Worst winter ever

[Hivemaker.]

How about a "mesh sugar shaker" ?

https://www.google.co.uk/search?q=m...tr:countryUK|countryGB&cr=countryUK|countryGB

They would be okay, as long as the mesh hole size is big enough to allow mites to pass through easily.

 

[Amari]

How about a "mesh sugar shaker" ?

https://www.google.co.uk/search?q=m...tr:countryUK|countryGB&cr=countryUK|countryGB

Thanks. The mesh on the models illustrated looks rather too fine

 

[MuswellMetro]

i prefer IBRA scientific method of assessing whether sugar dusting works rather than any anacdotal evidence provided by natural beekeepers

see attached pdf

sugar dusting has its place but only to see thout doing a beltsville test how many phoretic mites your bees have but even then it can kill open brood

 

[Thymallus]

It makes you question the effectiveness of icing sugar in varroa removal as shown in the video. Would you get the same numbers dropped merely by shaking bees without it? Its important because the subsequent calculations on varroa populations in the hive are assuming 100% efficiency of removal with the icing sugar roll.

 

[Thymallus]

see attached pdf

That is the problem with lovely sounding theories they are often brought crashing down to earth by stark ugly facts.

Thanks for posting the pdf of the paper, most enlightening

 

[Dishmop]

I wonder if there is a mistunderstanding here in that the video is testing to see if or what percentage (highly unlikely I think) of varroa are present...
whereas the PDF file is dusting honey bee colonies with
powdered sugar to reduce varroa mite populations

 

[MuswellMetro]

It makes you question the effectiveness of icing sugar in varroa removal as shown in the video. Would you get the same numbers dropped merely by shaking bees without it? Its important because the subsequent calculations on varroa populations in the hive are assuming 100% efficiency of removal with the icing sugar roll.

efficieny is not 100% of phoretic varoa mites , it varies in papers i have seen from 77% to 87% depending on levels of infestation (i.e. higher levels of infestation lower efficiency or apilcation method, i,e. rolling can be as high as 92% )

The underside of a varroa is shaped to act like a suction disc and bees find them very difficult to remove is lidged under their tergites

 

[wessexmario]

correct me if I'm wrong, but the Ellis sugar dusting treatment plan doesn't seem to take any account of the varroa life cycle.

by only dusting every 2 weeks, there would certainly have been many generations of varroa none of which were exposed to the treatment, by being in the brood cells during the treatments.
This too long treatment interval allowed the varroa population to completely recover between each treatment period, as shown by the results.

If the study had been done with a much shorter period treatment regime, it may well have produced very different results.
(or the cynical might say it was designed to fail or succeed, depending on the desired outcome)

 

[Hivemaker.]

I wonder if there is a mistunderstanding here in that the video is testing to see if or what percentage (highly unlikely I think) of varroa are present...
[/B]

There is completely, the test is to see if the mite levels present warrant treating.

The sugar roll test is good, and can be done a second time on the same bees by giving a second dose of sugar to check for any extra mites, the upside for many beekeepers is that it does not involve killing the bees.

The alternative alcohol wash test is much faster and more accurate if using the split container, two, preferably clear containers, with a mesh in between and hole in the top of one container, wash solution is then used to completely fill the bottom jar, and half fill the top one... which the 300 young bees are dumped into and lightly shaken/washed.

 

[mbc]

I think there are so many variables with icing sugar ( humidity and size of dust particles having the most effect) it can only realistically be used to give a very rough measure of, none, not many, some, quite a few, bloody eck!
Still a useful quick guide imho early season before there's any drone brood to sample.

 

[pargyle]

I shall let you figure out the answer to this question you are all expectant about all by yourself, simply by suggesting you look up work by Kate Thompson.

The forum has watched, with interest, Catherine Thompson's PhD work and subsequently published paper .. perhaps you should search the forum for the previous threads on the subject.

But ... to save you a little time I will offer you my, hopefully, grammatically correct view of her work (and she emailed me a copy of her published paper so I have read it !) .. The findings are based on such a small sample of bees, (only 34 accessible feral colonies, all within England, with a random selection of paired, managed hives), that I find it difficult to see how her results could be extrapolated to a statement that suggests, on a national basis, feral bees cannot survive as a result of DWV/Varroa.

The statistics in her paper show only marginal differences between feral colonies, managed colonies treated for varroa and a very small number of managed untreated colonies. They do not support any statement that suggests feral colonies will expire within 2 or 3 years - which some people seem to feel was the nub of the study.

She admits that "However, we can conclude that the sampled feral population contained many of the parasites commonly found in managed populations. Therefore, our study provides no evidence that feral-nests reduce parasite load compared to managed nests. However, our results do not address the consequences of the measured pathogen burden in feral nests, and it remains possible that feral colonies are more able to cope with the observed pathogen load than their managed counterparts." = No **** Sherlock ?

It's a study that is still work in progress as far as I can see .. she hoped to find that feral colonies were genetically closer to AMM than managed colonies and found that both the feral colonies and the managed colonies she investigated were actually, genetically, very similar.

There are few, if any, fully supported hypotheses in Thompson's study.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0105164

One uncharitable reviewer went further " It seems she pretty much took the common beekeeper's lore for granted - 'all ferals are escapees, and they only last a year or two.... people see bees every summer, but they are replacements."..

There was some pretty poor and rather amateurish methodology applied: The 'managed' colonies were selected on a random basis from apiaries that were between 1.4 and 10.7Km of the feral colonies - but no account was taken of the quality of beekeeping management or lack of it. The feral colonies were selected from people who reported 'long established colonies' that 'they knew of' on the assumption that these may be nearer to AMM stock .. although, upon study, the genetics of these proved to be nearer to their managed counterparts - indeed, some managed colonies were nearer to AMM than the feral colonies. No samples were taken from areas where you could expect to find AMM influenced stock.. Wales and Scotland for instance and I feel the study was geared more to what was available to study rather than running true to the originally published scope: Viz:

http://www.google.co.uk/url?sa=t&rc...ii8naB_CNF5Qxq6ciAkY4Zw&bvm=bv.89381419,d.d2s

So .. quoting Kate Thompson as a point of reference does not really cut it as far as I am concerned. Sorry ..

 

[Hivemaker.]

The forum has watched, with interest, Catherine Thompson's PhD work

Yet another peer reviewed research paper not worth a damn then.

 

[pargyle]

Yet another peer reviewed research paper not worth a damn then.

I am rapidly coming to that conclusion ... I think the original hypothesis was worthy of exploration but I think the difficulty of finding and assessing legitimate samples left her in the position of many PhD students .. looking for an answer and a paper where, perhaps, there is no answer in the research. However, the nature of a PhD is to expound and prove a hypothesis ... so a thesis has to be produced.

 

[Finman]

However, the nature of a PhD is to expound and prove a hypothesis .

When you make an biological research, the purpose is not prove a hypotesis. It is better to say, that in feral hive research there are simple questions, does Britain has any more feral bee stock and does it stand varroa.

It has been found many times that there are feral bee stocks in the world, which continue their living with varroa, even if they are not varroa resistant.

 

[jenkinsbrynmair]

quoting Kate Thompson as a point of reference does not really cut it as far as I am concerned. Sorry ..

Flawed from start to finish as far as I'm concerned - a bit like the childish hinting and not saying anything of worth or substance that has emanated from one poster and filled up the last couple of pages of what could have been a half decent thread

 

[Thymallus]

However, the nature of a PhD is to expound and prove a hypothesis ... so a thesis has to be produced.

Close, but really it's to test a novel idea not necessarily prove it.
The main purpose of the thesis is to demonstrate how you carried out the work and can discuss and also be critical of your work.
The worst possible case scenario is to think you know the answer before you do the research....lots of bums get bitten by that.

 

[jenkinsbrynmair]

The worst possible case scenario is to think you know the answer before you do the research

Which is more or less what she did - selecting only the areas of the country more likely to qualify her theory ranging far and wide and chasing (anecdotal admittedly) evidence a bit further away from varroa 'ground zero' might have resulted in a slightly more credible paper

 

[Thymallus]

I always taught people to examine the data. The premises assumed may be open to debate but the data (if collected correctly) is not. Although there are often several ways of interpreting it.
Her results on DWV are hard to argue against.
You cannot dismiss the whole caboodle because one bit of happens to be thought wrong.

 

[Finman]

I always taught people to examine the data. The premises assumed may be open to debate but .

How many decades? Does varroa have any mystery, what you should reviele out. It is quite simple creature and easy to notice, compared for exeample to nosema.

 

[Thymallus]

Which is more or less what she did - selecting only the areas of the country more likely to qualify her theory ranging far and wide and chasing (anecdotal admittedly) evidence a bit further away from varroa 'ground zero' might have resulted in a slightly more credible paper

What you appear to be saying is that her data backs up her hypothesis in the areas she studied. But your opinion is she would have found different results if she had extended her survey to other regions.
This means, at least in the areas studied she is correct, but her hypothesis may need adjusting if she had used other areas.
Perhaps you could let us know your data and rationale to back up this opinion?