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.
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 firstname.lastname@example.org 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.
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...
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.
If that word is not in your everyday vocabulary, just think of a symbiotic relationship where one organism transports another organism of a different species for the benefit of both.
And there you have it--at least part of it--of what evolutionary ecologist Leslie Saul-Gershenz of the University of California, Davis, is doing.
Saul-Gershenz researches 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.
She and Neal Williams (her major professor) of UC Davis and Jocelyn Millar of UC Riverside just received a grant to study digger bee ecology and conservation. They're working with SaveNature.Org, which Saul-Gershenz co-founded.
The relationship between the bee and the blister beetle is part of it.
What's this symbiotic relationship about? 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, Saul-Gershenz says.
Like to read more about this exciting research? Saul-Gershenz and Millar published their blister beetle/digger bee work, "Phoretic Nest Parasites Use Sexual Deception to Obtain Transport to their Host's Nest," in the Proceedings of the National Academy of Sciences (PNAS, 2006).
That led Pulitzer Prize-winning author Natalie Angier to feature their work in "The Art of Deception," published in the August 2009 edition of the National Geographic magazine. Most recently, U. S. Department of Agriculture (USDA) Forest Service entomologist Michael Ulyshen, writing for the Journal of Natural History, mentioned their work in "Bugback Riding: Transportation for the Masses" (September 2011).
Saul-Gershenz said she became interested in the subject while she was a graduate student at San Francisco State University. She wrote "Beetle Larvae Cooperate to Mimic Bees" in the journal Nature (2000).
Of her newest grant, she says: “Our preliminary data show that the blister beetle exploits four other native California bees including important pollinators in the genus Habropoda and Anthophora." Historically, M. franciscanus was known to be a nest parasite of Anthophora edwardsii distributed throughout California.
You may know Saul-Gershenz as a past president of the Pacific Coast Entomological Society. In 1991, she became the first female president in its 91-year history.