Common folks have a hard time believing that some plants are detrimental to pollinators such as bees. Because of the lack of information and awareness on the matter, some even make a mistake of planting these vegetations in their gardens, thinking that they are helping the declining bee population when in fact they are doing the opposite.
Why Some Plants Are Toxic To Bees: Theories
It remains a mystery as to why certain flora is poisonous or harmful to bees in some way. Back in elementary school, children were taught that butterflies and bees love flowers, so much so that they even help in the plant propagation process called pollination. But why are there plants that actually kill bees? Here are some of the most interesting theories that may explain this.
The “Pollinator Fidelity Hypothesis” explains that certain plants are created to be pollinated by specific insects. This theory proposed by scientists in 1981 stated that the toxic nectar found in certain flowers are designed to repel instead of attracting the so-called “generalist pollinators.” This is because these insects that include bees are deemed less effective in pollinating a certain plant species.
Another theory why some plants are toxic to bees is the “Nectar Robbery Hypothesis.” Scientists who came up with this one explained that certain plants have evolved into creating a protective means for them to avoid getting sucked dry of nectar without actually getting pollinated. This means plants have come up with a way to prevent insects like ants, who sometimes suck the sweet substance from flowers, from coming back to take nectar and pollen without initiating the pollination process.
On the other hand, the “Drunken Pollinator Hypothesis” describes how plants release a nectar that causes certain insects— like wasps— to get intoxicated. In this theory, scientists explained that the “drunken pollinators” end up pollinating better because they tend to clean themselves less, thus, transferring more pollen from one flower to another.
Plant Species That Aren’t Bee-Friendly
- Rhododendron and Azalea
This plant genus under the Ericaceae family has been discovered to have nectar that is poisonous to bees which is why apiary workers keep their beehives under wraps during the rhododendron’s flowering season. On top of that, honey produced from the nectar of azalea and rhododendron is contaminated that it is not safe for human consumption.
- Angel’s Trumpet
Also known as the trumpet flower, this ornamental plant produces mass death in bees despite its sweet smell. Because of this, experts recommend planting honeysuckle instead to achieve the same flowery scent in your garden without causing harm to honeybees.
While this plant appears harmless because of its festive colors, it can actually cause butterfly death and a beehive wipeout. This is because the nectar of its flower tends to become more concentrated once stored in the hive, thereby increasing the amount of toxin it contains. To achieve the same brightly-colored effect on your garden without harming bees, plant snapdragons instead.
- Yellow Jessamine
While very attractive, these aromatic plants can actually kill bees through the toxins contained in its vines and flowers. In fact, the effect of yellow jessamine toxin to bees can be likened to that of the severity of hemlock poisoning.
- Mountain Laurel
The evergreen shrub called mountain laurel produces nectar that can also contaminate honey, making it bitter in taste and even toxic to both bees and humans.
- Stargazer Lily
Stargazer lilies are pretty to look at, but its pollens can kill bees.