vaporising:size of colony/brood nest:no. of mites:time of year

[bontbee]

Can anyone point me to any tables/guidelines/research that correlates the above. It occurred to me that none of the stuff I've looked at compares the mite kill using a vaporiser with the size of the colony/amount of brood. I can only find figures that relate to natural mortality or drone uncapping. How would I assess the varroa burden based on the numbers of mites killed and, thus, whether a follow up treatment would be necessary? I've only ever been a trickler and, in theory at least, there is no brood to muddy the waters! I have very variable sized colonies coming out of winter with the consequent variability in the size of mite rearing brood nests!

Could anyone comment on the five day interval between treatments recommended on the forum compared, to the varrox instructions to do a follow up after two weeks? http://www.biovet.ch/en/images/stories/products/Varrox/PDF/Varrox-Verdampfer.pdf Two weeks would seem to allow plenty of time for "new" mites to dive back into brood...

Am I trying to overcomplicate things??? Thanks in advance for any help available.

 

[bontbee]

Can anyone help, please? or - What am I missing? or - Am I on everyone's ignore list? and - Would I know if I were?!
ta

 

[Hivemaker.]

The treatment is assuming there is no brood in autumn/winter, but if unsure they recommend a follow up treatment two weeks later.

Have to go out now, but will give some info later about the rest, if no one else does.

 

[jenkinsbrynmair]

I don't think there are any tables for any form of mite control - the varroa calculators are all geared up to guess (yes, I said guess because IMHO none are worth the hassle) the varroa infestation by using natural mite drops not post treatment mortality.
Trying to guess how many mites are left after treatment wound depend on knowing exactly how many bees were in the colony to start with and how many mites each bee had on it.
A big mite fall could mean (and I would go with this) you've got most of it or it could mean there's more there!. FWIW last autumn I had one hive which had a heavy mite drop even on the third vaping. Come the new year there was hardly any mites when vaped and the colony was absolutely bursting a feew weeks ago.

 

[Erichalfbee]

Yes the varroa instructions are for brood free colonies.

 

[wessexmario]

yes, mite drop both before and after treatment is only an indication that there are mites, it gives little indication of how many there actually are.

Before treatment you could have - a small drop with a large mite population or a large drop because you have more hygenic bees with a smaller mite population.
After treatment you could have a small drop because for whatever reason the treatment wasn't effective, or a large drop because there were millions of the little bu@@ers and there are still millions of them left.

As JBM has found, I've also seen very varied drops between 3 consecutive treatments, sometimes after one treatment nothing or almost nothing, and after another a huge drop, but no rhyme or reason apparent for the difference between treatments or when the bigger drop occurs.

The best way to really determine the amount of infestation is to cut out a section of capped drone brood, and check the number of varroa for a given number of cells.

 

[wessexmario]

Could anyone comment on the five day interval between treatments recommended on the forum compared, to the varrox instructions to do a follow up after two weeks? http://www.biovet.ch/en/images/stories/products/Varrox/PDF/Varrox-Verdampfer.pdf Two weeks would seem to allow plenty of time for "new" mites to dive back into brood...

The 3x 5 day interval is based on the life cycles of both the varroa, and the bee.

The 5 day interval is so that any phoretic varroa is caught between emerging from a newly emerged bee, until the time the female finds another cell just about to be capped. Performing that 3 times, covers the 14 days that drone larva are capped.

So, if the first of your 3x 5 day treatment was done on the day after a drone cell was capped, then the varroa in that cell would emerge just in time to be caught by the 3rd treatment.

The varroa after emerging are phoretic for a number of days, and the brood are variously in a continuous transition from egg to emerging, so the second treatment halfway between should capture those missed by the first and last treatments; Otherwise if there were only 2 treatments at a 10 day internal (ie just the first and last) then a varroa that emerges a couple of days after the first treatment (the oxalic remains scattered around the hive and will continue to be effective for a few days) may be sealed into a cell before the tenth day second treatment.

The repeated treatment is essential when there is sealed brood.
4x 4 days would be as much if not more effective, but increasing the interval and/or reducing the number of treatments from 3x 5 days would quite dramatically reduce the effectiveness.

 

[chrisb]

nice reply wessex

 

[MuswellMetro]

instruction vary, THE API-BIOAL instruction say 2.4g (2.g net oxalic) sublimated only once per year or 5ml of syrup per seam of bees , up to twice per year

So be careful what you write in your VMD records on veterinary medicines applied to the hive as technically you would be in breach of the regulations on residue as API-BIOXAL will only have been tested for residue for one sublimation not 2 over 14 days or 3 over 15 days. Not all SBI wil turn a blind eye to such minor indiscrections , i was told off for using three tubs of apiguard an a massive 14x12 with a super for extra space, " you will have higher thymol residues than allowed, follow the instructions blah blah blah "

 

[Erichalfbee]

instruction vary, THE API-BIOAL instruction say 2.4g (2.g net oxalic) sublimated only once per year or 5ml of syrup per seam of bees , up to twice per year

So be careful what you write in your VMD records on veterinary medicines applied to the hive as technically you would be in breach of the regulations on residue as API-BIOXAL will only have been tested for residue for one sublimation not 2 over 14 days or 3 over 15 days. Not all SBI wil turn a blind eye to such minor indiscrections , i was told off for using three tubs of apiguard an a massive 14x12 with a super for extra space, " you will have higher thymol residues than allowed, follow the instructions blah blah blah "

I suppose the answer might be to lie and say you don't treat?

 

[Hivemaker.]

Sent you a PM bontbee.

 

[mbc]

Sent you a PM bontbee.

Be a gent and make it public HM, there's a lot of interested vapers out here

 

[jenkinsbrynmair]

I suppose the answer might be to lie and say you don't treat?

 

[mbc]

+1
But its a shame they make this the easy way out because it will wildly skew any stats they gather.

 

[bontbee]

The best way to really determine the amount of infestation is to cut out a section of capped drone brood, and check the number of varroa for a given number of cells.

Last year I was drone uncapping in just about every colony and found it hard to find any of the little beasties at all. With Apiguard, several colonies then dropped many more mites than I've seen for a very long time! (I'm not a counter, my scale is something like nowt, b****r all, hmm and oh b****x).

The 3x 5 day interval is based on the life cycles of both the varroa, and the bee.

The 5 day interval is so that any phoretic varroa is caught between emerging from a newly emerged bee, until the time the female finds another cell just about to be capped. Performing that 3 times, covers the 14 days that drone larva are capped.

So, if the first of your 3x 5 day treatment was done on the day after a drone cell was capped, then the varroa in that cell would emerge just in time to be caught by the 3rd treatment.

The varroa after emerging are phoretic for a number of days, and the brood are variously in a continuous transition from egg to emerging, so the second treatment halfway between should capture those missed by the first and last treatments; Otherwise if there were only 2 treatments at a 10 day internal (ie just the first and last) then a varroa that emerges a couple of days after the first treatment (the oxalic remains scattered around the hive and will continue to be effective for a few days) may be sealed into a cell before the tenth day second treatment.

The repeated treatment is essential when there is sealed brood.
4x 4 days would be as much if not more effective, but increasing the interval and/or reducing the number of treatments from 3x 5 days would quite dramatically reduce the effectiveness.

Thanks Wessxmario, splendidly clear explanation! - that's what occurred to me, and exactly why I couldn't understand why the official instructions were for a two week interval - plenty of time for all the little critters to get breeding again

I suppose the answer might be to lie and say you don't treat?

I was just cleansing the woodwork, yer honour...


And thank you to everyone else for responding.

Since posting, a colleague vaped my bees and, so far, the drops include:

4 mites in a (full!) 5 frame BS nuc with 3+ frames of brood;
48 in another (double-deckered) "nuc" with 8/9 seams of bees and 5 of brood;
nearly 100 in a colony that has 22+ seams of bees and at least 12 frames of brood.

(Can anyone advise how long I need to wait, post treatment, before supering, please?)

 

[misterbee82]

Do not treat while brood could be affected, also bear in mind the more chemical treatments you use the more contaminated your wax and honey will be.

 

[Gilberdyke John]

Do not treat while brood could be affected, also bear in mind the more chemical treatments you use the more contaminated your wax and honey will be.

Sorry to be critical of a new member but your introductory message to the group stated you have very little knowledge of beekeeping and it appears you are lacking in knowledge of the treatment regimes or effects of the use of Oxalic Acid, either by trickling in sugar syrup or by sublimation (aka inaccurately known as vaporisation).
You may care to spend a useful hour or two looking at the previous discussion threads in the forum via the search function. There is a wealth of information available in there.

 

[wessexmario]

I did a back of fag packet calculation in a post some time ago...
( posts 52, 66 & 72 in this thread http://www.beekeepingforum.co.uk/showthread.php?t=34688 )
it showed that the oxalic added to a hive after three treatments would be a fraction of a percent of the natural range of oxalic acid already present in honey.

So, undetectable from the untreated product and certainly no risk to bee or human.

 

[jenkinsbrynmair]

Sorry to be critical of a new member but your introductory message to the group stated you have very little knowledge of beekeeping and it appears you are lacking in knowledge of the treatment regimes or effects of the use of Oxalic Acid, either by trickling in sugar syrup or by sublimation (aka inaccurately known as vaporisation).
You may care to spend a useful hour or two looking at the previous discussion threads in the forum via the search function. There is a wealth of information available in there.

 

[bontbee]

Thanks again, wessexmario.