A study conducted by Imperial College London, in which free-foraging bee colonies were placed in the field, has shown that exposure to neonicotinoid pesticides can affect colony development.
To date studies looking at the effect of neonicotinoids on bees have either been in the lab, or in the field where colonies are placed next to treated crops. The latest study balances the pros and cons of these two approaches. This allowed the team of researchers to control pesticide exposure and closely monitor colony activity and development.
Unlike some previous studies they did not find any large effect on bee foraging behaviour following neonicotinoid exposure. However, they did find evidence that the colony produced a lower number of new queens and males, which underpins colony success.
Senior author Dr Richard Gill from the Department of Life Sciences at Imperial said: “Neonicotinoids found in the environment are unlikely to directly kill individual foraging bees, but when exposure is relatively persistent and combined with other stressors associated with land use change, they could have detrimental effects at the colony level.” The team hope to improve the automation of the study to make it as easy as possible for companies to test new pesticides in ways that reflect real-world scenarios.
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