A new study provides evidence of a link between neonicotinoid pesticides and honeybee colony losses. The study led by Fera, a former UK government agency of the Department for Environment, Food and Rural Affairs, combined large-scale pesticide usage and yield observations from oilseed rape fields in England and Wales with data on honeybee loses between 2000 and 2010. According to the research, published in the journal Nature Scientific Reports on Thursday, the total area of land planted with oil seed rape in England and Wales more than doubled from 293,378 hectares to 602,270 hectares over that period. At the same time, the number of seeds treated with Bayer’s imidacloprid pesticide increased from less than 1% of the area planted in 2000 to more than 75% of the area planted with oilseed rape in 2010. The scientists found that farmers who used neonicotinoid seed coatings subsequently used less insecticides to control pests. However, more honey bee colonies were lost as the usage of imidacloprid increased over the 11 year period. The authors said that honey bee colony losses were also linked to adverse weather and showed regional patterns, with beekeepers in Wales suffering the highest losses. Honeybees are important pollinator, being responsible for pollinating at least 90% of commercial crops, especially oilseed rape. The authors conclude: “As long as acute toxins remain the basis of agricultural pest control practices, society will be forced to weigh the benefits of pesticides against their collateral damage. Nowhere is this tension more evident than in the system with the world’s most widely used insecticide, the world’s most widely used managed pollinator and Europe’s most widely grown mass flowering crop.” A European-wide two year ban on neonicotinoids linked to bee deaths came into effect in December 2013. However, the British government temporarily overturned the ban last month on two pesticides for use on oilseed rape. (ab)