Help Oxalic Acid.

**Black Comb** · 05-01-2014, 05:55 PM

Did you use thymol in the autumn?

**snimmo243** · 05-01-2014, 06:45 PM

Hi Black Comb
I didn't treat in the autumn as I followed the Beebase advice that comes out when you use the calculator which said treat in 10 months!
Maybe won't do that again

Steven

**Jon** · 05-01-2014, 08:10 PM

I don't rate that beebase dropcount at all. I suppose it must give a very rough guide.
The best way to estimate mites is to take a sample of 300 bees and shake them in icing sugar to get a mite count.
The sugar dislodges the mites.
Can't do that at this time of year though.
I have had colonies with a low natural drop produce hundreds when treatment is applied.
I treated all of mine with Oxalic about 2 weeks ago. Some dropped only 1 or 2 mites whereas others dropped 100+

**snimmo243** · 05-01-2014, 09:18 PM

I will be going back in a week to check the count after treatment yesterday, it will be interesting to see what has been dropped

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**mbc** · 05-01-2014, 10:34 PM

Originally Posted by Jon

I don't rate that beebase dropcount at all. I suppose it must give a very rough guide.

I agree. I would go further and say it would be better not to publish it at all rather than mislead people to such an extent. The problem is that despite the caveats that go with the varroa calculator people tend to overlook the massive margin of error and take the "estimated" numbers as gospel as its published by the NBU and therefore they expect the content to be factual.
FWIW I like to dust a few colonies with icing sugar and measure the drop, early in the season before there's enough drone brood to sample. I'm shy about letting on about the dusting though, just in case word gets out I'm using it as a varroa control !

And none of my colonies are getting oxalic this year as I trialed treating some and leaving others last winter, the latter group getting on much better on the whole, though one apiary needed a remedial spring treatment with thymol.

**snimmo243** · 05-01-2014, 10:46 PM

I think from now on I will revert to pen and paper and do the calculation myself. What is FWIW by the way

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**mbc** · 05-01-2014, 11:06 PM

Oops ! I just read back a page and saw post#60. My apologies, I wasnt referring to you as "people", just generalizing.

Its the extrapolating from natural drop thats iffy rather than the beebase calculator per se IMHO.
FWIW = for what its worth

**nemphlar** · 06-01-2014, 01:08 AM

I'd go so far as to say that natural drop counting is pointless, there are too many variables and whatever treatments you use, the winter OA treatment is always worth doing whatever your seeing in the lead up

**gavin** · 06-01-2014, 01:39 AM

Originally Posted by nemphlar

I'd go so far as to say that natural drop counting is pointless, there are too many variables and whatever treatments you use, the winter OA treatment is always worth doing whatever your seeing in the lead up

Perfectly agree (FWIW!). Some colonies drop few mites yet harbour a fair load (how do they hide the mites?!). A heavy fall of mites on the board is bad news, a light one shouldn't make you complacent. Sampling drone brood in a few places or powdered sugar rolls or similar are more reliable. And ... that calculator is naive. There are so many factors that can affect the build-up (or lack of it). Various resistance mechanisms in the bees, sudden influxes from other colonies, maybe even pathogens of the mite. The NBU should have it heavily surrounded by caveats, and they don't as far as I can see.