I didn't crawl through all the references in the site Isis gave, but I did not find the answers to the questions readers have asked, specifically what are the smoker fuels purpoeted to knock down Varroa.
 
My recollectrion is that there was a lot of hope about 5 years ago that smoker fuels may be a good weapon against V.d.  The big three I remember being touted wete cedar chips, grapefruit leaves and bobs (seed heads) of staghorn sumac (Rhus typhina).  My recollection is also that at best these fuels worked well in the lab, but the hopes and promises were dashed in the field.  At the time however, there were great hopes.  Grapefruit trees were nearly denuded in Florida, at least one major supplier offered sumac bobs in their catalog, and ebay entrepeneurs made a killing!
 
A quick Google search on "staghorn varroa" offers a bit of the history, as does a search of the BEE-L archives.
 
Aaron Morris - thinking if it sounds too good to be true....

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