oxalic acid treatment

[Jon]

Some of mine need double brood from May - July but they always overwinter in a single box.
One colony of mine had 20 frames of brood in mid May last year.
I thought it might be hybridised but it was 85% amm according to wing morphometry.
I used it as my main queenright queen rearing colony and got a load of queens from introduced grafts.

I treat any spare comb or comb taken from dead colonies with 80% acetic acid fumes for a week.
I spent a few hours this afternoon cleaning nucs and apideas with Virkon.
I think Virkon kills amost everything apart from AFB spores.
It costs next to nothing to clean up old comb and equipment like this. Better safe than sorry.
Of course Oxalic acid is officially used as a general hive and equipment cleaner!

[EmsE]

I have to confess that I use a double brood in winter not because the bees need it, but because it makes me feel better.

[Jon]

I find mine do not need the extra stores. A typical colony of mine overwinters with about 30lbs of stores which is about 6 full deep frames of honey.
the extra space is actually a big disadvantage in Spring as the bees have a bigger volume to heat and brood build up will be slower.
If brood rearing starts in the top box, this should be less of a problem as the heat will be at the top.

[EmsE]

I like to know that the bees have the option of moving further up if it's too cold for the colony to move sidewards. The previous Autumn I did feed too much and was left with loads of brood frames full of sealed stores in the spring. I cut back this year but still stuck with the double brood box (albeit one hive is a brood & 1/2 due to bad planning)

[Eric McArthur]

Hi Jon
Jon wrote:
The other point to note is that if a cluster is divided between the top box and the lower box, splitting it in December would be a disaster.
Who in their right mind would want to split a cluster of bees in mid winter?
Applying Oxalic is an invasive process in itself but splitting a cluster is not a good idea.
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In the period prior to the trickle method, the colonies were actually split apart in late November/December and both sides of the occupied combs were SPRAYED with 3 – 4 mls of oxalic acid solution, which they tolerated better than the trickle. I have the original paper (in German) describing the Fischermühle, German 5 year trials. As a matter of fact Ian Ferguson, Kelvin Valley BKA has practised this method for many years and still does!
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Calum wrote:
Hi Jon,
I do not like doing it myself, but a lot of beekeepers here split the box to apply the oxalic solution to make sure they get it on the cluster.
- If the cluster is between boxes they just carry on and apply the solution to the lower box half of the cluster.. The risk is crushing the queen when closing the box but they all assure me she does not hang about in the open.

It is very invasive but it is done in under a minute.!
...........................................
Thanks for that Calum!
Eric

[Eric McArthur]

Hi EmsE
Eric wrote:
Consider 7, “between frame” spaces occupied by bees; each space received 5mls of solution; a total of 35 mls of solution is delivered. A quick calculation of the amount of active ingredient delivered indicates that only 2.23/50 x 35 = 1.56 g of active ingredient is delivered. This is quite a short fall.
Take note of what Calum has written - and use what I wrote and his experience wisely -as and when! Talk to Ian Craig!
In the case mooted the colony will be under dosed, regardless! Look at the weight of active ingredient relative to the volume, 2.32 g is the 10 comb dosage!

Eric

[gavin]

The method which seems to be most popular in the UK is the one described by Wally Shaw:

http://www.dave-cushman.net/bee/wallyshaw.html

and is one of the alternatives tested by Charriere and Imdorf:

http://www.culturaapicola.com.ar/apu...tamientos..pdf

A key feature is the use of 5 ml *per seam* of bees. The solution is the 4.5% oxalic acid dihydrate in 1:1 syrup (aka 3.2% oxalic acid) as also recommended by Thornes, although weaker solutions are recommended too in the Swiss paper.

I don't know why you are adding this confusion about the amount dosed to the colony Eric, the instructions are clear: 5 ml per seam of bees not a certain weight of oxalic acid per colony.

Anyway, hasn't the time passed for the annual oxalic acid arguments?! It is usually a November/December debate.

[Calum]

I find mine do not need the extra stores. A typical colony of mine overwinters with about 30lbs of stores which is about 6 full deep frames of honey.
the extra space is actually a big disadvantage in Spring as the bees have a bigger volume to heat and brood build up will be slower.
If brood rearing starts in the top box, this should be less of a problem as the heat will be at the top.

Hi Jon,
the bees normally move from the bottom brood box to the top one as they get through their stores.
A weaker colony will stay in the bottom, but they are usually the ones that couldnt fill a second brood box with stores in the previous autumn so shouldnt be on a second one in the first place.

I have been told that a really strong colony on one box can gather so much stores that the fill every frame full. When it gets cold they can have severe problems due to the stores acting like insulation and so preventing them from being able to keep the cluster warm.

As said I remove the lower box to refresh the comb so if they are not packed in then I leave them on one box till they need the space.

Never heard of Virkon is it water soluble of fat soluble? I only use oxalic or citric acid and vinager to clean my wax when it si molten.
The guy that does my foundation heats it at 120°C for 8 hours which kills a fair bit too...

[Jon]

Hi Calum. It's a water based product.
You dissolve one tablet in 500ml of water.
I use acetic acid for the comb and this stuff for boxes, dummy boards, dividers, apideas etc.

This is the stuff:

http://en.wikipedia.org/wiki/Virkon

http://www.hyperdrug.co.uk/prodinfo....ABS&Variation=

[Calum]

[QUOTE=Jon;4180]Hi Calum. It's a water based product.
You dissolve one tablet in 500ml of water.
I use acetic acid for the comb and this stuff for boxes, dummy boards, dividers, apideas etc.
[QUOTE]

still not quite clear on what you are doing.. you use the acetic acid on the melted wax?
Old comb gets too small for the brood after heavy usage (+pesticide buildup cannont be cleaned out).. When it is no longer possible to see light through it, it is recommended that it should be removed from the hive (at least here in Germany). Many beekeepers only use this for candles, most novices cannot do this as they dont have enough wax and so have to reuse it for foundation.