# Oxalic acid vapor issues



## dulley (Apr 20, 2009)

I have used an oxalic vaporizer for several years for varroa control. I have also lost more than 50% of my hives over that period. I have never seen a drop-off of dead varroa after vapor treatment like I did with Apigard and other chemical treatments. Has anyone who uses oxalic vapor seen where it actually killed mites and had a drop-off on a tray under the screened bottom board? Has anyone had a problem losing queens when using oxalic acid vapor? Thanks, Jim


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## Surviving Our Bees (Feb 14, 2021)

yes, the white board is a way to determine mite drop after a successful OAV treatment.

If you are using OAV, and not getting a mite drop, and then confirming a high mite load with a mite wash, the application or dose is not correct.

Use a bare minimum of 2 grams for a double deep. That's what the label states, but many beekeepers use 3-4g.

Be sure to use a band heater vaporizer.

Queens can get lost, but it's quite rare.


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## crofter (May 5, 2011)

There are pictures here on the forum of drops of a thousand. I think one username was Glock. I have not seen really large drops but I havent allowed mite load to get high. 

Colony losses at that high a percentage suggests there may be other factors at play such as not early enough treatements and/or calling it good. too early in the fall and having a resurgence later from robbing etc.
There has been increasing awareness of the need to get mites under control and keep them there during the time of brooding several rounds of winter bees. It takes several months after the last of the virus vectoring mites have been dispatched for the virus levels to drop to tolerable levels. You are not home free yet when the last mite dies!

There are 20 some different viruses affecting bees and their presence and level can vary greatly from one locality to another and from year to year. Nosema is another wildcard.

There has not been much in the way of reports of anything more than minor mortality that were not also suspect of having improperly mixed dribbles or someone having sourced "wood bleach" that may have been lye or bleach based rather than oxalic acid.


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## johno (Dec 4, 2011)

crofter said:


> There are pictures here on the forum of drops of a thousand. I think one username was Glock. I have not seen really large drops but I havent allowed mite load to get high.
> 
> Colony losses at that high a percentage suggests there may be other factors at play such as not early enough treatements and/or calling it good. too early in the fall and having a resurgence later from robbing etc.
> There has been increasing awareness of the need to get mites under control and keep them there during the time of brooding several rounds of winter bees. It takes several months after the last of the virus vectoring mites have been dispatched for the virus levels to drop to tolerable levels. You are not home free yet when the last mite dies!
> ...


If you are using OA vapor only to control mites you should be treating around 12 to 14 times a year, 3 weeks in summer with 2 treatments a week the same again in September and then 2 treatments when broodless November and December.


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## Cloverdale (Mar 26, 2012)

I see mite drops on the drawer, I use Johno’s pro vap. This past Fall there were a lot of mites even with using Formic Pro and OxV. I did not do counts this year, too many hives and heavy supers to move around for me. I heard that many other beekeepers noticed higher than usual mite loads too. I will not use Formic Pro again, there were queen problems with it, so I thought I would try Apivar this Spring instead of Autumn.


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## Surviving Our Bees (Feb 14, 2021)

Indeed cloverdale.

Agreed with Johno.

A lack of mites on the insert indicates a problem with the application method, or the death 50% rate is not from mites but another.


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## Mapleone (Jan 10, 2016)

I started using OA treatment several years ago and early on it worked well with only a couple of hive loss over the winter. This late Fall I treated all my 16 hives in three stages ( per Provap directions) to kill stages of mites. Hives where all very strong up until February. Weather here in CT turned for the worse and I lost them all. At first I thought it was starvation but after further investigation my alcohol wash mite counts are 13 to 18 per 300 bees Average. Is it possible the OA was bad or expired ( shelf life)? It was Wood Bleach and kept in a sealed container. Any thoughts on what could have caused this? Appreciate any input.


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## crofter (May 5, 2011)

Mapleone said:


> I started using OA treatment several years ago and early on it worked well with only a couple of hive loss over the winter. This late Fall I treated all my 16 hives in three stages ( per Provap directions) to kill stages of mites. Hives where all very strong up until February. Weather here in CT turned for the worse and I lost them all. At first I thought it was starvation but after further investigation my alcohol wash mite counts are 13 to 18 per 300 bees Average. Is it possible the OA was bad or expired ( shelf life)? It was Wood Bleach and kept in a sealed container. Any thoughts on what could have caused this? Appreciate any input.


"_This late Fall I treated all my 16 hives in three stages_" I think this is where the problem starts. Too late to get the required 2-3 rounds of brood raised in mite free conditions to get "Fat winter bees".


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## Mapleone (Jan 10, 2016)

Here is my timeline. 
3 treatment cycle on all hives ended 6/7/20
Fall 3 treatment cycle ended 9/26/20 
Hives wrapped and sugar boards placed for winter. 
The weather was on and off warm and really did not get cold until February. I don’t think I could have done anymore treatments. I have heard some people do OA treatments on a regular basis during the year


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## Mapleone (Jan 10, 2016)

Sorry winterized and wrapped 11/2/20


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## massbee (May 11, 2020)

Not enough. What were your counts in September? Did you treat after that or take counts after that? I’m in Massachusetts, lost 2, bees didn’t have mites but had lots of signs of mite vectored viruses.


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## Biermann (May 31, 2015)

My 2 C. I started with bees in 2015 and used Apivar by label spring (end Winter) and Fall. Lost 50% for two years each winter. Wash showed 2-4% mites in fall. Then I started with a pan style vaporizer and the losses did not change, but the whole treatment was agonizing, time wise. 2019 I build my first band heater VAP and treated 7x4 days apart with 3 gram on double deeps from the back. No loss in 19/20 and no loss 20/21. Today we had 16°C, 61°F and I started my first treatment and will check my bottom board on the day of the next treatment, Monday. The bees where out like mad today, calm and super sunny. I treat in the evening when everyone is home. The treatment per hive takes 20 seconds. My motto: the right 'puff' makes the difference!


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## crofter (May 5, 2011)

Mapleone;

If your treatment were three at seven day intervals that would not be sufficient if there is a high mite load in surrounding bees. Too many mites are drifting in between individual vaporizations and certainly between series. I dont give breaks between series and shorten the intervals down to 3 or 4 days. It is a bit different story when they definitely have no brood.

See Johno's post #4


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## Biermann (May 31, 2015)

crofter said:


> If your treatment were three at seven day intervals that would not be sufficient if there is a high mite load in surrounding bees. Too many mites are drifting in between individual vaporizations and certainly between series. I dont give breaks between series and shorten the intervals down to 3 or 4 days. It is a bit different story when they definitely have no brood.
> 
> See Johno's post #4


Well Frank, you mean me? I treat 7 times, 4 days apart, so 28 days total!


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## crofter (May 5, 2011)

Biermann said:


> Well Frank, you mean me? I treat 7 times, 4 days apart, so 28 days total!


 Sorry Joerg; You posted while I was replying to Mapleone. I agree 100% with your program. I edited my post to show who I was directing it too.


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## Biermann (May 31, 2015)

Sweet. Life is good, the bees are flying! I know we will pay for it, way to early for Alberta's Banana Belt.


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## Vance G (Jan 6, 2011)

dulley said:


> I have used an oxalic vaporizer for several years for varroa control. I have also lost more than 50% of my hives over that period. I have never seen a drop-off of dead varroa after vapor treatment like I did with Apigard and other chemical treatments. Has anyone who uses oxalic vapor seen where it actually killed mites and had a drop-off on a tray under the screened bottom board? Has anyone had a problem losing queens when using oxalic acid vapor? Thanks, Jim


You are aware that multiple oxalic treatments are required to properly control. your mite infestation? It only kills those mites exposed in the colony. Those in capped cells reproducing are unaffected. Mites have a 13 day breeding cycle so personally I treat three times every fifth or sixth day. That way I believe I catch the vast majority of the mites out in the open during one of those treatments. I also am always ready during the broodless portion of the winter to treat on a warm day when the bees are flying or at least loosely clustered. Another opportunity to decimate mites not safe in capped cells. I like Apiguard too! I rotate a treatment of it into my strong hives every other year. It is too rough on weak colonies so I do not use it on nucs or small splits IMO. You are right to be suspicious of mites in your winter losses. Sugar rolls or alcohol washes are also important in knowing what your mite levels are. I am a wimp and do not like killing bees to test so I use the sugar roll. Now that we can treat with OA when supers are on, It will be more important to regularly check mite levels and do on the spot treatments. At least that is my plan.


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## Murdock (Jun 16, 2013)

Mapleone, I use OAV and treat often. August 1st is the important date to start with in order to get healthy winter bees. Every 4-6 days in August... healthy winter bees make healthy bees for spring.


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## Mapleone (Jan 10, 2016)

I did an alcohol wash right around 9/5 and the majority of the hives showed zero mites. Only a couple had max of 3 mites per 300 bees. Therefore I thought I would play it safe and treat all 3 treatments spread over 7 days. Is it safe to assume going forward I should do the following:
1. Test regularly and treat accordingly 
2. August 1st start 3 treatment process and do every 3 to 4 days ( not 7 days)
3. Treat again as late as possible prior to Winter close up say late September weather permitting of course

Now that it appears to be safe to use OA with Honey supers on it could be more effective.
Last can someone explain the " Fat Bee statement"


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## crofter (May 5, 2011)

Mapleone said:


> I did an alcohol wash right around 9/5 and the majority of the hives showed zero mites. Only a couple had max of 3 mites per 300 bees. Therefore I thought I would play it safe and treat all 3 treatments spread over 7 days. Is it safe to assume going forward I should do the following:
> 1. Test regularly and treat accordingly
> 2. August 1st start 3 treatment process and do every 3 to 4 days ( not 7 days)
> 3. Treat again as late as possible prior to Winter close up say late September weather permitting of course
> ...


The fat bee concept seems to be that bees who have not nursed or foraged have a much much larger fat body which is the source for the first rounds of brood raised in the spring. They can survive for ~ 5 months whereas bees which have nursed and foraged time out at about 6 weeks of age. Hopefully these winter bees will also harbor a much lower level of virus.

On OA treatments; it seems that the shorter time interval between treatments eliminates the number of mites that slip through the 7 day period. Mite falls seem to indicate that the main effective time is the first 3 days after vaporization and it tapers off quickly. The next 4 days may allow mites to emerge and re enter cells unscathed. ( second and third time females can re enter cells immediately without a blood meal on a bee.)

When you shorten the time between treatments you must add more treatments to extend the time to cover the same 21 day period. Personally I keep repeating 3 or 4 day interval treatments till the dead drop level is near zero. No breaks between to allow a senseless recovery.


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## JWPalmer (May 1, 2017)

Mapleone, I treat with 3.5 grams of OA every 7 days starting in August and continuing through October. Then a single treatment at Thanksgiving and again at Christmas. This strategy has worked very well for me here in Virginia. I lose more hives to starvation than to mites.


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## Cloverdale (Mar 26, 2012)

JWPalmer said:


> Mapleone, I treat with 3.5 grams of OA every 7 days starting in August and continuing through October. Then a single treatment at Thanksgiving and again at Christmas. This strategy has worked very well for me here in Virginia. I lose more hives to starvation than to mites.


Hey JW, will you increase dosage if you keep supers on?


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## JWPalmer (May 1, 2017)

Probably not. Using a ProVap, I get a really nice cloud of OA dust that circulates throughout the hives. I typically do not treat until after harvest and have been storing the empty supers on top of the hives all along.


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## Cloverdale (Mar 26, 2012)

JWPalmer said:


> Probably not. Using a ProVap, I get a really nice cloud of OA dust that circulates throughout the hives. I typically do not treat until after harvest and have been storing the empty supers on top of the hives all along.


I do like the Provap also, so fast to treat. Our fence is hooked up to electric so it’s easy to plug in. I’m at about 20 now including dbl nuc, with 2 that are small clusters. Next week 50’s on one day. Very nice.


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## shinbone (Jul 5, 2011)

From my testing, capped brood or not, the OA seems to have little affect after 3 days. Making treating every 3 days optimal. Keep treating until you see no more mite fall. It'll take longer to get to zero mite fall when there is capped brood.


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## G3farms (Jun 13, 2009)

I finally gave in last fall and did my first treatments with OA. From what I am reading it was too little too late. I am still suffering hive losses. Seems like treatment free, at least for me is not going to work. Been keeping bees since '71 and can not take the losses anymore. Just too hard to see all of this empty equipment sitting around.

When can I start treatments again this spring??


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## johno (Dec 4, 2011)

G3farms said:


> I finally gave in last fall and did my first treatments with OA. From what I am reading it was too little too late. I am still suffering hive losses. Seems like treatment free, at least for me is not going to work. Been keeping bees since '71 and can not take the losses anymore. Just too hard to see all of this empty equipment sitting around.
> 
> When can I start treatments again this spring??


There is quite a lot of chatter from the Bee-L experts who continue to show their ignorance on the use of OAV claiming that it is so dangerous that there is no safe way to treat with OAV. However when one looks at statistics of road accidents and deaths I would assume that none of them would dare to drive on the roads. Beats me where they hide all those accidents and deaths to beekeepers from the use of OAV.


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## G3farms (Jun 13, 2009)

I had rather treat and loose a hive and at least know I did something, than to just see a dead out and know I did nothing.

You are right Johno, and you vaporizer works great also!!


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## Surviving Our Bees (Feb 14, 2021)

johno said:


> There is quite a lot of chatter from the Bee-L experts who continue to show their ignorance on the use of OAV claiming that it is so dangerous that there is no safe way to treat with OAV. However when one looks at statistics of road accidents and deaths I would assume that none of them would dare to drive on the roads. Beats me where they hide all those accidents and deaths to beekeepers from the use of OAV.


OAV is is an irritant, but I've never had any problems with OAV application. A thick shirt over my mouth, or even an n95 mask does a phenomenal job at preventing any irritation.


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## crofter (May 5, 2011)

G3farms said:


> I finally gave in last fall and did my first treatments with OA. From what I am reading it was too little too late. I am still suffering hive losses. Seems like treatment free, at least for me is not going to work. Been keeping bees since '71 and can not take the losses anymore. Just too hard to see all of this empty equipment sitting around.
> 
> When can I start treatments again this spring??


When it appears that the overnight temperature will stay above 40 F. Would be safe. The bees will not be clustered so the OA penetrates well and it gives the bees plenty of time to be able to reorganize cluster if needed.

After you establish a good program of mite control you may find there are not many mites around, come spring but whenever there is an exponential growth, getting your licks in early pays big dividends.


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## G3farms (Jun 13, 2009)

Thanks Crofter!
At the rate we are going I might get the first OA round in very soon.
American Elm bloomed about a week ago and I think Eastern Red Cedar bloomed the other day. A cool 46 here this morning but the sun is shining hard.


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## JWPalmer (May 1, 2017)

Temps are getting into the 60's here next week, we may even see 70 by Thursday. Bees will be getting a Spring OAV or two just to see where we are. Brooding is well under way but the Dec. treatment should have gotten most of the mites so this treatment is more precautionary. Besides, a zero mite report on my annual inspection looks good.


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## Mapleone (Jan 10, 2016)

Thanks everyone as this is very helpful and I agree I also made the mistake and did too little too late. Does everyone also agree OA is shelf stable if kept sealed and dry? Wood Bleach OA not being an issue with effectiveness?


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## JWPalmer (May 1, 2017)

OA is shelf stable. It is much easier to use if kept dry. I have never tried the Savogran wood bleach but there have been reports that it does not work as well as the Florida Labs product.


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## bushpilot (May 14, 2017)

I have used 3-year old FL labs OA, stored in its original (opened) zip lock style bag, and did not note any deterioration, color change, clumping, or any other physical change. Of course chemical or physical changes may have been occurring that I could not see, but it worked fine for the purpose of killing mites.


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## crofter (May 5, 2011)

I have noticed a difference in crystal structure between different sources. For a comparison think of the pouring and measuring difference between granulated sugar and icing sugar or table salt and pickling salt.
Some OA are more like table salt and some more like icing sugar. With greater surface area the finer particles might have a small difference in reactivity or dissolving. They measure differently and flow differently and probably weight to volumes vary. Prescribed amounts are in units of weight but how many of us weigh individual treatments? Fortunately the upper safety range is quite large, but if you are treating near the lower range of efficacy and stretching the treatment intervals, there could perhaps be issues


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## missybee (Sep 6, 2014)

JWPalmer said:


> Probably not. Using a ProVap, I get a really nice cloud of OA dust that circulates throughout the hives. I typically do not treat until after harvest and have been storing the empty supers on top of the hives all along.


I just started using our new ProVap ez 110, love it! Went from a hour to treat the hives to about 10 minutes. Seems waiting for the first warm up is the only time it takes time. I am doing a pre spring treatment, since the bees are mainly up in the upper brood box I have been inserting the tube in the upper entrance. Very nice cloud of OA drifting down and out of the hive. 

I have also placed the tube in the front entrance, but in the tear down of a dead out found a lot of OA crystals on the frames, ie too cold. So treating where the bees are when we hit around 45 or so. Right now back to 17f.


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## Gray Goose (Sep 4, 2018)

Mapleone said:


> Thanks everyone as this is very helpful and I agree I also made the mistake and did too little too late. Does everyone also agree OA is shelf stable if kept sealed and dry? Wood Bleach OA not being an issue with effectiveness?


I use the "real stuff" order some from Fla Labs. for me the time to get there and set up far exceeds the cost of the good OA.

GG


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## Issy-bees (Mar 4, 2021)

johno said:


> If you are using OA vapor only to control mites you should be treating around 12 to 14 times a year, 3 weeks in summer with 2 treatments a week the same again in September and then 2 treatments when broodless November and December.


I live in Western Washington.
This year I began last April with OAV, checked for mite drop at 24 hrs, (0 mites), waited a month and repeated. In Sept. I had not mites, but one showed up in a sugar roll, began OAV every 5-7 days until
November. Mite counts increased to over 300. My conclusion was that my girls were out robbing and bringing back more than honey. By late November I was down to 30, and stopped.

Over the past 4 years I have lost each hive and concluded that I would not lose another hive to mites. Both hives have wintered over this year, I have broodminder TH which indicated on March
1st that the queens are laying (up from 70* to 90*). I remain concerned as to the quality of the queens, but wintering over allows me to check the brood pattern to determine if I need to replace the queen, but for now I consider multiple OAV treatments a necessary but successful approach.


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## MtwWallace (Dec 11, 2019)

Mapleone said:


> I started using OA treatment several years ago and early on it worked well with only a couple of hive loss over the winter. This late Fall I treated all my 16 hives in three stages ( per Provap directions) to kill stages of mites. Hives where all very strong up until February. Weather here in CT turned for the worse and I lost them all. At first I thought it was starvation but after further investigation my alcohol wash mite counts are 13 to 18 per 300 bees Average. Is it possible the OA was bad or expired ( shelf life)? It was Wood Bleach and kept in a sealed container. Any thoughts on what could have caused this? Appreciate any input.


Do a sugar roll or alcohol wash mite count BEFORE treatment, wait 2 weeks after complete treatment then do a sugar roll or alcohol wash mite count again, this will tell you immediately if the treatment was successful, if not successful use a different Ox, I get mine from Florida Labs, pure.


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## TJC1 (Nov 11, 2012)

What Crofter said... +1


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## TehachapiGal (Mar 5, 2015)

I found vaporizing to be extremely difficult. Timing, accurate amount of Oxalic Acid, frequency of 3 treatments every 7 days, testing for dead mite counts for 3 days. Is it possible that your bees died from the hot end that touched the bottom frames? All my hive bottoms are the varroa mite bottoms where there is a space to insert the wand that is not high enough to touch the bottoms of the frames. The heat at the end of the wand, the cup holding the oxalic acid is very hot and if too close to the bottom frames, some folks have reported that their hive started on fire. Some of you should go to Randy Oliver's site about treatment with oxalic acid. Extended-Release Oxalic Acid Progress Report #5 - 2019 - Scientific Beekeeping

Keep in mind that you can also use Apivar, MiteAway or other strips to control mites. Be accurate at following the instructions. Most are temperature sensitive. Formic acid has a lot of problems like killing the queen. Using the oxalic acid drip method can also kill the queen if on her if the weather is cold.


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## bkochis (Nov 10, 2019)

TehachapiGal said:


> I found vaporizing to be extremely difficult. Timing, accurate amount of Oxalic Acid, frequency of 3 treatments


I noticed the OP never mentioned the actual mite count. 
Also, no one mentioned closing the hive for 10 minutes as recommended in BeeJornal, etc. I use a tshirt.
Break open Drone cells and look for mites if necessary. Been following Randy's work also, always great info.


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## Ruggggus (Jun 23, 2019)

All good discussion. I no longer do a wash because I don't see the reason, the OAV treatment is harmless to your bees if using a band heater type applicator correctly and having a screened bottom board with tray is key. Without it you can't know your mite drops. I have tried inserting a thin aluminum coil stock piece into my solid bottom board to catch mites but it just doesn't work well. I do actual counts of dead mites because I am still at the hobby level of colonies and am interested enough to invest the time. The first year I was amazed at the counts which I started in the fall with 3 to 4 day intervals and on 1 colony the count was growing when it should have been dropping. That is when I determine that besides killing the mites that are existing in your box you may be having to deal with hitchhikers coming in on your robber bees that have found a faltering colony elsewhere and are bringing mites home with their bounty. I have seen mite drops increase for weeks during treatment on a hive while the hive on its side drops to nothing. You must check the drops, is not a matter of doing a specific treatment and you're done. Many of my hives get treated 3 to 4 times 3 to 4 days apart but there are those that get that same treatment for a month and a half. I believe it is crucial that you are doing treatments just before they are done flying for the season (upstate NY winter) because of this robbing of a dieing colony, your mite counts could be 0 one week and over 1000 the next. Observation and timing are key in killing mites. If you're not getting mite drops with a band type OAV then you are not using pure oxalic acid or are applying it in a manor that doesn't allow the particles to follow through the hive. Open a vent on the top till you see particles emitting from it and then close it then you know the situation of the hive is complete (assuming you are treating from the bottom).
I have kept to the directed dose amount and been satisfied but have noticed that several beeks I have respect for are saying it isn't enough. My previous learning of pest management makes me want to stick to the prescribed but my life lessons makes me want to follow those I respect.


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## missybee (Sep 6, 2014)

I am on my forth treatment, since 2/1, all done around our bouncing temps. I saw (huge hive a bit nasty) a drop of around 15 mites the first time, 6ish mites the second time, 1 mite the third time. I just did one more treatment this am. Will see if any mites drop.

Of the other hives one had a drop, about 5, the rest none. If none seen I will wait until closer to supers being put on and start another round of treatments.


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## TJC1 (Nov 11, 2012)

Ruggggus said:


> All good discussion. I no longer do a wash because I don't see the reason, the OAV treatment is harmless to your bees if using a band heater type applicator correctly and having a screened bottom board with tray is key. Without it you can't know your mite drops. I have tried inserting a thin aluminum coil stock piece into my solid bottom board to catch mites but it just doesn't work well. I do actual counts of dead mites because I am still at the hobby level of colonies and am interested enough to invest the time. The first year I was amazed at the counts which I started in the fall with 3 to 4 day intervals and on 1 colony the count was growing when it should have been dropping. That is when I determine that besides killing the mites that are existing in your box you may be having to deal with hitchhikers coming in on your robber bees that have found a faltering colony elsewhere and are bringing mites home with their bounty. I have seen mite drops increase for weeks during treatment on a hive while the hive on its side drops to nothing. You must check the drops, is not a matter of doing a specific treatment and you're done. Many of my hives get treated 3 to 4 times 3 to 4 days apart but there are those that get that same treatment for a month and a half. I believe it is crucial that you are doing treatments just before they are done flying for the season (upstate NY winter) because of this robbing of a dieing colony, your mite counts could be 0 one week and over 1000 the next. Observation and timing are key in killing mites. If you're not getting mite drops with a band type OAV then you are not using pure oxalic acid or are applying it in a manor that doesn't allow the particles to follow through the hive. Open a vent on the top till you see particles emitting from it and then close it then you know the situation of the hive is complete (assuming you are treating from the bottom).
> I have kept to the directed dose amount and been satisfied but have noticed that several beeks I have respect for are saying it isn't enough. My previous learning of pest management makes me want to stick to the prescribed but my life lessons makes me want to follow those I respect.


This is my experience exactly - I'm in MA, fwiw. I use a pan vaporizer.


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## Robbin (May 26, 2013)

Ruggggus said:


> I no longer do a wash because I don't see the reason


I concur, if you've ever tested and found mites, you have them. Now I treat on a schedule. Another thing, if you can't get all your treatments in, get in the ones you can. My first treatment usually produces thousands of dead mites, you don't have to kill EVERY mite, thou that would be nice. You smash the mite load with each treatment. ONE TREATEMENT is lots better than NO treatments with OAV. I bought VAROMORUS TURBO PROPANE FOGGER OXALIC ACID VAPORIZER and can literally treat on a whim now. I really have no excuse!

Lack of mite fall is an application problem, also, I get my largest fall on the 3rd day, so don't count an hour after treatment.


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## Robbin (May 26, 2013)

MissyBee, If your mite load is that low, you don't need to treat at all. When I treat, I get THOUSANDS of mites. But I live in Florida, and you live in Maryland. Very big difference....


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## crofter (May 5, 2011)

Robbin said:


> MissyBee, If your mite load is that low, you don't need to treat at all. When I treat, I get THOUSANDS of mites. But I live in Florida, and you live in Maryland. Very big difference....



Hey Robbin, I dont know what the absolute facts might be, but my opinion is that in the face of exponential expansion of mite numbers a preflow count close to zero is a good target. If the total hive count is the accepted figure of 4 times the phoretic numbers, then when the mites under capping emerge, a different scenario will be seen.

My philosophy is to have the mites on their backs or at least never let them get up off their knees!


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## TJC1 (Nov 11, 2012)

crofter said:


> Hey Robbin, I dont know what the absolute facts might be, but my opinion is that in the face of exponential expansion of mite numbers a preflow count close to zero is a good target. If the total hive count is the accepted figure of 4 times the phoretic numbers, then when the mites under capping emerge, a different scenario will be seen.
> 
> My philosophy is to have the mites on their backs or at least never let them get up off their knees!


Or their burnt feet!


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## bushpilot (May 14, 2017)

I treat until I have two treatments in sequence with drops in the low single digits. And then I might still treat again...


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## missybee (Sep 6, 2014)

Robbin said:


> MissyBee, If your mite load is that low, you don't need to treat at all. When I treat, I get THOUSANDS of mites. But I live in Florida, and you live in Maryland. Very big difference....


Yep I know, but we had a big loss this winter, about 1/2, I treated with MAQS, did OA in the spring, not as aggressive as I am now. Did OA in the fall, not as aggressive as I should have. The year before apivar, never got the mites down. 
A few years back went into nectar flow with minimal mites, came out with them loaded with mites. 

This year I am going into nectar flow with as low a count as possible. Will watch during nectar flow, if need be treat, if not start aggressive OA in July and keep going like a few other have said it works for them. 

With the new vaporizer I bought it is so quick and easy now. Got all the hives done in the time it used to take me to do two, at around 3 minutes per hive.
Now around 30 seconds per hive.


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## Robbin (May 26, 2013)

missybee said:


> With the new vaporizer I bought it is so quick and easy now. Got all the hives done in the time it used to take me to do two, at around 3 minutes per hive


Now that is key, if it's fast an easy, go for it! Mine is fast and easy now, and it's more trouble to test then it is to treat so I just treat on a schedule. But I"VE NEVER seen might counts like yours. I'm not sure I get that low in the dead of winter because we have fly days all winter long. I can't remember a week we didn't get above 50 at some point. 

I'm curious, what about SHB. We are swamped with them. I use oil trays year round to cut down on them and almost all my hive losses are to them. Do you have them in Maryland? Mine survive year round here in the hives. My Mity Mite killer is a lot of trouble to use, but it kills SHB so when I find a hive that is really stressed by them, I get it out. 

Good luck!


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## missybee (Sep 6, 2014)

Robbin said:


> what about SHB. We are swamped with them.


We get some, I have more in the hives 1/2 mile from our house at a small farm then I have in our back yard hives. I have sprayed nematodes that kill the beetle larvae when they are in the ground. I have done it here x3 at the farm x1.

Something another bee association member said she is doing is vent boxes on the top of the hive. She says she has no issues with beetles since adding the extra air flow, so going to try that this summer. I cut a few of our spare boxes and made some. Mann lake sales them also. 

This was a screen grab from a meeting, i made mine with less holes, bug screen and anti bee screen over the holes, the bottom with hardware cloth to keep the bees out. Ours build burr comb anywhere they can.


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## missybee (Sep 6, 2014)

NemaSeek™ - Hi Beneficial Nematodes


When keeping bees, our number one priority is their health. Using harsh and toxic chemicals is not only bad for our bees it is bad for the ecosystem. ARBICO Organics is proud to introduce our newest beneficial nematode, Heterorhabditis indica (Hi). H. indica is a heat tolerant...



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The main thing is to have a brand new clean sprayer, like the cheap one gallon ones at home depot/lowes

You get some gel like stuff, mix in water, spray.


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## missybee (Sep 6, 2014)

Oh and the vent box is put over a inner cover, I use the mann lake winter inner covers, during the summer I will flip over and put the vent box on them. Nice big hole in the center to get the air going up and out of the vent box. We are hot and humid here, she also said the vent box helped them cap the honey faster. I have always used screened inner covers, these boxes will add more air flow.


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## Robbin (May 26, 2013)

I tried the nematodes and several ground drenches, they help, but they aren't hive savers. Oil trays that kill adult SHB are the only thing that really makes a difference and even that won't help a weak hive. I live in Florida, very hot, very humid, all my hives are ventilated. That doesn't help when it comes to SHB. At least not down here. I'm turning my oil trays into SHB traps, adding floats with honey on them to help attract them into the tray. They are a real problem here, I hate them the most. I also have one more problem I don't know the cause of. I lose about 60% of my queens on their mating flight. So the hive goes queenless. If I don't catch it, the hive weakens and the SHB will slime it. That is very frustrating, every other swarm results in a queenless hive so I try really hard to control the swarming. 

Enjoyed talking with you, haven't been on Beesource for a long time.


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## JWPalmer (May 1, 2017)

Robbin, good to see you back posting again. Read this recent thread and see if it applies to you too.









How to Increase Success Rate in the Mating Yard?


I work with Mike Palmer at French Hill in Vermont. We're under winter snow here now, and this is the time of year that we talk about ways to improve and make plans for next season. One of the things we're talking about is how to increase or rate of success in our queen rearing operation. We're...




www.beesource.com


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## missybee (Sep 6, 2014)

Robbin said:


> Enjoyed talking with you, haven't been on Beesource for a long time.


Enjoyed also, never know when you might get that tidbit of info that will help you or your bees.


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## Robbin (May 26, 2013)

JWPalmer said:


> Robbin, good to see you back posting again. Read this recent thread and see if it applies to you too.
> 
> 
> 
> ...


Thank you sir, I'll read that post.


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## OLD KENTUCKY (Feb 18, 2021)

Biermann said:


> My 2 C. I started with bees in 2015 and used Apivar by label spring (end Winter) and Fall. Lost 50% for two years each winter. Wash showed 2-4% mites in fall. Then I started with a pan style vaporizer and the losses did not change, but the whole treatment was agonizing, time wise. 2019 I build my first band heater VAP and treated 7x4 days apart with 3 gram on double deeps from the back. No loss in 19/20 and no loss 20/21. Today we had 16°C, 61°F and I started my first treatment and will check my bottom board on the day of the next treatment, Monday. The bees where out like mad today, calm and super sunny. I treat in the evening when everyone is home. The treatment per hive takes 20 seconds. My motto: the right 'puff' makes the difference!


What is a band heater VAP?
Thanks, 
OLD KENTUCKY


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## bkochis (Nov 10, 2019)

OLD KENTUCKY said:


> What is a band heater VAP?
> Thanks,
> OLD KENTUCKY


A round vaporizer like the Provap, where the vapor is pushed through a tube. I don't have enough hives to warrant one. I still use the pan on a stick type.


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## OLD KENTUCKY (Feb 18, 2021)

missybee said:


> We get some, I have more in the hives 1/2 mile from our house at a small farm then I have in our back yard hives. I have sprayed nematodes that kill the beetle larvae when they are in the ground. I have done it here x3 at the farm x1.
> 
> Something another bee association member said she is doing is vent boxes on the top of the hive. She says she has no issues with beetles since adding the extra air flow, so going to try that this summer. I cut a few of our spare boxes and made some. Mann lake sales them also.
> 
> ...


Do you use an inner cover when you use the vent boxes. 
Thanks,
OLD KENTUCKY


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## OLD KENTUCKY (Feb 18, 2021)

bkochis said:


> A round vaporizer like the Provap, where the vapor is pushed through a tube. I don't have enough hives to warrant one. I still use the pan on a stick type.


Thanks very much. I still use the pan type, but with my hive losses, I may just buy the Provap. The hive losses sure add up. Who has the Provap, and what is the cost.
Thanks very much for your reply. This year, I lost all 8 hives. All of them absconded, so I am starting over. I did treat with Oxalic acid, but evidently not enough. I retired from flying for Northwest Airlines. Years ago, I helped my Grandpa with the bees, but times have changed for this 81 year old guy. I love working with them.
OLD KENTUCKY


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## missybee (Sep 6, 2014)

OLD KENTUCKY said:


> Do you use an inner cover when you use the vent boxes.
> Thanks,
> OLD KENTUCKY


I am going to use the mann lake winter feeders/inner covers. Flip it over in the summer. Put the vented cover on top. I am also going to have some hives with the vent box right over the frames. See how those hives do. I have used screened inner covers for years now. This vent box will add a better air flow. 

Our bees build burr comb everywhere they can, even fill the shims with comb. One reason I made them and put screening on the bottom, keep the bees from building in the vent box.

Once supers are on, it will only be the vent box, no inner cover. When we feed in the fall it will be on top of the feed boxes.

In the winter I have the inner cover over the sugar blocks we put in the hive. I sit the sugar blocks on a queen excluder then the cover, keeps the blocks from sitting right on the hive frames. Gives the bees some bee space to get to the sugar. 











The one bee keep uses the vent box in the winter, fill it with cedar shavings.

We don't have a issue with moisture. I put green foam board below the lid and then a piece of the foil covered bubble wrap. So I won't use in the winter.


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## b2bnz (Apr 5, 2009)

bkochis said:


> A round vaporizer like the Provap, where the vapor is pushed through a tube. I don't have enough hives to warrant one. I still use the pan on a stick type.


I made my own with a small piece of copper tube and used a blow torch as the heat source. See Gas-Vap from the UK or make your own! Priceless!


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## Murdock (Jun 16, 2013)

Everyone using OAV needs increase their dosage and treat often during any dearth / robbing season.


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## Ruggggus (Jun 23, 2019)

I bought VAROMORUS TURBO PROPANE FOGGER OXALIC ACID VAPORIZER and can literally treat on a whim now. I really have no excuse!

Lack of mite fall is an application problem, also, I get my largest fall on the 3rd day, so don't count an hour after treatment.
[/QUOTE]

Agreed, the largest count is the second or third day every time. 

Robin, any knowledgeable estimate at what temperature the vapor is that you are putting into the hive. I assume you are not seeing dead bees and that the long tube cools the vapor to where it is not harmful to the bees but not so cool that it clogs. I see there are many recipes for what to treat with using this device. What have you chosen to use and have you tried other recipes before settling on what you use now?


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## Robbin (May 26, 2013)

Ruggggus said:


> I bought VAROMORUS TURBO PROPANE FOGGER OXALIC ACID VAPORIZER and can literally treat on a whim now. I really have no excuse!
> 
> Lack of mite fall is an application problem, also, I get my largest fall on the 3rd day, so don't count an hour after treatment.


Agreed, the largest count is the second or third day every time.



> Robbin, any knowledgeable estimate at what temperature the vapor is that you are putting into the hive. I assume you are not seeing dead bees and that the long tube cools the vapor to where it is not harmful to the bees but not so cool that it clogs. I see there are many recipes for what to treat with using this device. What have you chosen to use and have you tried other recipes before settling on what you use now?


I have no clue about the temp, just like I didn't when I was using the pan versions. I do set it on the lowest setting where I can still hear the burner (barely) and it produces vapor. If it's shooting droplets, it's not hot enough. I suspect it's possible to get it to hot. This seems to bother the bees more than the pan version. I suspect it's because you are spraying it and bees in direct path can't be happy about it. I hold the wand still, spray once, give them a few seconds the apply more in the same spot. Hopefully allowing bees to get out of the direct path. That said, treating a hive is literally seconds per hive. When treating is this easy, there is no excuse not to.

Mixing is something that I've continued to work on, I've started adding a little FGMO as a carrier. It fogs much better than the alcohol alone. I don't believe FGMO helps at all, I once did some prolonged testing fogging with FGMO. I didn't find that it helped even a little bit. But as a carrier for OA, I think it's going to be great. We are experimenting with just FGMO and OA, but not getting it into solution well, so our current mix is OA and Alcohol, heated and stirred until clear, then adding a FGMO and Soy Lecithin as an Emulsifier. We just started that, My first treatment with that will be next weekend. When I've scrubbed the details I'll put them on here if anyone is interested but it's about the same as a youtube video





I also figured out a better way to use my oil trays as a SHB trap. I started with small floats with honey as bait. But I found using poison for the SHB in the tray with honey in the tray. This is much better than the little traps stuck under the lid or in the entrance. And it lasts a lot longer then the oil in the tray does. Takes longer to set up. I've got oil trays on every hive and every nuc, so it was not expensive for me to do this, I had already invested the money in the oil trays. 

Good luck, hope this helps, I will tell you how mine is going later in the season. We are already at 80 degrees today and our flow is starting.


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## Robbin (May 26, 2013)

I spoke with the manufacturer of the vaporizer or and they said they get the best results with OAV by using 96% isopropyl alcohol. They said to light it and turn the flame down as low as it would go, then allow it to heat up for about two minutes. The goal is to get it hot enough to vaporize but not hot enough to evaporate. I'm going to try several more things, I'll let you know how it goes.


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## johno (Dec 4, 2011)

Robbin said:


> I spoke with the manufacturer of the vaporizer or and they said they get the best results with OAV by using 96% isopropyl alcohol. They said to light it and turn the flame down as low as it would go, then allow it to heat up for about two minutes. The goal is to get it hot enough to vaporize but not hot enough to evaporate. I'm going to try several more things, I'll let you know how it goes.


Robbin what folks really need to see is some pics of mite fall onto the sticky board the next morning after your treatment.


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## Robbin (May 26, 2013)

johno said:


> Robbin what folks really need to see is some pics of mite fall onto the sticky board the next morning after your treatment.


I will consider that. I no longer test or do sticky boards. I spent more time testing and counting dead mites (once I had over 6000 on a single board) than I was treating. But this is a completely new setup. Would be nice to prove it works well, but my problem is now, I have treated. Not sure any test I do now would mean anything. What I could do is treat the way I use to on one of the hives with my old wand method. I still have two of those. If I get a small might count, it should mean the new method is working, if I get a large mite count, it should mean the new method is not working. I've never treated a hive for the first treatment of the year that didn't have several thousand mites fall. So it's not like I don't have a ton of mites in my hives. 
But there is no way to get back to a "clean test" and start with an untreated hive.


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## johno (Dec 4, 2011)

Robbin said:


> I will consider that. I no longer test or do sticky boards. I spent more time testing and counting dead mites (once I had over 6000 on a single board) than I was treating. But this is a completely new setup. Would be nice to prove it works well, but my problem is now, I have treated. Not sure any test I do now would mean anything. What I could do is treat the way I use to on one of the hives with my old wand method. I still have two of those. If I get a small might count, it should mean the new method is working, if I get a large mite count, it should mean the new method is not working. I've never treated a hive for the first treatment of the year that didn't have several thousand mites fall. So it's not like I don't have a ton of mites in my hives.
> But there is no way to get back to a "clean test" and start with an untreated hive.


Robbin once you get to mid summer your hives should have plenty of mites so once you start treating with your new system you should see lots of mites fall if the system works out.


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## Robbin (May 26, 2013)

johno said:


> Robbin once you get to mid summer your hives should have plenty of mites so once you start treating with your new system you should see lots of mites fall if the system works out.


I think that is a plan, When I treat mid summer, I'll treat the two largest hives with the two different treatment styles. Sticky boards on both and we'll see how it goes.


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## jimbo3 (Jun 7, 2015)

Mapleone said:


> I started using OA treatment several years ago and early on it worked well with only a couple of hive loss over the winter. This late Fall I treated all my 16 hives in three stages ( per Provap directions) to kill stages of mites. Hives where all very strong up until February. Weather here in CT turned for the worse and I lost them all. At first I thought it was starvation but after further investigation my alcohol wash mite counts are 13 to 18 per 300 bees Average. Is it possible the OA was bad or expired ( shelf life)? It was Wood Bleach and kept in a sealed container. Any thoughts on what could have caused this? Appreciate any input.


I'm in CT, don't really remember weather turning that bad in February, and I'm in the northwest corner. Nothing out of the ordinary.


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