It's still more ambiguous than stated given the differing results per country(both positive and negative) and they didn't control for fungicide use.
We clustered sites into triplets (>3.2 km between sites) and randomly allocated sites to one of three treatments: (i) clothianidin applied at 11.86 to 18.05 grams of active ingredient per hectare (g a.i. ha−1) with a fungicide (thriam and prochloraz) and nonsystemic pyrethroid (beta-cyfluthrin) (trade name Modesto); (ii) thiamethoxam applied at 10.07 to 11.14 g a.i. ha−1 and combined with the fungicides fludioxonil and metalaxyl-M (trade name Cruiser); and (iii) control OSR receiving a commercial fungicide (thriam and dimethomorph in Germany and Hungary and thriam and prochloraz in the United Kingdom) but no neonicotinoid seed treatment.
Fungicides may have synergistic effects when used with pesticides. [0][1][2]
The other study, "Chronic exposure to neonicotinoids reduces honey bee health near corn crops" is a bit more credible. Corn is a non-uniform seed and more apt to ablate the seed coat and generate significant dust issues, hence Canada's regulation to for seed lubrication. Ground persistence and mobility make setting up adjacent pollinator refuge sites a potential source of neonicotinoids in addition to the irrigated surface water. That corn is wind pollinated and only provides a nutrient poor pollen kind of exacerbates that, I think.
Contrast that with western Canada where CCD hasn't been observed in canola regions, canola seed is uniform and canola provides both nutritious pollen and nectar.
I still don't think an outright ban at this point is the right choice especially given the limited alternatives and research into those alternatives. Organophosphates are significantly worse for both humans and bees. Pyrethrins aren't exactly safe for bees either, with both being broad-spectrum insecticides and requiring more frequent application via foliar spraying. Even IPM guidelines for a pest like the flea beetle rank several types of neonicotinoids above using pyrethrins[3].
There really aren't any easy solutions but, reevaluating the use of prophylactic seed treatment should be worth a consideration.
We clustered sites into triplets (>3.2 km between sites) and randomly allocated sites to one of three treatments: (i) clothianidin applied at 11.86 to 18.05 grams of active ingredient per hectare (g a.i. ha−1) with a fungicide (thriam and prochloraz) and nonsystemic pyrethroid (beta-cyfluthrin) (trade name Modesto); (ii) thiamethoxam applied at 10.07 to 11.14 g a.i. ha−1 and combined with the fungicides fludioxonil and metalaxyl-M (trade name Cruiser); and (iii) control OSR receiving a commercial fungicide (thriam and dimethomorph in Germany and Hungary and thriam and prochloraz in the United Kingdom) but no neonicotinoid seed treatment.
Fungicides may have synergistic effects when used with pesticides. [0][1][2]
The other study, "Chronic exposure to neonicotinoids reduces honey bee health near corn crops" is a bit more credible. Corn is a non-uniform seed and more apt to ablate the seed coat and generate significant dust issues, hence Canada's regulation to for seed lubrication. Ground persistence and mobility make setting up adjacent pollinator refuge sites a potential source of neonicotinoids in addition to the irrigated surface water. That corn is wind pollinated and only provides a nutrient poor pollen kind of exacerbates that, I think. Contrast that with western Canada where CCD hasn't been observed in canola regions, canola seed is uniform and canola provides both nutritious pollen and nectar.
I still don't think an outright ban at this point is the right choice especially given the limited alternatives and research into those alternatives. Organophosphates are significantly worse for both humans and bees. Pyrethrins aren't exactly safe for bees either, with both being broad-spectrum insecticides and requiring more frequent application via foliar spraying. Even IPM guidelines for a pest like the flea beetle rank several types of neonicotinoids above using pyrethrins[3].
There really aren't any easy solutions but, reevaluating the use of prophylactic seed treatment should be worth a consideration.
[0]: http://onlinelibrary.wiley.com/doi/10.1002/ps.4449/abstract
[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3558502/
[2]: http://lib.gig.ac.cn/local/ejournal/ETC/ETC1996/1504/ETC-199...
[3]: http://ipm.ucanr.edu/PMG/r783301411.html