Bumblebees are at least as important pollinators as bees, but not as many studies have been done on them. The more than a thousand bumblebees used in the research have been exposed to small amounts of different pesticides.
All have also been marked with a colour and a number so that researchers can see which bumblebee has been exposure to which pesticide. The bumble bees have now been released and are allowed to fly around and pollinate to see if the agent changes which flowers and plants they choose.