Take the nectar of the sticky monkeyflower, Mimulus auranticus.
UC Davis community ecologist Rachel Vannette and colleague Tadashi Fukami of Stanford University decided to examine microbial communities inhabiting the nectar of the sticky monkeyflower at the Jasper Ridge Biological Preserve in California's Santa Cruz Mountains.
Their paper, "Dispersal Enchances Beta Diversity in Nectar Microbes," published in Ecology Letters, revealed that contrary to popular assumption, “increased dispersal among habitats can actually increase biodiversity rather than decrease it."
The flower, in the family Phrymacease, is a native shrub common in chaparral and coastal scrub habitats of California and Oregon. It is primarily pollinated by Anna's hummingbird. Other common pollinators include bumble bees, carpenter bees, and thrips.
Dispersal is considered a key driver of beta diversity, which is “the variation in species composition among local communities,” Vannette said.
They are the first to publish work showing that increased dispersal can increase biodiversity.
In their experiment, they reduced natural rates of dispersal by eliminating multiple modes of microbial dispersal. “Specifically we focused in nectar-inhabiting bacteria and yeasts that are dispersed among flowers by wind, insects and birds,” they said. “We imposed dispersal limitation on individual flowers and quantified microbial abundance, species composition and microbial effects on nectar chemistry.”
The scientists “manipulated dispersal of nectar-inhabiting bacteria and yeasts via flower-visiting animals to examine how dispersal influenced microbial beta diversity among flowers. Our analysis suggested that this unexpected pattern might have resulted from stronger priority effects under increased dispersal.”
This work has direct implications for conservation of many organisms in addition to bacteria and yeast, suggesting that preserving routes of dispersal among habitat patches may be important in the maintenance of biodiversity. In contrast to previous work showing that dispersal can homogenize communities or make them more similar, the published work demonstrates that dispersal can in some cases generate communities that are more different from each other. The authors hypothesize that this could be driven by priority effects, where early arriving species change the species that can establish within that habitat.
Why focus on nectar-inhabiting microbes? Previous work by Vannette and others shows that microbial activity in nectar can alter nectar chemistry and influence plant-pollinator interactions by altering nectar chemistry. In the Ecology Letters study, microbes were also found to change nectar chemistry, explaining ~50% of the variation in sugar composition in the field. This suggests that nectar-inhabiting bacteria and yeast can influence the nectar rewards available to pollinators in a natural setting.
More broadly, “Studying the role of microbes in the environment addresses one of the biggest mysteries in science,” Vannette says. In her current work, she and her lab are investigating how microbial communities form, change, and function in their interactions with insects and plants. They are also researching how microorganisms affect plant defense against herbivores and plant attraction to pollinators.
Vannette, a former postdoctoral fellow at Stanford, joined the UC Davis Department of Entomology and Nematology faculty as an assistant professor in 2015.
Vannette's research was funded by the Gordon and Betty Moore Foundation through the Life Sciences Research Fellowship. Stanford also funded the research through grants from the National Science Foundation, the Terman Fellowship, and the Department of Biology at Stanford University.
Native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at UC Davis, greeted a visitor on Feb. 14 in his office in the Harry H. Laidlaw Jr. Honey Bee Research Facility.
This visitor didn't talk, though. She buzzed.
And she buzzed right over to his window.
Well, hello, black-tailed bumble bee, Bombus melanopygus!
"Guess all one needs to do is sit and wait," he wrote in an email to bumble bee enthusiasts. "Eventually a gyne will find her way into one's office. This one was buzzing against my window just a few minutes ago trying to get back outside."
She came to the right place.
Thorp, a noted expert on bumble bees, is the co-author of Bumble Bees of North America: An Identification Guide (Princeton University) and California Bees and Blooms: A Guide for Gardeners and Naturalist (Heyday). He also teaches at The Bee Course, an annual workshop hosted by the American Museum of Natural History at the Southwestern Research Station, Portal, Ariz. (The Bee Course is meant for "conservation biologists, pollination ecologists and other biologists who want to gain greater knowledge of the systematics and biology of bees," according to the website. This year's course is Aug. 21-31.)
The black-tailed bumble bee, native to North America, is one of only 250 species worldwide in the genus Bombus.
What's next with Thorp's bumble bee?
A nest box in an almond tree near the Laidlaw facility--feed her some honey, make her feel at home, "then let her fly out, hopefully to return and establish a nest."
Insect photographer and naturalist Allan Jones of Davis discovered and photographed three Bombus melanopygus foraging on manzanita on Jan. 27 in the UC Davis Arboretum. In doing so, he won the science-based, friendly competition among a small group of bumble bee enthusiasts in Yolo and Solano counties searching for the first bumble bee of the year.
But Allan Jones went looking for his bumble bee; Thorp's bumble bee came to him...
How it all began: Pollination ecologist Neal Williams, associate professor in the UC Davis Department of Entomology and Nematology and postdoctoral researcher Rosemary Malfi set out to research how the short-term loss of floral resources affects bumble bees, specifically the yellow-faced bumble bee, Bombus vosnesenskii, a common bumble bee native to the West Coast of the United States. Its importance to agriculture, including the pollination of greenhouse tomatoes, cannot be overstated.
So, "the bee team," led by Williams, decided they needed to weigh the bees as part of their research. They engaged mechanical and electrical engineers on the UC Davis campus to see if they could come up with a "bee scale" to weigh individual foragers.
They could and they did. The project is underway in a field west of the central UC Davis campus. The site includes fine-mesh tents filled with wildflowers to contain the bumble bees and an RV converted into a lab.
Fell began his piece with "How do you weigh a bee?"
"That's the question that brought together insect specialists at the University of California, Davis, and two teams of UC Davis engineering students this year, to try and solve what turns out to be a tricky technical problem," Fell wrote. "But the consequences are important: ultimately, understanding how California's native bumble bees respond to changes in the environment and the availability of flowers, and how we can protect these insects that are so vital to both agriculture and wild plants."
The entomologists worked with electrical engineers Anthony Troxell, Jeff Luu and Wael Yehdego, advised by Andre Knoesen, professor in the Department of Electrical and Computer Engineering, and mechanical engineers Lillian Gibbons, Laurel Salinas and Ryan Tucci, advised by Professor Jason Moore.
Fell wrote: "The electrical engineers had to solve the problem of taking the raw signal from the scale and obtaining time-stamped data for individual bees."
“We were working with very small signals, at the low end of the technology, so noise in the data was an issue,” Troxell related in the news story. "A bumble bee weighs between 150 and 200 milligrams, and to get useful information about bee health or how much pollen they are carrying, the scale would need to be accurate to less than one milligram. A conventional laboratory balance averages several readings over a few seconds — but bees are much too fast and jittery for that to work."
Williams described the bee scale as "a great example of interdisciplinary work." And indeed it is.
This project is sure to gain national and international attention. It's not just about the plight of the bumble bees but the unique collaboration between entomologists and engineers and the resulting device they successfully designed and crafted.
It's so blond that all you can say is "Wow!" It's sort of like the Reese Witherspoon of bumble bees. But then the gender doesn't match. Okay, the Owen Wilson of bumble bees.
The male Bombus vandykei, commonly called "The Van Dyke Bumble Bee," is a treasure for three reasons, not necessarily in this order: (1) it's a pollinator (2) it's a bumble bee and (3) it's the color of golden wheat.
We spotted a male Bombus vandykei foraging in our lavender patch last night around 6. Its color reminded us of two other bees: the male Valley carpenter bee (Xylocopa varipuncta), a green-eyed blond bee nicknamed "The Teddy Bear Bee"; and the blondest of the blond honey bees, the Italian Cordovan. The Italian, Apis mellifera ligustica, is a subspecies of the European or Western honey bee, Apis mellifera.
The Van Dyke Bumble Bee gets around. The species is found in the Pacific Coastal states, including Washington, Oregon and California. The boys are extensively blond, but the girls aren't. In fact, the females are often confused with the yellow-faced bumble bee, Bombus vosnesenskii, and the black-faced bee, Bombus californicus.
Bombus vandykei is one of about 250 described species of bumble bees worldwide. All belong to the genus, Bombus.
Want to know more about bumble bees and how to identify them? Be sure to pick up a copy of Bumble Bees of North America: An Identification Guide (Princeton University Press), co-authored by bumble bee expert Robbin Thorp, distinguished emeritus professor of entomology at UC Davis, and fellow scientists Paul Williams, Leif Richardson and Sheila Colla. It won a 2015 Outstanding Reference Sources Award, Reference and User Services Association, American Library Association.
If you click on the Princeton University link, http://press.princeton.edu/titles/10219.html, you'll hear the buzz. That's the buzz of bumble bees beckoning us to listen to them.
Doom or gloom? Boom or bloom?
Today is Earth Day, and millions of folks around the world stopped--at least for a moment--to pay tribute to the 46th annual observance. They planted trees, weeded their gardens, greeted pollinators, or just thought about environmental issues.
Every Earth Day, we pay special attention to the tower of jewels (Echium wildpretii). The biannual, native to the Canary Islands, off the coast of Morocco, is a favorite in pollinator gardens, including ours. Seven feet tall and graced with pinkish blossoms splashed with blue pollen, it lives up to its name...tower of jewels.
Then it morphs into a tower of bees. Hello, honey bees, bumble bees, sweat bees and carpenter bees.
As they dive in, will they not only survive but thrive? If we each do our part, we can help the pollinators thrive.
Happy Earth Day!