Imagine a solitary bee landing on a flower, grabbing the tube-like anther, and shaking it so hard that pollen flies out of it. This fascinating process aptly describes what happens in buzz pollination. Also called sonication, bees use this pollination technique to pollinate several types of plants and crops. In fact, buzz pollination is the primary way to pollinate tomatoes in a greenhouse.
The buzzword in the world of plants is “buzz pollination.” The flying pollinators make a “bee-line” for the anthers and use vibration to create high-frequency sounds to shake pollen from the anther cone. This fascinating phenomenon is one that still has many scientists “bee-mused.”
However, there has been a hive of activity among scientists to learn more about the science behind buzz pollination and its significance in plant reproduction. And the findings have been nothing short of bee-wildering.
This article sheds light on the incredible botanical boogie that takes place in buzz pollination when bees put on their best dance moves to shake it.
The Basics of Pollination
Pollination is a fundamental process in the reproduction of flowering plants. Pollinators transfer pollen from male flowers to female flowers of the same species. This transfer is essential for fertilizing and producing seeds, allowing the plant to reproduce, produce fruit, and ensure its survival.
Bees are the best-known pollinators. Studies show that honey bees (Apis mellifera) pollinate more than 130 types of fruits and vegetables and over 80 percent of all flowering plants. However, bumble bees (Bombus spp.) are two to four times more effective pollinators than honey bees. Interestingly, bumble bees are one of the species that utilize buzz pollination. In contrast, honey bees are unable to use this method.
What is Buzz Pollination?
Buzz pollination, or sonication, is a fascinating phenomenon in which certain bees use vibrations to extract pollen from flowers. Some flowers have pollen in tubular anthers that can only be extracted with the sonic vibration method. Therefore, this unique method of pollination has significant implications for both the flower and the pollinator.
How Does Buzz Pollination Work?
Buzz pollination works by the bees shaking the anthers of flowers so rapidly that they dislodge the pollen. The vibrations—also known as floral vibrations—create high-frequency audio sounds that cause the pollen grains to be forcefully ejected from the flower. The pollen is either distributed by the wind or hitches a ride on the bee’s back.
Crucial to the process of buzz pollination is the bee’s vibrations. Bees use vibrations to communicate, defend themselves, and collect pollen. In buzz pollination, the vibrations are called floral vibrations.
According to scientific research, bees use specific floral vibrations with different frequencies depending on the plant species.
Here is a step-by-step rundown of what happens during buzz pollination.
- Flower Selection: Buzz-pollinating insects, like bumble bees or certain solitary bees, seek flowers that require buzz pollination. These flowers have poricidal anthers, which have small openings to release pollen.
- Landing and Grasping: The bees land on the flower and use their legs and jaws to grasp the flower’s structure firmly. This provides stability for the upcoming vibrations.
- Floral Vibrations: The buzz-pollinating bees contract their flight muscles rapidly, causing high-frequency vibrations. This vibration travels through the insect’s body to its thorax and head.
- Dislodging Pollen: The rapid vibrations cause pollen to dislodge and get shaken out from the anthers. This releases clouds of pollen that land on the bees.
- Collecting Pollen: The pollen sticks to the bee’s hairy body.
- Pollinating Plants: After shaking the pollen out of the anther, the bees move on to the next flower and repeat the process. This repetition encourages cross-pollination as the insect transfers pollen from one flower to another.
What are the optimal buzz pollination frequencies?
The technical name is “fundamental frequency of floral sonication vibration.” In other words—how fast must the bee vibrate the anther to create a high-pitched sound and release pollen? Scientists say the optimal floral vibration for pollen release is 100 to 400 Hz.
Buzz Pollinator Bees Species
Not all bee species can pollinate flowers by the “shaking-all-over” method. And not all flowers require buzz pollination to be fertilized and produce fruit.
List of buzz-pollinating bee species:
- Bumblebees (Bombus spp.)
- Carpenter bees (Xylocopa spp.)
- Orchid bees (Euglossa spp.)
- Stingless bees (Melipona spp.)
- Sweat bees (Nomia spp.)
Each bee species has its unique preferences and capabilities as buzz pollinators. For instance, buff-tailed bumble bees (Bombus terrestris) and ridge-browed carpenter bees (Xylocopa frontalis) are effective pollinators of tomatoes in greenhouses. Generally, all bumble bee species are the exclusive pollinators for plants in the nightshade family (Solanaceae).
Which Crops Are Buzz Pollinated?
Buzz pollination is a unique process for pollinating several types of flowers, shrubs, and crops. Scientists estimate that around 9 percent of all flowers worldwide require pollination by bumble bees and other buzz pollinators. The most common buzz-pollinated crop is tomatoes. However, many more plant species require a “buzz” to get pollinated.
Plants that rely on buzz pollinators to reproduce:
- Tomatoes (Solanum lycopersicum)
- Blueberries and cranberries (Vaccinium spp.)
- Eggplants (Solanum melongena)
- Potatoes (Solanum tuberosum)
- Guinea flowers (Hibbertia)
- Rhododendrons (Rhododendron spp.)
- Flax lilies (Dianella)
- Sun pitchers (Heliamphora)
- Shooting stars (Primula sect. Dodecatheon)
Does Buzz Pollination Benefit Bees?
Buzz pollination is beneficial for bees because it allows them to extract large amounts of pollen from flowers efficiently. Rather than simply brushing pollen from flowers, these bees use their flight muscles to generate vibrations that dislodge pollen from the anthers.
By generating vibrations at the correct frequency and amplitude, bees effectively “shake loose” the pollen grains. The charged pollen grains also adhere to the bee’s body, aiding in their transfer from flower to flower.
However, while buzz pollination can benefit bees, it can also be a double-edged sword. Bees that engage in buzz pollination may also be effective pollinators of what some consider “weed” plants. These plants can be invasive and have potential ecological impacts if their populations are not properly controlled.
What Are Other Buzz Pollinators?
Bumble bees and several other bee species are known for their buzz pollination capabilities. Scientists still don’t know why other bee species, like honey bees, have not developed this technique. After all, buzz pollination is more effective for pollen and nectar extraction.
According to research, pollen-gathering hoverflies (Syrphidae) are capable of buzz pollination. Scientists observed that they could produce vibrations on a similar scale as buzz-pollinating bees. Scientists theorize that more buzz-pollinating flies could exist in nature.
How to Observe Buzz Pollination in Nature
Buzz pollination, also known as sonication or poricidal anther flicking, is a fascinating phenomenon observed when certain bee species visit certain plant species. To observe buzz pollination in nature, there are several key behaviors and characteristics to look for.
Tips on how to witness the fascinating way that bees pollinate flowers using vibrations:
- Identify plant species with flowers requiring buzz pollination for successful pollen release. These flowers typically have anthers with small slits.
- Look for buzz-pollinating bees. The easiest ones to spot are bumble bees—large, stout, hairy bees with black bodies, a yellow stripe, and a fluffy white tail.
- Without disturbing the bumble bee, watch carefully how it attaches to the flower’s anther. It then “revs” up to start its buzzing action.
By understanding and appreciating the vibrational properties and the symbiotic relationship between certain plant species and buzz-pollinating bees, you can gain a deeper insight into the incredible mechanisms of nature’s intricate pollination processes.
Buzz Pollination — FAQs
Buzz pollination is a fascinating phenomenon involving vibrations that certain bees create to extract pollen from flowers. Here are some commonly asked questions and answers about buzz pollination.
Is there a relationship between floral vibrations and bee size?
Yes, there is a relationship between floral vibrations and bee size. Different bee species produce vibrations with distinct vibrational properties, including the dominant frequency and vibration amplitude. These properties can vary depending on the bee’s thoracic muscles and the flower’s mechanical properties.
Can technology mimic buzz pollination?
The most common method to pollinate tomatoes artificially is by using an electric toothbrush. The vibrations of the toothbrush can mimic the way buzz pollinators operate. Other gardeners experiment with tuning forks to create high-frequency audio processes. However, they have limited success and are time-consuming.
A 2022 study in the United States aims to develop technological replacements to mimic the effect of bumble bees and other buzz pollinators.
However, for most gardeners, using real live bumble bees to pollinate crops like tomatoes, potatoes, and eggplants is cheaper and less time-consuming. But replicating the precise and intricate interactions between bees and flowers remains a challenge.
How can I support buzz-pollinating bees and their habitat?
Planting native flowering plants, avoiding pesticide use, and providing nesting sites can create a favorable environment for buzz-pollinating bee species. Also, you can encourage buzz pollinators by providing a welcoming habitat for bumble bees and carpenter bees.