# Too late to treat? In Michigan



## oldsap (May 1, 2016)

Probably too late with fall temps. But if you are using an oxalic vaporizer it is cheap enough that you won't be out much anyway. A lot of the hives I have checked lately still have a lot of brood, so more winter bees are on the way.


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## AR1 (Feb 5, 2017)

Any reason not to stick in a few Apivar strips? Even if it's a bit 'too late' I'd think it would do some good.


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## snl (Nov 20, 2009)

As long as it’s above 37 degrees, OAV is an option.


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## mathesonequip (Jul 9, 2012)

check for mites with a count from a sample. the results will likely show treat. treat them now. fall is a good time to treat, maybe the best time to re-treat or first time to treat with counts that are just borderline high.. next year keep track of mites. in the fall oxalic acid is a good choice, see SNL's post above. OAV is fast acting so to get above 37 degrees for a couple of hours should not be a problem in the fall even in northern areas.


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## DaisyNJ (Aug 3, 2015)

Why would it be too late to treat unless you are ONLY using temperature sensitive treatment ? OAV, Apivar are better than doing nothing.

Weather projections for Grand Rapids, MI area show above 50F day time temperatures. FYI.


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## beemandan (Dec 5, 2005)

DaisyNJ said:


> OAV, Apivar are better than doing nothing.


True but has likely missed the window for healthy winter bees.


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## DaisyNJ (Aug 3, 2015)

beemandan said:


> True but has likely missed the window for healthy winter bees.


Agreed but it gives them a chance vs having whatever brooding that goes on from now through march to be infected continuously. All of this is assuming the hive in question is being overrun with mites & virus.


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## frankthomas (Aug 2, 2012)

For OAV you need 3 treatments 4 days apart correct?


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## oldsap (May 1, 2016)

Doing something is better than doing nothing. But you need to be mindful of ambient temperature when using mite treatments. Up north here in Mason county the weather is finally looking like October. That is one reason why it could be too late. The other is the virus load may be too high. But doing nothing could send your bees to your neighbors and killing their bees.


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## beenoob (Jun 16, 2016)

Im a little confused here. Is there a theory that treating in the fall is too late, I may be missing something being newer, but Im told after supers are off this is the best time to treat using OAV. 

OAV shot before supers on in Spring and OAV 3x 7days treatment in the fall once supers are off. Its worked for me.


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## TWall (May 19, 2010)

I have done OAD between Thanksgiving and Christmas the past few years with good success the past few years.

Tom


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## beenoob (Jun 16, 2016)

TWall said:


> I have done OAD between Thanksgiving and Christmas the past few years with good success the past few years.
> 
> Tom


Has this been your ONLY treatment the entire year?


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## beemandan (Dec 5, 2005)

beenoob said:


> Im a little confused here. Is there a theory that treating in the fall is too late,


The way it works….winter bees have to be especially hardy. They need to remain alive and vigorous for a number of challenging months. The colony reduces brooding in the weeks leading up to colder weather. If those winter bees are parasitized during development they will be less likely to survive the winter. To make matters worse, the nurse bees that nurture them during development must also be especially healthy or they will not attend to them well….and the resulting winter bees will be less likely to survive.
The theory I subscribe to is that there needs to be at least two cycles of healthy bees before they begin to make winter bees. That means that an end of season EFFECTIVE mite treatment should be completed 60 days before cold weather for the healthiest overwinter bees are faced with cold temperatures.


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## TWall (May 19, 2010)

beenoob said:


> Has this been your ONLY treatment the entire year?


Yes.


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## allniter (Aug 22, 2011)

if U do OAV
DAY 1 TREAT
DAY 7 TREAT 
DAY 14 TREAT ---U have treated 14 day --remember BROOD hatch take 21 days--I would treat one more time --that is if U have cap brood --if they capped brood one day before U treated on day one


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## John Davis (Apr 29, 2014)

Capped brood time is 12 days, mites enter the cells about a day before capping, 3 treatments on the 7 day schedule covers it including the additional time if they are raising drones.


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## mathesonequip (Jul 9, 2012)

if there is little or no brood [fall brood shut-down] then one OAV treatment is plenty. there is some indications that a lot of oxalic acid is not the best for queens under all conditions. i got this from a university researcher. she told me that if mite levels are close to treat / no treat levels, then hold off till fall even with OAV....... if real high treat, but queen performance may be noticed, if the mites are high in early august then panic and treat.


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## niki.nicole (Apr 30, 2016)

I did a mite count last weekend and two hives had under 10 per sample and one had 20. Should I treat now or wait till there is little to no brood. I'm feeding because two hives were light (the ones with the lower mite counts) and those two oddly have more brood. They are all double deeps--two 8 and one 10. The 10 was really weak and is the result of the leftovers of an absconded hive, an absconded nuc, and one queen-right nuc. The queen laid a STORM in the last few weeks and it looks good--apart from being light on stores. 

I've treated it twice since fall, each about a week apart. Should I do it again, or wait until the queens stop laying?


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## snl (Nov 20, 2009)

niki.nicole said:


> I've treated it twice since fall, each about a week apart. Should I do it again, or wait until the queens stop laying?


I'd do it now (several times) and again when there is little to no brood.


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## niki.nicole (Apr 30, 2016)

Several times? Even though Mathesonequip mentioned it might be bad for queens? I had two abscond for (according to my human senses) no reason. They had stores, room, no pests and low mites. But off they went. This happened to one hive last year, but they were weak and were invaded by wax moths. I'm bummed that I'm not going into winter with nucs, but hopefully I'll have 3 hives when spring comes around.


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## snl (Nov 20, 2009)

niki.nicole said:


> Several times? Even though Mathesonequip mentioned it might be bad for queens?


Yes, several times as you've brood and need to capture those mites as they emerge with the brood. As to queens, I have two hives that I keep for OAV testing purposes.  I have confined the marked queens to 3 frames in the hives, constantly moving brood out of her confined space and replacing with empty drawn comb. I vaporize those hives approximately every 7-10 days from April till now. I have found NO evidence that OAV is harmful to the queens or brood. When I've removed brood from her confined space, I marked the frames and watched the brood go from egg to emerged bee with NO harm.
I have no idea where those who say that multiple OAV treatments harm the queen get their information.


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