> We did not treat colonies in winter...

Sorry.  I was thinking of the oxalic vapour treatments, which I assume were tested after the end of brood rearing in late fall and early winter.  I wondered if you did a finishing treatment after them or verified the remaining mites somehow.

>2. Hard to manipulate wrapped colonies in our climate during winter with too many interruptions to collect sticky boards and replacing them. Bees might even die due to all of these exposures to freezing temp.

Yes.  That is a difficulty with wrapping.  In my case, previously with my individual hive wraps and now the EPS boxes, hive access can be minimally disruptive unless boxes must be lifted off. Top access is easy and Apinovar-type floors make bottom monitoring simple and minimally disruptive.   Nonetheless, I wonder if all my treating and sliding the sample drawers in and out will kill colonies.  So far, they seem just fine.

>3. We suppose to take out used strips after 42 days. If we don't we might be breeding faster resistance to Apivar. This is even harder on bees to open hives to take strips out.

In my case, I just lift the lid and lift part of the pillow.

>Our research as you mentioned in previous e mail showed that best results obtained when treatment was in  early spring...  mites within 42 days of treatment are  almost zero. These colonies most likely will not require a second treatment in fall under our conditions. 

Yes.  I discovered that years ago with Apistan.  Everyone was using two to four strips in fall and getting variable results.  A friend told me that he was using one strip in spring and saving product, reducing contamination, and not treating colonies which had died in winter.   Since the clusters were smaller, many or most hives needed only one strip.  In fall, many of the the dropping mites were close to the cluster and were able to get back on a bee.  In early spring, the cluster was up top and the falling mites had little  chance of finding alive bee to ride back up.  That way semi-resistant mites that were only stunned by the fluvalinate were culled in a way they were not in fall.  Using that trick, and regular monitoring, we observed very low mite loads and no varroa problems for years.

Anyhow, any info you -- or anyone -- might have about mite survival profiles in wintering hives especially after oxalic vapour treatment will be appreciated.  I suppose I should also ask Cor.  So far, I haven't.

>Happy new year to Bee-L members.

Yes indeed.  2012 is almost here.

             ***********************************************
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

Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm