my apologies for not quoting individual sections...i thought that this was well known and well accepted, at least since the work of martha gilliam.  here are a few cites:

bacillus and chalkbrood:

http://www.vita-europe.com/Map_enscript/frmbuilder.php?dateiname=%2Fen%2Fdevelopment%2Fchalkbrood.htm

http://www.ars.usda.gov/is/AR/archive/aug98/bees0898.htm

http://www.cals.ncsu.edu/entomology/apiculture/PDF%20files/Johnson_et.al.2005.pdf

http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0325-75412004000100011

http://www3.interscience.wiley.com/journal/119173621/abstract?CRETRY=1&SRETRY=0

http://www.beesource.com/forums/showthread.php?t=216617

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