Today's guest blog is written by Senior Policy Officer, Stephanie Morren, covering two new papers on the effects of neonicotinoids on birds and what this means for pesticide policy in the UK.
Neonicotinoids (NNs) are the largest group of systemic insecticides used around the world to protect a wide variety of crops from agricultural pests. Systemic pesticides are chemicals that are absorbed by the plant when applied to seeds, leaves or soil. In 2013, in response to growing evidence of the impact of NNs on bees, the European Union placed a moratorium on three kinds of NNs, restricting their use in flowering crops that attract honeybees and other pollinating insects. In 2018, the EU banned the three main NNs for all outdoor uses.
NNs were once hailed as an environmentally-friendly solution because they were highly effective at controlling pests and their application as seed-coatings removed the need for risky spraying which often damaged hedges and neighbouring land. However, evidence is now mounting for the negative impacts on wildlife. Specifically, we now know that minute traces of NN in the pollen of crops like oilseed rape affect the ability of bees to forage and navigate with serious implications for colony growth and survival.
In 2012, scientists discovered that buff-tailed bumblebee colonies produced 85% fewer queens when exposed to NNs (c) Grahame Madge (rspb-images.com)
Despite this evidence, NNs are widely used in many countries and food grown with NNs is imported into even those countries with a ban (effectively offshoring the impact). Even in the EU, “emergency authorisations” are routinely given for these chemicals to be used under the argument that there is no alternative.
One of the reasons behind the belief that these chemicals are of minimal risk to wildlife, was the assumption (as per the instructions for use) that any treated seeds should be buried so that birds and other wildlife cannot access them.
Our latest studies
Dr Rosie Lennon from York University, the RSPB, and other partners recently published two papers documenting widespread exposure of farmland birds to clothianidin – one of the now-banned pesticides – as a consequence of typical farming practice in England. The first study monitored consumption of exposed seeds by farmland birds using camera traps and measured pesticide levels in the birds’ blood. The second study analysed blood and liver samples from hunted gamebird carcasses.
The study on farmland birds, found a route of exposure from the treated seeds into the birds' plasma (c) Rosie Lennon
The studies found that clothianidin-coated seeds were left exposed on soil surfaces on 38 of the 39 fields checked soon after sowing, and that 89% of individual gamebirds and 51% of farmland songbirds (from 21 different species) contained clothianidin residues in their blood or livers.
Whilst exposure on its own doesn’t prove any negative impact, a woodpigeon was found to have ingested 65% of the amount required to impair reproduction in just one single feeding visit, and the two birds with the highest concentration found in their blood (a tree sparrow and a yellowhammer) were behaving as though intoxicated. Usage of pesticide seed-treatments carries a responsibility to bury all of the seed out of the reach of wildlife but that was clearly not happening on the 25 study farms.
What does this mean for the future?
Whilst this study was conducted before the EU ban, the UK will soon not be subject to EU laws, and therefore there is a risk that pressure to make trade deals with other countries such as the US will lead to weakening of standards, and potentially bring back these harmful pesticides for use in the UK.
Yellowhammers were one of the 21 species seen to have ingested NN treated seeds (c) Jack Farrer (rspb-images.com)
A recent report called Toxic Trade describes not only the risk to the environment and human health from a reduction in pesticide standards, but also the risk to British farmers as they are either undercut by cheaper imports or unable to export to their biggest market, the EU.
Neonicotinoids and bees may seem like old news. But this issue goes much wider than bees and neonicotinoids. It is about ensuring that any new trade deals and regulatory framework protects environmental standards and supports farmers to produce food without further damaging our already degraded countryside.
As the Agriculture Bill continues to pass through the Houses of Commons and Lords this month, there is an opportunity for Government to formally commit, in law, to uphold British farming production standards as we negotiate trade deals and in our general trade policy. The Bill should ensure that imports are produced to at least equivalent standards as those required of producers in the UK.
Continue reading
Would you like to be kept up to date with our latest science news? Email with the heading 'enewsletter' to be added to our quarterly enewsletter.
Want our blogs emailed to you automatically? Click the cog in the top right of this page and select 'turn blog notifications on' (if you have an RSPB blog account) or 'subscribe by email'.