reading about chalkbrood

[Kathyp]

i have been doing some research on chalkbrood, since it seems to be a reoccurring problem for me.  i found it in a 2nd hive this year.  while there is no chemical treatment, there are recommendations.  most we are familiar with, such as increasing air circulation, re-queening, etc.  this year i also learned about using tree tea oil, and in one hive, this seems to have helped.

one other interesting thing i have run across.  this has to do with raising the temp inside the hive.  there is some evidence that the fungus does not thrive in hot temps.  i did not crack the tops of my hives in our current hot weather.  i will be interested to see if there is a difference although it will be hard to draw a conclusion at this time of year.

has anyone else tried this or even heard of high temp effect on chalkbrood?

[Michael Bush]

Putting a hive in full sun seems to help, which probably increases the temperature and decreases the humidity.  Also keep in mind:

"Lower pH values (equivalent to those found in honey, pollen, and brood food) drastically reduced enlargement and germ-tube production. Ascosphaera apis appears to be a pathogen highly specialized for life in honeybee larvae."--Author. Dept. Biological Sci., Plymouth Polytechnic, Drake Circus, Plymouth PL4 8AA, Devon, UK. Library code: Bb. Language: En. Apicultural Abstracts from IBRA: 4101024

Sugar syrup is much higher pH than honey.

http://www.bushfarms.com/beespests.htm#chalkbrood

[Brian D. Bray]

Full sun and ventilation are usually what it takes to prevent chalkbrood.  I put cider vinegar in my syrup when feeding which lowers the ph a tad and also helps with nosema.  I haven't had a case of nosema or chalkbrood since switch to SBB and vented tops of some type.  Now I've gone to bottomless hives with top entrances.  This allows the bees to move air freely and they seem to leave by the top and return via the open bottom.