Sussex bee scientists question value of neonics ban
Posted on behalf of: Laboratory of Apiculture and Social Insects
Last updated: Wednesday, 26 June 2013
Honey bee on Sedum
The European Commission’s two-year moratorium on the use of neonicotinoid insecticides is no “triumph for bee conservation”, say University of Sussex bee scientists.
In fact, say Norman Carreck and Professor Francis Ratnieks from the Laboratory of Apiculture and Social Insects (LASI), scientific evidence both against and in favour of the ban is “far from clear-cut”.
Neonicotinoids are a group of systemic insecticides used as a seed dressing for food crops that has been linked with a decline in the numbers of both managed species (honey bees) and wild species (bumblebees, solitary bees).
In April 2013, the European Commission voted on and implemented a two-year moratorium on the use of three neonicotinoid insecticides on “bee attractive crops” following risk assessment reports from the European Food Standards Agency.
Norman Carreck, who has been keeping bees for more than 30 years and has been studying bee diseases for more than 20 years, says: “It is not clear what purpose this two-year moratorium will serve, unless it is used to answer some of the outstanding questions.”
Professor Ratnieks’ and Mr Carreck’s review of the research literature and the controversy surrounding neonicotinoids is published today (26 June) in Research Fortnight.
The review’s observations include:
- Declines in bee populations pre-date neonicotinoids by several decades, so they can’t be the sole cause of decline. Declines are more likely due to a complex combination of changes, including agricultural intensification and habitat loss.
- Lab studies point to subtle, sub-lethal adverse effects on bee brains, individual bees or colonies, but so far these effects have not been seen in the field.
- Existing lab and field studies, including those by universities and agencies such as the government’s Department of Food and Environment Rural Affairs (Fera) are inconclusive and few in number. The authors comment: “These experiments highlight areas that need attention, particularly the extent of wild bees’ exposure to neonicotinoids. But even if governments can be persuaded to fund such work, it will be hard to design a research programme that will answer the question definitively owing to, for example, the fact that there are 250 bee species in the UK alone.”
- The neonicotinoids ban means that farmers who grow oilseed rape may well resume frequent insecticide spraying, as occurred ten years ago, probably using synthetic pyrethroids. Little is known about the sub-lethal effects of this and other, older pesticides.
The authors conclude: “Many fundamental questions remain unanswered, and may still be so when the moratorium ends. We risk having the same debate in two years’ time.”