QUEEN BEES, ESSENTIAL POLLINATORS FOR BIODIVERSITY AND AGRICULTURE, SHOW SURPRISING BUT ALSO worrisome behavior: THEY CHOSE TO HYBERNATE IN SOIL CONTAMINATED BY PESTICIDES RATHER THAN IN SOIL FREE FROM CHEMICALS. THIS DISCOVERY, THE RESULT OF A RESEARCH BY THE UNIVERSITY OF GUELPH, CANADA, raises serious questions about the health of these insect colonies and the sustainability of agricultural ecosystems in a world increasingly characterized by pollution.
The unusual behavior of bumblebee queens
In a series of field experiments, Canadian scientists offered bumblebee queens (Bombus impatiens) two soil options: one contaminated with trace amounts of pesticides commonly used in agriculture and the other completely free of chemicals. Surprisingly, the queens preferred contaminated soil and chose it twice as often as the untreated soil. This behavior has left researchers baffled. But why do bumblebee queens prefer frequently polluted land?
Pesticides and soil: a worrying link
Scientists hypothesize that pesticides may alter the olfactory or sensory cues that guide queens’ decisions, making artificially treated soils attractive for reasons not yet fully understood.
One theory suggests that fungicides, by eliminating disease-causing microorganisms such as fungi and nematodes, can create an apparently safer environment for bumblebee queens to overwinter. However, this theory has not yet been fully scientifically validated.
However, this preference for contaminated soil can be harmful in the longer term. Even if there are no immediate fatal consequences, constant exposure to low levels of toxic substances can significantly impair the vital capabilities of bumblebees. Studies highlight how these chemicals disrupt insects’ neurological and physiological systems, compromising their ability to orient, feed and reproduce. The cumulative impact of these changes not only weakens the health and resistance of colonies, but also contributes to the decline of an already endangered species. Which negatively impacts the biodiversity and productivity of ecosystems that depend on pollination.
Furthermore, a significant decline in bumblebee populations in the agricultural sector could seriously endanger the production of many crops, with significant consequences for the global food supply.
Gaps in pesticide risk assessment
The study highlights a serious gap in environmental risk assessment pesticides: that is, the need to consider the soil as an important route of exposure for bumblebees, especially for the queens that come into contact with them during hibernation. To date, most research has focused on the direct effects of pesticides on bees during foraging, neglecting the role of the soil as an essential habitat for hibernation and queen survival.
The observation of this anomalous behavior therefore underlines the urgency of a revision of the current regulations.
It is critical that agricultural and environmental regulations take into account long-term exposure to pesticide residues in soil and their potential impact on pollinator health. This approach also requires the development of more sustainable agricultural practices that minimize the use of persistent chemicals and limit the accumulation of toxic residues in soil.
But let’s get to know these extraordinary insects better.
Bumblebees: incredible pollinators
Bumblebees, scientifically known as Bombusare insects of the family Apidae.
They are easily recognizable due to their more robust build than the apidue to the presence of hair and bright stripes of color, usually in combinations of yellow, black and white. These pollinators mainly inhabit the temperate and cold regions of the Northern Hemisphere and are widely found in Europe, Asia and North America.
Their adaptability allows them to thrive in a wide range of habitats, ranging from grasslands and montane forests to agricultural environments. Essential for biodiversity and agriculture, they stand out for the “buzz pollination” o vibrant pollination: Their powerful vibrations allow them to release large quantities of pollen from flowers that are difficult for other insects to access. Their diet consists mainly of nectar, which provides energy, and pollen, a basic protein source for larval growth.
Bumblebees love roses
The colonies, hierarchically structured, include a queen, numerous workers and some males. Unlike bees, the life cycle of bumblebees has a seasonal duration. They are born in the spring, reach their maximum development in the summer and die in the fall. With the arrival of winter, only the new queens survive and take refuge in safe and isolated places where they can spend the cold season. hibernation.
This rest period is essential for their survival: metabolism slows down, allowing the queens to conserve energy until spring, when they emerge from “hibernation” to establish new colonies.
Curiosity
In popular culture, these creatures are often seen as symbols of industriousness and adaptability. A curious urban legend states that, due to their stocky body structure and relatively small wings, they should not be able to fly according to the laws of physics, but they do so anyway, defying apparent limitations. Although disproven by science, this idea has helped give them an aura of resilience and tenacity. Furthermore, in many traditions, bumblebees represent abundance and prosperity.
As for their evolutionary history, it is truly fascinating: they were able to tolerate low temperatures and were among the few insects to colonize cold regions, adapting to survive harsh climates through strategies such as hibernation.
In short, their protection goes far beyond simple ecological value: it is a tribute to life’s extraordinary ability to adapt and renew, demonstrating that each small creature plays a unique and irreplaceable role in the great network of biodiversity.
Sources
Rondeau, S., Raine, N. et al. (2024), Bumblebee queens (Bombus impatiens) prefer pesticide-contaminated soil when selecting underground hibernation sites, Science of The Total Environment.
New York Times, “Bumblebee Queens Prefer Pesticide-Contaminated Soil,”