While some plants are wind-pollinated or pollinated by other insects and animals, bees account for the vast majority of pollination services throughout the world. The process of bee pollination is beneficial to both the plants and the bees, as plants need an efficient way to create seeds and bees need pollen to supply protein to their colonies.
What Is the Importance of Pollination?
Pollination is the movement of pollen grains from the male part of a flower (stamen) to the female (pistil). Without pollination, plants would not be able to reproduce, so plants that are not able to move the pollen themselves (self-pollination) must rely on an outside pollination mechanism to do so.
Without pollination to produce new seeds, plants would cease to grow, which would be devastating to our ecosystem and our food supply.
Why Are Bees Good Pollinators?
Here are the main reasons bees make such good pollinators:
- Their size and shape make them uniquely able to access parts of particular flower species that other pollinators have trouble entering.
- The fur on their bodies provides an efficient mechanism for transferring pollen within a flower and to other flowers they visit on their foraging trips.
- Buzz pollination – or sonication – is a unique and effective method for loosening pollen from the stamen so it can be transferred to the pistil.
- Various bee species have different life cycles and emerge ready to forage at different times of the year. That means flowers will have access to pollinators during most or all of their blooming seasons.
- The bees are motivated to pollinate because they need the pollen and nectar produced by the plants. This symbiotic relationship ensures that plants and bees will work together to get what they need.
How Do Bees Pollinate?
Honey bees disperse pollen by simply landing on a flower. When they hop from bloom to bloom, the fine grains of pollen dust is released into the air and come down to settle into their statically-charged hairs. They then move the pollen down their bodies and into a receptacle called the corbicula on their hind legs. The corbicula is also known as the “pollen basket.”
While they are collecting pollen for their own purposes, the grains move from the male part of the plant to the female part, which eventually results in an “offspring” seed.
Bumblebees and solitary bees shake the pollen from a flower using a method called sonication. It’s also referred to as “buzz pollination.” The bees contract their indirect flight muscles so rapidly that it produces vibrations strong enough to expel pollen from a flower’s anthers.
Most of these bees don’t have a corbicula but do have an area of dense hairs called the scopa. Here the pollen settles and will stay secure while they fly back to the nest.
How Do Bees Know Which Plants and Flowers to Pollinate?
It seems reasonable to assume bees would be attracted to flowers based on visual and scent cues. Bright colours and a sweet nectar smell, for example, will likely be seen as favourable foraging plants.
One way bees can determine if a flower is a good pollen source is through the science of electricity. Pollen has a negative charge, while bees’ charge is positive. When flying through a field or meadow, bees are able to detect an electric charge, and this cue lets them know where pollen can be found.
And it’s not just nectar that has a scent – pollen does too. Bees can sniff out a good pollen source while foraging. But how do they know if the pollen is of high quality and nutritious? The truth is that honey bees won’t be able to get direct evidence of a pollen’s quality because they don’t sample it, and the only bees back at the hive who do taste it is the nurse bees since they must ingest it to manufacture royal jelly.
Recent studies have shown that even the nurse bees may not be using nutritional quality to determine which pollen they will use to make royal jelly. It is possible that any feedback foragers receive from the hive may come only after it is known how the health of the colony has responded to the pollen used by the hive.
But bumblebees do sample the pollen while foraging. A substance on the surface of the pollen called pollenkit contains free amino acids and fatty acids, and bumblebees can taste it to determine if the pollen has a high protein-to-lipid ratio. Using either their antennas or mouthparts, bumblebees can detect whether or not a particular pollen is nutritious.
How Do Plants Attract Bees?
Thinking about a particular flower’s “motives” in attracting pollinators to disseminate its genes, it would be reasonable to think that each plant or flower species would emit unique cues to help identify itself to the bees seeking its rewards.
Logic would have one believe that all flowers in the same colour family would be able to distinguish themselves with unique scents or that flowers with similar scents would try to differentiate themselves with contrasting colours. This is what is called a competitive view of flower evolution.
But reports published in two scientific journals suggest that flowers take a different approach to attracting pollinators. Instead of trying to stand out as a unique species, different flower species tend to “work together” to send out reliable signals that will attract a greater number of pollinators to the area.
This way, they are encouraging many bees to visit even if flowers from another plant species are pollinated when foraging occurs.
There are also plants that try to repel pollinators because they lose too much pollen when bees transport it away. These plants work to protect their pollen reserves by producing toxins that make bees ill. Having had a bad experience with a particular flower, a bee will learn not to visit it again.
How Many Plant Crops Will the Average Bee Pollinate in Their Lifetime?
The average honey bee can visit 5,000 flowers in a single day. If the average lifespan of a worker bee is around 8 weeks (given the most generous estimate), and the worker bee begins foraging at around 10-days-old, the forager will “work” for about 46 days. Multiply 5,000 by 46 and the result is 230,000 flowers in the bee’s lifetime.
This figure will, of course, differ among bees of other species as their life spans may vary.
What Type of Bee Pollinates the Most?
An ecologist from Wageningen University in the Netherlands gathered data from a team of 58 researchers who had observed and identified nearly 74,000 bees across five continents.
Their data concluded that about half of the pollination for commercial crops was done by Apis mellifera – the commercially managed species of honey bees. The remainder of the crop pollination was the work of wild bees, with bumblebees coming in second place.
But when identifying pollination of plants other than commercial crops, it was wild bees that did most of the work, foraging mainly on wild plants. And these plants, although not directly associated with an economic value, are vital for the ecosystem since they feed birds and other kinds of wildlife.
Do Bees Pollinate Fruits and Vegetables?
Bees pollinate more fruits than vegetables, but there are some well-known vegetables pollinated by bees:
Bees pollinate trees, and among the most common trees they pollinate are fruit trees (apples, peaches, pears, plums), maples, lindens, and black tupelo (where the flavorful tupelo honey is sourced.
Bees also pollinate some lesser-known trees, such as American Sweetgum, Sourwood, Crapemyrtle, Serviceberry, and Black Locust.
What Effects Do Bees Have on Fruit That Has Been Pollinated and Fruit That Hasn’t?
Despite the fact that some fruits are known to be self-pollinating, they may produce a better quality and higher-quantity harvest when they are cross-pollinated with other plants of either the same or different species.
For example, strawberries and raspberries can self-pollinate but reap benefits when they receive pollen from a different raspberry plant. They would not be able to access this pollen on their own but need a bee or other pollinator to transfer it while they are foraging.
Similar to strawberries and raspberries, self-pollinating apple varieties like Granny Smith, Golden Delicious, and Braeburn will produce more fruit if cross-pollinated.
Do Bees Pollinate Sunflowers?
Bees love sunflowers due to their giant, colourful heads which boast an ample supply of nectar and pollen. Also, the central part of each flower’s head has its own supply of nectar and pollen in smaller individual tubes. Honey bees are the primary commercial pollinator of sunflowers, but tall flowers are also favoured by bumblebees and many other wild bees.
Do Bees Pollinate Grapes?
Most grapes that are cultivated are hermaphroditic, so bees are not necessary for their pollination.
But bees still help grapevines to grow by pollinating other plants – like grasses – that deplete nitrogen. Since nitrogen balance is essential for vine health, many wineries depend on the presence of bees in their vineyards to provide optimal soil conditions.
Do Bees Pollinate Cotton?
Although many cotton plants are self-pollinated, others require the assistance of animal pollinators like bees. Studies have shown that the cotton bolls pollinated by insects (bees included) are fluffier and more weighty than those that are merely self-pollinated. When cotton bolls are larger and heavier, the cotton yield is greater, and that means higher profits for those who grow the plants.
Do Bees Pollinate Hops?
Hops are primarily wind-pollinated, and honey bees don’t seem to be interested in what the plants have to offer. However, hops may be able to provide something that bees weren’t expecting: protection from varroa mites. Hop beta acids (HBA) extracted from Humulus lupulus are being used to repel pests. In a 2012 study, 100% of mites that were wiped with a 1% HBA solution died. HBA is a natural pesticide and is not harmful to bees or humans.
Do Bees Pollinate Vanilla?
The plant most often used for commercial vanilla production is the Vanilla planifolia, also known as Flat-Leaved Vanilla. The plant is native to Mexico but is now grown mostly in Madagascar and Indonesia. It’s a very difficult plant to pollinate using animal pollinators because its anatomy makes it difficult for a typical honey bee to access it.
One of the only bees capable of pollinating Vanilla planifolia is Melipona beecheii, native to Mexico. This bee has had to face hurricanes, pesticides, and threats from the logging industry, and is now considered endangered. Due to the rarity of the Melipona bee, the commercial vanilla industry depends on hand-pollination, which is a time-consuming and labour-intensive process. That’s why vanilla beans are so costly.
Do Bees Pollinate Cannabis?
Most cannabis plants are wind-pollinated, although animals do provide a fraction of the pollination. It’s not a colourful plant, and it doesn’t have a smell that’s attractive to bees. But the main reason bees tend not to pollinate cannabis plants is that it doesn’t contain any nectar.
Although the male cannabis plants do provide some pollen, it’s thought to be a coveted source only during a pollen dearth.
Are There Problems With Bee Pollination?
While bees make up the majority of pollinators, there is a danger in relying on only this insect family to take care of all pollination services.
Disease, parasites, pests, and commercial management of honey bees pose threats to the business of pollinating worldwide. With honey bees – a mostly managed species – contributing to over 80% of the cultivated crop pollination, it’s risky to depend on them when they have recently been prone to threats like varroa mites, murder hornets, and diseases. And disease can very likely spread from honey bees to other bee species.
Non-bee insects like flies and wasps also play a significant role in pollinating crops and are more adaptable to changes in land use than are bees. They also tend to make more visits than bees to wild, native plant species. If bee populations continue to decline, non-bee insect pollinators may be able to pick up some of the slack.
What Would Happen if Bees Didn’t Pollinate?
If bees did not pollinate, there is no reason to think that humans would become extinct. Many plants are self-pollinated, wind-pollinated, or pollinated by other insects and animals.
However, bees are responsible for pollinating one-third of the world’s crops, and if these fruits and vegetables were absent from our diets, humans would face a nutritional deficit. The problems would be worse in poverty-stricken regions of the world that are already dealing with a lack of nutritious food options.
Also, given that many of the animals we eat rely on feed that is a direct result of bee pollination, humans would see a shortage of meats and dairy products. Because of classic supply and demand theory, the products that were available would likely be unaffordable for those who are socioeconomically challenged.
Are There Other Pollinators Besides Bees?
Even though bees do the majority of pollinating, other insects like butterflies, moths, wasps, beetles, flies, and mosquitos are pollinators as well. Birds and bats also pollinate, and even some small mammals (rodents, shrews, and marsupials) can be counted as pollinators.
If a Bee Pollinates a Crop or Fruit Can It Still Be Considered Vegan?
Vegans seek to avoid – as far as is possible and practicable – the exploitation of or cruelty to animals. That belief applies mainly to food but also holds true for clothing and other items.
The reason vegans do not eat honey is that beekeepers – according to their definition – exploit honey bees by robbing their hives of honey to sell for human consumption. Some see pollination as just a byproduct of the bees’ foraging activities. It’s not like they were intending to pollinate crops- the bees need the nectar and pollen the plants provide, and they do not care about the fruits and vegetables that result.
But others see it differently, especially for managed bees that are used for agricultural purposes at huge factory farms. It is easier to see these actions as exploitative, and possibly harmful, due to the rise in monoculture plantings that reduce biodiversity. For vegans who see bees being treated like a commodity, they would absolutely agree that crops pollinated by bees are taboo.
The question vegans must answer is whether any animal participation is forbidden or just that which appears to exploit the bees. It is a question that is not easily answered, and a subject of debate for many who practise veganism.