Oxalic Acid Sublimation / Varroa

[Karsal]

Just an update on the results of my oxalic acid sublimation. Yes through inexperience I've lost a colony and hopefully saved two others.
However the one that is thriving has had a bottom sticky board under the OMF while I was away for a fortnight on holiday.
There wasn't one varroa mite on the sticky board at all.
Could this be the result of sublimating Oxalic acid over a 20 day period at 5 day intervals a while ago?
Not sure whether to give them a puff this weekend just to confirm low numbers of varroa or they are still there in the hive and non of the b$ggers have fallen through the mesh.

 

[MartinL]

Not sure whether to give them a puff this weekend just to confirm low numbers of varroa . . . . .

Playing with fire there!

Intended use is during winter with NO BROOD!

 

[Hivemaker.]

Not sure whether to give them a puff this weekend just to confirm low numbers of varroa or they are still there in the hive and non of the b$ggers have fallen through the mesh.

Doing a sugar roll or alcohol wash test would quickly give you an idea of the current percentage of varroa infestation.

 

[jenkinsbrynmair]

Playing with fire there!

Intended use is during winter with NO BROOD!

It won't harm the bees or the brood in the slightest - just not so effective as it won't affect mites sealed in with the brood

 

[Gilberdyke John]

Playing with fire there!

Intended use is during winter with NO BROOD!

You seem to have missed the various discussions and published research where oxalic sublimation is used during brood periods by three separate applications 5 days apart.

 

[Brigsy]

Does anyone have an idea or link to the drops that one should expect after treatment? My Nuc supplier stated that there was high varroa in his area currently and treated once prior to delivery. I have noticed a few drones being ejected with DWV so I have given treatment 2.

Day ones' count was void as the sticky board was a bit large and the debris was scraped off when I withdrew it. Day 2 with a narrower board has a count of 38 in 24 hrs.

If this is as hijack pls delete and I will start a thread on it.

 

[Hachi]

Does anyone have an idea or link to the drops that one should expect after treatment?

Done properly you should expect to zap them all

 

[Eyeman]

You seem to have missed the various discussions and published research where oxalic sublimation is used during brood periods by three separate applications 5 days apart.

When this was last discussed we were pointed to a thread on beesource that used OAV during the winter months. I've not seen the results of anything that supports OAV every 5 days is highly effective when brood is present. Please enlighten us!

 

[charlievictorbravo]

Done properly you should expect to zap them all

My understanding is that you will get 95% of the phoretic mites but not those tucked away in brood cells - that's why, when there's brood, you do the sublimation three times at 5 day intervals. To verify this for yourself, draw a time line that incorporates what you know about how long mites remain phoretic before finding a host's brood cell.

CVB

 

[Brigsy]

Indeed. That's what I understood.

I'm not sure what sort of daily drop I should anticipate after a sublimation for the next few days.


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[charlievictorbravo]

Does anyone have an idea or link to the drops that one should expect after treatment? My Nuc supplier stated that there was high varroa in his area currently and treated once prior to delivery. I have noticed a few drones being ejected with DWV so I have given treatment 2.

Day ones' count was void as the sticky board was a bit large and the debris was scraped off when I withdrew it. Day 2 with a narrower board has a count of 38 in 24 hrs.

If this is as hijack pls delete and I will start a thread on it.

Only using one day's data is not advisable but needs must when the devil drives. Using the NBU Varroa calculator (pretty discredited but not much else available) and your 38 mites in one day, you could have 1500 mites in the colony. If 30% are phoretic and your treatment kills 95% of those, you could have a drop after treatment of 425 mites ± 100.

Those numbers are not much better than guesstimates but it gives an idea of the scale of the mite problem you appear to have. Hope that helps.

CVB

 

[Brigsy]

Thanks CVB. I have seen that calculator but I think it is intended for natural drop? Rather than post treatment.

Either way, I hope I am doing the best for the bees as I clearly have an infestation.

I will carry on with the other treatments and then do a 'natural' drop count in the next few weeks.

Fingers crossed I can get this under control before I need a super for honey.

 

[charlievictorbravo]

Thanks CVB. I have seen that calculator but I think it is intended for natural drop? Rather than post treatment.

Either way, I hope I am doing the best for the bees as I clearly have an infestation.

I will carry on with the other treatments and then do a 'natural' drop count in the next few weeks.

Fingers crossed I can get this under control before I need a super for honey.

Sorry, my misunderstanding - I thought it was a natural drop checked by you after you received the nuc.

CVB

 

[Gilberdyke John]

When this was last discussed we were pointed to a thread on beesource that used OAV during the winter months. I've not seen the results of anything that supports OAV every 5 days is highly effective when brood is present. Please enlighten us!

I was going to explain about zapping mites after emerging from their hidey holes in brood cells but cvb has already done so. Thanks cvb.

 

[Brigsy]

Sorry, my misunderstanding - I thought it was a natural drop checked by you after you received the nuc.

CVB

Not at all. I probably explained myself badly. Thanks.

 

[oliver90owner]

Not thought of opening some (drone) brood as a check? So easy and sooo simple.

 

[Brigsy]

I have. I think I counted four drone cells yesterday. Still a small colony building from a nuc very recently.

I counted 32 varroa on the inspection board yesterday. Second treatment due tomorrow.

 

[Brigsy]

Todays drop 30. Sigh.

 

[charlievictorbravo]

It looks like you're heading for a 5-day drop of about 150 which should be 95% of the phoretic mites = 160 phoretic mites in total. If this is 30% of the total population then you appear to have started out with a mite population of about 530, which is not too terrible although do not forget the immortal words of Finman "they will double in a month"!

CVB

 

[Brigsy]

That adds up. Thanks very much. Another zap coming up Tuesday morning as I can't get to them Monday. Going to keep at it.

Thanks.