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How long between OA vape treatments for infested colony?

2649 Views 17 Replies 11 Participants Last post by  Cloverdale
I purchased a few nucs last weekend and just moved them from their nuc boxes into their 10 frame boxes. One of the colonies was absolutely infested with mites. Deformed wings everywhere and each individual bee had visible mites on them. I already treated them with one round of OA vapor. The question is: when should I next OA vape them? I know you usually wait 5 days but in an emergency situation should I vape them again tomorrow or is that too soon?
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If every bee has a mite, I would posit that colony is already dead, they just dont know it yet.
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As grozzie said, things look grim for the colony. However, I'd suggest OAV, two to three days apart. I think the most dead mite drop is on day 2 or 3. No harm in trying some OAV.
You can also put in as sticky board( political sign board with some vegetable/canola oil on it and some 1/8 wire mesh on top).
I don't know as though OAV every day is going to accomplish anything more than what two-three days apart does.
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It's said the OA crystals last in the hive for up to 3 days. So like said above, treat 2-3 days apart for really infested hives as it's the crystals that are thought to physically kill the mites.

I've rescued some abandoned hives in the past that were just as you described. Don't lose all hope yet. I did 12 treatments, 3 days apart, at which point I would barely get 1 mite to drop after 48 hours and the colony is crushing it right now. 12 seemed excessive, and my back would agree, but that's how many it took to get the mites to nearly 0.

You may wan to document the high mite load and contact the supplier...seems sketchy to sell nucs with preexisting issues.
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@mtnmyke
What time of the year did you "rescue" that colony? I can see how a colony can recover if it has a brood cycle or 2 to raise clean healthy brood.
If OP is an area where bees can still raise brood ( looks like Tuscon, AZ by the look of the screen name ) then it's possible that multiple treatments can help. Seeing bees with deformed wings in a nuc is worrisome though.
If there's capped brood, treating every 2-3 days won't killl mites in that brood until it emerges. I have very limited experience with oxalic acid but I imagine that 2 or 3 treatments should take take of any exposed mites, and then it's just a matter of treating to get the mites that came out with any brood after the initial treatments.

And I agree about documenting and notifying the supplier.
This was almost exactly a year ago.

And like the OP I'm in an area where winter is our "bee season". The winter rains bring the flowers and the summer is the hardest time for us.

Since he's not going into snow or extreme colds - and OAV is about the cheapest method of treatment you can come up with. I say treat them!

The only other option is to not treat, at which point they would certainly die. A few pennies in treatments and some time should give that hive a decent chance at success.
The normal treatment interval is every 7 days for three doses.
Mites are killed for about three days after the vaporization since it takes that long for the bees to clean the crystals out of the hive.
Mites are not ready to go back into brood and reproduce as soon as they come out with the emerging brood, Sammy Ramsey confirmed this in a presentation to our group this past month so you kill most of what emerges on the 4-5-6th day when you treat again on the 7th.
So with drones (14 day capped brood) in the hive you get most of the Mites with the three dose regimen.
Lots of folks are reporting that they are treating closer together to get more complete control.
In your case with a very infested hive I would try to get them cleaned up quickly. Treat on a yard basis, bees drift and Rob spreading mites quickly.
Mites are not ready to go back into brood and reproduce as soon as they come out with the emerging brood,
Could you post the source material of this info? It's pretty widely accepted, from very reputable sources, that this isn't true. Maybe of the offspring, but the mother mite is ready to go.

This is why so many of us treat 3 days apart, to catch ALL the mites once the crystals are no longer present.
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Kamon Reynolds has a great series on going nuclear on a ridiculously infested hive. Its on YouTube. Summary- OAV every few days, Apivar strips, requeening, maybe replace comb, reduce size of space, feed feed feed both sugar syrup and protein. It can be done but will require serious intervention. Many would not go that effort but I would.
Source was Sammy Ramsey in his recent presentation about the trophilalaps mite (don't hold me to the spelling) in his conversation about the differences in the reproductive cycles he referred to a delay in the mother varroa mite being ready to re-enter a cell to reproduce again, I would give you a written reference if I had one. His work has been delayed by covid like a lot of other things so he would not let us record the session since he can't publish yet. He made the same request in his earlier presentations on varroa until he could publish.
I feel that he is a reliable source.
I understand the thought process in treating on short interval.
Sammy did not say what the mother mite delay timing was but his indication was several days, not several hours.
At some point the additional work outweighs the benefits
Each one of us makes that decision.
Covering the capped brood timing is the most important thing whether it is once and done broodless or 14 days drone brood.
Also understanding varroa levels and the effect of mite influx from robbing, drift, or crashing "mite bomb" colonies.
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Sammy did not say what the mother mite delay timing was but his indication was several days, not several hours.
Most of the literature I've read suggests it's an average of 4.5 days from emerging till entering another cell.
Most of the literature I've read suggests it's an average of 4.5 days from emerging till entering another cell.
Agreed. I always like being wrong, proof I'm still variable of learning, but that's what I've read and experienced in my own hives.

Also understanding the "robbing, drift, or crashing "mite bomb" colonies" would mean that bees could potentially be bringing in fresh mites throughout the treatment period. Since these mites could be ready to enter a cell to reproduce, they could easily be missed by a treatment outside of 3 days - since there are no present crystals to kill them.

Regardless, it doesn't hurt the bees to do treatments every 3 days. Since that's how long the crystals last in the hive, that's how often I prefer to treat. I'd rather make sure I have crystals in the hive for the whole treatment period than not. And since it's such a fast treatment per hive, and a few pennies, why not?

I'd still love to read Sammy's research if you could remember to post it here when published.
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Kamon Reynolds has a great series on going nuclear on a ridiculously infested hive. Its on YouTube. Summary- OAV every few days, Apivar strips, requeening, maybe replace comb, reduce size of space, feed feed feed both sugar syrup and protein. It can be done but will require serious intervention. Many would not go that effort but I would.
Wow. Cool that it was recorded. Learning experience for sure.
But is it worth it? Personally I wouldn't spend that much time and resources on a single colony that has fallen to that state.
Wow. Cool that it was recorded. Learning experience for sure.
But is it worth it? Personally I wouldn't spend that much time and resources on a single colony that has fallen to that state.
Its a personal choice. It’s not the bees fault (usually) for falling into disrepair so if I can do something I will do it.
On the subject of oxalic acid you may find this article from Journal of Apicultural Research of interest,It covers the subject of OA in a very thorough manner. https://www.tandfonline.com/doi/full/10.1080/00218839.2015.1106777
I purchased a few nucs last weekend and just moved them from their nuc boxes into their 10 frame boxes. One of the colonies was absolutely infested with mites. Deformed wings everywhere and each individual bee had visible mites on them. I already treated them with one round of OA vapor. The question is: when should I next OA vape them? I know you usually wait 5 days but in an emergency situation should I vape them again tomorrow or is that too soon?
I'd be going back to whomever you purchased the nucs from and asking for a full refund.......did you ask if they treated their bees for mites?
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I'd be going back to whomever you purchased the nucs from and asking for a full refund.......did you ask if they treated their bees for mites?
Strongly agree. In VA, one must have a Certificate of Health, issued by the State Apiarist, before one can sell nucs, queens, or comb. In this case, I doubt such a certificate would have been issued to the apiary in question.

So Tucson, it has been 10 days. How did the first two treatments go?
Anatomy of a mite crash.

Thanks to Mike B (Wildbranch) for posting this in another forum.
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