A series of studies funded by Bayer and submitted to European regulators by the company to support claims that its neonicotinoid pesticides do not harm bees have been criticised by a leading scientist and an industry expert.
The news comes as environment secretary Michael Gove announced the UK would back a European move to ban neonicotinoids, also known as neonics, due to mounting scientific evidence linking the chemicals to bee deaths.
The European Commission is likely to move to ban neonics by the end of the year, with a vote expected in December. The ban would go beyond current restrictions on the chemicals in Europe that have been around since 2013.
Neonics have long been linked with declining bee populations, but the issue has been subject to significant debate, with manufacturers insisting their products do not harm bees when used correctly.
‘Severe limitations’
But speaking to Unearthed, a leading scientist noted that the Bayer-funded research was hampered by “bad experimental design” making it difficult to draw conclusions about the effect of neonicotinoids on bees.
The studies were described as “statistically flawed” by Professor Ben Woodcock, who has published a number of papers on neonics, including the Bayer and Syngenta funded CEH study.
Matt Shardlow, the chief executive of the conservation organization Buglife, told Unearthed that the Ecotoxicology studies had “severe limitations”.
Related
- Neonicotinoids: Landmark European Court Verdict Could Change Bee Deaths Debate
- New Evidence Shows Bayer, Syngenta Fought Scientists For Data On Bee Study
- Despite Ag Industry Efforts, First Bee Species Listed As Endangered
Woodcock told Unearthed: “It’s an interesting series of studies all using the same experimental platform. However, it’s pseudo-replicated. It can’t be used to argue that neonicotinoids are either harmful or not harmful to bees.
“In the case of this study this means that their experimental plots are not independent, an important requirement for robust statistics. Experiments should make observations from independent experimental plots (e.g. multiple fields treated with and without neonicotinoids in different locations), and by doing so they are able to make predictions about what happens to bees not just in those experimental plots, but everywhere.
“However, by sampling repeatedly from the same two experimental locations (one treated and one not treated with neonicotinoids) this study has violated this statistical assumption. This means they cannot reliably make a prediction about what happens to bees outside of the two locations they ran their experiment in. While this provides interesting results, from a policy perspective this lack of generality limits the value of this piece of evidence.
“One of the problems with pseudo-replication is that you can’t separate out the difference between the natural background variation we see between experimental sites and the effect of the neonicotinoids on the bees.”
Woodcock, who told Unearthed in July that he felt Bayer and Syngenta had looked to undermine the quality of his work, added: “This study can’t be used to infer anything, least of all there is no effect of neonicotinoids. Given the sensitivity of this issue this amazes me.”
Matt Shardlow, the chief executive of the conservation organization Buglife, told Unearthed that the Ecotoxicology studies had “severe limitations”.
He said: “The methodology of the study published in the November 2016 edition of Ecotoxicology has a number of severe limitations. The study compares one site where neonicotinoids were used on oilseed rape with another nearby site where other insecticides were used; the other insecticides are not documented so it is not clear what the control was.
“The bumblebees were only exposed to the neonicotinoid-treated areas for three weeks and were then retired to a nature reserve for the rest of the year. In reality bumblebees in agricultural landscapes are exposed to neonicotinoids in planting dust and wildflowers as well, including commonly used neonicotinoids such as imidacloprid and thiamethoxam.
“The study does not report on the levels of imidacloprid and thiamethoxam in the pollen and nectar, if there were more of these toxins present in one of the sites then this could throw the results. The study only measures effects from a small part of the actual annual exposure to neonicotinoids, for only one type of neonicotinoid, on one site and in one year. This does not reflect the complexity of environmental situations or the level of neonicotinoid exposure that bees face in the real world.”
In response to these comments, a Bayer spokesperson said: “the studies contribute valid findings which make an important contribution to correctly assess the potential effects of oilseed rape grown from clothianidin-treated seeds on bee species with different life cycles.”
“The results demonstrate that the previously authorized seed treatment of oilseed rape with clothianidin does not harm colonies of honey bees and other bee species.
“Briefly summarised: the criticisms expressed does not add new facts to the scientific audience, overall. Some points of criticism are based on misinterpretations of the scope of the study and the linked statistical analysis.”
Ecotoxicology’s editor’s declined to comment for this story when contacted by Unearthed.
Stinging criticism
Bayer is not the only firm to have seen a study it backed receive criticism from scientists.
A study published by the journal Plos in October 2013 and led by Syngenta’s Peter Campbell examining the impact of the chemical thiamethoxam on honey bees was dismissed by scientists from St Andrews University as “inadequate” last year.
The review concluded: “Given that the data, in this case, are largely uninformative with respect to the treatment effect, any conclusions reached from such informal approaches can do little more than reflect the prior beliefs of those involved.”
We put all this criticism to Syngenta, and they sent back a statement from Andrew McConville, Syngenta’s EAME corporate affairs head.
He said: “The conclusion of low risk in Pilling et al, was informed by an expert analysis of the full biological and chemical data generated in this study. Subsequently published honeybee field effect studies conducted with thiamethoxam seed treated oilseed rape have reported similar conclusions. The criticism by St Andrews University of the independently reviewed Pilling et al study was rebutted in a paper published earlier this year.”
Top photo | A crop dusting plane from Blair Air Service dusts cotton crops in Lemoore, Calif. (AP/Gary Kazanjian)
Unearthed is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 International License.
The post As Europe Readies Ban on Bee-Killing Pesticides, Attention Turns To Bayer-Funded Studies appeared first on MintPress News.