Buzz power: How well a flower transmits vibrations might make it more attractive to a bee
Bees are attracted to certain flowers (and avoid others) for numerous different reasons such as the floral colors and aromas, the pattern of the petals, the electrical field surrounding a flower, and the nutritional or toxic content of the pollen. Of course, how all of these diverse qualities come together to create ideal attractiveness varies from one bee species to the next. But what if there is yet another floral quality that some bees also consider: how well a flower transmits their buzzing?
A recent study from the University of Stirling looked at three different ways that the buff-tailed bumble bee buzzes and creates vibrations: during flight, in defense, and while trying to shake pollen free from a flower. Even though all are generated by the same group of muscles, these buzzes are qualitatively different from each other in terms of velocity, acceleration, frequency and displacement.
“Think of vibrations as a kind of tool,” says Dr. David Pritchard, a post doc in Biological and Environmental Sciences at the University of Stirling and lead author of the study. “Our study shows that rather than having a single tool for all purposes, bumble bee vibrations are more like a toolkit, with different tools for different tasks.” Defensive buzzing from the buff-tailed bumble bee is louder because it’s likely more effective at scaring away a predator, while floral buzzing is faster because it’s likely more effective at dislodging pollen.
Floral buzzing is a particularly interesting behavior to look at because, as we all know, bees are intimately connected to the flowers they frequent. So Dr. Pritchard and his colleague, Mario Vallejo-Marín, also tested floral vibrations on two closely related species of nightshade, both of which attract and reward pollinators solely with pollen. And they found that one type of nightshade transmitted vibrations from buff-tailed bumble bees much better than the other. From the bee’s perspective, this means it would be easier and less costly to get pollen from one type of nightshade than the other – which is certainly something that could have an impact on the decisions this bee makes when foraging.
If this variability in transmission holds true across a wide range of flowering plants, it’s entirely possible that bees of all sorts would be faced with the challenge of only being able to buzz with enough power and speed to shake the pollen from some flowers but not others. Currently, says Dr. Pritchard, floral buzzing is mostly associated with bumble bees. But flower-buzzing bees come in a range of sizes, from very large carpenter bees to tiny sweat bees.
And, still, the one thing we don’t know yet is whether or not any of these bees consider how well a flower transmits their buzzing when making foraging decisions.
“There is still a lot we don’t know about buzz pollination,” says Dr. Pritchard. “But we are lucky that there is such a diversity of flowers and bees involved in buzz pollination for us to study.”
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Bee presentations from the annual meeting of the Ecological Society of America
The ESA held its annual meeting this week, entirely online. Bees and bee-related topics were well represented by the various presenters. You can search for "bee" and "bees" on the annual meeting website to find the abstracts. But to get you started, here are a few topics that I found interesting this year:
How bee identities and traits are affected by urbanization, Ourania Nikolaidis
Reproductive success of an endangered plant as invasive bees supplant native pollinator services, Alyson DeNittis
Potential roles for microbes in the interaction between leafcutter bees (Megachile spp.) and plants, Victoria Luizzi
Using next generation sequencing to decipher native bee foraging behavior, Lila Westreich
Conservation
Washington traps first Asian giant hornet
(WSDA) The hornet was found in a WSDA trap set near Birch Bay in Whatcom County. This was the first hornet to be detected in a trap, rather than found in the environment as the state’s five previous confirmed sightings were. “This is encouraging because it means we know that the traps work.”
Economics
USDA annual honey bee colonies report is available
(USDA NASS) The total number of colonies has increased, but so has the number of colonies lost to colony collapse disorder. Varroa mites are a top stressor. Read the full report. You can also read past reports.
Policy/Law
Lawsuit launched to protect Minnesota’s endangered rusty patched bumble bee
(Center for Biological Diversity) The Center for Biological Diversity filed a formal notice today of its intent to sue the city of Minnetonka for failing to protect endangered rusty patched bumble bees from a planned mountain-bike course in Lone Lake Park, home to one of the largest populations of the bee in the state. “The Endangered Species Act is 99% effective at protecting our most imperiled wildlife, but it can only work when its mandates are followed.”
Science
What’s the best method to monitor wild bees?
(Entomology Today) “Of methods to collect bees, sweep netting vastly outperformed all other methods in terms of the number of bees and number of species... I also found that there were huge disparities in the representation of honey bees and native bees according to sampling method.”
This rare, mutant honeybee is both male and female
(National Geographic) While checking his hives this June, a master beekeeper discovered something highly unusual. Whereas all the other honeybees in the hive had normal black eyes, one insect sported a pair of creamy yellow peepers that were impossible to miss. And that wasn’t all. When the beekeeper looked closer, he realized that not only were the bee’s eyes off-color, but they were abnormally large. In fact, they looked like the radar-dish eyes typical of male honeybees, or drones, despite the fact that the rest of the bee—the abdomen, stinger, and wings—were clearly female.
A guide to entomology outreach, even during a pandemic
(Entomology Today) Entomology outreach is an essential part of inviting the public to learn about and engage with insects. Frequently, graduate students are at the forefront of engaging the public in this field. However, not every graduate student is prepared to interact with a pre-entomologist, nor are they convinced that this is an important activity. Here is a beginner’s guide to initiating outreach.
Society/Culture
When it comes to de-stressing, Slovenians turn to bees
(NPR, audio) For centuries, the central European nation has used the sound of buzzing bees to relax its citizens. When students become restless in class, they go listen to the school's bee hive to de-stress.
Childhood connection to nature has many benefits but is not universally positive, finds review
(British Ecological Society) A recent literature review found that children are happier and more likely to protect the natural world when they have a greater connection to it, but this connection is complex and can also generate negative emotions linked to issues like climate change.
One More Thing…
Drawing with Ants by Amy Dyer: This is a nerdy exploration of ants, coding and digital art that results in some absolutely beautiful images.