He gave a review of the evidence base on neonicotinoids and pollinators from the point of view of the crop-protection industry at SCI seminar "Are Neonicotinoids Killing Bees?" in London last week. Campbell said more than 20 scientific studies that state neonicotinoids are unlikely to be responsible for decline in bee health were not highlighted in newspapers or on television, while studies saying neonicotinoids caused bee decline were regularly cited.
Disease and parasites, beekeepers' practices, climate and weather, environment, habitat and nutrition could cause bee decline, he added. "The expert view is losses are caused by a combination of stressors, in particular varroa destructor mites and associated viruses such as DWV, but there is a huge focus on neonicotinoids."
Campbell pointed to limitations in exposure-only studies. "Modern analytical methods have incredibly low levels of detection - for instance, for neonicotinoids less than 1ng/g, which are well below reported bee effects levels in labs."
The presence of a measured residue does not mean there is a risk and toxicity data as well as timing and duration of exposure must be considered in parallel, he added, while some forced field exposure studies do not reflect the real exposure and risk under field in-use conditions.
Campbell also criticised the limitations of correlative studies, saying correlation is not causation and there are many other primary causes for decline in wild bee populations such as habitat and forage availability.
He said the challenges facing the crop-protection industry include intentional bias and selective use of data, unintentional bias, industry regulatory data not being publicly available, scientists' motivation being seeking/securing research funding, the political environment in which pesticides are not seen as vote winners and publication bias - "bad news sells."
Campbell added that the scientific principle of hazard versus risk is often ignored. "Honeybee declines began before the wide use of neonicotinoids and there is poor geographical correlation between neonicotinoid use and honeybee decline."
Recently published EU pollinator health data from the EU COLOSS and EPILOBEE group showed colony losses in 2013-14 were nine per cent, the lowest since the international working group started collecting data before the neonicotinoid ban, he pointed out. But in 2014-15, after the ban, colony losses rose to 17.4 per cent.
Studies Research papers cited in neonicotinoid production debate
Scientific studies stating that neonicotinoids are unlikely to be responsible for decline in bee health: Imdorf et al, 2006; Genersch et al, 2010; Cresswell, 2011; Schneider et al, 2012; Cresswell et al, 2012; Blacquiere et al, 2012; Oliver, 2012; Pilling et al, 2013; Cutler et al, 2014; Cutler & Scot-Dupree, 2014; Staveley et al, 2014; Carreck & Ratnieks, 2014; Collinson et al, 2015; Rundlof et al, 2015 (honeybees); Kerr et al, 2015; Thompson et al, 2015; Dively et al, 2015; Thompson et al, 2016; Piiroinen et al, 2016 (bumblebees); Piiroinen & Goulson (bumblebees); Rundlof et al, 2016; Fairbrother et al, 2014