From: Alida Francisco Janmaat <[log in to unmask]>
Subject:      Varroa and Chalkbrood
<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.
 
I had an experience that might be supportive of this.  It occurred in 1989
while trying to treat TM with menthol crystals in the spring (March).  An
unusual hot spell set in for two days resulting with highs reaching 90+/- F
(33C) and then the temps returned to seasonal levels.  The crystal packets
were placed in the top center of the top (2 BCs) chamber.  This was an out
apiary that I couldn't get to quickly.  I feared that the intense vapors
would drive the house bees from the brood chambers.  When I did inspect the
eighteen formally strong colonies in this location, Chalk was very
prominent.  I had, in earlier years, seen small patches of chalk and sac in
several of the colonies.   Now every colony showed chalk to some degree.
Some colonies suffered a 50% loss of brood.   I had not been feeding syrup
or pollen and had not seen chalk to this degree before this occasion.
This, thankfully, was a one time event..
 
D.Pritchard
Belvidere, NJ
[log in to unmask]