LASI annual report

[sussexbaker]

For anyone that's interested LASI have published their annual report. Available here (PDF)

 

[Hivemaker.]

.....

Our results showed that applying oxalic acid directly as a gas via sublimation was superior to application as a solution via spraying or dribbling. Sublimation gave greater varroa kill at lower oxalic acid doses and gave no increase in bee mortality either soon after application or four months later. In fact, colonies treated via sublimation had more brood than untreated control colonies. The sublimation method is also quick and easy because it is applied via the hive entrance.
One year later, we retested the sublimation method and obtained the same result.
Just 2.25g of oxalic acid per hive kills 97% of the varroa.

 

[pargyle]

.....

See : Pete ... you were there first.... who needs the scientists when you've got a forum like this ...

 

[Tom Bick]

The only problem I have with the LASI recommended oxalic treatment either dribble or sublimation is to inspect your colonies and if brood present either remove the brood or damage/ kill the brood and leave for 48 hours for the bees to remove the brood. Alternatively check for brood a week later. Way to much interference in my book.

 

[For want of a better word]

What have I been dripping and dribbling on about for the last half a decade!

VAPORISE !!!!​

Yeghes da

 

[itma]

The only problem I have with the LASI recommended oxalic treatment either dribble or sublimation is to inspect your colonies and if brood present either remove the brood or damage/ kill the brood and leave for 48 hours for the bees to remove the brood. Alternatively check for brood a week later. Way to much interference in my book.

It is necessary for their experiment.
Otherwise, the small difference between trickling and vaporising would be obscured by the vagaries arising from variable amounts of brood being present.

If you are determined to maximise your midwinter varroa cull, then you need to either do the brood-cull (offending Hivemaker's ideas of avoiding early inspections) OR repeat the vaporising treatment several times (offending Ratniek's idea of it being a one-shot 'effective' treatment).
Anyway both of those refinements detract from the description of vaporising as being 'quick'.

On the other hand, if you think IPM is a more realistic approach than trying for a once-a-year varroa treatment, or you have neighbours downwind, or perhaps just feel that (per hive) the investment before vaporising is excessive ... then keep trickling. Its very nearly as lethal to varroa as vaporising, and a perfectly reasonable approach for a few hives.

 

[For want of a better word]

... then keep trickling

or you could try icing sugar!

 

[Tom Bick]

It is necessary for their experiment.
Otherwise, the small difference between trickling and vaporising would be obscured by the vagaries arising from variable amounts of brood being present.

If you are determined to maximise your midwinter varroa cull, then you need to either do the brood-cull (offending Hivemaker's ideas of avoiding early inspections) OR repeat the vaporising treatment several times (offending Ratniek's idea of it being a one-shot 'effective' treatment).
Anyway both of those refinements detract from the description of vaporising as being 'quick'.

On the other hand, if you think IPM is a more realistic approach than trying for a once-a-year varroa treatment, or you have neighbours downwind, or perhaps just feel that (per hive) the investment before vaporising is excessive ... then keep trickling. Its very nearly as lethal to varroa as vaporising, and a perfectly reasonable approach for a few hives.

I don't have a preference one way or the other regarding oxalic it's a good treatment if needed. My point is they actually recommend people inspect midwinter to check for brood prior to oxalic treatment. Their argument is and valid by removing or killing the brood you will get a max kill of varroa but they refuse to accept they will cause damage to colonies by doing these winter inspections.

 

[itma]

... My point is they actually recommend people inspect midwinter to check for brood prior to oxalic treatment. Their argument is and valid by removing or killing the brood you will get a max kill of varroa but they refuse to accept they will cause damage to colonies by doing these winter inspections.

Yes, AND unless the colony is broodless, you couldn't tell from the remaining varroa whether the colony had been vaporised (once) or trickled.

Their results showed that the two methods were actually extremely close in effectiveness - but in any 'executive summary' (like that linked in the OP) they just say that vaporising is more effective - which isn't the full story.

 

[Hivemaker.]

Their results showed that the two methods were actually extremely close in effectiveness - but in any 'executive summary' (like that linked in the OP) they just say that vaporising is more effective - which isn't the full story.

No it certainly is not the full story, if you trickle multiple times the same as you can with sublimation, then you will soon find that the trickling method is a far more effective method for killing off the entire colony.

 

[Tom Bick]

Yes, AND unless the colony is broodless, you couldn't tell from the remaining varroa whether the colony had been vaporised (once) or trickled.

Their results showed that the two methods were actually extremely close in effectiveness - but in any 'executive summary' (like that linked in the OP) they just say that vaporising is more effective - which isn't the full story.

We are getting our wires crossed I am not interested in either method of oxalic or how effective it is what I don't like is their recommendation to do winter inspections to check for brood.

 

[For want of a better word]

No it certainly is not the full story, if you trickle multiple times the same as you can with sublimation, then you will soon find that the trickling method is a far more effective method for killing off the entire colony.

Yeghes da

 

[itma]

No it certainly is not the full story, if you trickle multiple times the same as you can with sublimation, then you will soon find that the trickling method is a far more effective method for killing off the entire colony.

Just as I have never proposed multiple trickling (and have previously posted that the possibility of repeat treatment in case of brood presence was a potential advantage of vaporisation) so Ratniek is against repeat treatment, and in favour of midwinter inspection for brood culling!

 

[itma]

We are getting our wires crossed I am not interested in either method of oxalic or how effective it is what I don't like is their recommendation to do winter inspections to check for brood.

Yes.
That inspection is only needed to maximise the efficiency of whatever Oxalic treatment. And yes, one would expect that such handling would generate other risks to the colony.

My point was the additional explanatory one that, without that inspection and brood-cull, maximising the effectiveness of both treatments, without that, they couldn't show the difference in effectiveness.

If you don't cull the brood (or repeat vaporise) the effectiveness of both treatments will be lower and remarkably similar - as the presence of any brood 'sheltering' varroa will contribute a bigger effect than the difference between the methods.

 

[wessexmario]

it's not really a problem as we normally get a warmish week one side of christmas or the other, and delaying by a week or two is inconsequential, you just need to pick your moment to start the oxalic treatment.
As with all things beekeeping, doing a quick inspection in winter isn't a case of following a set of rules, but being aware of all the factors.

If it's warmish then by all means check the frames,
if it's hovering around zero, don't bother with an inspection and no need to open the hive at all; just whack the vapouriser under the omf - there will be less brood if any during a really cold spell.


PS, getting back to the original post... Thanks, the LASI report is a good read.

 

[farbee]

See : Pete ... you were there first.... who needs the scientists when you've got a forum like this ...

We do; Hivemaker is an applied scientist in my way of thinking.

 

[drstitson]

The trickling was of course researched and promoted on continental mainland europe where they have proper winters and hence much more likely to have extended broodless periods (DOI: my hives have been under 1m of snow of last 3 weeks).

plus the dosing recommended was designed for larger hives (MD/JLS) than UK nationals.

 

[jenkinsbrynmair]

The only problem I have with the LASI recommended oxalic treatment either dribble or sublimation is to inspect your colonies and if brood present either remove the brood or damage/ kill the brood and leave for 48 hours for the bees to remove the brood. Alternatively check for brood a week later. Way to much interference in my book.

I am not interested in either method of oxalic or how effective it is what I don't like is their recommendation to do winter inspections to check for brood.

My point is they actually recommend people inspect midwinter to check for brood prior to oxalic treatment. Their argument is and valid by removing or killing the brood you will get a max kill of varroa but they refuse to accept they will cause damage to colonies by doing these winter inspections.

The problem we're seeing here is that they don't really see what is happening to the colony after they fiddle around with them - all they are interested in is counting any remaining varroa - it's the beekeepers they employ that see the effect of excessive interference. And do they really notice the effect on the honey yield amongst other things?
They're scientists not beekeepers and they are so immersed in their little hobby horse they will not see (or be interested) in the big picture.

 

[itma]

To add to Mr Jenkins scepticism, the OSR/Neonic stuff makes me wonder if they are actually 'good' scientists.

Specifically - they are recording rather few waggle dances steering new foragers towards known OSR.
And they jump to the conclusion that bees don't actually forage much on ORS. Beekeepers that think so are wrong, and they have the evidence.
Or so they think.

How about an alternative explanation - we know (from Goulson) that their local OSR had plenty Neonics (and sprays too).
How about that relatively few manage to navigate their way back from the OSR to the hive and, of those few, only a few consider it worth advertising that nectar source?
Their results only count those who survived the danger and returned!
Wouldn't that be at least as fitting an explanation of their observed waggle dances as their "neonics on OSR are harmless because bees don't forage much on OSR" idea?

In another study, the dose was based on the assumption that a colony would forage exclusively on a treated crop. But this is unlikely, as there are usually alternative food sources. We decoded honey bee waggle dances and analysed the pollen loads of returning foragers to investigate honey bee foraging on oilseed rape (OSR) in the Brighton / University of Sussex area, where it widely grown. OSR is the most important insect-attractive UK crop whose seeds were treated with neonicotinoids. We found was that when hives were more than c. 2 km from the nearest OSR field, they did not forage on OSR. In hives located 0.8 km from the nearest field, dance decoding showed foraging in OSR fields of c. 23% (that is 77% of the foraging was in other locations). Pollen analysis showed that only 13% was from OSR. Although a field of OSR in bloom would appear to be a magnet for bees, and pull in all the foragers, this is not the case.

 

[Tom Bick]

The problem we're seeing here is that they don't really see what is happening to the colony after they fiddle around with them - all they are interested in is counting any remaining varroa - it's the beekeepers they employ that see the effect of excessive interference. And do they really notice the effect on the honey yield amongst other things?
They're scientists not beekeepers and they are so immersed in their little hobby horse they will not see (or be interested) in the big picture.

Spot on

At least one of them is a beekeeper and pops up on a face book group I frequent advising people to to do the winter inspections as they found no ill effect when they did it but did they look for it? I doubt it. This same person worked on some calculations of the effects of beekeeping in London and some of the work is still quoted today the problem was they were found to be thirty times out by the number of beekeepers just about making every other person a beekeeper and a hive on every street corner. When this mistake was pointed out they refused to say it effected the result.