by editors A. Bagnères-Urbany and G. Bloomquist and published in 2010 by Cambridge University Press.
The Other Insect Societies by James T. Costa, and published in 2006 by the Belknap Press of Harvard University Press.
Now, back to what may be a sad ending.
Following Saul-Gershenz' one-hour talk, the Nor Cal Entomology Society members will discuss the future of the organization, founded in 1930. Then it was known as the Northern California Entomology Club. Membership continues to be open to all interested persons, with dues at $10 a year. Currently the society meets three times a year: in Sacramento, at UC Davis, and in Concord.
Nor Cal Entomology president Robert Dowell of the California Department of Food and Agriculture will moderate the disussion.
“We have reached a critical juncture in the existence of the organization,” secretary-treasurer Eric Mussen, Extension apiculturist with the UC Davis Department of Entomology and Nematology, wrote to the members in an email. “At its beginning, the society served as the meeting place for entomologists mostly from UC Berkeley and UC Davis, as well as other members who appreciated their lively discussions of research and pest control. Representatives from industry and regulatory establishments also participated. A revolving system of society chairs was instituted and membership was good.”
“Over time, the climate has changed. UC Berkeley no longer has an entomology department or hardly any entomologists anymore,” said Mussen, who will retire from UC Davis in June 2014.
Those planning to attend to hear the talk and discuss the future of the organization should contact Mussen at ecmussen@ucdavis.edu or telephone him at (530) 753-0472 by Nov. 1. And oh, yes, there's a luncheon to be served by Kinder's Meats. Mussen is taking reservations (and payment) for that, too.
- Author: Kathy Keatley Garvey
A pond attracts dragonflies and damselflies.
Last weekend, though, we spotted a damselfly a good 65 feet away from our pond. It touched down on our passion flower vine (Passiflora). Lights, camera, action...
The enlarged photo revealed a surprise: a cluster of something reddish-orange beneath the thorax.
Now that's something you don't see every day!
"Water mites," said native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis. (There are also images on BugGuide.net.)
"Phoresy," said entomology graduate student Lesle Saul-Gershenz, and professor Sharon Lawler, both of the UC Davis Department of Entomology and Nematology. Phoresy is a symbiotic relationship in which one organism transports another organism of a different species. Bottom line: these bright red mites, from the tick family, are hitchhikers that feed on body fluids. They jump off when the host drops down over a new pond or wetland.
What's the effect of water mites on damselflies? Surely, that parasitic load of arachnid hitchhikers must be cumbersome.
Scientists Jose Andres and Adolfo Cordero of the Universidade de Vigo, Pontevedra, Spain, took a close look at parasitism in their research “Effect of Water Mites on the Damselfly, Ceriagrion tenellum,” published in a 2002 edition of Ecological Entomology.
They pointed out:
1. "Water mite parasitism is expected to have an important effect on damselfly survivorship and reproductive success, because mites drain considerable amounts of body fluids from their hosts," they wrote in their abstract. "This study tests the effect of water mite parasitism in a marked population of the damselfly Ceriagrion tenellum during 1995 (individuals marked as mature adults) and 1996 (individuals marked as tenerals)."
2. "Almost all teneral individuals were parasitized (98%) and mites were aggregated strongly on some individuals. Parasite load increased during the season."
3. "Parasites had no effect on the probability of recapture of hosts as mature adults. The average daily survival rate of lightly- and heavily-parasitized individuals, estimated with Jolly's stochastic method, did not differ significantly."
4. "In 1995 parasites had a significant effect on host mating success. The probability of mating was about 25% lower for heavily parasitized males than for lightly parasitized males. Lightly parasitized males also mated more times than heavily parasitized males, even if heavily parasitized males lived longer. In 1996, parasitism did not have an effect on male mating success. In both years mites had no effect on female lifetime mating success."
In conclusion, they found that "water mite parasitism does not reduce damselfly survivorship, but it could reduce male mating success in some circumstances. Further long-term studies are needed, especially in populations with a lower incidence of parasitism."
As for our little damselfly, it lumbered away with its distinctive load of little red hitchhikers clinging to its thorax...
- Author: Kathy Keatley Garvey
It's not often you see a monarch butterfly and a digger bee in the same photo.
Such was the case on a recent visit to a lantana patch at a west Vacaville home.
The monarch butterfly touched down on a blossom and was beginning to nectar when along comes a digger bee, a male Anthophora urbana (as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at the Universit of California, Davis.)
"Maybe it was planing on dive bombing the big intruder from his territory," Thorp said. "However, these males are not known to be especially territorial. Maybe he's just checking out the competition for nectar."
This is the solitary, ground-nesting bee that Leslie Saul-Gershenz, graduate student in the Neal Williams lab at UC Davis, is researching. She's published research on a species of digger bee, Habropoda pallida, a solitary ground-nesting bee, and its nest parasite, a blister beetle, Meloe franciscanus, found in the Mojave Desert ecosystem.
Now she's also including Anthophora.
“Our preliminary data show that the blister beetle exploits four other native California bees including important pollinators in the genus Habropoda and Anthophora," she recently told us.
Historically, the blister beetle, Meloe franciscanus, was known to be a nest parasite of Anthophora edwardsii, distributed throughout California.
See her amazing photo of the parasitic larvae of the blister beetle on the digger bee, Habropoda pallida, on the UC Davis Entomology website.