Sublimation procedure

[jenkinsbrynmair]

I have not heard about a lower temperature limit but I suppose it could be to ensure the bees are not tightly clustered but it does seem to conflict with LASI's insistence of only vaporising a broodless colony.
CVB

Why does it conflict? - I think we should take this myth about brooding being all dependant on temperature with a large pinch of salt, regardless of how cold it is, bees will be starting to brood once the solstice passes and most of my bees have a brood break at the end of August.

 

[charlievictorbravo]

Why does it conflict? - I think we should take this myth about brooding being all dependant on temperature with a large pinch of salt, regardless of how cold it is, bees will be starting to brood once the solstice passes and most of my bees have a brood break at the end of August.

So can you think of an explanation as to why there should be a 4°C lower temperature limit for vaporising?
CVB

 

[drex]

The bees are thought to be too tightly clustered for the vapour to penetrate

 

[jenkinsbrynmair]

So can you think of an explanation as to why there should be a 4°C lower temperature limit for vaporising?
CVB

As Drex says - very much the same as OA trickling shouldn't be conducted in temperatures below 4°C neither should sublimation, you want the bees to be loosely clustered or even active to ensure the sublimate gets everywhere.

 

[pargyle]

The bees are thought to be too tightly clustered for the vapour to penetrate

Welll ... that may be true in timber hives, without any insulation and potentially holes open in the crown board but in my Paynes poly hives, with 100mm of celotex in a super above a polycarbonate crownboard where there are no holes and the bees have propolised to the top of the hive - I could see bees walking about on the top of the frames yesterday and the outside temperature never got above 3 degrees C.

So ... depends on your hive I would imagine.

 

[benjamind]

Does anybody have any chapter and verse on this? I Googled Sussex Plan but could not find the above temperature limits or the reason for it.

4C was mentioned during a talk at LASI as the lower limit for opening the hive to remove any remaining patches of brood and thus ensuring completely broodless when treating.

 

[pargyle]

4C was mentioned during a talk at LASI as the lower limit for opening the hive to remove any remaining patches of brood and thus ensuring completely broodless when treating.

Nobody in their right mind would be opening a hive in less than 4 degrees and lifting out frames to remove brood ... the LASI situation was largely experimental and I don't think it is representative of proper beekeeping. I endorse their results but I rather deplore their insistence that all brood should be removed - let's live in the real world.

 

[madasafish]

To avoid worrying about all this, my diary is pencilled in "Treat in second or third week December."

I have done that for several years now, looking at forecasts to avoid cold days in advance. Seems to work based on varroa levels in summer.

(Or maybe my bees are varroa resistant through my carefully chosen breeding program - which out of modesty I have omitted to mention before )

 

[Arfermo]

To avoid worrying about all this, my diary is pencilled in "Treat in second or third week December."

I have done that for several years now, looking at forecasts to avoid cold days in advance. Seems to work based on varroa levels in summer.

(Or maybe my bees are varroa resistant through my carefully chosen breeding program - which out of modesty I have omitted to mention before )

Coulldn't agree more - winter time is best though I don't usually bother until first week in the NY. Suits me best that way.

 

[victor meldrew]

Welll ... that may be true in timber hives, without any insulation and potentially holes open in the crown board but in my Paynes poly hives, with 100mm of celotex in a super above a polycarbonate crownboard where there are no holes and the bees have propolised to the top of the hive - I could see bees walking about on the top of the frames yesterday and the outside temperature never got above 3 degrees C.

So ... depends on your hive I would imagine.

I use 100 mil insulation with wooden hives . One was a little lighter than the rest . So I added fondant above the crown board . I carefully lifted the roof off , again carefully lifted the insulation .the freezer bag holding the remnants
of previously applied fondadt was full of bees . I’d already prepared a replacement , it needed a puff of smoke and a wait with insulation on then a quick swap ! They were active ok !
I’m sure the disturbance of a cloud of HOT OA vapour would have them shift themselves! I have no top ventilation neither do I block the entrance as I have under floor entrances from which I’ve never seen vapour escape .

 

[Gilberdyke John]

On another forum, I was told that LASI has said that OA vaporisation should not be carried out on bees at temperatures below 4°C or rather that it should only be done between 4°C and 16°C. It was said that the source of this temperature range is LASI's instruction sheet, 'how to apply OA via sublimation as part of the Sussex plan'.

I have not heard about a lower temperature limit but I suppose it could be to ensure the bees are not tightly clustered but it does seem to conflict with LASI's insistence of only vaporising a broodless colony.

Does anybody have any chapter and verse on this? I Googled Sussex Plan but could not find the above temperature limits or the reason for it.

CVB

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