apiguard in November?

[drstitson]

"And one from the Jeremy Clarkson school of beekeepering"

Don't you mean Bob Flowerdew?

 

[Erichalfbee]

Is it a good idea to put the inspection trays in for a week or two after applying oxalic? I mean not maybe on the day you do it but the day after.Don't mites continue to drop for two weeks?

 

[Chris B]

Back to the original question. Is it too late for Apiguard?
The answer is it will achieve a half decent knockdown because it is unseasonably mild - at the moment at least. Lots of colonies have been brooding more than normal and varroa will have taken advantage too.
However, at this stage I'd still be inclined to wait for an oxalic acid opportunity. It's important to catch them broodless i.e. a good few weeks into a cold spell. Otherwise it will be less effective than giving Apiguard now.

 

[For want of a better word]

"And one from the Jeremy Clarkson school of beekeepering"

Don't you mean Bob Flowerdew?

Was that the Stig of the Dump lookalikee fellow who bathed in recycled cider?

​

​

 

[Skyhook]

I put in Apiguard end of August, two trays. One hive had a natural mite drop of about 5 a day, after putting on apiguard the drop went up to 300 then gradually went down to only a few.
Yesterday I checked the natural drop and it has gone back to pre-apiguard levels ie 4-5 a day. Given the unusually mild weather would it be acceptable to put in apiguard again? Or is once a year enough?

I intend to OA at the end of the year as I did last year- the evidence seems to be overwhelming that it does no harm and a lot of good.

If I had a really high infestation at the moment I would be tempted to to a quick knock-down treatment now to limit the numbers until OA time sorts them out, and a single tray of apiguard might fit that bill if it's still mild enough where you are- but don't think of that as a substitute for OA.

 

[drstitson]

"Was that the Stig of the Dump lookalikee fellow who bathed in recycled cider?"

No. The boilersuited plaited gardeners QT panel member. Presume his hives would be made out of a stack of old tyres.

 

[Suzi Q]

Ok, will treat with oxalic then, I actually haven't got any Apiguard to hand and waiting a couple of days will lose this opportunity. Thanks for tip of warming it, Heather, will take up a flask of hot water to allotments!

 

[Nose Ma]

Not having kept bees since the arrival of Varroa can anybody tell me the pH of the Oxalic Acid being used.

I am just a little concerned about all the talk of dribbling acid on to bees.

I don't know about the rest of you but I shake acid all over my chips.

pH is dependent upon concentration, so the answer is a difficult one. I don't have any to hand, but am happy to do a litmus test on it over Christmas. In any event, the question is difficult:

Acid strength is quantitatively measured using "pKa" which is the readiness of the acid to give up its loose-bound H+ ion. Weak acids are ABOVE -2, tending to range through to 12. Strong acids (HCl, H2SO4 etc) are weird, as they tend to fully dissociate, so they have "theoretical" pKa values.

Here are few to help you:

"STRONGER"
Oxalic acid: has two (!) 1.27 and 4.27, values since it is a symmetrical dicarboxylic acid (a diprotic acid)
Citric acid has three(!): 3.09, 4.75 and 5.41. (tri protic) A lemon is a 0.3 mole/litre concentration of citric acid.
Formic acid (one of the things in bee venom) is 3.77
Acetic acid: 4.792 - dunno the concentration on your chips.
"WEAKER"

(pKa values are from my very old Chemistry constants book, lemon trivia from Wikipedia)

 

[Heather]

Sooorrreee about saying caustic. I am no chemist - I meant it was in a safe solution to use whereas the crystals are capable of damage ??burning the skin.
First year I did make correct solution from crystals and no bees died, varroa drop good- but I didnt wear a mask and had a rough throat for a couple of days.
Now I just buy the stuff already made up.

Far too late for Apiguard.. dont care what the temperature is today. 3 week course and we could be into frosts soon.

 

[itma]

I put in Apiguard end of August, two trays. One hive had a natural mite drop of about 5 a day, after putting on apiguard the drop went up to 300 then gradually went down to only a few.
Yesterday I checked the natural drop and it has gone back to pre-apiguard levels ie 4-5 a day. Given the unusually mild weather would it be acceptable to put in apiguard again? Or is once a year enough?

Have you seen the FERA "Managing Varroa" booklet?
(Its a free downloadable pdf if you don't have it. https://secure.fera.defra.gov.uk/beebase/downloadNews.cfm?id=93)

Explains lots of stuff before making suggestions, hence the graph you should look at is near the back, fig 50 on page 31.
A natural mite drop of 4 or 5/day from a full colony at this time of year isn't something they say you should worry about.

But if its mild, and you have the hive open, a dusting with icing sugar shouldn't do any harm. And while it won't do nearly as much good as a 'proper' Apiguard or Oxalic trreatment (for example), it should do SOME good.

Anyway - the big idea is that 'one treatment per year' is never enough, and that we should be doing 'Integrated Pest Management' - hitting the mite from different directions at different times of the year.

As one looking to do Oxalic for the first time this winter, I'll be buying a dispenser bottle of premixed syrup from a supplier like Th*rnes, AND an empty dispenser bottle to practice with. (Total cost about £4 + delivery)


From what little I can gather about its effect, its not the acidity of the dilute syrup (something like vinegar) that causes harm, so much as its poisonous effect (which is why humans don't eat Rhubarb leaves.) Don't even think about licking your fingers!

 

[oliver90owner]

but am happy to do a litmus test on it over Christmas

Nice gesture but an utter waste of time and effort. Oxalic acid solution will turn blue litmus red. As will many other stronger and weaker acids.

Doubtless the pH of a solution in water can be found from the 'net somewhere. From memory it is a slightly stronger acid than ethanoic.

RAB

 

[Nose Ma]

but am happy to do a litmus test on it over Christmas

Nice gesture but an utter waste of time and effort. Oxalic acid solution will turn blue litmus red. As will many other stronger and weaker acids.

Doubtless the pH of a solution in water can be found from the 'net somewhere. From memory it is a slightly stronger acid than ethanoic.

RAB

Er, when I use it litmus paper has a variety of sensitivities and colours, you match the intensity of the colour to the pH. Very Deep Red = very acidic, working down to the neutral orange through shades of red, and then out to blue. Just go and google some, and you'll see they come with a really neat colour chart. Here's an example - http://www.virtualvillage.co.uk/litmus-paper-test-strips-001494-001.html

Ethanoic = acetic acid, and oxalic has a "stronger" pKa value, so is more acidic at the same concentration, see original post.

 

[greatbritishhoney]

Just one other point about doing Oxalic - IMO it is best to do it on a cold but dry day. You want the bees to still be fairly tightly clustered. If you do it on a very mild day you will end up with a loose cluster and probably a face full of bees.
As someone else said - no more than 1 minute with the crownboard off.

Certainly wouldn't bother with Apiguard at this time of year.

 

[itma]

Er, when I use it litmus paper has a variety of sensitivities and colours, you match the intensity of the colour to the pH. Very Deep Red = very acidic, working down to the neutral orange through shades of red, and then out to blue. Just go and google some, and you'll see they come with a really neat colour chart. Here's an example - http://www.virtualvillage.co.uk/litmus-paper-test-strips-001494-001.html

Nose Ma, you are referring to "pH paper" - actual "Litmus" gives just one step-change in colour at a specific pH threshold (7 neutral), hence its use as a titration indicator.

The advert you linked describes the product wrongly.

Ethanoic = acetic acid, and oxalic has a "stronger" pKa value, so is more acidic at the same concentration, see original post.

As you posted its slightly stronger, so 3% oxalic isn't very different to 5% Acetic (pickling vinegar) -- BUT its acidity is NOT the whole story!

 

[Nose Ma]

Nose Ma, you are referring to "pH paper" - actual "Litmus" gives one step-change in colour at a specific pH threshold, hence its use as a titration indicator.
As you posted its slightly stronger, so 3% oxalic isn't very different to 5% Acetic (pickling vinegar) -- BUT its acidity is NOT the whole story!

Fair enough, I just refer to the name on the box it comes in.

 

[Finman]

pH VALUE IN TRICKLING SYRUP

I happened to have trickling stuff and pH meter quite close to each other.
Trickling syrup pH is 1,2

but what you talk about pH, IT HAS NOTHING TO DO WITH VARROA CONTROL.

oxalic acid happens to be body's natural chemical and usual in plants. What ever acid is not valid.

Now I took one part trickling syrup and 3 patrs water. PH was 1,7.
So, what then. This stuff does not affect on varroa.

 

[Nose Ma]

pH VALUE IN TRICKLING SYRUP

I happened to have trickling stuff and pH meter quite close to each other.
Trickling syrup pH is 1,2

Easy answer!

Is that 1.2 for us UK (using decimals where Mainland Europe uses commas)?

 

[For want of a better word]

"Was that the Stig of the Dump lookalikee fellow who bathed in recycled cider?"

No. The boilersuited plaited gardeners QT panel member. Presume his hives would be made out of a stack of old tyres.

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NATIONAL TYRES ?

 

[The Cumbrian]

pH VALUE IN TRICKLING SYRUP

I happened to have trickling stuff and pH meter quite close to each other.
Trickling syrup pH is 1,2

but what you talk about pH, IT HAS NOTHING TO DO WITH VARROA CONTROL.

oxalic acid happens to be body's natural chemical and usual in plants. What ever acid is not valid.

Now I took one part trickling syrup and 3 patrs water. PH was 1,7.
So, what then. This stuff does not affect on varroa.

Thank you Finman. They are talking about pH because I asked about it. To me many people were talking about "pouring acid" on to the bees as if it was a very dangerous corrosive acid.

I had a feeling that any possible damage to the bees was not necessarily due to the acid nature of the liquid but the rest of the chemistry.

Which it appears it is.

Thanks again for the detail.

 

[greatbritishhoney]

I had a feeling that any possible damage to the bees was not necessarily due to the acid nature of the liquid but the rest of the chemistry.

.

I know nothing about the science of it all, but if I had to hazard a guess I would say any damage is most likely to be due to the disruption of the process rather than the acid itself. Bees are not really meant to be messed about with in the depths of winter. I only do oxalic acid if I really think there is a need for it.