Nosema disease and tracheal mites were apparently the least damaging factors, while higher fatality cases were associated with varroa mites either alone or in combination with other factors (> 85%), followed by low bee populations associated to other factors The relative weight of nosema disease in the mortality of overwintered colonies is a controversial matter. However, there is no conclusive evidence to affirm that Nosema is an important factor in the recent honey bee die-offs worldwide. It is possible however, that the same honey bee parasites may cause varying degrees of damage depending on their geographical locations. It is relevant to highlight that surviving colonies had mean varroa infestation levels lower than 3% Varroa destructor is the main culprit for the death and reduced populations of overwintered honey bee (Apis mellifera) colonies in Ontario, Canada 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 Access BEE-L directly at: http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A0=BEE-L