As a subscriber to American Bee Journal, I follow Randy Oliver's column with interest; indeed it is often the first part of the magazine to be read. I like the way he tries to take the pulse of beekeeping experience, and unearth the science behind it, or indeed vice versa. His articles are reproduced for free on his website shortly after print publication.

His recent two-part series entitled Neonicotinoids: Trying To Make Sense of the Science is well worth reading. I would say it is the most even-handed review of the topic I have seen, and of direct relevance since it is written by beekeepers for beekeepers.

Perhaps the most important comment comes late in the 2nd article, after he has reviewed the scientific consensus and the practical experiences of beekeepers (original emphasis retained, with apologies to Gavin):

Quote Originally Posted by Randy Oliver
The Absence of any “Smoking Gun”

If neonics were actually causing colony mortality, it should be child’s play to demonstrate—just feed a colony syrup or pollen spiked with the insecticide and see how long it takes to kill it. The fact is, that try as they might, no research team has ever been able to induce colony mortality by exposing the bees to field-relevant doses of any neonicotinoid (although one can get a significant kill from corn planting dust). Nor has any investigation ever been able to link neonic residues in the hive to colony mortality. Every claim that neonics are causing serious bee mortality is unsupported supposition, not backed by any concrete evidence.
Neonicotinoids: Trying To Make Sense of the Science

Neonicotinoids: Trying To Make Sense of the Science - Part 2

Can I please recommend that those interested take the time to read and digest what is quite a lengthy pair of articles, and some of the referenced materials, however stimulating you may find the summary quoted above

Enjoy!