Did my First OAV Treatment Today

[blackforest beekeeper]

Before starting the treatments I suddenly was getting a mite fall of 10 to 12 per day from the one hive. I was monitoring the hives weekly and when I spotted the increase in the mite drop went to a daily count for the hive . The hive was showing bees with DWV also. I should of done a sugar roll or alcohol wash before starting the treatments but didn't think of it. Getting a baseline would of been a big help.

hey nr1!
When was that, where are You at?
If I had that kind of mite-drop, lets say August, I`d treat. I`d probably treat in July then, if I counted... (usually I got some idea of what is going on, though these days I don`t "count" any more, I just sort of gauge it by eye). Best thing You could have done in my eyes (I  would have): make a late split. Take out all sealed brood and OAV twice within three days (that will get the mites way down cause they can`t hide in the cells). The brood: Either let it hatch and then OAV, too. But they usually don`t make a queen (at least mine never did!) at this time of year. And not with so many mites (90% of all the mites in that hive have gone with the brood). Or go for something harder, something that works inside the cells, like formic acid, to get rid of the mites in that hive.
If you put that box next to the original box or on top, you can reunite after all are hatched and treated if you need strong hives for winter.
if you got a mild climate, leave it.
There is one guy in Germany, has got a kind of bee-school, he takes out ALL the brood or even all the frames (he has no more than 6 Jumbos in the brood-nest) and melts them down (after last honey-flow). Then gives frames with foundation and in the next 7 or 9 days he treats twice with OAV. That was that till winter for him usually.
I usually use the brood, make nucs (with the old queen) and treat them with formic acid.

This scientist I was speaking of says: a 100 in summer, 10 in fall, 1 in winter (natural drop) is a MUST for treating. (full grown colony, half for nucs I`d say)
I go way below: 10 in summer, 2-3 in fall, 0,5 in winter (winters I treat them all, no matter what, these days).
now when is fall, when is summer....?

Last year still I only treated the ones that needed it. This year I treated them all and hardly any needed it. Because last year the ones NOT treated showed a mite drop too high later on, though by the book they shouldn`t have.

The scientist lives because he is dealing with bees. Some people lives because they sell the yield from the bees. Different goals there...

another thing: mite count does fluctuate.

[Beeboy01]

I'm in Florida and the high count started the first week of August which is about right for the mite population curve. I held back treating because of being at the end of a honey flow and the hive is a good producer.

This is the first or second time I have had to deal with a mite problem, most times before the hive dies off and I wonder what happened or I treat with strips. I got tired of loosing hives so changed my beekeeping methods with mite counts and better screened bottom boards.

 The club president was pushing mite counts and control all year long and I finally listened for a change.

From what I can find performing a brood break along with OAV treatments is the best for mite control. I just wasn't comfortable trying a brood break with the hive and went with just OAV treatments.

We don't have a natural brood break due to winter here in Florida, it's above freezing most of the year with the queen laying year round.

I'm eye-balling the mite drop in the other hives right now and they all look good. It's just #3 that has the mite problem.

 

[blackforest beekeeper]

Florida... been there once. I?d like it.
Don`t know about bee-keeping there. But for sure, 10-12 a day is a reason for treating.
brood-break and OAV is good. Controlling all year round is good.
You`ll do fine that way.

[Beeboy01]

Here's the graph with the four day treatment points plotted. Looks like I'm getting ahead of the mites with a 33% reduction on each of the peaks as compared to the 7 day treatments which showed only 10% to 15% reduction per treatment
. I'm wondering what the lethal dose 50 is for oxalic acid delivered by a vaporizer since there is a large drop 24 hours after treatment then a greatly reduced drop later.
After 3 four day treatments I'v decided to increase the treatments to every two days targeting the mother mites that only stay phoretic for  a short time. Looks like it is working, the last count was only 90 and hammering them every two days seems to keep the hive at a LD50 or better for the mites if the drop numbers are a proper indication of the effectiveness of the OAV. Not sure how much longer I'm going to keep up the treatments, maybe five 2 day treatments to cover an entire mite life cycle.

My gut feeling is that shorter treatment spacing is way more effective than the recommended 5 or 7 day treatments and seems to be supported by the data points on the graph.

Using OAV for mite drops as a monitoring tool is viable but there isn't enough data present yet to connect mite drops and total mite population in a hive. A possible comparison of sugar rolls or alcohol washes with OAV treatments would be a help but there are a lot of other variables to be considered like hive age and how advanced the infestation is.

Hope this graph has helped understanding OAV treatments, I've learned a lot and will follow up with a final photo of the graph showing the results when I think I've the mites under control.

Ed   

[blackforest beekeeper]

Here's the graph with the four day treatment points plotted. Looks like I'm getting ahead of the mites with a 33% reduction on each of the peaks as compared to the 7 day treatments which showed only 10% to 15% reduction per treatment
. I'm wondering what the lethal dose 50 is for oxalic acid delivered by a vaporizer since there is a large drop 24 hours after treatment then a greatly reduced drop later.
After 3 four day treatments I'v decided to increase the treatments to every two days targeting the mother mites that only stay phoretic for  a short time. Looks like it is working, the last count was only 90 and hammering them every two days seems to keep the hive at a LD50 or better for the mites if the drop numbers are a proper indication of the effectiveness of the OAV. Not sure how much longer I'm going to keep up the treatments, maybe five 2 day treatments to cover an entire mite life cycle.

My gut feeling is that shorter treatment spacing is way more effective than the recommended 5 or 7 day treatments and seems to be supported by the data points on the graph.

Using OAV for mite drops as a monitoring tool is viable but there isn't enough data present yet to connect mite drops and total mite population in a hive. A possible comparison of sugar rolls or alcohol washes with OAV treatments would be a help but there are a lot of other variables to be considered like hive age and how advanced the infestation is.

Hope this graph has helped understanding OAV treatments, I've learned a lot and will follow up with a final photo of the graph showing the results when I think I've the mites under control.

Ed   

Hi Ed,
I?d not overdo it. NO treatment is wholesome to bees.

[Beeboy01]

Good point, I'll keep it in mind before continuing excessive treatments.

[Ben Framed]

Good point, I'll keep it in mind before continuing excessive treatments.

Beeboy01. I certinally don't know all the ins and outs of it but; you are doing a swell experiment here and an experiment is just that .  This is how we learn. It's not my hive and easy for me to say sock it to the mites but that wouldn't be fair in the case you lost your hive by (over treating if over treating is possible).   But I will add, I have read somewhere, I am thinking Australian research, which states that we can't over treat with OA. Please don't quote me as I read this a while back and memory is foggy. But if you are game, and are doing this not only to save the hive but to learn from your own research. I say do what yout hut tells you and keep up the good work, keep learning.  Thanks Philllip Hall.

[Beeboy01]

Ben Framed, I'm not too worried about loosing the hive from excessive OAV treatments, currently my yard is going strong enough so I could split out a replacement or two come spring and still be ahead by the early flow. I'm more interested in running the treatments till the mite drop gets to an acceptable level, maybe under 20 after a treatment. 
  It's all new territory, haven't found anything the documents every other day treatments. There is some data on three day treatments which was shown to work for a heavily infected hive.

Black Forrest Beekeeper, I'll keep you advice and monitor the hive's health as I continue, no need to kill the patient to prove the surgery worked.
 
I think that it is telling that the four day treatments showed a much greater reduction in the mite drop over 4 treatments when compare to the same number of seven day treatments. A treatment plan of six or seven treatments 3 days apart is starting to look optimal. 

The beekeeping community need to work and document on using OAV as a monitoring tool also now that it is legal in the US. JMHO

[Ben Framed]

✅.  👍🏻

[Beeboy01]

Mite drop count on the second day after the first two day treatment is 40. I hit the hive with OAV for the second two day apart treatment. Hopefully this will be close to the last of the treatments. Curious as to what tomorrow's count will be.

One interesting thing is that the highest mite drop for the seven day treatments came 48 hours after treatment but when the hives were treated every four days the largest drop occurred after only 24 hours. This also appears to  be occurring with the two day treatments. Not sure if it means anything, maybe there is a higher residual of oxalic acid left in the hive with the shorter treatment spacing and the overall toxicity is increased for the mites which provides quicker knockdown in 24 hours.

Ed

 

[blackforest beekeeper]

Mite drop count on the second day after the first two day treatment is 40. I hit the hive with OAV for the second two day apart treatment. Hopefully this will be close to the last of the treatments. Curious as to what tomorrow's count will be.

One interesting thing is that the highest mite drop for the seven day treatments came 48 hours after treatment but when the hives were treated every four days the largest drop occurred after only 24 hours. This also appears to  be occurring with the two day treatments. Not sure if it means anything, maybe there is a higher residual of oxalic acid left in the hive with the shorter treatment spacing and the overall toxicity is increased for the mites which provides quicker knockdown in 24 hours.

Ed

 

Thought of extra punch for your situation: treat when all ladies are at home. nightfall eg.

About one week after the last treatment most mites should be down that will make it down.
OA seems to be only active for an hour or two. the delayed drop is mites that have got a hit on a sublethal level and die later on. also, of course, there will be mites that still make it into brood and die there. so these will fall later when the bee hatches out. and this will falsify your natural mite drop count somewhat to the worse.

[Beeboy01]

Well today's count was only 55 and I'm going to stop treating the hive but keep doing the counts, it was a successful experiment as far as I'm concerned.

 Although it's not the recommended treatment schedule I would say that 6 treatments three or four days apart would be optimal. Hitting the hive every two days is excessive unless there is a major infestation and quick knockdown is needed.

 I need to find some base line numbers for natural mite drops over the upcoming weeks and possibly do a alcohol roll in about a month on some of my hives.
 
  Anyways hope everybody enjoyed this and learned something, I sure did.

 
Thanks also to Blackforrest Beekeeper and Ben Framed, their input was a big help.

[blackforest beekeeper]

if there is a big knockdown needed, taking out the brood is the easiest and quickest way. Also the most secure. Leaving one frame of open brood then and removing it after most of it is capped. Removing it then: You got a clean hive.
No treatment needed, if wanted.

[Beeboy01]

I was just seeing what the most efficient method of using a OAV wand was without performing a brood break or performing any other major manipulation of the hive.
  Since OAV is a newer treatment here in the states and in Florida where we don't have a real brood break I was curious as how to make it work on it's own.
     

[Groundhawg]

I've read that study been done, after the oav treatment under a microscope the bee scientist can see the
tiny holes burned into the bee's exoskeleton.   The result is a shorten lifespan bee.   I will never use oav again otherwise I
would use my homemade oav invention under the hive to burn it in.  Now I use an IPM method to remove the mites entirely.
Because some mites are still inside the cap broods, if not done right according to the timing of newly emerged bees with the
attaching mites on, the entire hive may crash over this winter.    There are some who miss the timing of treatment resulted in a
dead out.   Time it out!

How about sharing that information on OAV treatment harming bee.  Just where and when did you
 "read" that study.

[Ben Framed]

There is only one apiary that I know of that claimed their bees can kill the mites and handle the SHB also.  On you tube vids I've
seen one bee carried the SHB off its hive.  So both the mites resistant and SHB carrying bees are out there.  Maybe it is time that you do some research to
find those bees.   I would if I'm in your situation.  For now do what you can to ensure their survival.

Beepro, I have a feral hive that I acquired back in April which was in the siding of a lady's house. I have seen these bees dragging out SHB. This is my first year and I assuned this was common practice among bees?  The workers are grayish-yellow, But the queen is grayish-yellow with a blackish tail,  almost solid black tail.  They are very hard workers and though they have never offered to swarm, I have split them 3 times. Thanks, Phillip Hall "Ben Framed"

[blackforest beekeeper]

Found some instructions on OAV-treatment which came with my gizmo, see further up the thread.

These instructions are meant for our climate. We got a winter and almost always they will be brood-free in winter. Mine always were.

End of flows will usually be mid-July. For very few regions it may be later (heather, forest).

The manufacturer says, OAV has an effect a week long.

In August, (if too many mites, earlier), he suggests 3 treatments with 4 days apart. Another guy, commercial beekeeper, who uses this gizmo, too, suggests 4 treatments with 4 days intervals. I would suggest that, too. In case of doubt (many mites falling after treatment), I`d do a fifth. This is for breeding colonies!

If You remove all brood and give foundation at this point, after about a week one treatment should suffice. (this is from the commercial guy).

Manufacturer: 2nd week of September 1 treatment.
if weather stays fair, after 10 days treat the stongest colony again and if in 2 days the mite drop is more than 200, treat all colonies.
if weather is foul and bees have to stay in, no treatments should be necessary (due to re-invasion).

in the broodless period: 1 OAV. for us that would be november/december. The commercial guy suggests two treatments two weeks apart, even if broodlessness has not been achieved. (well, what you gonna do anyway then?)

It is common and I think there is some regulation in Germany, not to treat after last of December and not before the last honey-pull. no spring-treatments. It will probably not hurt, if allowed, to give another OAV before first brood has been capped in spring. If necessary. and of course, if broodlessness is achieved in Jan/Feb, you might do it then. albeit - the earlier those mites are dead, the better.

[Beeboy01]

black Forrest Beekeeper, Thanks for posting the OAV instructions, they pretty much confirm what my experiment showed. My best mite kill came when I started a 4 day treatment plan instead of the seven day plan I started with. I also treated every two days at the very end of to target the breeder mites that only spend a short time outside the brood cell. Not sure if the two day treatments had any added effect when compared to the four day treatment plan.
  Its been a week since my last treatment and the mite drop has steadily decreased from 50 per day down to today's count of only five mites. I'm planning a alcohol wash on the hive next week to develop a baseline.     

[TheHoneyPump]

I really enjoyed the read on this one.  It has been great to see the daily numbers, the setting of those numbers to a trend, then adjusting the treatment plan (days between shot) based on what the data was showing.  Great stuff!

One piece of the puzzle that was asked further up is the estimation of how many watts the heater is.  Any idea what current that glow plug is pulling?  An important parameter for anyone intending to build themselves one.

Also, what is the dose of OA used (grams) per treatment?  And, how long is the device left in the hive to vaporize the full dose.

[Beeboy01]

Honeypump,  the heater rod pulls about 150 watts, some pull more wattage but the one I used is smaller in diameter which helped keep a thin profile for the heater block which allows it to slip into the hive or under the screened bottom board. A thin design was one of the goals in building it and I was able to get the heater block to be only 5/8 of an inch thick. Good thermal conduction between the heater rod and heater block is needed and thermal grease is recommended around the rod. I used a few wraps of aluminum foil instead which has worked so far.

I'm using 2 grams or 1/8 of a teaspoon per deep super of brood which is the recommended dose, instead of weighing the dose I used a 1/4 teaspoon measure which is close enough to a 4 gram dose for the double deep. Using measuring spoons is the method the commercial OAV wand vendors recommend and I did't see any reason to reinvent the wheel in this case.

The temperature shutoff switch turns the current off at 350 degrees or about 3 minutes after starting the treatment, having an indicator light on the wand is a big help. I leave the wand in the hive for another 3-4 minutes with power off to finish vaporizing the oxalic acid. The extra time allows me to prep the next hive in my yard. I can treat all 5 of my hives in under an hour. The heater block gets cooled in a container of water and wiped off between hives. I don't immerse the electronics, just the end of the heater block to cool everything off.

So far the treatments have worked on #3 with no signs of any mites even after a 72 hour count and I'm happy with the results.