Colony Collapse Disorder has been in and out of the media since 2006. With conspiracy theories and non-science abounding, it can be hard to separate truth from fiction.
Last semester, Dr. Diana Cox Foster of Penn State spoke at Iowa State about her work with CCD. She has been studying bees for 20 years and heads a diverse team of researchers working to solve the mystery. She said that there there are quite a few “theories” that her team disagrees with. In particular, she said that CCD is not caused by the rapture or the Russians. She puts cell phones and genetically engineered crops in the same category, choosing instead to focus on legitimate leads. She says that there are many reasons why their group is not looking into these as possible causes, but one reason sticks out: some Amish and organic beekeepers whose hives are isolated from genetically engineered crops, many pesticides, and cell phones in the case of the Amish have experienced CCD, while some conventional beekeepers have not. In other words, there isn’t a common thread connecting colonies that have collapsed.
Despite the fact that scientists like Dr. Cox Foster have spoken on the lack of legitimacy of these theories, people continue to write about them, such as this example from the always creative Global Research. I won’t pick the article apart due to time constraints, but wanted to show the range of views. A lot of mainstream articles have less extreme views, but few if any make an effort to debunk the incorrect theories. Instead, they reinforce them! Karl over at Inoculated Mind has a nice post summarizing some issues with the cell phone and GMO theories that’s over a year old. If only the reporters would research as he did.
There is abundant evidence that the Bt protein Cry1Ab doesn’t affect non-target insects. A meta-analysis from Jan 2008 of 25 independent studies found “that Bt Cry proteins used in genetically modified crops commercialized for control of lepidopteran and coleopteran pests do not negatively affect the survival of either honey bee larvae or adults in laboratory settings.” A meta-analysis from May 2008 of a public database found no significant effect on type or number of arthropods in Bt and non-Bt crops. They did find, as have many others, that various types of insecticides decreases the type and number of arthropods.
A quick lit search did come up with a June 2008 study that showed decreased learning ability in bees that were force fed syrup containing very high concentrations of Bt that are not found in nature. This data might indicate the need for more research on bee physiology, but doesn’t mean that Bt isn’t safe for bees in the field.
Now that we know what it’s not, I’ll share with you what Dr. Cox Foster thinks are the most likely causes and solutions…
First is simple stress. This image of an almond grove from Klausesbees (which incidentally may be the same one that Dr. Foster used in her presentation) shows that bees don’t have many dining options. Instead of having wildflowers or even another crop such as strawberries under the almond trees, the grove is a virtual pollen desert when the trees aren’t in bloom. Other crops used to be grown with hedgerows separating smaller farms, but these have been all but eliminated as farms are consolidated. This type of agriculture is what led to bees being trucked across the country to keep up with crop flowering. Bees did not evolve in the conditions of being moved from state to state, feeding on one type of plant one day to something entirely different the next. A related problem could be the sugar and corn syrups that bees are fed before the crops bloom, just because bees haven’t evolved with this as a food source. The stress of the move and of the ever changing food sources might be too much to bear. The solution to this would be to have areas set aside for wildflowers that would both encourage natural bee hives and serve as a food source to local cultivated bee colonies when the local crops are out of season.
Second is a combination of mites, viruses, and other diseases. Dr. Cox Foster and her associates have sequenced DNA samples from bee hives and found a variety of surprising things, including Aspergillis fungus and the parasite Leishmania. Israeli virus (IAPV) correctly predicted collapsed hives more than any other factor. The virus is transmitted by Verroa mites (shown here in a photo from the USDA ARS). When bees are stressed, they are especially susceptible to mites which in turn makes them susceptible to disease. Royal jelly from China, used to feed prospective queen bees, was also found to contain IAPV. Also contributing to susceptibility is the decrease in genetic diversity among bee hives. One possible solution to the problem is breeding or engineering resistant bees. For example, Arizona beekeepers who have Africanized bees haven’t experienced CCD. Another solution is to develop “biocides” which would be like a medicine to help the bees fight off mites and disease. Vaccines aren’t an option because bees don’t have an adaptive immune system. Beekeepers who irradiate box components before placing a hive inside have had some success, because irradiation kills mites and bacteria.
Third is pesticides, less likely, but still under consideration. Researchers found copious residues of miticides (which some beekeepers apply to bees or to boxes) and other pesticides in the bee wax that beekeepers buy and place in new hives. Use of formic acid, considered a natural substance because it is produced by some species of ants, is widespread and may play a role in increasing bee stress and susceptibility to disease. Bees are affected by a wide range of insecticides, which obviously could play a role. However, there is no common pesticide reside in colonies that experience CCD.
Another hive related possibility is a little more difficult to understand and quantify. Some commercial beekeepers try to get a lot out of their hives. One practice that Dr. Cox Foster questions is too-frequent hive “splitting” because it leads to bee stress. I was also able to find some ruminations on the net that the large cell size used by commercial beekeepers to encourage bee growth may also encourage mite infestations, but couldn’t find any actual data on the subject (anyone need a summer project?).
After her presentation, Dr. Cox Foster shared these links that include more information and info on how individuals can help: The Pollinator Partnership, Mid-Atlantic Apiculture Research and Extension Consortium, and The Status of Pollinators in North America. Another source is the USDA Agricultural Research Service, who has multiple fact sheets, including Colony Collapse Disorder: A Complex Buzz.
One last thing I’d like to share before I end this post – bees are not the only pollinators out there. Of course some aspects of agriculture would have to change if we were no longer able to cart bees across the country, but it wouldn’t be the end of agriculture as some people have said. A Slate article from 2007 called Bee Not Afraid explains. Much of the information in the article matches things that Dr. Cox Foster said in the course of her lecture and in the Q&A session that followed./