On 06/04/16 14:00, Ari Seppälä wrote in regards to Chalkbrood 
reappearance in restocked sterilised equipment:

"In Finland it is common to shake swarm AFB hives. The treated hives 
show supricingly often chalkbrood, and it must come with bees as nothing 
else is transferred to the new hive from old.

I think it breaks out so easily because bees have hard time starting 
from just foundations in the new hive. Its interesring that same 
happened with irradiated that are drown combs."

Peter Loring Borst  2016-04-04 17:48 stated:

"As I said in a previous post, I had 400 or so hives
irradiated, put fresh bees into the equipment and
they soon broke down with chalkbrood."

Irrespective of whether or not the irradiation dose was adequate to kill 
spores of Ascophaera apis, (the causative organism of chalkbrood) in the 
equipment, those spores are ubiquitous in the environment and any bees  
used for restocking are very likely to be carrying them. One spore is 
enough to reestablish infection.

The real take home message however, is that if you are seeing chalkbrood 
at all in your hives, then the genetics of those bees are non hygienic. 
It really is as simple as that. So breakdowns of chalkbrood and AFB are 
to be expected, especially if stresses such as nutritional limitation or 
excessive demand for new comb establishment are placed on them.

The solution is simple. Test for hygienic behaviour...in your 
apiaries...in your nucs, and especially those hives used for breeding 
stock. Test the hygienic behaviour of new queens sourced from outside 
suppliers. The pin-prick method is quick, cheap and effective. Anybody 
can do it. Once you have those results you can take effective remedial 
action, even if it means changing the source of your queens, or putting 
pressure on your supplier to improve his or her breeder selection.

PeterD
In Western Australia where a long hot and dry summer has been really 
tough on both the bees and beekeepers. Ideal conditions for disease 
breakdowns.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html