Why are bees so important?
Despite their small stature, bees play an oversized role in protecting biodiversity. Biodiversity refers to the variety of life in different ecosystems, meaning the array of plants and animals that inhabit a given region.
Bees are essential because they support the reproduction of plants through pollination. When a bee lands on a flower, the pollen sticks to the bee because it is covered in little hairs that attract the powdery substance. With this feature, bees carry and distribute pollen from flower to flower, fertilizing cultivated plants as well as wild plants, including trees. This process later yields fruits, vegetables, and seeds.
The vast majority of flowering plants rely on pollinators to reproduce. Bees are responsible for fruits and vegetables but also chocolate, spices, nuts, coffee... Hence, bees are major and direct contributors to our food security and a cornerstone of our food system. The honey-makers play a crucial role in supporting the growth of plants and trees, which in turn serve as vital
sources of shelter and food for a diverse range of species in various ecosystems.
How glyphosate-based formulations threaten bees
Bees can be exposed to this chemical either by direct contact or by ingestion via food and contaminated water. Several scientific findings have exposed that glyphosate and glyphosate-based herbicides (GBH) are toxic to bees in many ways.
Glyphosate and GBH have been shown to:
- disrupt the gut microbiome and make the bees more susceptible to disease
- disturb the development of bee brood (eggs, larvae and pupae of honeybees)
- negatively affect the thermoregulation of the colony
- have a negative impact on reproduction
- disrupt the foraging abilities and navigation
- have a negative impact on learning ability and memory
- Cause a change in the movements of antennas after exposing the harvester bees to sublethal doses (50-100 ng) of glyphosate, showing antenna hypoactivity in the nocturnal awakening intervals.
Additionally, interaction with other chemicals (cocktail effect) and also other ingredients (e.g. co-formulants) used in glyphosate-based herbicides can increase the overall toxicity. All these negative effects combined significantly weaken the bee colony and its survival.
Resources
Briefing :
PAN Europe (2023): GLYPHOSATE BASED HERBICIDES & THEIR IMPACT ON BEES’ HEALTH
Articles :
Science (2018) : covering a study on how glyphosate disrupts the microbial community in the bees' digestive system, making them more vulnerable to infection.
Nouvelobs (2018) : same as the Science article but in French
Friends of the Earth (2021) : Foods bees pollinate
The Guardian (2022): a summary of a study published in Science on how Glyphosate impairs collective thermoregulation in bumblebees and threatens the survival of the hive
UNEP (2022): Why bees are essential to people and the planet
PAN EUROPE (2023): Yes, glyphosate is harmful to bees
Scientific research papers
Defarge, N. et al., “Toxicity of formulants and heavy metals in glyphosate-based herbicides and other pesticides”, (Toxicology Reports, 5, 2018).
Blot et al., “Glyphosate, but not its metabolite AMPA, balters the honeybee gut microbiota”, (PLoS ONE 14, 2019).
El Agrebi, Noemie, et al., “Honeybee and Consumer’s Exposure and Risk Characterisation to Glyphosate-Based Herbicide (GBH) and Its Degradation Product (AMPA): Residues in Beebread, Wax, and Honey.” (Science of the total environment 704, 2020).
Battisti et al., “Toxicological status changes the susceptibility of the honey bee Apis mellifera to a single fungicidal spray application”, (Environ. Sci. Pollut. Res. 28, 2021).
“Is glyphosate toxic to bees? A metaanalytical review”, (Sci. Total Environ. 767, 2021).
Van Bruggen, A. H., et al, “Indirect Effects of the Herbicide Glyphosate on Plant, Animal and Human Health Through its Effects on Microbial Communities”, (Frontiers in Environmental Science 9, 2021).
Costas-Ferreira and Faro, “Toxic effects of glyphosate on the nervous system: a systematic review”, (Int. J.Mol. Sci. 23, 2022).
Goodwin and McBrydie, “Effect of Surfactants on Honey Bees”, New Zealand Plant Protection 53 (August 1, 2000): 230–234. (2023).
Helander et al., “Field-realistic acute exposure to glyphosate-based herbicide impairs fine-color discrimination in bumblebees”, (Sci Total Environ, 2023)