Using bees for pest control isn’t a practice most people are familiar with, but the technology—sometimes known as bee vectoring—was actually initiated more than 25 years ago when Drs. John Sutton and Peter Kevan from the University of Guelph in Ontario, Canada, and Dr. Lee Shipp from Agriculture and Agri-Food Canada started conducting studies on the benefits of the fungus Clonostachys rosea.
In a nutshell, it is a technology in which bees are used to multi-task. As they flit from flower to flower, they not pollinate the plants but can be trained to apply organic pesticides or fertilizers to the crops. While this isn’t particularly helpful for the home gardener, it offers huge benefits to large-scale farmers.
How Bees Work
‘Busy as a bee’ is not just a cute saying. A single bee can visit as many as 2,000 flowers in a single day, according to Illinois State University, and some experts say that number is as high as 5,000. The Ontario Beekeepers Association estimates that the average bee colony has up to 80,000 worker bees, which means one colony has the potential to pollinate 160,000,000–400,000,000 flowers a day. Though this does not take into account that not all worker bees gather pollen from flowers, it nevertheless shows the huge agricultural impact that bees have on food crops.
Without bees, there would be a tremendous impact on our diets as well as the overall landscape of the planet. Bees have a tremendously important job. And now, thanks to studies conducted by Canadian researchers, their job is even bigger. Not only can bees pollinate our food crops, they can also help to protect them from pests and fungal diseases.
Using bees to vector microbial controls is done using commercially raised bees that walk through special trays when they exit the hive. These trays contain organic biological controls and fertilizers that stick to the bees’ legs much like the way pollen sticks when bees land on flowers.
As the bees go from flower to flower, these powdered pesticides are dusted onto each flower. The trays are good for about 21 days and the biological controls can continue to be applied through a crop’s flowering phase.
Powdered controls that the bees carry are organic. No health risks to bees or people are posed and they can effectively reduce the need for chemical sprays. This results in estimated 30 per cent higher yields or more from organically treated crops while reducing the negative environmental impact of chemically produced foods.
It’s estimated that 80 per cent of our food crops are pollinated by honey bees. However, bumblebees are the bees typically chosen for the task of vectoring control agents to crops for several reasons. Bumblebees are less aggressive than honey bees. They are also able to carry more of the biological control agent and can fly in climates less hospitable to honey bees. Additionally, they are maintenance free and don’t require special equipment.
Pesticides and Bee Safety
Unless you’ve been living under a rock, you already know that bee populations are facing serious decline. The idea of using bees to deliver pesticides may not seem like a good one until you realize that these are natural controls used to target specific pests and fungal diseases.
Strawberries, for example, are prone to a fungal disease called gray mold, which is caused by the necrotrophic Botrytis cinerea fungus and is particularly difficult to control. Studies have found that applying Clonostachys rosea, another naturally occurring fungus, is an important component in the control of gray mold because it helps to prevent the development and growth of Botrytis without the need for chemical fungicides that tend to inhibit plant growth. Uninhibited plants grow larger and produce more berries.
Bees encounter Clonostachys naturally as they move from plant to plant and are unharmed by the fungus. They can safely collect the powdered form of this control as they leave their hives and spread it among strawberry crops while they pollinate, increasing yields and improving plant health.
Beauveria bassiana is another naturally occurring fungus that acts as a parasite to various pests. It’s even being investigated for use in the control of mosquitoes and bedbugs. It has proven to be effective in the control of aphids, lygus, thrips, and whiteflies in hothouse tomatoes and peppers. This natural pesticide is harmless to bees, meaning they can easily distribute it without worry.
By combining these two biological controls into one powder, bees can effectively deliver pest and disease control while pollinating. Greenhouse growers were thrilled with this discovery because it not only improved harvests but also saved labor by reducing the need to spray chemicals. However, this same technology can also be used for outdoor crops.
Wide Usage Means Bigger Harvests Overall
Strawberries aren’t the only crop that can benefit from bees working double duty. Vectoring has been used to protect other crops including apples, blueberries, canola, sunflowers, tomatoes, and other crops that are susceptible to the same diseases. Work is also being done to use bees to help protect other crops including almonds, stone fruits, pears, squash, cucumber, and berries.
In August 2016, the bio-pesticide BVT-CR7 was submitted to the EPA after eight months of testing to ensure its safety for bees, humans, and the environment. This product is an organic strain of a naturally occurring fungus that targets Alternaria, Anthracnose, Botrytis, Monilinia, and Sclerotinia, acting as a preventative and greatly reducing the need for fungicidal sprays. It has also been show effective in increasing crop yields by 30 per cent or more according to trials. The EPA will review CR7 over an 18-month period.
Once the approval process is complete, it is hoped that the amount of chemical controls used on food crops will decline drastically. What this means is that bees may end up eventually taking part in saving themselves from decline by helping to reduce the amount of bee-damaging chemicals used in agriculture.
Beneficial Insects — Other Superhero Sidekicks
Bee vectoring is part of integrated pest management, which is a method of managing pests with as little impact on the environment as possible. Even if you are unable to take advantage of bee vectoring technology in your home garden, you can still reap the benefits of beneficial insects. And bees aren’t the only insects that will work to protect your plants.
A typical garden has way more beneficial insects than harmful ones, which may be a surprise if you’ve always believed that all bugs are bad. In fact, a diverse ecosystem within your garden means you’ll have healthier soil and healthier plants, which means better yields for you. Here are a few helpful insects that you’ll want in your garden.
Not to be confused with the invasive Asian beetles, ladybugs—or lady beetles—have a voracious appetite for aphids. Sometimes their larva will also eat whiteflies. Encourage them with cilantro, dill, fennel, tansy, and other pollen producing flowers.
Lacewing larvae eat many different pests including mites, caterpillars, mealybugs, and aphids. They enjoy many of the same plants as ladybugs.
Also known as hoverflies, these predators eat mealybugs, aphids, psyllids, and whiteflies. They are attracted to lavender, coriander, lemon balm, and many other herbs.
Spiders eat a wide range of insects and you don’t really need to do anything to attract them. If there is a food source, there will be spiders.
These predators eat thrips, mites, and other tiny insects. They also like spearmint, alfalfa, fennel, marigolds, and caraway.
Usually the presence of pests will attract the corresponding predator insect, but you can also buy beneficial insects from many garden catalogs. Keep in mind, some insects that are considered beneficial will also eat other beneficials; case in point: the praying mantis.
If you want to take advantage of beneficial insects, it’s important that you don’t spray chemicals on your garden. Most insecticides will kill all insects, regardless of their role in your garden.