How bees see: Tiny bumps on flower petals create intense color and attract pollinators

How bees see: Tiny bumps on flower petals create intense color and attract pollinators
by Adrian Dyer and Jair Garcia, The Conversation
July 26, 2021

The intense colors of flowers have inspired us for centuries. They are celebrated through poems and songs praising the red of roses and blue of violets, and have inspired iconic pieces of art such as Vincent Van Gogh’s sunflowers.

But flowers did not evolve their color for our pleasure. They did so to attract pollinators. Therefore, to understand why flowers produce such vibrant colors, we have to consider how pollinators such as bees perceive color.

When observed under a powerful microscope, most flower petals show a textured surface made up of crests or “bumps.” Our research, published in the Journal of Pollination Ecology, shows that these structures have frequently evolved to interact with light, to enhance the color produced by the pigments under the textured surface.

Sunshiney daze
Bees such as honeybees and bumblebees can perceive flower colors that are invisible to us—such as those produced by reflected ultraviolet radiation.

Plants must invest in producing reliable and noticeable colors to stand out among other plant species. Flowers that do this have a better chance of being visited by bees and pollinating successfully.

However, one problem with flower colors is sunlight may directly reflect off a petal’s surface. This can potentially reduce the quality of the pigment color, depending on the viewing angle.

You may have experienced this when looking at a smooth colored surface on a sunny day, where the intensity of the color is affected by the direction of light striking the surface. We can solve this problem by changing our viewing position, or by taking the object to a more suitable place. Bees, on the other hand, have to view flowers in the place they bloom.

We were interested in whether this visual problem also existed for bees, and if plants have evolved special tricks to help bees find them more easily.

How bees use flower surfaces
It has been known for some time that flowering plants most often have conical-shaped cell structures within the texture of their petal surfaces, and that flat petal surfaces are relatively rare. A single plant gene can manipulate whether a flower has conical-shaped cells within the surface of a petal—but the reason why this evolved has remained unclear.

Past research suggested the conical petal surface acted as a signal to attract pollinators. But experiments with bees have shown this isn’t the case. Other explanations relate to hydrophobicity (the ability to repel water). But again, experiments have revealed this can’t be the only reason.

We investigated how bumblebees use flower surfaces with or without conical petal shapes. Bees are a useful animal for research as they can be trained to collect a reward, and tested to see how they perceive their environment.

Bumblebees can also be housed and tested indoors, where it is easier to precisely mimic a complex flower environment as it might work in nature.

Flowers cater to a bee’s needs
Our colleague in Germany, Saskia Wilmsen, first measured the petal surfaces of a large number of plants and identified the most common conical surfaces.

She then selected some relatively smooth petal or leaf surfaces reflecting light from an artificial source as a comparison. Finally, blue casts were made from these samples, and subsequently displayed to free-flying bees.

In the experiment, conducted with bumblebees in Germany, a sugar solution reward could be collected by bees flying to any of the artificial flowers. They had to choose between flying either towards “sunlight”—which could result in light reflections affecting the flower’s coloration—or with the light source behind the bee.

The experiment found when light came from behind the bees, there was no preference for flower type. But for bees flying towards the light, there was a significant preference for choosing the flower with a more “bumpy” conical surface. This bumpy surface served to diffuse the incoming light, improving the color signal of the flower.

The results indicate flowers most likely evolved bumpy surfaces to minimize light reflections, and maintain the color saturation and intensity needed to entice pollinators. Humans are probably just lucky beneficiaries of this solution biology has evolved. We also get to see intense flower colors. And for that, we have pollinators to thank.

OSU study will provide insight into optimal nutrition for bees

OSU study will provide insight into optimal nutrition for bees
July 26, 2021

CORVALLIS, Ore. – A new grant will allow Oregon State University researchers to study the nutritional value of more than 100 bee-pollinated crops, native plants and commonly used ornamental plants, a project that could help scientists better understand the global decline of bee populations.

Certain plants attract bees more than others, but whether those flowers contain the optimal nutrition needed for the insects has yet to be determined. The grant will allow researchers in the Honey Bee Lab led by Ramesh Sagili, OSU associate professor of apiculture and OSU Extension specialist, and Priyadarshini Chakrabarti, former OSU research assistant and new assistant professor at Mississippi State University, to begin to fill that knowledge gap.

With the $500,000 grant from the U.S. Department of Agriculture’s Agriculture and Food Research Initiative, the team hopes to improve bee nutrition by building a database of macro and micronutrients found in the flowering plants used in the study. Poor nutrition due to agricultural mono-cropping and loss of habitat is an important factor in bee declines and the researchers anticipate alleviating this problem by providing better forage choices for bees backed by science-based results.

In addition to beekeepers, land managers, conservation groups will benefit from the data base. The public also will be able to use the information to choose the most nutritious plants for both native and managed bees.

With global decline in both native and honey bee populations and given the importance of honey bees for commercial pollination of hundreds of crops, choosing the best supplemental forage can help mitigate poor nutrition in bees. Well-nourished bees can also better withstand things that plague them like Varroa mites, pesticides, parasites and loss of habitat.

“If you look at it from the human side, the healthier you are, the better you can fight off diseases, parasites and other health issues,” Sagili said. “With a better immune system, you’re stronger and more resilient. It’s the same with bees. Nutrition is their first line of defense against stressors.”

Optimal nutrition has been shown to enhance resistance to stressors and increase survival and longevity, according to Chakrabarti. Even though there has been much research done to determine the causes of honey bee decline, few studies have addressed the underlying problems of bee nutrition.

For the past few years there has been a significant movement to improve nutrition and increase habitat for bees and to provide better forage, Chakrabarti said. For farmers, it’s important to understand the nutrition contained in pollens from significant crops like almonds in California, a $7 billion industry that relies on honey bees for pollination.

“There are efforts geared toward famers so that they can plant supplemental forage adjacent to their orchards or fields to provide the additional nutritional resources that bees need,” Sagili said. “Seventy-five percent of honey bee hives managed by beekeepers in the United States go to California’s Central Valley in February to pollinate the almonds and they need forage before the almonds come into bloom. That’s a big, big problem. There might be some wild mustard or dandelion, but it’s really meager and there is no other source of pollen for bees.”

Beekeepers feed the honey bees with sugar syrup and protein supplements when natural forage is unavailable, which is not the optimal diet but can sustain bees for the short term.

The impacts of certain fungicides – called sterol biosynthesis inhibitors or SBI – will also be investigated to determine their effect on the availability of pollen sterol and bee health, Sagili said. Pollen sterols are a type of lipids that are required for development and growth of bees. Findings from examining the impacts of SBI fungicides on sterol availability in pollen will not only show how these widely used fungicides may affect bees, but also demonstrate for the first time if this group of fungicides could compromise the quality of pollen.

Sagili and Chakrabarti are looking for community scientists to help with the study. Those interested in participating can contact Sagili at 541-737-5460; or, and Priya Chakrabarti at

Citrus Blossom Honey Samples Needed

TBA is a member of the American Honey Producers Association and received a call for citrus blossom honey samples for research purposes – please read below if you’re interested in participating.

Hello Honey Industry Partners!We would appreciate your assistance in spreading the word on our continuing research project. We are collecting samples of citrus blossom honey from locations in North America. There is a sample collection form included (download here: ). We are requesting 118 mL/4 oz samples. Senders are not responsible for costs related to testing. These samples will be collected by QSI America and the testing will be used to support a future identity standard for citrus blossom honey.

Timing is a bit urgent to obtain samples this season. The sooner you are able to share this opportunity with your constituents, the better this project will be. Thank you for your support!

The USP Honey Expert Panel On behalf of
Norberto Garcia, Chair and
Gina Clapper, Senior Scientific Liaison with FCC and US Pharmacopeia

Please contact Gina with any questions or comments (

Why honeybees may be key to understanding alcohol addiction

Why honeybees may be key to understanding alcohol addiction
Worker bees experienced withdrawal symptoms when alcohol was removed from food.
ByJulia Jacobo
June 15, 2021, 5:01 PM • 5 min read

The behavior of honeybees may hold the key to future studies of alcohol addiction, according to new research.

Worker honeybees that were fed alcohol-spiked food, a sucrose solution with about 1% ethanol added, for a long period of time experienced withdrawal symptoms when cut off from the solution, according to a study published Tuesday in the scientific journal Biology Letters.

Researchers from the Polish Academy of Sciences observed that when access to the solution was discontinued, the bees exhibited a “marked” increase of consumption of ethanol as well as a slight in crease in mortality, according to the study. The bees would then willingly consume sugar solutions with alcohol concentrations as high as 20% and then display behaviors similar to alcohol-intoxicated humans, including impaired locomotion, foraging and learning, researchers said.

The extent of the behaviors was dependent on how much ethanol was consumed.

The results of the study demonstrated that the worker bees could develop a dependence on alcohol, especially interesting considering that naturally occurring nectar is often contaminated by alcohol that fermented from yeast, the scientists said.

Among the honeybee workers, foragers outside the hive appeared to show the greatest resistance to the detrimental effects of the alcohol, likely due to evolution as the foragers occasionally encounter ethanol in nature, according to the study.

Honeybees not only willingly consume alcohol but are predisposed to alcoholism, according to recent research.

The results of the study provide new evidence of their suitability as a model for studying alcohol addiction, researchers said. Invertebrate model species are widely used to study alcoholism, according to the study.

“To understand alcohol abuse, the utilization of animal models is essential,” the researchers said.

Angelina Jolie Poses Covered with Bees to Raise Awareness for Conservation Efforts

Angelina Jolie Poses Covered with Bees to Raise Awareness for Conservation Efforts
Angelina Jolie said she felt “very honored” to participate in the National Geographic photoshoot
By Benjamin VanHoose
May 20, 2021 09:05 AM

Credit: Photograph by Dan Winters/National Geographic

Angelina Jolie got up close and personal with bees for her latest call to action.

Alongside a bold new portrait taken by photographer Dan Winters for National Geographic’s World Bee Day exclusive interview with Jolie, the star shared why it’s more important now than ever to protect the bee population.

“With so much we are worried about around the world and so many people feeling overwhelmed with bad news and the reality of what is collapsing, this is one that we can manage,” Jolie, 45, told the magazine. “We can certainly all step in and do our part.”

“I don’t think a lot of people know what damage they’re doing. A lot of people are just trying to get through their day,” she added. “They want to do good. They don’t want to be destructive. They don’t know which thing to buy. They don’t know which thing to use. So I think part of this is wanting to help it be simple for everybody, because I need that.”

Jolie — who has been designated the “godmother” for Women for Bees, a program launched by the United Nation’s UNESCO and Guerlain to train and support female beekeeper-entrepreneurs around the world — said it’s up to everyone to pitch in however they can.

“I have six kids and a lot happening,” she said, “and I don’t know how to be the ‘perfect’ anything. And so if we can help each other to say, ‘This is a way forward, simple, and this is something you can do with your kids.’ ”

As for how she pulled off the stunning snapshot, Jolie said she couldn’t shower for three days beforehand.

“It was so funny to be in hair and makeup and wiping yourself with pheromone,” the Those Who Wish Me Dead actress said. “We couldn’t shower for three days before. Because they told me, ‘If you have all these different scents, shampoos and perfumes and things, the bee doesn’t know what you are.’ … Then you put a few things up your nose and in your ears so you don’t give them as many holes to climb in.”

Chinese Flea Beetle

What’s Happening: APHIS plans to release 2 non-native pests (a moth & a beetle from China) to eventually eradicate the Tallow tree from Texas, and all the USA. Tallow has been in the USA since the 1700s and is an important source of nectar and pollen for up to a million beehives … Read more