I'm sure the people doing the research have looked into this, but what miteacides have been introduced within the last 3 or 4 years?
Although the problem has been named 'Colony Collapse Disorder', most of the reports that I have read sound more like major absconding than actual colony deaths. Of course you can't rely on reporters to get the facts right with anything that they don't understand.
Moderators, would it be possible to gather all posts related to this into a single post, perhaps in the 'Disease and Pest Controll' forum? Information on it is kind of spread around here, there, and in the General forum.