Newly published work by Engelsdorp et al, fails to link CCD with a particular pathogen, but flags the levels coumaphos as the most reliable indicator of NON-CCD colonies. The implications of these findings are discussed. 

This is not to say that there is a direct link between coumaphos and absence of CCD, although there could be if effective mite control translates into generally more robust colonies. They also found higher levels of non-beekeeper applied chemicals in the non-ccd hives.

The absence of a single pathogen in common in all CCD hives is baffling, but could indicate that either pathogens are opportunistically preying upon CCD hives, or that the key pathogen has not yet been identified. As I mentioned in the previous post, CCD *appears* to be contagious, at least under certain circumstances.

quotes:

> The discriminatory value of coumaphos in brood suggests that healthy colonies had mite popu- lations that were more aggressively or persistently controlled by the beekeepers. Although varroa mite levels were not different between CCD and control populations at the time of sampling (vanEngelsdorp et al. 2009), it is possible that mite populations differed at some time before sample collection. CCD may therefore be a consequence of elevated levels of mitesÑrelative to mite levels in control coloniesÑ some time before sampling.

> The ability of individual pathogen loads to distinguish CCD and non-CCD colonies was minimal. This conÞrms previous Þndings that none of the pathogens quantiÞed by this effort can be implicated as the sole “cause” of CCD. This is not to say, however, that disease agents play no role in CCD, because they clearly do. 

> This analysis also provides further evidence that CCD is probably the result of several factors, acting in concert, which together decrease colony Þtness and make affected colonies more susceptible to disease.

Weighing Risk Factors Associated With Bee Colony Collapse Disorder by Classification and Regression Tree Analysis
DENNIS VANENGELSDORP, et al. J. Econ. Entomol. 103(5): 1517-1523 (2010); DOI: 10.1603/EC09429

             ***********************************************
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