What are the primary causes of bee losses? The Bee Informed Partnership has worked hard at getting to the bottom of this, although their data relies heavily on what beekeepers perceive as the main factors. This may not get at what the real causes are, but it's a start:

> Respondents were asked to identify why they thought their colonies died. The top five reasons given to explain death were poor quality queens, starvation, mites, CCD, and weather. Other factors that were mentioned, but were reported by fewer than 8% of respondents were management (7.8%), weak colonies in the fall (7.4%), Nosema/dysentery (4.4%), nutrition (3.5%), stress (3.1%), viruses (3.1%), and pesticides (2.6%). -- A Survey of Honey Bee Colony Losses in the U.S 2008

More recently:

> Twenty-one percent of 3,389 beekeepers indicated  that they did not know the cause of death of the colonies in their operation that had died.  Among beekeepers who experienced losses and indicated at least one reason why they lost colonies, the top five most frequent reasons given, in order, were: starvation; weak colonies in the fall; poor wintering conditions; poor queens; and varroa mites.  [Additional reasons included: Nosema, CCD, Pesticides and Small hive beetle.] -- A national survey of managed honey bee 2010-11 winter colony losses in the USA: results from the Bee Informed Partnership

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As we can plainly see, beekeepers consistently perceive pesticides as one of the least likely causes. It is a source of constant bewilderment to many of us, why starvation always ranks at the top of these lists. It seems that this would be the easiest thing to prevent or remedy. With weather, on the other hand, there's nothing to be done. Again, with the constant complaining about poor queens, one wonders, why do they not change their management techniques? Buying cheap mail order queens may not be a good plan. 

P

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