Gasvap Modifications

[sean-a]

Nothing slapdash about it.
It is a researched position.
No downside to giving the bees too much, apart from the cost. I bought 2.5kg for just over £20, call it £25 for simplicity, so 2500p bought 2500g which works out at roughly a penny a gram.
The extra 4g costs me 4p, but by the time I have it vaporisiing and the nozzle in the hive, I have lost a bit and a bit leaks out the floor...reckon that there is not too much wasted on the bees.

Downside of giving the bees too little is that the mites survive but weaken or kill the bees
Hard to know how much is too little

 

[pargyle]

Nothing slapdash about it.
It is a researched position.
No downside to giving the bees too much, apart from the cost. I bought 2.5kg for just over £20, call it £25 for simplicity, so 2500p bought 2500g which works out at roughly a penny a gram.
The extra 4g costs me 4p, but by the time I have it vaporisiing and the nozzle in the hive, I have lost a bit and a bit leaks out the floor...reckon that there is not too much wasted on the bees.

Downside of giving the bees too little is that the mites survive but weaken or kill the bees
Hard to know how much is too little

Right.... for any beginners reading this and taking any notice of Sean-a's personal opinion. Please note ... the proven and recognised dosage for treatment of varroa by sublimating oxalic acid is 2.5 gms per colony.

There is no benefit from overdosing and none of the manufacturers of authorised OA treatments and those people who have investigated and tested unauthorised treatments recommend using any more than 2.5 gms.

Sean-a is entitled to his personal opinion but please accept that it is just HIS PERSONAL OPINION and should not be followed.

 

[Erichalfbee]

Right.... for any beginners reading this and taking any notice of Sean-a's personal opinion. Please note ... the proven and recognised dosage for treatment of varroa by sublimating oxalic acid is 2.5 gms per colony.

Is that irrespective of box size? National, double brood, 14x12, Langstroth?

 

[jeff33]

Is that irrespective of box size? National, double brood, 14x12, Langstroth?

And nucs? I always put less in nucs, just under 2gr.

 

[pevanstone]

I use a gas vap, have a pocket full of caps for it.
Fill them all brim full of OA - and then zap the hives one after another
If I can, the empty cap is dropped off onto a puddle on one of the hives - usually a poly one...quick sizzle and it's cooled
Either way they are cool enough to recharge or pop back into the pocket of my beesuit with bare hands by the time I have finished with the previous hive.
Don't bother weighing the OA, and am maybe using 3g - could be 2 or 4 but the bees don't mind.
Get a few ghost bees stumbling out completely covered in white, but even they seem fine.

Mites....not so much!

The mites must love you.

 

[Erichalfbee]

And nucs? I always put less in nucs, just under 2gr.

My 14x12s get 3g

 

[sean-a]

@pargyle

Can I refer you to Al Toufailia, Hasan (2016) Integrated control of honey bee diseases in apiculture. Doctoral thesis (PhD), University of Sussex.

http://sro.sussex.ac.uk/id/eprint/62056/

"The sublimation method used pure OA. We applied the three equivalent doses (0.56, 1.125, and 2.25 g) plus an additional higher dose (4.5 g). We decided to use a fourth higher dose because there was less background information on varroa mortality using sublimation. In addition, our pilot research had shown that this high dose appeared not to cause high bee mortality, meaning that it could, if necessary, be used to control varroa in hives."

This published academic research found a reduction in Varroa infestation of 98.2% with 4.5g vs 93.1% at 2.25g
In terms of Estimated Mortality at 4.5g it was 94.2% against 89.7% for 2.25g

Both the statictics above on mortality and reduction of varroa are higher with 4.5g than 2.25g
(In the interests of balance, the study also found 1.125g had a reduction of 96.7% and mortality of 93.1%)

Are you able to point me to any study which contradicts this?

 

[pevanstone]

View attachment 35043I did mention the word 'prototype'......

I have a sum l spend on bee bits and bobs.£700.this year some of it on blow lamps,rothenburger £93 the one with the kit £50 ish cooking types 7 and 15 then a rothenburger copy for £29,it looks an exact copy,all these have a 22mm nozzle except true rothenburger.the copy rb came with 3 nozzles one of which was 22mm.that is why l bought it.l am trying to get away from gas refilling.screw in cylinders are heavy.The ones that sort of clip on can be dangerous you can get a pool of gas twix lamp and can.the bk with tripod,May l suggest a wood cross with bolt and spring washer this would compensate on uneven ground.l now have in the post a small lamp with hose for small cylinder.l did my first gas vap on a bad day,time and tide were against me.l had trouble with caps.l think caused by bad burn and fumble fingers.l made caps with compression fittings they went well.The original gas vap is well made for a reasonable price,the maker did the research and l think deserves the reward.

 

[sean-a]

The mites must love you.

What mites?

 

[jenkinsbrynmair]

Is that irrespective of box size? National, double brood, 14x12, Langstroth?

It is according to the LASI work on OA sublimation

 

[pargyle]

It is according to the LASI work on OA sublimation

Yes... that and Pete Little's work. I don't think it's going to make a lot of difference between 2.5 and 3.0 gms ... but more than that is not necessary - despite the odd member who seems to think that his bees need a lot more.

 

[jenkinsbrynmair]

doubling the amount for a mere 5% increase (on paper, in laboratory conditions) in effectiveness

 

[pargyle]

@pargyle

Can I refer you to Al Toufailia, Hasan (2016) Integrated control of honey bee diseases in apiculture. Doctoral thesis (PhD), University of Sussex.

http://sro.sussex.ac.uk/id/eprint/62056/

"The sublimation method used pure OA. We applied the three equivalent doses (0.56, 1.125, and 2.25 g) plus an additional higher dose (4.5 g). We decided to use a fourth higher dose because there was less background information on varroa mortality using sublimation. In addition, our pilot research had shown that this high dose appeared not to cause high bee mortality, meaning that it could, if necessary, be used to control varroa in hives."

This published academic research found a reduction in Varroa infestation of 98.2% with 4.5g vs 93.1% at 2.25g
In terms of Estimated Mortality at 4.5g it was 94.2% against 89.7% for 2.25g

Both the statictics above on mortality and reduction of varroa are higher with 4.5g than 2.25g
(In the interests of balance, the study also found 1.125g had a reduction of 96.7% and mortality of 93.1%)

Are you able to point me to any study which contradicts this?

From the same Study - if you take the time to read the full paper:

"The third advantage of sublimation is that it is the simplest method, and quick. In particular, because it does not need the beekeeper to open the hive, it is less work and is well suited for use in winter (Radetzki & Bärmann, 2001a, 2001b), when colonies are broodless but are not normally opened for inspection. It could be applied, for example, on rainy or cool days when opening a hive is not good beekeeping practice (Crane, 1990; Gould & Gould, 1988). The time taken to apply 2.25g of OA via sublimation, which we consider to be a recommendable dose, is under three minutes per colony. This is slightly more, by about half a minute, than for trickling but less than for spraying."

If you would care to show me someone who RECOMMENDS 4.5gm (or in your case probably more than that) ?

 

[sean-a]

Clearly you take the view that I am wrong in my position on dosage, and are entitled to that view.
I don't think however that you are entitled to attack my position on the basis of pseudoscience without presenting your scientific evidence for your position.

I think that you will find that the recommendation for that dose was based on time taken to sublimate 4.5g vs 2.25g at 4.3mins per colony rather than 3.0m per colony.
Personally, I'm not bothered about an extra 78 seconds per hive, I also don't recognise that time as it takes me less than 4.3 to sublimate a hive.

The study I quoted does not say that the higher dose was in any way disadvantageous to the bees or the honey.
It actually showed higher mite mortality and lower levels of mite infestation with the higher dose.

I have read the full paper, his PhD thesis, together with other academic papers on the topic.

"Pete Little (Hivemaker) did some experiments increasing the dose above the recommended levels and found that there were no obvious signs of distressing the bees but ... increasing the dose did not show any improvement over the mite killing"

This is not a controlled experiment, peer reviewed and published in an academic journal. I know because I have looked for it in scientific journals and it has not been published.

However there is published academic research using higher doses which do show some increased efficacy of Sublimated OA, although this is not a huge improvement but..... importantly it also shows no negative effects on bees and OA does not appear in honey.

Excess OA doseage is deleterious for bees when trickle treated in excess concentrations, and also there are indications that multiple treatments in a year are damaging, also needs to broodless. Not so for topical application by sublimation.

Unless you can show me the paper and scientific evidence that supports your viewpoint your opinion is no more valid than mine.

 

[pevanstone]

WELL i have to say thanks for the picture. As a 40mm round will go 2.2km i am thinking i could mount mylself at home and hit all three of my apiaries! Seriously great and def food for thought, once i start using it i will find out if i need a stand or not. I am hoping with my tin and the caps it is so quick to move from hive to hive and reload i do not need. thanks

I have a sum l spend on bee bits and bobs.£700.this year some of it on blow lamps,rothenburger £93 the one with the kit £50 ish cooking types 7 and 15 then a rothenburger copy for £29,it looks an exact copy,all these have a 22mm nozzle except true rothenburger.the copy rb came with 3 nozzles one of which was 22mm.that is why l bought it.l am trying to get away from gas refilling.screw in cylinders are heavy.The ones that sort of clip on can be dangerous you can get a pool of gas twix lamp and can.the bk with tripod,May l suggest a wood cross with bolt and spring washer this would compensate on uneven ground.l now have in the post a small lamp with hose for small cylinder.l did my first gas vap on a bad day,time and tide were against me.l had trouble with caps.l think caused by bad burn and fumble fingers.l made caps with compression fittings they went well.The original gas vap is well made for a reasonable price,the maker did the research and l think deserves the reward.

 

[sean-a]

doubling the amount for a mere 5% increase (on paper, in laboratory conditions) in effectiveness

Depends what you measure JBM
5% increase in efficacy if you measure 98.2% vs 93.1%
If you measure mite mortality by the number of mites left alive...one had 10.3% and the other 5.8%, that is 77% more mites left behind with the lower dose.

The trials were conducted in the field, not in the lab.

 

[jenkinsbrynmair]

The trials were conducted in the field, not in the lab

so no real evidence that the extra few percent can be taken as an across the board figure anyway

 

[JamezF]

David Evans summarised his view of the research regarding OA dosage in November last year (mostly in the part headed "Dosage, again", but there's interesting stuff in the comments too):

Repeated oxalic acid vaporisation - The Apiarist

I'd read it as suggesting that a 4g dose will kill a higher percentage of mites, but it may not be a sufficiently large increase over 2g to make a real difference and that more research is probably required into dosage, timing and probably other variables too (hive volume, perhaps, given that the US recommendation is based on the number of brood boxes).

I'm really not sure that increasing the dosage is giving the anti-vaping brigade that much more ammunition than using a non-approved product or performing repeated applications (even with an approved product) mind...

James

 

[Newbeeneil]

Another discussion that seems pointless. As long as the oxalic acid is used above the optimal dose there seems to be little down side apart from cost.
Arguing the point seems pointless as it’s just a matter of opinion and we are all entitled to our own.

 

[jenkinsbrynmair]

it’s just a matter of opinion and we are all entitled to our own.

even if it is wrong