# Mite testing methods



## Ski (Jan 18, 2007)

Collect 300 bees in a jar with a #8 screened lid put in two heaping tablespoons of powdered sugar and shake for 20-30 seconds then shake out the powdered sugar through the screen into a pan or lid of water the sugar dissolves and the mites float.
Here is a link to North Carolina State University with some slides covers sticky board as well as rolls and a wash.

http://www.cals.ncsu.edu/entomology/apiculture/Html files/VarroaSampling.ppt.htm


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## Michael Bush (Aug 2, 2002)

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1115&context=extensionhist


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## Kingfisher Apiaries (Jan 16, 2010)

Thanks all. I think i found what i was looking for in a old ABJ. 

thankx 

mike


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## Ski (Jan 18, 2007)

The link above no longer works.
Here is the new link. But now you have to go to "extension" then "Beekeeping notes" then down to "2.03 for Varroa mites".


http://www.cals.ncsu.edu/entomology/apiculture/


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## Tourist (Feb 25, 2011)

Just for future reference, Lee, Reuter and Spivak have an interesting method outlined in the December 2010 American Bee Journal, page 1151. It doesn't kill the bees and sounds effective, I'll be trying it out this year. (It's the one Ski pointed out)


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## BeeLee (Sep 16, 2010)

Tourist, I'm the Lee part of that, so let me know if you have any questions. Also, if you do end up using the method, let me know how it works for you. I would love to get some practical feedback.


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## Barry (Dec 28, 1999)

The link to the frame is:

http://www.cals.ncsu.edu/entomology/apiculture/Beekeeping_notes.html

Also, I at least give credit to David R. Tarpy for including Adrian Wenner's work on the Dance Language article. Even included him in the references. More than most do.


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## Kingfisher Apiaries (Jan 16, 2010)

Question for beelee- how accurate is the sugar roll? How many mites get stuck in crusted sugar in the jar and mess up the counts? Is there a better way? How accurate is this?-http://www.extension.umn.edu/honeybees/components/pdfs/posters/varroamites_155.pdf

Thanks

Mike
Kingfisher Apiaries


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## BeeLee (Sep 16, 2010)

First: how accurate is the sugar roll?
The guy that developed the method (Macedo) found that the PS dropped 92.9% of the mites in the sample. 
I sampled 72 colonies first with PS, then washed them in alcohol and I found the PS removed about 89% of the mites. This is how it broke down:
72 colonies tested
in 55 samples, I recovered all the mites in PS
in 11 samples, I missed one mite
in 4 samples, I missed 2 mites
in 1 sample I missed 3 mites
in 1 sample I missed 4 mites (I found 3 in the sample). 
I don't know why I missed 4 mites. I find that one disturbing. 
The key to the PS sample is to let it set for a min - apparently the heat generated by the bees helps dislodge the mites, but don't set them in the sun on a hot day since too much heat will make them damp and kill them - then to shake the jar hard. You have to do it hard. Generally when people do this for the first time they don't shake hard enough for fear of hurting the bees, but if you don't shake hard you won't get as many mites as possible. 

How many mites get stuck in crusted sugar in the jar and mess up the counts?
It is a rare occasion I find that. I like to have lots of back-up jars to switch out the really crusty ones. It is getting the bees or sugar damp that really affects the accuracy for the worse. 

Is there a better way?
Alcohol is more accurate, but it kills the bees and I find it more of a pain to process. I've been doing tons of alcohol samples lately since I can do nosema on the same bees, but I miss the days of getting a count in the field. So, I find PS the easiest way. I like sticky boards fine, but the drop can be variable from day-to-day, so you should leave them in there for a week. You also have to go back to the apiary and count the mites on the stickyboard, which I think takes even more time. Ether roll is the worst. It only gets about 70% of the mites. 

How accurate is this?
The statistic gods out there that develop sampling plans for other animals or plants claim that one should aim for a sampling plan with a precision of 0.25 for field use, so that is what I used. Precision is the standard error divided by the mean. Let me think about how to explain exactly what that means in non-stats speak. 

Katie


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## Tourist (Feb 25, 2011)

BeeLee said:


> Tourist, I'm the Lee part of that, so let me know if you have any questions. Also, if you do end up using the method, let me know how it works for you. I would love to get some practical feedback.


Wow, thanks for your input, I will certainly let you know what the outcome is.

I had a heck of a time with the sugar dusting onto a board method - seemed to work okay in the spring, but in the fall it was so variable because the populations were so much larger, often hardly any sugar reached the board, not to mention mites. So I'm looking forward to something that is very practical in the field and less of a hassle than the alcohol wash. The easier it is to do, the more blanket treatments can be avoided.

Thanks!


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## Kingfisher Apiaries (Jan 16, 2010)

Thanks. What about the method that you put the jar with sugar and bees over a pool of water and let them naturally drop? 

mike


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## TWall (May 19, 2010)

Mike,

Precision versus accuracy. A mite count can be very precise, all mites that are removed are counted. But, it may not be an accurate measure of the mite population of the hive. Maybe the sample was taken from a hot pocket of mites? Or, maybe the sample underestimated the mite population.

Without rereading the paper I will ake some generalized comments that may be neither accurate or precise!

IPM sampling protocls are developed to provide a tool to assess pest levels to help decide when, and if, treatment is warrented. The fact that it is a sample means it is only a small glimpse of the total population. If enough samples are taken it gives a person a general idea of what is happening in the total population.

The data provided shows, I believe, that the PS roll gives a good representation of the mite load in a hive. The data also shows there is some variability, which is expected. If you did five samples from the same hive you could get five different numbers. Those numbers could be both precise and accuarate for that sample.

What the researchers have found is that by following this protocol they are confident you can get a accurate estimate of mite populations. The more samples you take the more accurate the estimate. This is true of any sampling procedure. 

Clear as mud now?

Tom


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## Kingfisher Apiaries (Jan 16, 2010)

No, actually very clear. I do not use very many IPM methods, so this is the only way for me to test. No SBB to look at natural drop.

mike


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## BeeLee (Sep 16, 2010)

Sorry for the delayed response. I’ve been swamped. That is a great answer, Tom! What they generally teach is stats class is the dart board analogy. Getting close to the bull’s-eye is accurate and hitting the same spot every time is precise. The precision I was struggling to explain is a statistics definition and what exactly it means. Or, when you get your mite count, how close are you to the colony infestation.

Okay, I assume you are interested in how precise the 300 bee sugar shake for a single colony is and not 300 bees from each of eight colonies for the apiary sampling plan. If I am wrong, let me know. So, I will just talk about the colony level sampling plan. 

We started out with a precision C=0.25 since it is generally accepted for pest management decisions (although, I personally think it should be a bit higher). What this means is your estimate of the mite density with be within 25% of the actual density. But this precision required only sampling 140 bees and we wanted the colony plan to jive with the 300 bee recommendation from the apiary level plan (plus, 300 bees is what other researchers have been recommending in previous years and it just makes everything simpler), so the precision increased. *Key part*: by sampling 300 bees you will either get with in 16% of the mean if the mean is more than 5 mites/100 bees or you will get within +/- 0.8 mites if the mean is less than 5mites/100 bees. 

If this is confusing, let me know and we can talk stats.



Kingfisher Apiaries said:


> Thanks. What about the method that you put the jar with sugar and bees over a pool of water and let them naturally drop?
> 
> mike


I’ve not just let the mites drop into a pool of water before, but my guess would be that you wouldn’t get as many if you shook for two reasons. One, there would be less heat since the bottom would the screen. Two, the shaking really seems to help get them off. Since you can still get mites well into the min of shaking.

Katie


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## Michael Bush (Aug 2, 2002)

>First: how accurate is the sugar roll?
The guy that developed the method (Macedo) found that the PS dropped 92.9% of the mites in the sample.

Paula is definitely not a guy... but those were her results. Further research by Nick Aliano has shown that percent is related to several factors including how crowded the bees are, how hot they get etc.

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1180&context=entomologyfacpub


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## BeeLee (Sep 16, 2010)

Michael Bush said:


> >Paula is definitely not a guy...


I think I combined Nick and Paula's names in my head. Sorry, Paula if you are out there!


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## Michael Bush (Aug 2, 2002)

I'm fortunate enough to have seen both of them present their findings in person. So it's difficult for me to confuse them...


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## BeeLee (Sep 16, 2010)

Michael Bush said:


> I'm fortunate enough to have seen both of them present their findings in person. So it's difficult for me to confuse them...


Do you know if Paula is still in bee research? She really had an impact. I think Nick still is...


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## Kingfisher Apiaries (Jan 16, 2010)

Still kinda clear as mud, tell me in layman's terms. 

What is y'alls threshold for treatment? 5 per 100? 10 per? 

Thanks

mike


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## Michael Bush (Aug 2, 2002)

>Do you know if Paula is still in bee research? She really had an impact. 

I don't know. I don't think she's at UNL anymore.

>I think Nick still is... 

Last I heard Nick was still at the University.


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## muskratcreekhoney (Mar 30, 2010)

I liked this one, lots of pictures and very specific. http://www.michiganbees.org/2010/08/sugar-dusting-your-vorroa-mites/


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## BeeLee (Sep 16, 2010)

Oh, you want to be told what number to treat at. Well, as Dr. Huang said in the MI link, it depends on where you are. It also depends on time of year, how stressed your colonies are, and what kind of beekeepers you are (queen breeder, commercial migratory, hobby). I can’t tell you. I wish I could. The goal of my project was to develop a sampling plan to help people monitor their mite levels before and after treatment to help them find what mite level to treat and if the treatment worked. 

In the MI link, Dr. Huang says the Delaware threshold in fall is 10-12 mites/300 bees – which is about a 7-8% colony infestation (including brood). In a MI fall, he says to treat at 6 mites/300 bees - which is a 4% colony infestation. The Georgia and UK thresholds for stationary apiaries in the fall are (or at least used to be) 15 mites/300 or about a 10% colony infestation. By the way, I found that ½ cup is closer to 400 bees than 300, and ¼ cup is about 200, and just over .4 cups is about to 300 bees.

The precision for my study helps you estimate the mite number per 100 bees within about 0.8 mites in a colony.


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## BeeLee (Sep 16, 2010)

Kingfisher Apiaries said:


> Still kinda clear as mud, tell me in layman's terms.


Is that at least somewhat clearer, Mike? Thanks for bearing with me. I am trying to get better at explaining things. I skipped lots of details which I find I have a hard time doing. 

Katie


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## Kingfisher Apiaries (Jan 16, 2010)

Thanks. That helps. OK say that i am a semi migratory sideline beekeeper with around 20 hives that plans to grow to 50 hives by the end of this year. I move almost every hive at least 1 time a year, most more than that, and some as much as 5 times a year. I also breed queens and sell honey. Most hives are way below what you are saying (2-5 mites for the ENTIRE sample) but some, including a breeder hive, had a bunch, as in like 20 per sample. That hive has been totally treatment free since 2009 (she is still marked). It is beyond me why the have not been killed yet. The ones that were high We (me and my helper) dusted the fool out of. The breeder hive is not being used for any breeding work until they can consistently keep mite levels low. 

Hope you can advise. 

mike


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## BeeLee (Sep 16, 2010)

I wouldn't treat at 2-5 mites either and 20 I would defiantly take some action. 20 mites isn't that strange of a number to have and the colony to still be alive. It would be strange, however, to not do anything if you find that many mites and the colony survive. 20mites/300 bees is about a 13% infestation if there is brood, so it is just above some of the other thresholds.

If the breeder with 20 mites has been around since 2009 without any interference and your goal is to breed mite resistant stock, then I wouldn't hesitate to use her again as a breeder. A multiple year test like that is a great way to tell resistance and 20 mites after that long of a time isn't bad at all. The mite population was bound to grow, but the queen's genes are the same and if her bees were able to keep them at bay for that long that is a sign of resistance. If she is the only one that has that history, then I would use her. 

Katie


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## Kingfisher Apiaries (Jan 16, 2010)

Well, The ones that were high were that breeder and some previously feral ones that I will shake nucs out of. They may have a high level now, but after this afternoon they will get more than they bargained for, going to shake nucs out of em. I find a practical use for everything
The breeder queen from 2009 that has the high levels I plan on grafting from. I will not sell from her just use them in my operation. Sound OK? 

Mike


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## BeeLee (Sep 16, 2010)

Of course that sounds okay! Do whatever you think is best. I totally understand not wanting to sell her progeny and to see what her daughters are like in your own colonies. My point was that if you have never had a colony go for that long untreated, then you may want to consider keeping those genes around. 

Good luck with the queen season!

Katie


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## Kingfisher Apiaries (Jan 16, 2010)

Well now I have people begging for their nucs to be headed up by one of her daughters, oh well LOL
Mike


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## FarmerFrazier (Oct 12, 2010)

I didn't beg! But I would have if need be


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## Kingfisher Apiaries (Jan 16, 2010)

No, not you others.....

mike


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## Tourist (Feb 25, 2011)

Okay, so I'm back to report on Katie's sugar shake method.

I had planned on using it in the spring, but I just ended up not having enough time and did a blanket treatment of formic. It set them back, but I ended up having a good season anyways. Bees peaked at the right time and all that.

So I chose to do the sugar shake a couple of weeks ago at the end of August. I found the method worked quite well from a sort of mechanical perspective. There were two of us - one getting frames ready to sample from while the other did the shaking. Interestingly enough, we didn't have much for problems we thought might arise. The mites didn't get hung up in the sugar in the jars and the bees were easily rolled over backwards off the frame. 

We ended up sampling every hive (250+) and roughly 30 of the nucs. I was pleased to see that in hive where there was noticeable varroa - ie. hitchhiking on bees, in drone larvae, etc) we also got high counts. Surprisingly, some of the duds that were queenless and without any capped brood didn't have high varroa counts. I would have expected those to be higher, but they weren't. The nucs had, across the board, lower counts, but this is to be expected with the break in their brood cycle in early June. I have hives in fourpacks, and found that often two hives that were side by side would both have high counts (in the 20s or so)... those **** opportunistic mites. One hive was also worth noting. It got the highest count in the operation: 60. I came back 5 days later to put in strips and the colony had already collapsed. Unfortunately all that varroa was spread to it's neighbours. I guess the moral would be to isolate high counts in faraway apiaries if you are able to check every hive.

I chose to put strips in anything with a count higher than 15. Anything with a count from 3-15 will get oxalic in November and anything with less than 2 mites I will possibly leave until spring treatment. But I'm not sure, I might get worried and just oxalic everything that didn't have Apivar. It's going to be really interesting to have these figures for the spring and see which colonies survive. This is an excellent way of narrowing down what is killing bees over the winter - I'll know what's got high counts and see if deaths correlate with digits after I unwrap.

I actually found all of this to be quite satisfying work, but I imagine if I had higher mite counts it would be much less fun.

Dan


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