A class of pesticide called neonicotinoids has been associated with the decline of wild-bee species across the United Kingdom.

Small and short-term studies have shown that the chemicals — which were first used widely in the country in 2002, before being placed under a 2-year moratorium by the European Union in 2013 — can harm bee reproduction. To look for long-term effects at the population level, Ben Woodcock at the NERC Centre for Ecology and Hydrology in Wallingford, UK, and his colleagues compared maps of pesticide use on oilseed rape (canola) crops with surveys of 62 wild-bee species across the United Kingdom from 1994 to 2011. They found correlations between neonicotinoid exposure and population declines in bees that forage on the crops, and even in some that don't.

The team estimates that the chemicals are linked to population losses of more than 10% for 24 bee species.

Nature Commun. 7, 12459 (2016)