Icing Sugar and Varroa control

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plumberman

House Bee
Joined
Jul 14, 2009
Messages
470
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Location
Surrey
Hive Type
National
Number of Hives
5 and ahem "a few more"
One of my strongest colonies has shown a persistently high varroa count ( about 12 daily ) over the past three months. They missed apiguard last autumn ( superceded late and I was concerned that apiguard might have reduced winter bee rearing), but got oxalic acid in the winter. They had a brood rearing break of about a month in May when I did an artificial swarm. I had hoped this might have helped keep mite numbers down. My other 4 colonies have a mite count of less than 2 daily.

I regularly cull drone brood ( there is a super frame in the brood box) although last time there were a fair number of mites in the drone brood.

There is no sign of any varroa related conditions: lots of healthy brood, no obvious wing or body deformities and they are piling honey into the supers.

I thought I would giving icing sugar a go: they are on brood and a half so used about 1.5 cups altogether.

Mite drop remarkable - video clip shows the varroa once I had scooped them altogether off the screen board. Quality is not brilliant, but you can clearly see the movement.This happened within about 3 minutes after the treatment. Bees not hugely impressed and some 'ghost' bees hung around outside for a bit as you can see in the clip. They have now all gone in and it would appear to be business as usual.

I accept that this is not a "major" treatment and not a controlled scientific test, but given the lack of signs of disease and assuming an ongoing monitoring regime, it does seem to do the trick in a reasonably spectacular fashion . I would estimate there were about 300 mites present after the treatment. DEFRA ( if that is what they call themselves these days) seem to suggest that >1000 mites per colony would have been accompanied by signs of varroa infestation. I think reasonable to assume that these 300 mites seen instantly may represent 20 -30% of the total population, a result that at least will check the mites for a period. The other advantage is that I can keep the supers on.

On the assumption I see no evidence of any problems related to the icing sugar, I will probably repeat in in 14 days or so depending on the varroa count. All being well they will get Apiguard in the late summer and oxalic acid again in the winter.

[ame]http://www.youtube.com/watch?v=nYZ5sdC5j5Q[/ame]
 
Very interesting, and thanks for the video too.

I may give this a go too.

I had to cut some brace comb off a frame yesterday which was being used to rear drones. I'm going to cut it open and see what the varroa level looks like in the developing larvae.

FG
 
Useful info thanks, seems a viable and relatively non-evasive option to reduce mite loading mid season, suprising how quickly you saw drop. R
 
Yes - that was the article that made me think it was worth a go. There are also various articles suggesting that it made little difference. There is a Latin phrase in the medical word "primum non nocere" which means "firstly, do no harm", and this treatment seems to fit in well to that notion.
 
Sorry, but not really addressing the problem. Likely 80% of your varroa are in cells reproducing right now. So even a 20% efficacy, while a help, will nowhere near reduce the mite levels to manageable proportions. You need '(capped) broodless' colonies for a good knock-down with this method.

Regards, RAB
 
Sorry, but not really addressing the problem. Likely 80% of your varroa are in cells reproducing right now. So even a 20% efficacy, while a help, will nowhere near reduce the mite levels to manageable proportions. You need '(capped) broodless' colonies for a good knock-down with this method.

Regards, RAB

Where did I say that I was addressing the problem? What I did say was that it was " a result that at least will check the mites for a period".

I wasn't advocating anything more than a biotechnical method that will allow me to hold off more major treatment for a period whilst causing minimal short term or long term problems to the colony.
 
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MITES OR HONEY!


What I would do in that case is that

a) make a false swarm and clean the flying bee part

b) make a brood brake in main yield and kill mites when bees have emerged.

- I have used much "kill the queen system" to get better main yield.

- false swarm becomes when I cut swarming fever.

To disturbe the hive every week with sugar sounds bad.

80% of mites are under brood caps.
 
I doubt this colony will get through the winter if something is not done about the high varroa levels now. I do not think you can wait until August.

If you are not going to sell the honey and use it only for your own consumption then formic acid treatment would be effective. You could take away the supers for the time you are doing the treatment but this might induce swarming. I would trickle 30ml of 60% formic acid onto a bit of cardboard resting on the brood frames. Repeat the treatment after a week and then a third time. The varroa drop will be massive I suspect from what you describe about the effects of icing sugar. As already described the varroa knocked down by the icing sugar were probably only 10 or a most 20% of the population - and they will breed faster than you can knock them down with icing sugar no matter how often you do it.

Alternatively, you could take away the queen and put her in a 2 or 3 frame nuc. Any eggs she lays now will be no use for the main flow in July so the main honey harvest will not suffer. I would treat the nuc with about 10mls of formic acid and trickle oxalic acid on the main colony in 3 weeks time after removing any drone brood and the supers for a week. Alternatively, use formic acid. Again, don't try and sell the honey but it won't kill you if you keep it for your own use.
 
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Although a bit out of date the CSL leaflet on varroa control is still a good guide. There is a growing belief that daily mite drop rates are not a reliable guide to varroa levels but this applies more to low rates masking a high level - 12 a day is well in the "Red Light" zone - see page 29/33 of the guide, which you can find here: https://secure.fera.defra.gov.uk/beebase/index.cfm?pageid=167
 
If you knocked off 300 mites with one application of icing sugar then this will indicate a problem and if you check the packet of icing sugar you will see it has an additive in it to stop it all sticking together I dont know this as fact but have been told that this additive can be harmful to the bees over a long period so if possible try and grind up pure sugar for each application.

One final point is it not to late to perform a shook swarm on this hive and sacrifice the brood and most of the mites to.
 
Thanks for all the advice. I think I will go the queenless way as per Rooftops.

I want to requeen anyway because of this problem, and have already ordered a replacement. Presumably allow one of the emergency QC's to go to maturity.

Would you suggest remove before hatches then reunite ( suspect this would not give sufficient time for all the capped brood to hatch out), or let the (potential) scrub queen mate, then remove? I'm concious that before I reunite with new queen, it might be difficult to find the emergency queen.
 
I believe the additive is starch.

Hi Rooftops the packet I have has the anti caking agent E554 : Sodium aluminium silicate as an additive.
I dont know if this is bad for the bees I suspect its may be like most things a sprinkling every now and again is fine but perhaps people who cover the bees on a regular basis perhaps bad.
 
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