Unsure What's Going On In This Hive

[blackforest beekeeper]

Sugar shack still kills B?s but only about half of the sample.   

Do the bees die after the fact or something?  Because I hardly ever have more than 1 or 2 dead bees in my rolls.

if you sit with them for a while?...

what was the daily mite-count on the drawer BEFORE the treatment? as You seem to have one, though You might call it diferently.

[The15thMember]

Sugar shack still kills B?s but only about half of the sample.   

Do the bees die after the fact or something?  Because I hardly ever have more than 1 or 2 dead bees in my rolls.

if you sit with them for a while?...

what was the daily mite-count on the drawer BEFORE the treatment? as You seem to have one, though You might call it diferently.

Sorry, blackforest, maybe I'm just having trouble understanding what you mean.  I don't usually count daily mite drop, I count weekly mite drop on my bottom boards.  The week before I put the MAQS in the weekly drop was 70 mites.  The week that the treatment was in was 335 mites.  I'll check the bottom boards in a few days to see what the drop was this week, now that the treatment is essentially over.  Does that answer your question?   

[blackforest beekeeper]

Hi 15th member.
Course You don`t count daily.
Dividing by the number of days in between counts will give the daily count. So there is a common basis.
So it was 10 mites/d. That`s definitely too much, esp. for this time of year, and treatment was needed very urgently. For November around our place 1 mite/day would a treatment be needed.
Now it`s hard to say how many mites are in the colony from that count. Factor would be 300 to 100, depending on breeding asf. in summer you could say: Factor 300, in winter: 100.
so let`s say a factor of 150. Makes 1500 mites in the colony.
You milked out 300 something. Some more for the ones dropped off in flight.
Still mite have 1000 of the critters going in there....
That is too much or calling things very close till being able to dribbel OA in winter.
Of course, this is theory and I sure as heck would like a peek at those brood-combs of Yours.

A veritable natural mite drop can be counted two weeks after the end of treatment with formic acid.

The sugar roll You just made: how many mites in the colony does that add up to?

I said Idon`t count any more. IF I counted, I would treat a lot earlier than the treatment-thresholds suggested.

[blackforest beekeeper]

I would not count on formic acid working well in temperatures in the 50s as You described. if it was very sunny and very dry during the time, maybe....
Formic acid is difficult, the MAQS in Germany are not considered a very good product, as they lack punch.

[The15thMember]

I would not count on formic acid working well in temperatures in the 50s as You described. if it was very sunny and very dry during the time, maybe....
Formic acid is difficult, the MAQS in Germany are not considered a very good product, as they lack punch.

I believe it was in the 60's most days last week, some days were sunny and some days were cloudy.  I'm not recollecting it raining for more than like one day, but I'm not totally sure. 

Hi 15th member.
Course You don`t count daily.
Dividing by the number of days in between counts will give the daily count. So there is a common basis.
So it was 10 mites/d. That`s definitely too much, esp. for this time of year, and treatment was needed very urgently. For November around our place 1 mite/day would a treatment be needed.
Now it`s hard to say how many mites are in the colony from that count. Factor would be 300 to 100, depending on breeding asf. in summer you could say: Factor 300, in winter: 100.
so let`s say a factor of 150. Makes 1500 mites in the colony.
You milked out 300 something. Some more for the ones dropped off in flight.
Still mite have 1000 of the critters going in there....
That is too much or calling things very close till being able to dribbel OA in winter.
Of course, this is theory and I sure as heck would like a peek at those brood-combs of Yours.

A veritable natural mite drop can be counted two weeks after the end of treatment with formic acid.

The sugar roll You just made: how many mites in the colony does that add up to?

I said Idon`t count any more. IF I counted, I would treat a lot earlier than the treatment-thresholds suggested.

Ok, so correct me if I'm wrong, but it seems like in your country you attempt to gauge the number of mites in the colony, whereas here we are more interested in the percentage of mites to bees in the colony.  I'm not sure how to convert between a percentage and a hard number.  Anyone have some baseline data here for how many bees are roughly contained within 1 box, or on 1 frame so we could convert the percentage to a number or vice versa?   

[TheHoneyPump]

This may be helpful and useful.  Actually the whole site there is a good read for anyone like a dry sponge that needs a good soaking.

http://www.dave-cushman.net/bee/beesest.html

...

[blackforest beekeeper]

If You tell me in what kind of climate You keep bees, I could tell You if our numbers would be adequat.

The numbers I put on are for full size colonies. For nucs, usually they are halved - the thresholds, not the Factors!
As the hives have a different number of bees and brood during the course of the year, thresholds change over the course of the year, too.
I guess looking at mites/per bee could result in a good management of mites. It doesn`t matter if you measue a length in inches or mm. It`s all about knowing how to do it.

So tell me: if 10 mites/day natural drop correspond to something between a 1000 mites and 3000 mites in the colony. What would be the percentage You usually gauge the mite-load with?

To go on the system I am most familiar with (I usually don`t think about the number of mites in the colony, I keep on treating with formic acid (sponge towel every 5 or 6 days) or OAV until the fall from treatment lessens significantly). I know that if I have 10 mites/day in July, I`d better to something about it in the pretty near future. The colony might not be at risk yet, but I want a late split and I NEED healthy winter-bees.

Just to do some math: In July, we might have 30000 bees in a standard-colony, just to put out a number. 10 mites/day would be considered juuuuust bearable by me. At that time we`d have factor 300, so there would be 3000 mites or 10% mites/bee.
In December a good-sized colony might still have 10000 bees, maybe a bit more, usually less. A drop of 0,5 mites/day make treatment juuuust necessary. Factor would be 100. So 500 mites to 10000 bees. Thats 5%.
A sound colony is said should not have more thatn 50 mites going into spring. So if the numbers are right (which they are not, they are not a hundred percentage proof, but a guideline), we should have 450 dead mites on the drawer over the course of 2 or 3 weeks after dribbling OA if the bees could not fly during these weeks.

Did I get that right? So....it seems to me, for my location it would be good to distinguish the mite load in percent in the course of the year, too.

And when treating and looking at the drawer after treating, the accumulated dead mites should make a dent in the overall-population, if the treatment was effective. So it is sort of important to know the numbers until one can do the mite-control in sleep.

[blackforest beekeeper]

If You tell me in what kind of climate You keep bees, I could tell You if our numbers would be adequat.

The numbers I put on are for full size colonies. For nucs, usually they are halved - the thresholds, not the Factors!
As the hives have a different number of bees and brood during the course of the year, thresholds change over the course of the year, too.
I guess looking at mites/per bee could result in a good management of mites. It doesn`t matter if you measue a length in inches or mm. It`s all about knowing how to do it.

So tell me: if 10 mites/day natural drop correspond to something between a 1000 mites and 3000 mites in the colony. What would be the percentage You usually gauge the mite-load with?

To go on the system I am most familiar with (I usually don`t think about the number of mites in the colony, I keep on treating with formic acid (sponge towel every 5 or 6 days) or OAV until the fall from treatment lessens significantly). I know that if I have 10 mites/day in July, I`d better to something about it in the pretty near future. The colony might not be at risk yet, but I want a late split and I NEED healthy winter-bees.

Just to do some math: In July, we might have 30000 bees in a standard-colony, just to put out a number. 10 mites/day would be considered juuuuust bearable by me. At that time we`d have factor 300, so there would be 3000 mites or 10% mites/bee.
In December a good-sized colony might still have 10000 bees, maybe a bit more, usually less. A drop of 0,5 mites/day make treatment juuuust necessary. Factor would be 100. So 500 mites to 10000 bees. Thats 5%.
A sound colony is said should not have more thatn 50 mites going into spring. So if the numbers are right (which they are not, they are not a hundred percentage proof, but a guideline), we should have 450 dead mites on the drawer over the course of 2 or 3 weeks after dribbling OA if the bees could not fly during these weeks.

Did I get that right? So....it seems to me, for my location it would be good to distinguish the mite load in percent in the course of the year, too.

And when treating and looking at the drawer after treating, the accumulated dead mites should make a dent in the overall-population, if the treatment was effective. So it is sort of important to know the numbers until one can do the mite-control in sleep.

darn - I correct:
0,5 mites per day in December are 50 mites, of course. So anything above that would be good to dribble on. And with 10000 bees the percentage would be 0.5%. Sorry about that.
The count of 5 mites/day in December should yield 450 dead mites.... sorry.

I just read somewhere: in November, 1 mite/day would be the threshold for treating. So we talk of 100 mites in the colony or 1% mites/bees.

[The15thMember]

This may be helpful and useful.  Actually the whole site there is a good read for anyone like a dry sponge that needs a good soaking.

http://www.dave-cushman.net/bee/beesest.html

...

I end up on Dave Cushman's website all the time, as I am a sponge who can never be soaked enough. 

If You tell me in what kind of climate You keep bees, I could tell You if our numbers would be adequat.

The numbers I put on are for full size colonies. For nucs, usually they are halved - the thresholds, not the Factors!
As the hives have a different number of bees and brood during the course of the year, thresholds change over the course of the year, too.
I guess looking at mites/per bee could result in a good management of mites. It doesn`t matter if you measue a length in inches or mm. It`s all about knowing how to do it.

So tell me: if 10 mites/day natural drop correspond to something between a 1000 mites and 3000 mites in the colony. What would be the percentage You usually gauge the mite-load with?

To go on the system I am most familiar with (I usually don`t think about the number of mites in the colony, I keep on treating with formic acid (sponge towel every 5 or 6 days) or OAV until the fall from treatment lessens significantly). I know that if I have 10 mites/day in July, I`d better to something about it in the pretty near future. The colony might not be at risk yet, but I want a late split and I NEED healthy winter-bees.

Just to do some math: In July, we might have 30000 bees in a standard-colony, just to put out a number. 10 mites/day would be considered juuuuust bearable by me. At that time we`d have factor 300, so there would be 3000 mites or 10% mites/bee.
In December a good-sized colony might still have 10000 bees, maybe a bit more, usually less. A drop of 0,5 mites/day make treatment juuuust necessary. Factor would be 100. So 500 mites to 10000 bees. Thats 5%.
A sound colony is said should not have more thatn 50 mites going into spring. So if the numbers are right (which they are not, they are not a hundred percentage proof, but a guideline), we should have 450 dead mites on the drawer over the course of 2 or 3 weeks after dribbling OA if the bees could not fly during these weeks.

Did I get that right? So....it seems to me, for my location it would be good to distinguish the mite load in percent in the course of the year, too.

And when treating and looking at the drawer after treating, the accumulated dead mites should make a dent in the overall-population, if the treatment was effective. So it is sort of important to know the numbers until one can do the mite-control in sleep.

Okay, this whole conversation is sort of confusing to me for some reason.  So what you are saying is that in order to gauge the success of the treatment, you have to know the population of mites before and after the treatment, so that you can tell how many of the mites the treatment killed.  Isn't the sugar roll giving me that information?  Instead of figuring out the mite/bee ratio for the whole hive (which seems to be essentially what you are doing), I'm just figuring out the mite/bee ratio from the roll, and applying that number to the hive.  Why is knowing the number of mites beneficial?  That's the part I don't understand.  My mite percentage went down from 5% to 1%, so what information is that not telling me?  Or to phrase it another way, what information does your method of calculating mite infestation tell you that mine does not?  Essentially, why is your method better?  Or are you just trying to relate my information to your method of mite tracking, so you can evaluate my situation?           

So tell me: if 10 mites/day natural drop correspond to something between a 1000 mites and 3000 mites in the colony. What would be the percentage You usually gauge the mite-load with?

Sorry, I'm not understanding this question.  Could you possibly rephrase it? 

If You tell me in what kind of climate You keep bees, I could tell You if our numbers would be adequat.

I'm not sure how to answer that question succinctly.  What exactly are you looking for here?  I'm in hardiness zone 6a, but I don't think that's a measurement that is used worldwide.  Um, we are technically considered temperate rainforest.  The hottest it gets is generally the upper 90's in the summer days and the coldest it gets is generally the 30's for winter highs.  Right now it's about 50-70 degrees on any given day, we have some rain, but it's occasional compared to the amount of rain we got this summer, which was ridiculously wet.     

[Van, Arkansas, USA]

BlackForest: First thank for your post.  Second in spring the ratio would be 10% and 30% for 1,000 and 3,000 respectively, assuming you 10,000 total bee population.

Summer, 30,000 bees the ratio is 3.33 and 10%.  So please verify if I understood your math correctly.

All those hives are in serious trouble, unless treated in June, latest July; or drone brood removed as in Beepro natural mite eradication.

Do I understand, my ratios correct???

Thanks Buddy.
Blessings
Van

[Ben Framed]

A Canadian beekeeper just put out a video that you might find interesting about the mite and oxlic acid.

[blackforest beekeeper]

This may be helpful and useful.  Actually the whole site there is a good read for anyone like a dry sponge that needs a good soaking.

http://www.dave-cushman.net/bee/beesest.html

...

I end up on Dave Cushman's website all the time, as I am a sponge who can never be soaked enough. 

If You tell me in what kind of climate You keep bees, I could tell You if our numbers would be adequat.

The numbers I put on are for full size colonies. For nucs, usually they are halved - the thresholds, not the Factors!
As the hives have a different number of bees and brood during the course of the year, thresholds change over the course of the year, too.
I guess looking at mites/per bee could result in a good management of mites. It doesn`t matter if you measue a length in inches or mm. It`s all about knowing how to do it.

So tell me: if 10 mites/day natural drop correspond to something between a 1000 mites and 3000 mites in the colony. What would be the percentage You usually gauge the mite-load with?

To go on the system I am most familiar with (I usually don`t think about the number of mites in the colony, I keep on treating with formic acid (sponge towel every 5 or 6 days) or OAV until the fall from treatment lessens significantly). I know that if I have 10 mites/day in July, I`d better to something about it in the pretty near future. The colony might not be at risk yet, but I want a late split and I NEED healthy winter-bees.

Just to do some math: In July, we might have 30000 bees in a standard-colony, just to put out a number. 10 mites/day would be considered juuuuust bearable by me. At that time we`d have factor 300, so there would be 3000 mites or 10% mites/bee.
In December a good-sized colony might still have 10000 bees, maybe a bit more, usually less. A drop of 0,5 mites/day make treatment juuuust necessary. Factor would be 100. So 500 mites to 10000 bees. Thats 5%.
A sound colony is said should not have more thatn 50 mites going into spring. So if the numbers are right (which they are not, they are not a hundred percentage proof, but a guideline), we should have 450 dead mites on the drawer over the course of 2 or 3 weeks after dribbling OA if the bees could not fly during these weeks.

Did I get that right? So....it seems to me, for my location it would be good to distinguish the mite load in percent in the course of the year, too.

And when treating and looking at the drawer after treating, the accumulated dead mites should make a dent in the overall-population, if the treatment was effective. So it is sort of important to know the numbers until one can do the mite-control in sleep.

Okay, this whole conversation is sort of confusing to me for some reason.  So what you are saying is that in order to gauge the success of the treatment, you have to know the population of mites before and after the treatment, so that you can tell how many of the mites the treatment killed.  Isn't the sugar roll giving me that information?  Instead of figuring out the mite/bee ratio for the whole hive (which seems to be essentially what you are doing), I'm just figuring out the mite/bee ratio from the roll, and applying that number to the hive.  Why is knowing the number of mites beneficial?  That's the part I don't understand.  My mite percentage went down from 5% to 1%, so what information is that not telling me?  Or to phrase it another way, what information does your method of calculating mite infestation tell you that mine does not?  Essentially, why is your method better?  Or are you just trying to relate my information to your method of mite tracking, so you can evaluate my situation?           

So tell me: if 10 mites/day natural drop correspond to something between a 1000 mites and 3000 mites in the colony. What would be the percentage You usually gauge the mite-load with?

Sorry, I'm not understanding this question.  Could you possibly rephrase it? 

If You tell me in what kind of climate You keep bees, I could tell You if our numbers would be adequat.

I'm not sure how to answer that question succinctly.  What exactly are you looking for here?  I'm in hardiness zone 6a, but I don't think that's a measurement that is used worldwide.  Um, we are technically considered temperate rainforest.  The hottest it gets is generally the upper 90's in the summer days and the coldest it gets is generally the 30's for winter highs.  Right now it's about 50-70 degrees on any given day, we have some rain, but it's occasional compared to the amount of rain we got this summer, which was ridiculously wet.   

I try to compare the methods, yes.  And give advice, if needed. I don`t think THP has been using a lot of formic acid up till now?
I told You: it doesn`t matter wether one measures a length by inches or mm. I just need to be able to compare, get the factor between inches and mm so to speak.

The 5% before treatment, I guess I missed that. Good, so treatment worked somehow.

You count the mites on the bottom-board. If  you don`t put that in a percentage-number, what is it gonna tell you? Why do You do it? There must be some way to get from that to the percentage-numbers you speak of?

By the way: I think I calculated something wrong earlier:
I assumed some 30000 bees in July per colony. I guess that was too little. I am not sure about real numbers, as one can read a wide spectrum. I never counted them....
So let?s say 40000 bees and a factor of 250 (300 is probably really high) when 10 mites/day are falling we get a (theoretical) total load of 2500 mites to 40000 bees which would in percent be: 6.25%.

So: When is treatment said to be needed when using sugar roll or alcohol wash and the result in percentage given? For US/CAN I mean. I can look up the numbers for Germany.

One more thing which will make things different: I assume in the US and CAN spring treatments are common. Not so in Germany. They are illegal for reasons of food-safety. So we have to have the mite-problem solved by early fall with a little possibilty of correction in winter; till next occassion after the last honey-flow the following year.

[blackforest beekeeper]

BlackForest: First thank for your post.  Second in spring the ratio would be 10% and 30% for 1,000 and 3,000 respectively, assuming you 10,000 total bee population.

Summer, 30,000 bees the ratio is 3.33 and 10%.  So please verify if I understood your math correctly.

All those hives are in serious trouble, unless treated in June, latest July; or drone brood removed as in Beepro natural mite eradication.

Do I understand, my ratios correct???

Thanks Buddy.
Blessings
Van

uh .... I just corrected one of my calculations. I guess, the ratio I would go for pretty immediate measures in July would be 6.25%. You probably read that already. In most cases I don`t let things get that far. Or: if I find a few like that in my apiary I would think of measures for all in the near future.

Spring: there should be no more than 1% if population was down to 5000. 50 mites over the winter as max is what is told.
In late fall or winter: treat anything above 0.5% when broodless. That corresponds to mite-drops of about 0.5 mites/day for a normal colony, I guess.

I don`t give much on drone-brood-removement. First it`s a lot of work. Second up till now my colonies where fine till last flow anyhow. Third I need the drones for my queens. That`s another topic. Most beeks in G. cut out drone-brood, I think. It is recommended.

You know: These factors corresponding to the natural mite-drop: I am quite unsure how accurate they are. with a "100-300" there is quite some inaccurracy already.
All I can say: I get along with the mite-count on the drawer fine. This sort of gauging is accurate enough. Furthermore when I get a high mite count  I look at the colony real closely. There are many signs for sickness or health. Shiny bees are good, large bees are good, normally stacked feed/honey is good. Dull bees, small bees, crippled bees (very bad!), mites to be seen, caved in cappings of brood-cells, a lot of dark bees is bad.
I know commercial outfits going only by these signs, no counting of mites at all. Takes a lot of experience to do that.
I don`t suggest to do this! Any gauging is being on the safe side.

[blackforest beekeeper]

@15th member:
I just looked up hardiness zone 6a. I lived in that zone for 1 year in northern Ohio. So I get the feel still.

[The15thMember]

I try to compare the methods, yes.  And give advice, if needed. I don`t think THP has been using a lot of formic acid up till now?
I told You: it doesn`t matter wether one measures a length by inches or mm. I just need to be able to compare, get the factor between inches and mm so to speak.

The 5% before treatment, I guess I missed that. Good, so treatment worked somehow.

You count the mites on the bottom-board. If  you don`t put that in a percentage-number, what is it gonna tell you? Why do You do it? There must be some way to get from that to the percentage-numbers you speak of?

By the way: I think I calculated something wrong earlier:
I assumed some 30000 bees in July per colony. I guess that was too little. I am not sure about real numbers, as one can read a wide spectrum. I never counted them....
So let?s say 40000 bees and a factor of 250 (300 is probably really high) when 10 mites/day are falling we get a (theoretical) total load of 2500 mites to 40000 bees which would in percent be: 6.25%.

So: When is treatment said to be needed when using sugar roll or alcohol wash and the result in percentage given? For US/CAN I mean. I can look up the numbers for Germany.

One more thing which will make things different: I assume in the US and CAN spring treatments are common. Not so in Germany. They are illegal for reasons of food-safety. So we have to have the mite-problem solved by early fall with a little possibilty of correction in winter; till next occassion after the last honey-flow the following year.

Okay, now I understand what you are after.  I really only count mites on the bottom board to get a rough gauge on if the population is going up or down and at what rate it's changing.  I learned the hard way this year that that information is not enough, and I will now be doing sugar rolls more frequently than I have in the past.  I'm not using the bottom board count to get to a percentage, only to keep very general tabs on the mite situation week to week.  If I want to really know my mite numbers, like for example, if the number of mites on the bottom board is concerning to me, I'll do a sugar roll.  I'm a first year beekeeper whose mite plan this year failed, so I'm currently putting together a new mite strategy for next year.  Therefore, other than regurgitating some numbers I've seen in passing, I can't say at what number exactly of mites on the bottom board I'd be concerned, at what percentage from a sugar roll I'd treat, or how that all varies by the time of year.  I'm sure I'll learn those things as I head into next spring, but at this point I'm not qualified to answer those questions because I'm just too new of a beekeeper.  Perhaps someone else would care to weigh in and provide some of that information?         

[blackforest beekeeper]

@15thmember:
yes, thank you. Of course. I assumed you had the numbers at hand. my mistake. 

if you do the bottom-board-count: if you get around 10 per day in summer, rings the bell. I hear alarm-clocks at 5 per day. Want those healthy large colonies if possible.
good luck to you and your bees! you`ll be doing fine.

[TheHoneyPump]

My input:

Mites on the bottom board are irrelevant. Mite drop is an indicator but with respect to mite load and management plans it is irrelevant.
Mites on the bees is the data needed. Mites on the bees is only acquired by sampling; sugar shake or alcohol wash.  Multiply sugar shake by 1.3 to improve accuracy to that of alcohol.   The gold standard is the alcohol wash.
Sample size matters.  The bigger the sample the more accurate the results will bee.  The standard is 1/3-1/2 cup which is approximately 300 bees.  Use 1/2 cup, divide the result by 3.  Use 1 cup, divide the result by 6.
Sample location matters. Which bees are sampled.  The bees in the heart of the nest the more accurate the results will bee.
Sample timing matters.  4 times per year minimum.  1) in spring just before brooding.  2) early summer just before supering.  3) end of summer right after removing supers.  4) late fall just before wintering.
What to do with the sample results matters.  Firstly, accept that there will ALWAYS be mites. Be pragmatic, zero is impossible. The standard threshold to treat varies by the beekeeper and economics play a big role in the decision when the number of hives goes up.  The web is full of varying guidelines.  Mine are this:  0 - 2 no treat, 3 - 5 treat by preferred method, over 6 pull out the heavy hitter arsenals.  Time of year matters.  In the fall anything over 3 gets the heavy treatment.
Which treatment plan to use matters.  On low mite load, basic IPM and soft treatments are effective to manage them and keep them in check (spring and summer only). On high mite load infestation, heavy handed hard treatments are necessary to knock them down else you WILL lose the hive AND infect your neighbours.  Be a good neighbour. Know your mite loads and keep them in check.

IMHO
Hope that helps!

[blackforest beekeeper]

My input:

Mites on the bottom board are irrelevant. Mite drop is an indicator but with respect to mite load and management plans it is irrelevant.
Mites on the bees is the data needed. Mites on the bees is only acquired by sampling; sugar shake or alcohol wash.  Multiply sugar shake by 1.3 to improve accuracy to that of alcohol.   The gold standard is the alcohol wash.
Sample size matters.  The bigger the sample the more accurate the results will bee.  The standard is 1/3-1/2 cup which is approximately 300 bees.  Use 1/2 cup, divide the result by 3.  Use 1 cup, divide the result by 6.
Sample location matters. Which bees are sampled.  The bees in the heart of the nest the more accurate the results will bee.
Sample timing matters.  4 times per year minimum.  1) in spring just before brooding.  2) early summer just before supering.  3) end of summer right after removing supers.  4) late fall just before wintering.
What to do with the sample results matters.  Firstly, accept that there will ALWAYS be mites. Be pragmatic, zero is impossible. The standard threshold to treat varies by the beekeeper and economics play a big role in the decision when the number of hives goes up.  The web is full of varying guidelines.  Mine are this:  0 - 2 no treat, 3 - 5 treat by preferred method, over 6 pull out the heavy hitter arsenals.  Time of year matters.  In the fall anything over 3 gets the heavy treatment.
Which treatment plan to use matters.  On low mite load, basic IPM and soft treatments are effective to manage them and keep them in check (spring and summer only). On high mite load infestation, heavy handed hard treatments are necessary to knock them down else you WILL lose the hive AND infect your neighbours.  Be a good neighbour. Know your mite loads and keep them in check.

IMHO
Hope that helps!

those numbers percentages?

[blackforest beekeeper]

I went and looked about practice in middle-Europe. Didn`t cover all of it, of course.
The sugar-roll-method seems to have been invented in the German bee-institute of Kirchhain. At least that is what a couple of sources on the net told me.
Nevertheless it does not play a role in gauging the mite-loads. All countries have official guidelines, varying according to laws and climate. The ones I know use the mite-count on a drawer underneath the screened bottom. This drawer is supposed to be ant-tight and so forth so the dead mites stay where they fell. (mine are not, but it works anyway).
Commercial beeks often only look at a random sample out of all colonies. I have not heard of any one using any "sharper" measuring methods, I mean more accurate ones like alkohol wash or sugar roll.
Every beekeeper I know who is really doing this (and acting accordingly) has close to zero losses. In Germany, about 95% of all bees are kept over a screened bottom. Doesn`t mean all of them are tended well...
So I guess looking at the drawer and the dead mites is allright for Europeans at least....
sharp enough as it cuts.

[TheHoneyPump]

Yes.  Number of mites per 100 bees = percent.   

Example1:
Sugar shake method
1/2 cup bees.  (300+ bees)
18 mites counted
Divide by 3 =
6 mites per 100 bees
Multiply by 1.3, factor for sugar vs alcohol
    6 x 1.3 = 7.8 mites per 100 bees. Call it 8

This example is 8 mp100 = 8 percent.  Infestation and contagion. Attack level. Get out the hard treatment arsenals.


Example2:
Sugar shake
1 cup of bees (600+ bees)
12 mites counted
Divide by 6 =
2 mites per 100 bees
Multiply by 1.3, factor for sugar vs alcohol
    2 x 1.3 = 2.6 mites per 100 bees. Call it 3

This example is 3 mp100 = 3 percent. Control and manage level.  Use whatever IPM, soft treatment, or treatment free method of your preference.