Why are neonicotinoids considered harmful to bees?

Neonicotinoids are classified as harmful to bees primarily due to their systemic nature, which allows these chemicals to be absorbed by plants and transported throughout their tissues, including flowers. When plants treated with neonicotinoids bloom, the pollen and nectar produced can contain these harmful chemicals. As bees forage for food, they collect this contaminated pollen and nectar, leading to exposure to the pesticides.

This systemic movement increases the risk of sub-lethal effects on bees, which may not result in immediate death but can impair their ability to navigate, forage, reproduce, and communicate. Over time, such exposures can contribute to declines in bee populations and overall health, posing significant risks to ecosystems and agriculture, where bees play a crucial role in pollination.