On Tue, 8 Sep 2009 22:32:51 -0500, Bob Harrison <[log in to unmask]> wrote: >Pesticides are one of the four possible causes of CCD the CCD working group has published. There are far more than 4 possible factors involved. The most recent work by Dennis vanEngelsdorp, et al, refers to *61 meaningful variables*. And, they concluded that there was *no evidence* supporting pesticides as causing or precipitating colony collapse. * * * Of the more than 200 variables we quantified in this study, 61 were found with enough frequency to permit meaningful comparisons between populations. None of these measures on its own could distinguish CCD from control colonies. Moreover, no single risk factor was found consistently or sufficiently abundantly in CCD colonies to suggest a single causal agent. Chronic or sub-lethal exposure to agricultural- or beekeeperapplied pesticides can weaken the honey bee immune system, hampering the ability of bees to fight off infection. This study found no evidence that the presence or amount of any individual pesticide occurred more frequently or abundantly in CCD affected apiaries or colonies. This study suggests that future, longitudinal studies should focus on monitoring parasite (varroa mite), pathogen, and pesticide loads while quantifying pesticide tolerance in study populations. More specific studies that investigate potential interactions among pesticides and pathogen loads are also warranted. Levels of the miticide coumaphos were higher in control populations than CCDaffected populations. Citation: vanEngelsdorp D, Evans JD, Saegerman C, Mullin C, Haubruge E, et al. (2009) Colony Collapse Disorder: A Descriptive Study. PLoS ONE 4(8): e6481. Published August 3, 2009 *********************************************** 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