You've heard about the "birds and the bees", but today we are going to tell you about the flowers and the bees, an ever more incredible love story!
Bees play an essential role in health and biodiversity of the ecosystem. This means they have a huge influence on our daily lives from the food we eat, the houses we live in, and the air we breath.
There has been a growing concern regarding the decline in bees and how it has impacted the ecosystem. In this blog post, we discuss the bees' impact on the environment, the reasons for the bees' decline, and give some tips on how we can help them not only survive, but thrive!
Bees and Pollination
Bees and flowering plants are completely dependent on each other for survival. In order to reproduce, approximately 90% of flowering plants depend on bees and other pollinators for cross-pollination (the transfer of pollen from one flower or plant to another flower or plant.) These plants include most of the plants that supply our basic needs like food, shelter, and oxygen. The bees, meanwhile, depend on the flowers to provide the nectar and pollen (the food that bees eat).
While bees are excellent pollinators, the process of pollination is completely incidental. The bees' goal is to collect as much food possible to feed larvae and to store food for the winter. Bees forage for food by putting their long straw-like tongues into the flower's nectary to suck up the nectar and nibble on the flower's anthers (male part) to detach the pollen (plant sperm). Once the pollen is detached, the bee will pass the pollen grains from leg to leg and, with a bit of nectar, stick the pollen into balls on their hind legs called pollen baskets. Nectar is the bees' source of carbohydrate and pollen is the bees' source of protein.
Foraging for pollen and nectar is a very messy job and the bees find themselves covered in pollen. The pollen grains stick to the millions of hair that cover the bee's body. Bees even have hair on their eyes! As the bee continues to forage, she will fly onto another flower - typically of the same plant - and the pollen that was stuck to her hair falls into the flower's pistil (female part) and fertilizes the plant's ovary. Once the plant is pollinated, the flower shrivels up and a fruit or vegetable, begins to grow in the ovary. Once the fruit is mature, it contains the plant's seeds. The fruit then falls from the plant or is eaten and relieved in which the seed plants itself into the ground and a new plant begins to grow!
Fun Fact: Bees are extremely organized! Whenever a honey bee leaves the hive for her foraging trip, which ever flower she first lands on she will only visit that same plant during the remaining of the trip. This allows pollination to be even more successful! Honey bees will even store all of the nectar in the same area in the hive, making it easy for beekeepers to harvest mono-floral honey like our blueberry, raspberry, and buckwheat honey!
Bees and Flowers - a bee-autiful love story
Although this co-dependent bond seems like a lucky coincidence, it is a relationship that has been in the making for millions of years! Bees and flowers evolved together creating this perfect harmony that the whole ecosystem relies on. Bees evolved from an ancient predatory wasp that lived around 120 million years ago. Much like our honey bees today, these ancient creatures would build their nests, defend their homes, and forage for food to feed their offsprings. Rather than foraging for pollen and nectar, these ancient wasps were carnivorous eating other insects similar to modern wasps.
Scientists believe that bees likely appeared at the same time as flowering plants about 146 to 74 million years ago during the Cretaceous period. Somewhere along the way, it seemed more beneficial to forage for pollen (protein) and nectar (carbohydrate) than to hunt for meat. Pollen varies from 2.5% to 61% protein depending on the plant variety. Beef is about 26% protein.
The transformation in the bees' diet was not their only evolutionary change. Bees developed physical traits that allowed for easier foraging. Their long straw-like tongues are able to reach deep into the flower to attain the nectary. They also have bristles on their legs, abdomen, and mouthparts to help detach pollen from the flowers and brush the pollen grains off their hairs onto their pollen baskets. According to the Mother Earth News, most solitary bees collect pollen on the bottom of their abdomen by belly-flopping onto flower blossoms, allowing a 95% pollination rate. Solitary bees can visit more than 2000 flower blossoms a day, making them efficient and important pollinators.
This co-evolution between the bees and flowers is so intricate that some specific flowers are only compatible with specific bees! Interested in learning more about bee evolution and behaviour, check out the Museum of the Earth's online exhibit about bees.
Meant to Bee
Since a bee's only goal when visiting flowers is to forage for food, flowers had to find ways to outmaneuver bees for more successful pollination! Flowers will typically only release a small amount of nectar and pollen at a time to encourage bees to visit multiple flowers. In the video below, you can see bees visiting multiple sage flowers. All flowers differ in shape, size, patterns, colour, and fragrances in order to attract different bees. Some flowers even have barriers and entrapments allowing only certain bees to access the pollen and nectar!
For example, the bee orchid lures male orchid bees who require its scent oils to attract female bees. The male bees are trapped by the flower long enough for it to deposit a sac of pollen onto the bee. Once he escapes, he spreads the pollen as he visits multiple orchid flowers to create the perfect cologne. Due to this mating behaviour, male orchid bees are essential pollinators to 600-700 different orchid species. This process is called Perfumed Pollination, which you can learn more about in the video below:
Another type of pollination is Buzz Pollination. There are over 22,000 plant species that have anthers (male part) that are completely sealed except for a small pore at the top allowing only certain species of bees to access the pollen. These poricidal anthers require buzz pollination, a technique bees use by holding onto flowers and vibrating their flight muscles to release the pollen. We commonly hear bumblebees performing buzz pollination in our pollinator garden while visiting wild roses! Not all bees are able to pull off buzz pollination, including honey bees, making them ineffective pollinators for certain plants.
Native bees, who are mainly solitary, are essential in pollinating our native plants. Trees and other plants that are pollinated by bees and other pollinators grow bigger and stronger than unpollinated ones. Sequentially, pollination helps strengths the soil, provides cleaner air, and feeds and gives habitat for wildlife. Overall, bees help bring a healthy ecosystem.
Bees and Farming
Due to the bees' role in pollinating plants, it is no surprise that bees play an essential role in agriculture. When you think of agriculture, you may be picturing fields of corn, soybeans, and wheat, which are mainly pollinated through wind-pollination. Approximately 30% of plant crops are pollinated by bees including most of our fruits, vegetables, nuts, spices, and most importantly ... chocolate and coffee ;)! For these plants, wind pollination is simply not enough.
Proper pollination improves the quality of the fruit by providing better yields, fruit size, nutritional value, and shelf life. Farmers rely on specific bees and pollinators to provide the best pollination for their companion plants. Bananas, mangos, and blue agave (base ingredient of tequila) are typically pollinated by bats. Commercial apple orchards rely on mason bees to pollinate apple blossoms. Mason bees are known to be 120 times more efficient in pollinating apple trees than honeybees. Even some fruiting plants require teamwork between different bees for proper pollination. For instance, bumblebees and solitary bees feed from different parts of strawberry flowers which this combination results in bigger, juicier, and more evenly-shaped strawberries.
To provide communities with the best yields, farmers have had to learn to work with nature. For example, tomatoes have very small flowers so they require buzz pollination in order to produce the best fruit but are often grown in greenhouses. As a way to adapt, SunTech Greenhouses in Manotick have bumblebee colonies in their greenhouses to help pollinate their tomato plants!
According to the U.S. Food and Drug Administration, pollinators provides about 15 billion dollars into the value of crops. Without bees and pollinators, we will be faced with food shortages and economical consequences. Wildlife would also suffer from the loss of food, habitats, and nesting grounds. Without the bees, there would be an unimaginable collapse in the ecosystem.
Why are bees declining?
Bees are faced with many threats including climate change, habitat loss, monoculture, and agricultural chemical use. Together these factors increasingly put stress on bee populations. Weaker bees and colonies are also more susceptible to parasites and diseases reducing their chances of surviving the winter.
While losses are typically low in Canada, this past spring (2022) beekeepers around Ontario are experiencing ground breaking losses between 50 to 80% of their honey bee colonies. These extreme losses have prompted us to write this blog post in hopes to encourage others to understand the importance of bees to our ecosystem and why these drastic losses are occurring.
Although we might think that having 25° celsius temperatures in early to mid May would be beneficial to bees, pollinators, and plants - instead, it can throw off the precise co-evolution between the bees and flowering plants. Plants have evolved to have different blooming times throughout the growing season to reduce competition with other flowers for pollinators. This has allowed bees to have food from early spring to late fall. However, if warmer temperatures encourage flowers to bloom earlier than their seasonal range, they may not coincide with the emergence of newly hatched bees, and may not benefit from their pollination. Flowers are now blooming a month earlier than they did 45 years ago.
According to Mother Earth News, climate change has also affected the migratory patterns for pollinators like butterflies. Researchers in Illinois recently confirmed that the eastern monarch has declined by 80% in the past 40 years and western monarchs by 99%. Climate change is believed to largely be responsible for the decline in butterflies, reducing from millions to less than 10,000 migratory butterflies seen in California since the 1980s.
The warm weather in early spring can also give parasites a longer breeding period, making it more difficult for bees to survive the winter. This is one of the leading theories for the high bee mortality observed over the winter 2021-22: it is suggested that the weather conditions in 2021 (early warm weather and long summer) allowed varroa mite populations to become stronger and more harmful to the bees, leading to high winter losses.
Diseases and parasites
Varroa mites (varroa destructor) are a significant problem for honeybees. These mites would be equivalent to humans having dinner size plate ticks on their backs. Left unchecked, varroa reproduce under the capped brood (larva) and their population can grow exponentially over the summer season. These parasites attach themselves to adult bees and feed off of the bees' fat bodies over the winter. They are also a significant vector for viruses and can lead to deformed wing syndrome and other honeybee illnesses. Monitoring varroa levels and using approved treatments for varroa are important actions beekeepers take to control varroa levels.
Urban development and intensive agricultural practice has resulted in major habitat loss for bees, pollinators, and other wildlife. Most bees find shelter and nesting grounds under leaves, in holes of trees, and the stems of dead plants. The lack of habitat reduces the bees' chance of surviving the winter. Solitary bees require certain dwellings to lay their eggs which the pupa (3rd stage of bee cycle) remain throughout the winter until the bee hatches out in the spring. Cleaning gardens, yards, forests, and other natural spaces in the early spring wakes the bees and other beneficial insects, forcing them to leave their refuge and resulting in death due to low temperatures.
Monoculture and Lack of Food Diversity
Along with habitat loss, intensive agricultural practices has taken away wildflowers to focus on monocultural plants as a method to keep up with the growing human population. Monoculture is practice of planting a single crop, often covering hundreds of acres. Most of the crops within this agricultural practice are wind-pollinated and the remaining crops that are pollinated by bees will only bloom a few weeks a year leaving little food for the bees.
Monoculture is not only practiced by farmers. The idea of having a perfect green lawn is also an example of monoculture that provide no benefit to bees and other wildlife. While agricultural monoculture is not great for the bees' diet, green lawns do not serve any purpose other than for aesthetics. Both monocultural practices are seen harmful to the survival of the bees.
Almond farming is just one example of the effect of monoculture farming on bees. Almonds bloom for a few short weeks in February and because these trees are planted in an enormous monoculture, there are insufficient wildflowers to support wild bees year round. As a result, in order to guarantee proper pollination of their trees, roughly 80% of all honey bee colonies in the United States are sent to California to pollinate the almond tree blooms. This intense practice can cause transportation stress for honey bees, risks of spreading diseases, and exposure to pesticides used on the trees. These honeybees may then out compete the remaining native bees who are already struggling to survive from the lack of food and habitat.