Oxalic 6%, Payn*s in the Arse!

[Skyhook]

Putting my hard hat on before asking Q ....

I was told last week by my instructor that oxalic acid treatments are bad for the queen, that if you are going to use it, it can only be used ONCE in the lifetime of a queen and it can often cause her to become drone laying and be superceded.

I have NO experience with oxalic acid, and no one locally I know here uses it as part of their varroa management. Is this possibly because we only now have resistant varroa in NI, and not in my area (that we know of)? Is oxalic something I am going to have to integrate into my varroa control from now on?

Thanks

This would seem to have been disproved. It seems that OA can be harmful to workers- the difference may be that the queen does not clean herself or any other bees, and therefore the workers ingest some while she does not.

The only exception (anecdotally) would seem to be that OA is the death-knell to a hive heavily infected with Nosema, though whether this is by killing the queen or by killing workers I don't know. It seems logical though- if ingested OA can damage the gut lining as is suggested, it's going to make easier access for the Nosema from the gut into the body.

 

[BeeJayBee]

I was told last week by my instructor that oxalic acid treatments are bad for the queen, that if you are going to use it, it can only be used ONCE in the lifetime of a queen and it can often cause her to become drone laying and be superceded.

I have been told the same, by several experienced beekeepers.

This would seem to have been disproved. It seems that OA can be harmful to workers- the difference may be that the queen does not clean herself or any other bees, and therefore the workers ingest some while she does not.

The way you say it, it seems logical.

Do you have any idea where the research was done?

 

[alanf]

Makes expensive proprietry treaments and premixes seem awfully wasteful of the pennies, when this treatment works, is readily available and so very very cheap...

Its so cheap and easy that saving the leftover oxalic from a batch is not sensible, its only worth pennies and it does go off.

Agree entirely.

Following links I found this paper, which I can't find an existing link for on this site. Prandin et al 2001 http://www.apidologie.org/articles/apido/pdf/2001/05/prandin.pdf "A scientific note on long-term stability of a home-made oxalic acid water sugar solution for controlling varroosis"

It's analysis of the stability of oxalic solutions. They were working with oxalic solution in sugar syrup: 1Kg sugar, 1Kg water, 100g Oxalic dihydrate - 4.2% anhydrous, the Italian favourite. Key finding is that fructose in oxalic acid solution converts to HMF and the rate increases with temperature.

Fresh solution = 1.2 milligrams/Litre HMF
16 months at -20C = 4 mg/L HMF
16 months at 4C = 50 mg/L HMF
16 months at room temperature in the dark = 1945 mg/L HMF
16 months at room temperature in the light = 2107 mg/L HMF

Where HMF concentrations for honeybees under 30 mg/L is 'safe', over 150 mg/L is toxic and increases mortality - Jachimowicz and El Sherbiny (1975). The commercial preparations have no additional ingredients listed that would suggest they behave differently. Keep an oxalic treatment on the shelf and it's poison. Freezing it helps, dark doesn't. You have no obvious indication of how any commercial preparation has been stored and for how long; in a warehouse, lorry or shop shelf at ambient temperature for weeks, maybe months as far as I have seen. It's not just cost that makes fresh solution a better choice than a commercial preparation.

 

[Skyhook]

I have been told the same, by several experienced beekeepers.



The way you say it, it seems logical.

Do you have any idea where the research was done?

Sorry, I read a lot and take too few notes.

 

[user 6228]

Agree entirely.

Following links I found this paper,... You have no obvious indication of how any commercial preparation has been stored and for how long; in a warehouse, lorry or shop shelf at ambient temperature for weeks, maybe months as far as I have seen. It's not just cost that makes fresh solution a better choice than a commercial preparation.

Seems to imply that the commercial preparations should be made with Glucose and not just "Sugar".

 

[alanf]

Seems to imply that the commercial preparations should be made with Glucose and not just "Sugar".

Now there's a worthwhile research topic for a commercial supplier. All the oxalic research I've seen used sugar, i.e. sucrose, so we know it works. The only reason you would think of using glucose rather than sugar is if you were concerned about shelf life, that is you were supplying commercially. If a supplier can prove glucose + oxalic is just as effective and doesn't degrade in the bottle to anything harmful, then they have a viable product on hand.

The downside is it's all commonly available ingredients so there's nothing to stop anyone else selling the same mix. So it's unlikely that any supplier would put money into it.

 

[farbee]

Normally yes. You MAY split the box if you wish and put in an extra 5ml per seam in the bottom box, but there is no saying that the actual cluster in a double deep winter set up is any bigger than in a single. We would tend to just treat the seams from the top and leave the cluster unbroken. More risk of queen damage that way and probably outweighs any advantage from shoving in extra oxalic.

Having said that we very rarely winter anything on other than singles.

Thanks.

 

[dpearce4]

now we have had some temps well below freezing the queen will be off lay. can anyone remind me how long after this time would be best to treat.

if i remeber its about 2weeks but suffering a bit of brain freeze with the cold weather.

 

[Finman]

.
Is this the same gang which invents bad news about European Union?

.

 

[Finman]

Thanks.

Don't thank, because you cannot put another dosage into lower box.

Original recipe is 40 ml to one box hive and 50 ml to two box hive. That is maximum.

 

[yzalich]

now we have had some temps well below freezing the queen will be off lay. can anyone remind me how long after this time would be best to treat.

if i remeber its about 2weeks but suffering a bit of brain freeze with the cold weather.

Hi
21 days all her brood will be emerged by then!

 

[yzalich]

Originally Posted by blackcavebees View Post
I was told last week by my instructor that oxalic acid treatments are bad for the queen, that if you are going to use it, it can only be used ONCE in the lifetime of a queen and it can often cause her to become drone laying and be superceded.


The trickle treatment is recommended to be only applied ONCE if applied in late winter. It may be applied several times during summer if necessary. Formic acid is a better treatment in summer though!

 

[Finman]

.

This will be never ready in UK.

In Denmark questionaire told this way varroa treatment in 2005

Formic acid is used by all beekeepers, but in different ways. The use of the krämer board is the most predominant method. Used by 60,0% of the beekeepers. The use of free formic acid is also common used. Several beekeepers remarks that the free formic acid is used only in nearby apiaries. The nassenheider evaporator is used by 15,0%.



Oxalic acid is used by all beekeepers except 2. Spraying of oxalic acid was used some years ago, but is not used anymore. Trickling is the dominant method. Evaporation of oxalic acid was only used by one beekeeper. This beekeeper used this method as the only treatment.

 

[Finman]

Originally Posted by blackcavebees View Post
I was told last week by my instructor that oxalic acid treatments are bad for the queen, that if you are going to use it, it can only be used ONCE in the lifetime of a queen and it can often cause her to become drone laying and be superceded.


The trickle treatment is recommended to be only applied ONCE if applied in late winter. It may be applied several times during summer if necessary. Formic acid is a better treatment in summer though!

All what you say now is 2-hive owners' knowledge.

Some years ago it was said ONCe but now that has changed.

Queen accidents have not reported. They live 3-4 years as they have done before.

You can trickle allways colony when it has not brood. Swarms are good object.

 

[Black Comb]

When mixing, do you need a "safety kit" - special gloves, mask etc.?
If so, can you recommend one.

Mixing my own for first time this year.

 

[Ely]

When mixing, do you need a "safety kit" - special gloves, mask etc.?
If so, can you recommend one.

Mixing my own for first time this year.

Probably yes, if you are going to be very careful. I don't bother though. It is pretty straight forward unless you are planning on chucking it in your face or drinking it. It doesn't explode or give off fumes when you mix it.

 

[Into the lions den]

When mixing, do you need a "safety kit" - special gloves, mask etc.?
If so, can you recommend one.

Mixing my own for first time this year.

Well we dont use any special gear................in the solution form at 3% its not a big issue as you would require to actually ingest a fair amount of the stuff to do you any harm............BUT.....and a chemist friend highlighted this, the crystals themselves, particularly if they get airborne and you inhale them (might happen if you dropped the container and it flew everywhere), can be dangerous. For the same reason this guy would not use the sublimation/vapourisation method.

However, fair to point out we DO perform the mixing in a place where there is plentiful running water and all the safety gear on hand should it be needed.

 

[Finman]

When mixing, do you need a "safety kit" - special gloves, mask etc.?
If so, can you recommend one.

Mixing my own for first time this year.

Use a spoon. You need not take it with fingers.

 

[iand]

It was pointed out by a poster (with a knowledge of chemistry) this last year that the crystals we use are di-hydrate. Which gives it a damp rather than a dusty crystal consistancy. Which is how my oxalic appeared and as such is a much safer substance to handle. However as ITLD suggests plenty of water/appropriate safety gear on hand if needed.
Gloves is an absolute minimum (I wear specs anyway) but the main thing is the utensils you are using, ensure you do not touch any part of contaminated items, then wash them.

 

[farbee]

Use a spoon. You need not take it with fingers.