Bees are vital for the pollination of many crops and flowers, but they are facing multiple threats from habitat loss, climate change, diseases, and pesticides.
While some pesticides are designed to kill insects, others are supposed to be harmless or beneficial for plants.
However, a new study has revealed that some of these pesticides may contain "inert" ingredients that are more toxic to bees than the active ones.
The Hidden Danger of Pesticide Formulations
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Pesticides are widely used in agriculture to protect crops from pests and diseases. However, they may also pose a serious threat to bees and other pollinators, which are essential for food production and biodiversity.
Most pesticides are not pure substances, but mixtures of different chemicals, including active ingredients and co-formulants.
Active ingredients are the ones that are supposed to kill or repel the target pests, while co-formulants are added to enhance the performance, stability, or appearance of the product.
Co-formulants are often called "inert" ingredients, implying that they are harmless or inactive. However, this is not always the case.
A recent study published in Scientific Reports revealed that some co-formulants in a popular fungicide called Amistar are more toxic to bumblebees than the active ingredient itself.
The researchers exposed bumblebees to different components of Amistar, and found that alcohol ethoxylates, a type of surfactant, caused lethal and sublethal effects on the bees, such as reduced feeding, mobility, and survival.
Surfactants are commonly used in pesticides to help the active ingredients penetrate the plant or insect tissues.
However, they may also damage the bees' cuticle, which is their protective outer layer, and make them more vulnerable to dehydration, pathogens, and other stressors.
The study also showed that the toxicity of Amistar was not reflected by its active ingredient alone, which is azoxystrobin, a fungicide that is considered to be relatively safe for bees.
The researchers found that the formulated product was up to 1,000 times more toxic than azoxystrobin in isolation.
This means that the current regulatory tests, which only evaluate the active ingredients, may underestimate the real impact of pesticides on bees and other non-target organisms.
The findings of the study are not surprising, given that previous research has also shown that co-formulants can increase the toxicity of pesticides to humans and wildlife.
For example, a study from 2014 found that some herbicides, fungicides, and insecticides were more toxic to human cells than their active ingredients, due to the presence of co-formulants.
Another study from 2017 found that some neonicotinoid insecticides, which are known to harm bees, were more harmful when combined with co-formulants or other pesticides.
However, the problem is that co-formulants are often kept secret by the pesticide manufacturers, who claim that they are proprietary information or trade secrets.
This makes it difficult for researchers, regulators, and consumers to know what chemicals are actually in the products they use or encounter.
Moreover, co-formulants are not subject to the same safety standards as active ingredients, and are often assumed to be inert or negligible.
This may lead to the approval of products that are more hazardous than expected, and the exposure of bees and other living beings to unknown risks.
Therefore, there is an urgent need for more transparency and precaution in the regulation and use of pesticides.
The researchers of the study called for the disclosure of all the ingredients in pesticide formulations, and the testing of the whole products, not just the active ingredients, for their effects on bees and other non-target organisms.
They also suggested that consumers should avoid using pesticides that contain alcohol ethoxylates or other surfactants, and opt for organic or alternative methods of pest control.
By doing so, we may be able to protect the bees and ourselves from the hidden danger of pesticide formulations.
