Toronto: Long-term pesticide exposure affects individual bee behaviour, including pollen collection and the choice of flowers, a study using radio tracked bees has shown.
"Bees have to learn many things about their environment, including how to collect pollen from flowers," explained Nigel Raine from University of Guelph in Canada.
"Exposure to this neonicotinoid pesticide seems to prevent bees from being able to learn these essential skills." he added.
The researchers tracked individual bees leaving and returning to the colony, the flowers from which they collected pollen and how much.
Bees from untreated colonies got better at collecting pollen as they learned to forage. But bees exposed to neonicotinoid insecticides became less successful over time at collecting pollen.
Neonicotinoids make up about 30 per cent of the global pesticide market. Plants grown from neonicotinoid-treated seed have the pesticide in all their tissues, including the nectar and pollen.
"If pesticides are affecting the normal behaviour of individual bees, this could have serious knock-on consequences for the growth and survival of colonies," Raine explained.
Bumblebees may be much more sensitive to pesticide impact as their colonies contain a few hundred workers at most, compared to tens of thousands in a honeybee colony.
The research was published in the journal Functional Ecology.