The study, published by scientific journal Nature, discovered that bumblebees exposed to levels of the pesticide thiamethoxam, found in agricultural environments, collected pollen from apple trees less often and visited flowers less frequently. The study suggested that, at certain levels, the pesticide can have negative impacts on the bees’ pollination abilities, resulting in apples with fewer seeds. These results could indicate a risk of decreased agricultural output down the line.
The team, including researchers from Royal Holloway University of London, University of Reading and University of Guelph in Canada, discovered that trees pollinated by bumblebees exposed to pesticides produced apples with 36% fewer seeds, a factor closely associated with fruit quality in most apple varieties.
“We found effects of exposure to a neonicotinoid pesticide (thiamethoxam) on crop pollination services provided by bumblebees at the colony level,” said Irish researcher and lead author of the study, Dr Dara Stanley. “To our knowledge this is the first study to examine the impacts of pesticides not just on bees themselves, but on the crucial pollination services they provide to crops and wild plants.”
Ireland has 20 different species of bumblebees, along with a variety of other bee species, and a sizeable apple growing industry. The All-Ireland Pollinator plan, launched earlier this year, aims to make Ireland a place where pollinators, including bumblebees, can survive and thrive.