Sugar dusting

[Hivemaker.]

Yes that is what i am talking about, the researches, instructions for doing an accurate sugar roll or alcohol test seem to all state that the bees should be young nurse bees, taken from the brood nest, preferably from a frame of open brood, obviously making sure the queen is not included, but considering the greater effort to do this, compared to just shaking some bees from a honey super, i am wondering why go to the effort, seems they have it all wrong.

 

[B+.]

considering the greater effort to do this, compared to just shaking some bees from a honey super,.

I think consistency and repeatability are the most important considerations. Taking the sample from the super is reliable enough for simple monitoring.

 

[Finman]

.
Mites have been trickled since 1988 with oxalic Sugar syrup. Almost 20 years.
Now you are going to make science from nothing. Why?

Out professional beekeepers use trickling twice a year and they have 4 years old queens. Some have over thousand hives.

I have not noticed that any Queen had died for oxalic trickling.
But I have lost lots of colonies for varroa.

.

.

 

[Hivemaker.]

Taking the sample from the super is reliable enough for simple monitoring.

As accurate as taking a sample from the brood nest to ***** the total % of mite infestation of the entire colony?

 

[B+.]

As accurate as taking a sample from the brood nest to ***** the total % of mite infestation of the entire colony?

Aren't we going around in circles on this? How accurate does it need to be? It changes all the time so we're just putting a stake in the ground (or a cross on a piece of paper) to indicate a point in time. Its an estimate (but not a guess). If you want 100% accuracy you'll have to do far more work than makes sense.
I diligently counted all stages of mite on the sticky insert in the spring using a microscope...only be told by a Dutch breeder I know that he only counts the dark red adult stage. Are our figures comparable? I would say not (but I have yet to argue that point with Prof. Brascamp) and I may have to adapt my methods in future

 

[B+.]

As accurate as taking a sample from the brood nest to ***** the total % of mite infestation of the entire colony?

sorry. I think I miss read what you said and answered the wrong question.

samples and population statistics is a whole branch of mathematics. The important thing is that the sample is representative of the population.

 

[Hivemaker.]

How accurate does it need to be?

Within 2 %, which appears to be quite accurate of samples taken from the brood nest, but no need to use this method now as you state it is just as accurate with a sample taken from a top honey super, which is why i wonder why the eminent varroa/bee researchers recommend, and do, take samples from young nurse bees in the brood nest.

 

[B+.]

Within 2 %, which appears to be quite accurate of samples taken from the brood nest, but no need to use this method now as you state it is just as accurate with a sample taken from a top honey super, which is why i wonder why the eminent varroa/bee researchers recommend, and do, take samples from young nurse bees in the brood nest.

The normal rules that I remember are that 99.7% of all values appear within 3 standard deviations of the mean.
Short of sampling the entire colony (which would be ridiculous) a 30g sample from the super is the recommended approach for monitoring (I typically take 50g). You can certainly be much more invasive if you don't mind killing the colony to prove a point, but, I don't think this is what we're trying to do here.

 

[oliver90owner]

I think you are wrong on a couple points at least. Three standard deviations from the mean will give about a 95% confidence limit. Counting anything other than the 'dark red' stage is flawed in that all underdeveloped mites leaving with the emerging adult bee will perish, so it is not a measure of much, if anything, at all.

How about your definition of adult bee. It seems at variance to mine. I reckon there are young and old adult bees. My definition would mean one of your earlier posts makes the rest of your posts irrelevant!

 

[B+.]

Counting anything other than the 'dark red' stage is flawed in that all underdeveloped mites leaving with the emerging adult bee will perish, so it is not a measure of much, if anything, at all.

How about your definition of adult bee.

I agree. Its flawed from a comparability point of view too. You can't have one tester counting all stages when everyone else is counting only red mites. Its an argument I expect to lose but I wanted to find out how many mites had chewed carapace to try to find out why I was getting so low mite counts even without treatments.
Again...you are right...an adult bee is an imago. They perform different jobs in the hive and eventually become a forager. Occassionally, they can perform a job from earlier in their life when the need arises but usually its a linear process. Younger bees do all the jobs inside the hive and older bees become foragers.

 

[Hivemaker.]

a 30g sample from the super is the recommended approach for monitoring

For testing for the total % of mite infestation, recommended from supers by who?

 

[B+.]

For testing for the total % of mite infestation, recommended from supers by who?

Its not testing the total mite infestation. You'd have to kill the colony and count every mite to do that. Theres a difference between a sample and a population (which I am sure you know). However, the method is described here http://www.researchgate.net/publica...ce_to_Varroa_destructor_in_Europe._Apidologie

 

[Hivemaker.]

Its not testing the total mite infestation.

Thank you, that also seems to rely on spring monitoring of sticky boards.

The sugar roll from the brood nest is testing for the % (percentage) of total infestation, if in a sample of 300 nurse bees from the brood nest, say six mites are found, this corresponds to an infestation rate of approx 4% for the entire colony, no matter what size it is, how does this compare % wise to a sample of bees from the supers.

 

[B+.]

Thank you, that also seems to rely on spring monitoring of sticky boards.

Yes it does. The two estimates are linked. In fact, three are linked if you include pin-killed/freeze killed estimates too.

Did you read 4.1 in the link above?
"The bee sample is taken from honey combs of the uppermost box, since they have a more uniform infestation (repeatability of infestation was 0.85 from honey combs versus 0.63 from samples taken from the hive entrance and 0.74 from the central brood nest)"

 

[Eyeman]

Using samples from the supers to monitor mite levels

Randy Oliver has updated his excellent web site scientific beekeeping. IN the article: Messin’ With Varroa 2014 he did one of his trials and concludes:



Practical application: it may well be that samples of bees taken from the honey supers will work for monitoring mite levels. If you do so, you’d want to adjust for the generally lower infestation rate of those bees—for example, our normal late-season treatment threshold is 6 mites per half-cup alcohol wash, so we’d adjust it down to 5 mites. I’d appreciate it if anyone were willing to help us collect additional data.

Alec

 

[Finman]

Randy Oliver has updated his excellent web site scientific beekeeping. IN the article: Messin’ With Varroa 2014 he did one of his trials and concludes:

Randy Oliver 2014...

European Union Varroa Group made a huge work during years 1998-2006 to make sure how to treat mites with thymol, formic acid and with oxalic acid.

After that many have made their own scince to "create their own methods and studies".

To count mites with 95,5% propability.... Get a life!

.

 

[Cussword]

Soo, to get back to the OP, the results of dusting with icing sugar is not a good indication of your total Varroa count.

Would our experts agree?

C'mon, get over your bickering and answer the original NEWBEE question!!

 

[B+.]

To count mites with 95,5% propability.... Get a life!

All sampling methods are estimates Finman. You know that.
Unless you are going to kill the colony and count mites one-by-one you are always going to be reliant on sampling techniques. We don't want destructive (at the colony level) tests because we'd be no further forward. We have to use sampling.

 

[B+.]

C'mon, get over your bickering and answer the original NEWBEE question!!

We're not bickering. HM would have to delete the last 4 pages if we were! ;-)

The question was answered, complete with reference. Now we're discussing whether sampling techniques are enough or whether we want to kill the bees and have a 100% accurate figure.

 

[Finman]

All sampling methods are estimates Finman. You know that.
Unless you are going to kill the colony and count mites one-by-one you are always going to be reliant on sampling techniques. We don't want destructive (at the colony level) tests because we'd be no further forward. We have to use sampling.

Yes, I have a education of university researcher in biology. I have studied some statistics too. And I can say, that you need only kill mites. No sampling and no counting.

Keep the mites heads down. No matter, are they 100 or 1000.