Pesticides stop bumblebees from pollinating apple trees, research shows

New findings on neonicotinoids have important implications as many food crops and wildflowers rely on bee pollination to reproduce

Damian Carrington

Wednesday 18 November 2015 18.00 GMTLast modified on Wednesday 18 November 201518.01 GMT

The world’s most widely used insecticides harm the ability of bumblebees to pollinate apple trees, scientists have discovered. The finding has important implications for agriculture and the natural world, say the researchers, as many food crops and wildflowers rely on bee pollination to reproduce.

There is good evidence that neonicotinoids harm bees but the new research,published in the journal Nature, is the first to show a negative impact on the vital pollination services bees provide.

In 2013 the EU suspended the use of three types of the pesticide for three years. But has since approved two new types, while the UK has partly lifted the suspension after lobbying from farmers.

“Bumblebees are major pollinators of apples and many crops around the world,” said Prof Nigel Raine, at the University of Guelph, Canada, and one of the research team. “The findings of this study have important implications for both society and the economy, as insect pollination services to crops are worth at least $361bn worldwide every year, and are vital to the functioning of natural ecosystems.”

The research, carried out at the University of Reading’s farm in Berkshire, exposed bumblebee colonies to different levels of neonicotinoid found in normal fields and then tested their ability to pollinate apple trees. Compared to unexposed colonies, the exposed bumblebees visited fewer trees and collected less pollen, resulting in apples with one-third less pips. The number of pips is an important sign of pollination success because it is associated with higher quality fruit, which are more valuable to farmers.

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