Alida Francisco Janmaat wrote:
.
>
> Chalkbrood appears to be a problem when there are not enough adult bees in
> a colony to maintain the appropriate temperature in the brood nest.  If
> adult populations in colonies are beginning to decrease, yet brood
> production has not decreased, the brood may become
> chilled and chalkbrood will result.
 
> That's my two bits worth.  I look forward to reading your replies!
 
There is a good discussion on chalkbrood in the Jan 97 American Bee
Journal on page 52.
 
Don