by Diego Marroquin —
It is springtime, the weather is warming up, the snow is melting, and you are getting ready to plant various vegetables and beautiful flowers in your garden. Peppers, zucchini, tomatoes, lettuce, kale, and many other vegetables are commonly grown and are among the most loved vegetables that many of us grow in our gardens. Decorating the yard with flowers is also a staple of the seasonal changes. Spring is a beautiful time of the year for those who enjoy spending time outdoors and working in their gardens, but there is something that most people dislike: weeds! You could pull them out, but there are so many of them, it takes a lot of time, and it feels as if they will never go away. The solution is relatively simple, a quick trip to the store to buy weed killer chemical – a herbicide – and get rid of those annoying weeds. Easy to use, safe for pets and humans, and cheap, it may feel like a magical potion to solve your weed problems. Well, not so fast. If these herbicides kill weeds and many unwanted plants, what is the problem? The answer is that besides the weeds, you might be killing the bees.
Bees get their food from pollen and nectar that they collect from the flowers they visit. Although the herbicide helps you get rid of the weeds, this has an impact on the food sources of the bees. When you spray weed killer on your plants, many bees will visit the plants before the chemical kills the weed. Recent research shows that, Glyphosate, the active ingredient in some herbicides, causes changes in the gut microbiota of bees. The microbiota is a community of bacteria that helps the bee in many ways. The bacteria are distributed differently across the bee’s gut, and some predominate in specific areas (Figure 1).
(Raymann and Moran, 2018)
The bacteria in the gut help the bee fight against infection, in processing and breakdown of food, and with their jobs in the colony. The bee’s microbiota lives in a harmonious environment, and any disruptions to the environment can significantly affect the health of the bee. The microbiota is like an engine of a car. For the car to work correctly, all the parts of the engine must be in good condition. If a part is not working correctly, the whole car might be at risk of not working correctly. Glyphosate causes changes in the microbiota, and these changes decrease the bee’s life span (Figure 2), ultimately serving as a poison to bees. Its usage might be causing significant negative impacts on the bee populations.
(Raymann and Moran, 2018)
You might be wondering: a couple of bees are dying – what is the big deal? The issue is that many plants, including the ones growing in our gardens, require pollinators for their development. Many fruits and vegetables need pollinators to transfer the pollen, the sperm of the plant, to the pistil, the female organ of the plant. Bees are essential pollinators, and plants depend on them to reproduce. When the plants produce, we get the juicy fruits and vegetables that we love. Astonishingly, about 80% of crops for human consumption rely on bees. The use of herbicides can create problems with bees that we do not want. Exposures will cause the bees to get sick more easily, to not do their jobs correctly in their colonies, and will negatively impact their own food digestion.
Have you wondered what determines the price of fruits and vegetables? Part of it is the ability to produce and ship those fruits and vegetables. Farmers, and your garden, rely on bees for pollination. It turns out that the use of herbicides can significantly impact the price of food. Fewer bees mean less pollination, resulting in fewer fruits and vegetables, and ultimately in increasing costs. On an extreme no pollination occurs, resulting in the potential for a famine.
Herbicides puts the bees at a greater risk for disease and do not allow them to do their job correctly. These chemicals are convenient and safe for humans and our pets, but not good for the bees. We depend on bees to pollinate our food, and we should think about what is best for them. After all, weeds are a part of the ecosystem! By getting rid of them, we influence the various interactions that happen with the plants and other organisms in their ecosystem. Bees are crucial for the environment, let’s take care of them!
References:
Gallai, N., Salles, J.-M., Settele, J., Vaissière, B.E., 2009. Economic valuation of the vulnerability of world agriculture confronted with pollinator decline. Ecological Economics 68, 810–821. https://doi.org/10.1016/j.ecolecon.2008.06.014
Motta, E.V.S., Mak, M., De Jong, T.K., Powell, J.E., O’Donnell, A., Suhr, K.J., Riddington, I.M., Moran, N.A., 2020. Oral or Topical Exposure to Glyphosate in Herbicide Formulation Impacts the Gut Microbiota and Survival Rates of Honey Bees. Appl Environ Microbiol 86. https://doi.org/10.1128/AEM.01150-20
Motta, E.V.S., Moran, N.A., 2020. Impact of Glyphosate on the Honey Bee Gut Microbiota: Effects of Intensity, Duration, and Timing of Exposure. mSystems 5. https://doi.org/10.1128/mSystems.00268-20
Raymann, K., Moran, N.A., 2018. The role of the gut microbiome in health and disease of adult honey bee workers. Current Opinion in Insect Science 26, 97–104. https://doi.org/10.1016/j.cois.2018.02.012