Scientists from opposing sides of the debate clashed at a briefing organised to discuss the impact of the pesticides on pollinators in London this week.
However, they agreed research could go further to look at the pesticides’ impacts on wildlife, biodiversity and the wider environment, including water, and called on the Government to apply additional funding for independent trials.
The scientific briefing organised by the Soil Association on Thursday (April 28) heard there was a wealth of evidence surrounding the safety of neonicotinoids, but no definitive conclusion on their effects on bee health and whether they had led to population decline.
Dr Lynn Dicks, a research fellow at the University of Cambridge and lead author of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) thematic assessment of pollinators, pollination and food production, said while there were various reasons for bee decline, including climate change, land use change, pests and ‘intensive agricultural management’, neonicotinoids caused both lethal and sub-lethal effects on pollinators and evidence was ’conflicting’.
Dr Dicks said: “In my view there is no question that the current ban should be retained from a cautionary perspective.”
Professor Dave Goulson, a leading expert in the ecology of bees and other insects at the University of Sussex, said bees were exposed to a ‘lethal cocktail of chemicals’ after his studies showed low concentrations of the pesticides were present in the nectar and pollen of wildflowers growing in arable field margins and hedgerow flowers such as hawthorn, wild rose, blackberries and honeysuckle. He said these concentrations were sometimes much higher than those found in the crop.
Prof Goulson said: “Indeed, the large majority (97 per cent) of neonicotinoids brought back in pollen to honey bee hives in arable landscapes was from wildflowers, not crops.
“Both previous and ongoing field studies have been based on the premise that exposure to neonicotinoids would occur only during the blooming period of flowering crops and that it may be diluted by bees also foraging on untreated wildflowers.
“Here, we show that exposure is likely to be higher and more prolonged than currently recognised because of widespread contamination of wild plants growing near treated crops.”
Prof Goulson asked whether neonicotinoids were even necessary and pointed to high oilseed rape yields in 2014/15 despite industry claims the EU moratorium would wipe out production.
He also appeared to suggest growers were persuaded to use ‘unnecessary’ pesticides by agronomists funded by agrochemical companies - a suggestion which was rebuffed by NFU chief arable adviser Guy Gagen.
Scientists representing the agro-chemical sector who were present in the audience, including Peter Campbell, senior environmental specialist and head of product safety research collaborations at Syngenta, highlighted the firm’s own evidence, which showed ‘absolutely no effect on bees’.
“We rent 12,000 hives to produce the seeds we sell. They are next to neonicotinoid treated fields and we have had no problem with bee health,” said Mr Campbell, also highlighted a revered Swedish study which concluded neonicotinoids had an effect on wild bees, but not on honey bees.
Dr Julian Little, public and government affairs manager at Bayer, said while there was much talk of pollinator decline, there had been little discussion about increases in wildlife, for example new species of butterfly which he said had flourished in recent years.