I have some bad news for you. Bees evolved from wasps. *Gasp* I know, I was a bit conflicted as well when I learned that fun fact. We aren’t 100% sure how the evolution happened, but at some point, a wasp had a run-in with some pollen, began to consume it, and *poof* now we have honey bees who have a mutually beneficial relationship with flowers.
In fact, flowers evolved alongside bees to be more colorful and to be richer sources of pollen. When I learned this, I started to wonder how bees decide what flowers to visit and if they have taste preferences when it comes to pollen. Though bees gather the pollen on their legs or even on the hairs on their abdomen (I’m looking at you, mason bees), the adult bees don’t consume it. They bring pollen back to the hive to be repurposed into bee bread for developing larvae.
Through my research, I found out there are many different ways honey bees decide which flowers to visit, including color, taste, patterns, popularity, and even electrical fields. Let’s talk about each of these factors.
Take a moment to look at the pollen-laden plants in your neighborhood and you will see they contain a wide variety of pollen colors. Pollen can range from blue to yellow to red to green and everything in-between. In fact, you can notice the color differences both on the pollen baskets of honey bees and in the bee bread inside the hive.
Vegetation develops depending on the climate, the soil pH, moisture levels, soil drainage, and winter maximum and minimum temperatures. The plants we see outside are a function of our overall climate and growing conditions. Looking at the native flora in your area, it’s important to note bees seek out flowers depending on colors that are most noticeable to them.
Let’s back up and briefly discuss how bees’ eyes work.
Bees don’t see as many colors as we do, but they see a wider range within the colors they do see. They are trichromatic, just like us, however, the three base colors they see are ultraviolet, blue, and green. In fact, they even see what’s called “bee purple”, which is a mixture of yellow and ultraviolet. This color is not visible to the human eye. Bees cannot see red, which is why you may have heard they are most attracted to blue, purple, yellow, and white flowers. These are colors they can easily see.
Bees have other special skills when it comes to seeing the flower colors. First of all, they see color much faster than we do. They have a higher flicker threshold, which means they can distinguish colors even when flying past them at high speeds. Additionally, they can see iridescence, which means they can notice variations in colors based on the angle of the petals.
Put all of this together, and you have bees that seek out the colors of flowers most recognizable to them. In fact, if they don’t see flowers they want to visit, they will travel further to find them. Bees will also do more vigorous waggle dances for their fellow worker bees if there is a source of forage nearby with a wide variety of blooms. Bees know they need variety in their diet and they will seek out a variety of flowers.
Have you ever eaten pollen before? I admit I have — as an additive in my smoothies years ago. I wanted to like how it tastes, but it definitely can’t compete with a plate of fresh pasta with pesto or a bowl of vanilla ice cream with fresh strawberries. Plainly, it doesn’t taste good. Kind of chalky and fuzzy and bland.
Many a scientist wonders if bees can taste pollen as well and if they *also* would rather eat something else.
There’s a lot we don’t understand about taste perception in honey bees, but we do know that they tend to reject highly concentrated bitter and saline tastes. While I didn’t find a ton of studies into honey bee taste preferences, I did find one that explored bumblebee taste preferences, so take it with a grain of… sugar? While we obviously can’t apply the results to honey bees, understanding the behavior of any species of bee can be useful, at least for planting our gardens.
In the aforementioned study, scientists used six colonies of bumblebees and conducted multiple trials with each. They tagged the bees for documentation purposes and recorded their body temperatures using thermal imaging software.
In the study, scientists set up artificial flowers with anthers covered in a sucrose solution and anthers covered in a quinine solution. If you’re not aware, quinine is a component used in anti-malarial medication as well as in tonic water and has a distinct, bitter flavor. When they released the bees into this simulated floral environment, they ultimately spent three times as much time on the sucrose covered anthers.
The bees made return trips to all the flowers and it is during these return trips that scientists noted the bumblebees visiting the sucrose-covered flowers in lieu of the quinine covered blooms. This could indicate the bees don’t taste the pollen until they are in flight and then return to the flower where they harvested it.
What does this tell us?
Bees like it sweet and bees may not taste the pollen until after they depart from the flower. Flowers that contain richer, sweeter sources of nectar are more likely to attract pollinators and as a result, the pollen from these flowers is more likely to be dispersed.
Are you ready to go deeper into bee behavior? The behavior of bees transcends just color and taste. Yes, these small, short-lived insects can be incredibly complex in their habits. Take the example of flowers. We’ve already established color is important, but did you know bees also pay attention to patterns on flowers?
Some flowers have what’s called a nectar guide, which is a pattern on the petals that literally guides bees towards the nectar inside. These intricate patterns are intriguing for bees, to begin with, but they also facilitate learning; if a bee visits a flower with a particularly alluring nectar guide, and gets a sweet treat of high-quality nectar, they will look for flowers with similar patterns in the hopes of repeating their sugary find.
This benefits the flowers, too, as it keeps bees visiting flowers of their species and increases their chance of being successfully pollinated.
Remember how bees see in ultraviolet light? A simple, monotone flower to our eyes may actually have a nectar guide in the UV spectrum. Bees may be visiting a flower not just for its color, but also for a nectar guide we can’t even see.
Flowers carry a negative charge. Bees acquire a positive charge by bumping into small particles in the air as the fly, like dust particles, for example. When a positively charged bee travels to a negatively charged flower, pollen particles can jump to the bee before they even officially land on the petals.
Since bumblebees are often a popular species to study, it should come as no surprise that scientists recently looked into the electrical field that exists between flowers and bees using bumblebees as their test subjects.
Dominic Clarke and Heather Whitney from the University of Bristol recently studied bumblebees and proved they can sense this electric field.
For their study, they set up artificial purple topped flowers with designer electric fields. Then, they charged some of the flowers and covered them with a sugar solution and left some of the flowers uncharged, but covered with a bitter solution. The bees visited the charged flowers 81% of the time. If none of the flowers were charged, the bee would not visit them, even if the sugar solution was still there.
Clarke and his study lead, Daniel Robert, a sensory biologist, found bumblebees could recognize different shapes of sensory fields. In order to prove this, they took flowers of different sizes and shapes and sprayed them with different colors of electrically charged particles, applied in different patterns on the flowers. The bumblebees could tell the difference between the electric fields with 70% accuracy. That may not seem like an outrageously high percentage, but C’s are passing grades, even for bumblebees.
During another phase of their experiment, Roberts, Clarke, and Whitney set up two e-flowers with different shades of green. It took bumblebees 35 visits on average to be able to distinguish between the two shades. When they added an electric field to one of the flowers, it took the bees 24 visits on average to distinguish the shades.
It’s clear bees seem to recognize electric fields on the flowers they visit, but the unanswered question is how?
Our best guess? The electric field actually moves bees’ bodies slightly and they recognize this motion as the presence of the field. They recognize the presence of an electric field means pollen they can gather and bring home for their young.
When bees see other bees flying around flowers, collecting pollen and nectar, they recognize those other bees are on to something.
In the previous section, we talked about the bees’ ability to recognize electric fields. It goes one step further; bees increase the electric field of a flower by 25 millivolts when they visit it. This serves as a signal to other bees that the flower may be empty, drained of nectar by its previous visitor.
For some flowers, it benefits them to be truthful in signaling their nectar status to bees. If they repeatedly deceive the bees, the bees learn the flowers are in fact devoid of the resources they seek and will move on to other forage areas. For other flowers, they will “lie” as they don’t require as many visits as other flowers in order to achieve pollination. These flowers are more invested in quick turnaround than the long game with their neighborhood bees.
In any case, bees can sense these changes in the electric fields and will adjust accordingly.
For this study, scientists set up a mock foraging environment in a laboratory. They allowed a quantity of bees to forage while other members of their colony watched from behind a screen. Then, they swapped the groups and found that the bees who watched behind a screen visited the flowers they saw their colony members forage on minutes before.
These bees observed the behavior of other bees and trusted that if another bee visited a flower, it must be a good source of nectar and pollen. There’s power in numbers.
These small creatures are incredibly complex and have the ability to learn and respond to their environments, sometimes even more adeptly than we do.
While a lot of the studies I found featured bumblebee behavior, a great next step would be for these studies or the hypotheses they tested to be tested with honey bees. Honey bees are a different species than bumblebees and it would be great insight to know if they also behave similarly to bumblebees as it could inform how we support our beehives and create ideal forage environments in our own yards.
We can’t underestimate the importance of nutrition when it comes to raising bees, and as far as the bees are concerned, nectar and pollen are gold.