Varroa vs powdered sugar?

[top bar maker]

I was wondering if several treatments of powdered sugar timed to interrupt the life cycle of the varroa mite might be successful in lowering the mite population to "manageable" levels as the colony heads into winter. If the mites fall through the screened bottom onto the ground can they return to the hive like small hive beetles can? Would more or less continual applications of powdered sugar be harmful to the colony? I am developing a sugar duster to use in my top bar hive, but I have only one hive and I'm reluctant to put my girls in jeopardy. We are doing a mite count today and would do a count after every treatment. Anyone have experience with heavy use of powdered sugar? Thanks

[Jacobs]

Studies within the last year got disappointing results using powdered sugar for mite control (as opposed to using it in a sugar roll evaluation). I did it one time on a hive about 2 years ago and the bees hated it. I used a sifter and got every frame and it was time consuming and disruptive. You may be able to do it better with just the one level of comb with your top bar, and other than the disruption I don't think it would do much harm. (Too much powdered sugar into an open brood cell could obviously harm the developing brood.)

If you are going to dust, you want to do it in a way that you can remove the sugar that has come through the process. The sugar doesn't kill the mites, so my guess is that if you left the sugar and mites under the hive, they would dust off their feet and march back in at some point.

[ski]

I, like Jacobs, have only experimented with powdered sugar treatments. I did not do it long enough to get a positive or negative result, I gave it up to do Fogging. Powdered sugar did remove mites and they were still alive so yes they may renter the hive. I used a box to catch the powdered sugar and removed it with the mites.
But there are folks that do sugar treatments on intervals that say it works. Jennifer Berry from the University of Georgia reported at the 2010 EAS Bee conference that she is doing a study on powdered sugar treatments to see if it will keep the varrora count down as well as affects it may have on brood and honey production. Jennifer is also one person that says the powdered sugar treatments work.

You can also do a search on http://www.beesource.com/forums/. I know some folks call it BS lol but I think there is some good information there.
I have heard mixed results on the sugar duster that is on the market now, a few folks modified the duster to make it work better.

Good luck with your duster.

Also received this response from the eXtension site.

There are other people who had done some research on this area such as Amanda Ellis and others (Journal of Apicultural Research volume 48, 72-76. 2009). However, the authors found that dusting every two weeks for 11 months (120 g powdered sugar per application) had no effect on adult bee population, brood production, total number of mites in the colonies, mites on adult bees and mites in capped brood. For sure dusting will remove some mites from the colonies but not at significant lelvel.
-Lilia de Guzman

[top bar maker]

Well, we did the 24 hour mite count and had 1 lousy varroa mite. So much for the powdered sugar experiment. Maybe I'll dust them anyway just to see what happens. Also to see if my rig works. I'm not seeing any beetles either after we did the falling-into-oil trap on the new bottom board.
Hmm - I feel a top bar testimonial coming on! :)

[SmithN]

top bar maker,
Congrats on your mite count!!
That's very impressive for this time of year.

Would you please share with us how you do a 24 hr mite drop count in a top bar hive?

[harleechik70]

I had varroa in my hive last year and decided to try the powdered sugar, just to see if it would work. I read up on it and did it exactly as instructed and was able to restore the hive to their healthy state. I put the powdered sugar in an old shaker jar, opened up the hive, and sprinkled it heavily on each super, trying to get as many bees sprinkled as possible. They say the most important thing is to do it for 6 weeks in a row on the exact same day, and that's what I did. My bees loved it! I still do it occasionally, just for the heck of it---gives them a treat and encourages grooming!

And nothing is funnier than a sugar covered guard bee trying to intimidate you!!!