First study shows pesticide exposure can affect crop pollination by bees

First study shows pesticide exposure can affect crop pollination by bees

First Study Shows Pesticide Exposure Can Affect Crop Pollination By Bees

Researchers carry out first international study on the global effects of pesticides on bee pollination services provided by bumblebees

• Neonicotinoid pesticide exposure impairs crop pollination services provided by bumblebees
• Apple trees pollinated by bumblebee colonies exposed to pesticides produced 36% fewer seeds, showing a negative impact on pollination services to a crop of global economic importance
• Bumblebee colonies exposed to pesticides collected less pollen and visited apple flowers less frequently

Wednesday, 9 December, 2015:
For the first time an international team of researchers have shown that neonicotinoid pesticides impair the pollination services provided by bumblebees. The study was recently published in the scientific journal Nature.

Bees play a vital role in pollinating some of the most important food crops globally and have been declining in recent years. Until now research on pesticide effects has been limited to their impact on bees, rather than the pollination services they provide.

The study 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.

In addition, 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.

Irish researcher and lead author of the study, Dr Dara Stanley from Royal Holloway University of London and soon to be NUI Galway, said: “We found effects of exposure to a neonicotinoid pesticide (thiamethoxam) on crop pollination services provided by bumblebees at the colony level. 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.”

The team, who are part of The UK Insect Pollinators Initiative, looked at three groups of bumblebees exposed to varying levels of neonicotinoid pesticides in artificial nectar for 13 days. Two groups were exposed to levels of pesticides realistically found in agriculture environments, and the control group was exposed to a sugar solution containing no pesticides.

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.

The UK Insect Pollinators Initiative is joint-funded by the Biotechnology and Biological Sciences Research Council (BBSRC), Defra, the Natural Environment Research Council (NERC), the Scottish Government and the Wellcome Trust. It is managed under the auspices of the Living with Environmental Change (LWEC) partnership.

For further information on the All-Ireland Pollinator Plan visit: or


For more information contact Dr Dara Stanley on 086 8876602 or or Twitter: @darastanley

Contact Gwen O’Sullivan, Acting Press and Information Executive, NUI Galway on 091 495695 or