Bees are still being harmed despite tightened pesticide regulations

Bees are still being harmed despite tightened pesticide regulations - Trinity College Dublin

A new study has confirmed that pesticides, commonly used in farmland, significantly harm bumblebees – Ireland’s most important wild pollinators. In a huge study spanning 106 sites across eight European countries, researchers have shown that despite tightened pesticide regulations, far more needs to be done.

While the agricultural uses of insecticides have been in the spotlight for their negative effects on bees, it has remained unknown how the effects scale beyond single substances in focal fields.

Here, a large team of researchers answered recent calls for a more realistic assessment of the risks posed by mixtures of commonly used pesticides at landscape scales.

The findings, published today in the leading journal Nature, show that despite the world's most rigorous risk assessment process, the use of approved pesticides in European agricultural landscapes still negatively affects non-target organisms – significantly reducing the colony performance of bumblebees, a key wild and commercial pollinator.

Although not perhaps a major surprise, the results were nonetheless sobering. Bumblebee colonies exposed to these pesticides saw significant reductions in 1) total colony production (the number of cocoons), 2) maximum colony weight, and 3) the number of new queens.

The study can be read on the Nature website.