Interpreting mite counts during treatment

[Toni Bee]

Hi all --

I'm treating a midwinter mite problem with evaporated oxalic acid, and wonder if anyone could help interpret the mite drops that are now happening.

Before treatment, the 2 colonies dropped 43 and 19 mites a day (from a 3 day count). Now, after two treatments, the counts are 203 and 379 (over 4 days). This makes some sense: if the treatments work, mites should drop, right? There's brood and lots of bees in both boxes, btw.

When should the mite count start to drop, though, and when would high numbers mean that treatment isn't working?

My plan is to treat a final time today, take another mite count next week, and again the week after. Does anyone have any expectations or recommendations to share?

Thanks again,

Toni

[Michael Bush]

The oxalic keeps killing mites for about a week. Higher numbers after treating than before are good eveidence it's working. The counts should drop off after about a week. But if there is brood you might want to treat again in a week to catch the ones emerging.

[DANIEL QUINCE]

Tony,where did you buy the oxalic acid? Could you also give me the part #/description?
Thanks
Daniel

[Toni Bee]

Hi there Daniel --

DAP makes a product that is in many hardware stores: http://www.dap.com/product_details.aspx?product_id=324

The "Rainbow Wood Bleach" that I used came from a local paint supply store: you can just walk in and ask a clerk to point you to some wood bleach! It seems like most vendors do not want to ship oxalic acid, because it is a corrosive, so it's hard to find online. I bet a local paint or hardware store has it though.

The "Rainbow" product cost me $5.88 for a pound, and I use something like a heaping teaspoon for each dose (the dosing info I found was pretty variable, but the Canadian government instructs beekeepers to use 2 g for the vapourizer method -- http://www.honeycouncil.ca/users/folder.asp?FolderID=3254 scroll down the page to see).

The instructions for making the evaporator tool came from bwrangler at http://bwrangler.atspace.com/bee/goxa.htm and you can see what I have been doing via the link below. But I am no expert, just trying to learn myself.

[DANIEL QUINCE]

Thank you Toni. I keep learning about all these acids and/or oil and I noticed that most of the info, or at least the ones I found, do not explain HOW exactly does the acid or whatever kills the parasite. That will help me immensely in picking up a certain application style, as well as making a decision as of which substance/treatment to adopt. I guess all the beginners felt the same.

[peggjam]

Toni

Sounds like you had quite a mite load to begin with, MB's suggestion of another treatment is sound advice, and I would recommand a follow up treatment to that one, as more mites will hatch out with each batch of brood.

[Toni Bee]

You know, it has been hard to find out what the "mode of action" of the oxalic is -- how it actually kills the mites -- and I have been concerned that it might be "burning" the mites' shells. That kind of thing might not affect the bees in a few treatments, but might it get to them after 4-5? Any info on this is welcome.

[Michael Bush]

I've done two treatments before and did not notice any impact on the bees. I have not done more so I can't say after that. But Axtman is always recommending three a week a apart when there is brood present.

[drobbins]

it's been so warm here the bees never stoped raising brood
I gave em 3 treatments a week apart in december
no apparent problems and they're fat and happy today smile.gif
killed a couple hundred mites the first 2 treatments and only 20 or so the third
my mite counts were lower than yours to begin with
about 10/day

Dave

[George Fergusson]

I've vaporized 3 times on a number of hives and 4 on a few, one week apart. I did not notice any deleterious effect on the bees. Of course, some of the hives are dead now smile.gif I attribute that to treating when there was brood in the hive- even 3 treatments a week apart is less effective than I would like. For some of the hives, the damage had already been done.

We- at least I- don't really know why OA kills mites. There has been speculation.

[Hayseed]

"where did you buy the oxalic acid? Could you also give me the part #/description?"

I recently purchased a 2 pound container for $3.50 from:

http://www.marblekareproducts.com/PRODUCTS/POLISHING_COMPOUNDS/OXALIC_ACID.asp

Dale

[sqkcrk]

George, Seems to me that you treated too late and too much. When did you treat these colonies?

[drobbins]

another source for OA

http://www.chemistrystore.com/oxalic_acid.htm

since this is the 101 forum it's important to mention that the fumes from this stuff are nasty bad
don't breath the stuff or you'll be sorry

Dave

[George Fergusson]

>George, Seems to me that you treated too late and too much. When did you treat these colonies?

Beginning of August. The ones that have died were already showing signs of PMS- deformed wing virus, etc. They were dropping 70-90 mites a day by that time. It was too late. I doubt it was too much. The few that I did 4 times was because the first treatment I deemed ineffective due to operator error.

I also requeened a bunch and combined some. Those that I spent the most time (and money) on are still doing OK, but then, it's early. I was chatting with Tony J. the other day and he reminded me to not count my deadouts before the end of April smile.gif

I subsequently dribbled OA in early November on those colonies that were still showing significant mites drops.

Is it any wonder I want to try drone comb trapping this year?

[Michael Bush]

>don't breath the stuff or you'll be sorry

Instantly. Keep a smoker burning so you can keep track of the wind.

[sqkcrk]

Mike Palmer, of VT, treats his colonies with OA fumigation after they are wrapped. Even so, he is very consious of the wind direction. With this method of treatment and the raising of his own queens, he seems to have a very good handle on his beekeeping. His hives averaged over 200 lbs in honey production this past year. He is a stationery beekeeper.

[Jim Fischer]

Waiting until treatment to do your counts is
exactly like only looking at your gas gage
after you've run out of gas.

The point here is to monitor mite counts
at regular intervals to get an idea of
where the mite population is headed before
one makes a decision to treat. Sure, treatments
are going to make your mite counts spike all
over the place, and you should expect this,
and "ignore" those readings as being anything
but "natural mite drop counts".

The trick is to see a "natural mite drop"
stabilize at a much lower level some weeks
after treatment. Then you know that you
"did some good", at least knocking back the
mite population so that they are back on
the "linear" part of the population curve,
rather than up in the "exponential" part of
the population curve.

[Michael Bush]

>at least knocking back the
mite population so that they are back on
the "linear" part of the population curve,
rather than up in the "exponential" part of
the population curve.

And during brood rearing that's about all you can hope for. smile.gif

Of course the other reason to monitor before, during, and some time after a treatment is to see if the treatment was effective. It SHOULD go up during the treatment period. If there is no real change then it's probably not working.

[DANIEL QUINCE]

I run into a statement some ware saying that some of these treatments actually irritate the bees and will increase grooming activities resulting in more mite drops. Does the OA fall into this category?

[Michael Bush]

OA seems to kill the mites. I'm sure it also increases grooming, but the mites seem to die from it. I don't know the exact mechanism but one theory is that the acid corrodes the mouth parts of the mites.

[Toni Bee]

Hey there --

A friend of mine who reads Italian looked at a recent study from that country which seems to identify dessication as the method by which OA works. I'll try to find a citation...

[DANIEL QUINCE]

If that's desiccation (loss of water), it may be related with what Michael stated above, since I assume the only source of fluids for the mite is through the mouth. I also assume that if this is the case, it will take a No. of days before they die since they look pretty puffed up to me. I've never touched one. Do they have any body shield/skin or something like that? Do you have the source of info? I speak French and Romanian, and Italian is in between the two. I can give it a try.

[Toni Bee]

Hey Daniel, my friend checked and she said the study was about the dripping method, and it was a "perhaps" kind of thing. I have emailed some folks at USDA to see if they can tell me anything. On my own I found a study from 2001 that calls the mechanism "poorly understood" and which says that oxalic acid was more used (and studied) in Eastern Europe and the former USSR.

On the anecdotal side, it seems that my mite counts are dropping fast now, with 3 treatments behind us. New sticky boards are going in today for a proper count though.

[DANIEL QUINCE]

I've seen the "macaroni" system that you've got Toni. Ingenious. Over 1500 mites was kind of scary, so after seeing that I set some boards in my hives and I can't wait to get home today and see what the results are. I'm going to research the oxalic acid issue next week when I'll be in Romania. I've heard they are using "strange" things (to me anyway) that not too many of them can explain. Some inherited old treatments I guess.

[DANIEL QUINCE]

I found 8 and respectively 9 mites in the two hives. This is over a 22 hour period. Yesterday we had 40 deg. and today were around 34 all day. Does the outside temp. have any influence on mite drops? Also, from one of the hives I pulled out 4-5 dead bees stuck together with something like a cocoon web. I don’t have SBB on my hives yet, so the sticky board was on top of the bottom board. I’ll appreciate your comments.
Thank you
Daniel

[Toni Bee]

You know, I don't think anyone should consider my experience any kind of example. I got an email back from USDA, they said that the OA vaporizer treatment was ineffective and bad for the bees, so now I am just plain scared.

Your mite counts don't sound bad to me, but others here know more. Much more. But I have been told to leave boards in over at least 3 days, count, and divide, because different conditions can affect counts, perhaps -- as you mention -- temperature or others.

I am going to continue taking counts, and if the mite population ticks up again before the temperatures will allow me to use ApiLife Var, I guess that I will ahve to break out the CheckMite strips, something I really did not want to do.

[George Fergusson]

>because different conditions can affect counts, perhaps -- as you mention -- temperature or others.

The single biggest factor affecting drop counts is the amount of brood rearing going on. If they're not breeding, they're not dropping, the more they're breeding, the more they drop. Other conditions can affect drop counts too but they're not big factors- temperature and perhaps humidity, grooming (what factors affect that?), etc.

The phoretic period of mites is relatively safe time for them. Mite mortality while hanging on bees is very low. This is why 10 mites a day in the summer is nothing to worry about, but 10 mites a day in mid-winter with no brood in the hive IS something to worry about.

>they said that the OA vaporizer treatment was ineffective and bad for the bees, so now I am just plain scared.

Don't panic. Lot of people have vaporized OA in their hives. Share with us who said what.

[Jim Fischer]

> they said that the OA vaporizer treatment
> was ineffective and bad for the bees

Yeah, I'd also like to hear exactly who said
this, as I honestly don't think that "ineffective"
is a fair way to describe the results of the
studies published to date.

[Toni Bee]

I sent a message to Diane Sammataro, to whom I feel indebted for responding promptly and with concern. If I misinterpreted her advice, please make sure I get the blame, not her. Here is what she said:

I am a little concerned that you are vaporizing Oxalic, as it does not work very well, is very hard on the bees and even harder on people. Breathing in fumes or having contact (skin) can have long term detrimental effects on you. We tried a trial with Apilife Var which gave excellent results, and the trickle method for Oxalic. This has been used in Europe to good effect, in 1-3 treatments in sugar syrup.
The mode of action appear to be the low pH (acidic) qualities that cause mites to fall off and die. But it is not clearly understood as yet.
Please be very careful with OA. I am not sure where you are located, but Eric Mussen out of California has some good info on it on his web site out of the UC Davis campus. He is the CA state bee extension person and very knowledgeable.
Good luck.
Diana

[George Fergusson]

I certainly have a lot of respect for Ms. Sammataro, but I'm not sure how to interpret her statement that it "is very hard on the bees" in light of her real apparent concern, from subsequent comments, that it is "even harder on people". I wouldn't be jumping to any conclusions about the USDA's formal stance on this subject based upon what is written above.

Somewhere I remember reading about someone, and it might have been her, stating that evaporation wasn't effective because the actual amount of OA deposited in the hive was typically too small and was hard to control- in other words, it wasn't so much ineffective as it was hard to do right. I don't recall there being any mention of it being hard on the bees. I have heard of dribbling being hard on the bees.

I searched Google Scholar and came up with a citation for a 2000 paper by Ms. Sammataro discussing this. Google quoted this scintillating snippet:

... ineffective because an insufficient amount of vapor is released ... a US bee supplier
to produce formic acid gel packs ...

Unfortunately, the link takes me to an abstract which doesn't mention OA let alone vapor, and I'm not allowed access to the full text of the paper. Apparently, Google can search documents I'm not privy to. I'll try not to get annoyed that my tax dollars are being spent on research relevant to my work that I'm not allowed to see without crossing someone's palm with silver. Perhaps I'll write Ms. Sammataro and ask her for a copy smile.gif

Anyways, the picture that begins to form in my mind is a) The USDA folks feel the problem with oxalic acid vapor is in the delivery mechanism and b) The USDA for some reason is more interested in promoting the use of formic acid.

I'm interested to read what Jim has to say about this. I seem to associate him with some of the discussions on this subject that I remember. It sure would be nice to have Dianne Sammataro talk with us about this smile.gif

[Michael Bush]

>I am a little concerned that you are vaporizing Oxalic, as it does not work very well

In my experience it works VERY well.

> is very hard on the bees

I have not noticed any harm to the bees.

> and even harder on people.

Only if you breath it. smile.gif

>having contact (skin) can have long term detrimental effects on you.

Funny how many cleaning products have Oxalic in them. smile.gif

[Toni Bee]

http://www.mellifera.de/engl2.htm

Thought I would share this study with you. Not sure it cuts the mustard as a total scientific tour de force, but it represents the best efforts of a group of beekeepers with over 1,500 hives to look at the effectiveness and downside of oxalic vaporization.

In case it matters, I decided that three spaced treatments of my brood-rearing colonies was enough for now, and mite counts over 5 weeks are called for. My goal is not a silver bullet, but to get them into weather warm enough for a spring application of ApiLife Var. Of course, events in the apiary will determine what really happens, as I won't sit back and let them die.

[ February 17, 2006, 11:56 AM: Message edited by: Toni Bee ]

[Aspera]

I have no experience using oxalic. Diane Sammatero does raise some very important points about its safety. I noticed in the study cited by Toni, that the researchers were exceptionally cautious about OA's handling when vaporized. This is a good example for us to follow. Personally, I believe that the benefits of vaporizing OA do not outweight safety concerns. Pyrethrins have many decades of toxicity studies behind them and are commonly fould in human and animal approved topical medications. Despite this, I wouldn't dream of administering pyrethrins as a vapor, and I'm not going to try it with OA either. I respect all of you out there "on the cutting edge" of mite treatment, but worry that OA is being treated like its a "safe" substance. There are very few if any safe substances, and OA is a known kidney toxin.

[drobbins]

I would also like to point out to Toni that this picture from her website

http://citybees.blogspot.com/2006_01_01_citybees_archive.html

shows a picture of a dust mask
this will give little if any protection from OA vapors
I've used vaporized OA, I feel comfortable with it, but it's nasty stuff and you need to be carefull
at a minimum have a stiff breeze and make sure you're upwind
I bought an electric vaporizer so I can stand 30 - 40 feet away
a proper mask is ~ $30 at the hardware store
I'm not sure it's correct to call it a kidney toxin
it causes calcium to precipitate out of your blood and cause kidney stones
but that's just semantics
I don't want kidney stones
nobody wants kidney stones
it needs to be handled with care

oh, did I mention
"it kills the heck out of mites" smile.gif

Dave

[ February 17, 2006, 07:51 PM: Message edited by: drobbins ]

[Axtmann]

ToniBee

......I got an email back from USDA, they said that the OA vaporizer treatment was ineffective and bad for the bees, so now I am just plain scared.

Did they tell WHY?

There are many possibilities:

1. They have never used it or tested it the RIGHT WAY.
2. They used a pipe evaporator with to much acid and overheated the acid.
3. They told you this because it is not a registered treatment in your country
4. They might be sponsored from a company to support a registered product??
5. Maybe they like to go there one way without using the results from other countries and have no idea how to handle the situation.


As soon as you heat up OA with a propane torch to fast and to high… there is trouble. You can go in a few seconds over 1000º and this splits OA in carbon monoxide and carbon dioxide, in a high dosage can be deadly to bees.


Don’t be scared… Do you think scientists round the world are stupid?? OA is a registered Varroa treatment in many countries.
Ask your neighbors the Kanadiens, do you think they are stupid.

IMO it is one of the best treatments to get rid of the Varroa.

[George Fergusson]

There is another very good paper on that german site about Vaporisation of oxalic acid and working safety:

http://www.mellifera.de/Engli2.pdf

I've looked at both pages some time ago. They're both very good.

George-