Imidacloprid is more likely to be found in raw sugar and molasses than in refined sugar, without a doubt.  Raw sugar will likely have background levels of whatever persistant pesticides (pesticides that do not decompose readily in the environment) whereas molasses will have these background levels concentrated.  The sugar refining process produces molasses as a concentrate of the impurities removed from sucrose sugar.  Thus toxins and pesticides will be more concentrated in molasses than raw sugar alone.  The extracted impurities (molasses) also constutes almost all of the nutritious components from the extract of sugar cane or sugar beet as well.
 
So, for humans, raw sugar and molasses has the iron, vitamins, etc. that are good for us.  But for honey bees, it has all kind of indigestible sugars and components that will cause them to get sick and weak by way of gastric upset.  Raw sugar and molasses are bad for bees.  In fact, many organic types will tell you that molasses is a great way to poison garden pests, ants and such.
 
Happy beekeeping,         Eric


      

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