Weekends are when weird science news shows up in Google News scans, and last weekend was no different. A new paper by Chensheng Lu, Kenneth Warchol and Richard Callahan appeared to chaim that neonicotinoid insecticides led to bee colony collapse disorder. Lu had published a similar earlier paper in 2012 in the same journal and this was a follow-on.
Lu is a professor in Harvard’s Department of Environmental Health, and the co-authors are Massachusetts beekeepers. A couple of red flags here to the credulous press: Lu is not an entomologist, and the journal, Bulletin of Insectology is an obscure Italian journal published at the University of Bologna, and formerly titled Bollettino dell'Istituto di Entomologia "Guido Grandi" della Università degli Studi di Bologna. It has a journal Impact Factor of 0.375 this year. (Impact factor is a measure of how often journal articles are cited elsewhere.)There are a number of major entomology journals that Lu bypassed in selecting this obscure journal.
The authors fed bees sugar or HFCS solutions spiked with either imidacloprid or clothiandin, two well-known neonicotinoids, for 13 weeks. A control group was fed untainted sugar or HFCS solutions. Both groups thrived throughout the summer and fall. But at the end of the winter. 6 of the 12 neonicotinoid colonies were abandoned. One of the six control colonies was abandoned as well.
The authors take this to mean that the neonicotinoids cause Colony Collapse Disorder (CCD), but entomologists do not feel that he demonstrates this at all. In fact, what seems to have happened is that as the bee colonies declined as winter approached, there were fewer bees eating the same amount of insecticide, which eventually killed them.
It is interesting, however, that the bees thrived all summer and fall, before dying off in January and this is the kernel of a significant finding.
Moreover, the authors do not account for the fact the France still observes CCD each year, even though they banned neonicotinoids 5 years ago. Nor do they note that beekeepers in Canada and Australia and parts of Europe use neonicotinoids, but do not observe CCD. Finally, they do not note that CCD has been taking place regularly for hundreds of years. We reviewed this in an article last year.
Most serious, though, is the fact that the authors do not refer to many existing research papers contradicting their conclusions. For example, a recent article by Fairbrother et al. in Environmental Toxicology and Chemistry who reviewed existing studies and reviews to conclude:
All of the neonicotinoid insecticides have been reviewed and approved in many jurisdictions around the world, including Europe, Australia, Japan, Canada, and the United States; and they have been used for more than 15 yr on a variety of crops. Therefore, a signiﬁcant body of data from both laboratory and ﬁeld studies is available to assess the risks to colonies of honeybees. The available data indicate that there may be effects to individual honeybees housed under laboratory conditions and exposed to unrealistically high concentrations of the insecticides. However, under ﬁeld conditions and exposure levels, similar effects on honeybee colonies have not been documented. It is not reasonable, therefore, to conclude that crop-applied pesticides in general, or neonicotinoids in particular, are a major risk factor for honeybee colonies, given the current approved uses and beekeeping practices.
A similar review of Lu’s article was also published today by Jake Bova on the IFLS web site. Thanks to discussions with Linda Chalker-Scott and Joe Ballenger on Facebook for some of this information.
We don't know much that is new from Lu's paper, so you can relax.