Johansen and Mayer are quoted from the top in Reed Johnson's summary of the pesticide situation, 20 years later. 

> Most honey bee losses from 1966–1979 were attributable to organochlorine, carbamate, organophosphorus, and pyrethroid pesticide exposure. Efforts to restrict pesticide application during bloom provided some relief; however, the residual activity of some pesticides was never effectively addressed (Johansen and Mayer, 1990). Previous reviews and extension publications are available concerning the protection of honey bees from these 4 classes of pesticides (Johansen and Mayer, 1990, etc).

However, there is a lot of new information to take in. In many ways, the information presented in 1990 no longer applies.

> Colony losses were especially severe from 1981 to 2005 with a drop from 4.2 million to 2.4 million (NAS, 2007) although some of the decrease is attributable to changes in how colony numbers were estimated. The introduction of parasitic honey bee mites, Acarapis woodi (1984) and Varroa destructor (1987), contributed to dramatic bee losses. 

> At the same time, the control of crop pests in USA agriculture was rapidly changing. Genetically engineered (GE) crops were developed and extensively deployed, and two new classes of systemic pesticides, neonicotinoids and phenylpyrazoles, replaced many of the older pesticides described above.

> [A] major shift in USA agriculture has been the development and extensive deployment of neonicotinoid and phenylpyrazole pesticides. These pesticides are extensively used in the USA on field, vegetable, turf, and ornamental crops, some of which are commercially pollinated by bees.

> Registration review is replacing the EPA’s pesticide re-registration and tolerance reassessment programs. Unlike earlier review programs, registration review operates continuously, encompassing all registered pesticides. The registration review docket for imidacloprid opened in December 2008. The pending EPA review will consider the potential effects of the neonicotinoids on honey bees and other pollinating insects, evaluating acute risk at the time of application and the longer-term exposure to translocated neonicotinoids.

Meanwhile, researchers have conducted extensive analysis independently of the EPA:

> The recent phenomenon of CCD triggered a close look at the role of pesticides as a possible contributing factor to honey bee decline in general and CCD specifically. Mullin and Frasier used LC/MS-MS and GC/MS and a modified QuEChERS method to analyze for pesticide residues in honey bees and hive matrices in the USA and Canada to examine colonies exhibiting CCD symptoms. One hundred twenty-one different pesticides and metabolites were found. 

> Overall, pyrethroids and organophosphates dominated total wax and bee residues followed by fungicides, systemics, carbamates, and herbicides, whereas fungicides prevailed in pollen followed by organophosphates, systemics, pyrethroids, carbamates, and herbicides. Externally-derived, highly toxic pyrethroids were the most frequent and dominant class of insecticides samples. Contact pyrethroids, and systemic neonicotinoids and fungicides are often combined as pest control inputs, and many of the latter may synergize the already high toxicity of neonicotinoids and pyrethroids to honey bees.

Of extreme interest to beekeepers, however, should be Reed's concluding statements:

> Beekeepers searching for the primary source of pesticides contaminating bee hives need only to look in a mirror. Unfortunately, the regulatory system governing the veterinary use of pesticides in bee hives in the USA may be perversely contributing to the problem. …  A change in the regulatory system needs to occur to make effective and safe veterinary pesticides available to beekeepers and to spur research into the effects of candidate compounds on honey bee health. 

> Likewise, beekeepers need to realize that honey bee pests and parasites are community problems, as well as individual problems, and that pesticide labels are crafted to protect the sustainability of pesticides. The use of unregistered products is a serious threat to the beekeeping community and should not occur.

Pesticides and honey bee toxicity – USA*
Reed M. Johnson, Marion D. Ellis, Christopher A. Mullin, Maryann Frazier
Apidologie 41 (2010) 312–331 Available online at: www.apidologie.org

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm