Pesticides can impair brain growth in baby bumblebees, affecting their ability to perform a simple learning task as adults, according to a new study.
Imperial College London researchers used micro-CT scanning technology to reveal how specific parts of bumblebee brains grew abnormally when exposed to pesticides during their larval phase.
Most previous studies have tested the effects of pesticide exposure on adult bees because these individuals directly collect pesticide-contaminated nectar and pollen. However, this study shows that baby bees can also feel the effects of the contaminated food brought back to the colony, making them poorer at performing tasks later in life.
Lead researcher Dr Richard Gill, from the Department of Life Sciences at Imperial, said: “Bee colonies act as superorganisms, so when any toxins enter the colony, these have the potential to cause problems with the development of the baby bees within it.
“Worryingly in this case, when young bees are fed on pesticide-contaminated food, this caused parts of the brain to grow less, leading to older adult bees possessing smaller and functionally impaired brains; an effect that appeared to be permanent and irreversible.
“These findings reveal how colonies can be impacted by pesticides weeks after exposure, as their young grow into adults that may not be able to forage for food properly. Our work highlights the need for guidelines on pesticide usage to consider this route of exposure.”
Access the paper: Smith Dylan B., Arce Andres N., Ramos Rodrigues Ana, Bischoff Philipp H., Burris Daisy, Ahmed Farah and Gill Richard J. Insecticide exposure during brood or early-adult development reduces brain growth and impairs adult learning in bumblebees Proc. R. Soc. B