# Selecting for high mite infertility rate



## Oldtimer (Jul 4, 2010)

I haven't read the method used at the extension.org website, but over here it is done by many many hours of painstaking work with a pair of tweezers to uncap & pull larvae, and a magnification of from 10 to 30 depending what is best for your eyes.

This picture shows someone in a New Zealand lab examining mite families to see if bees have uncapped cells with a mite then re capped it, she can tell by mite frass and possibly a male mite egg or immature larva and maybe a female left in the cell. You would use exactly the same method to examine the size and fertility of mite families. However you will need a heckuva lot of data from quite a few hives to determine if one hive has mites with greater infertility. Then you need to determine if that is because of the mites, or something to do with the bees. To be honest what you are talking about doing is a massive task. To do it properly would involve a team of several full time people.


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## FlowerPlanter (Aug 3, 2011)

Here's a step by step recipe;

http://www.beesource.com/resources/...ney-bees-from-locally-adapted-stock-a-recipe/

If you have packages you want to get new queens from some where else. IMO your success will be determined by what's in your local area and what your queens will breed with.


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## SRatcliff (Mar 19, 2011)

Thanks OT! Do you think think the test could be accurately done throughout the season(rather than testing lots of colonies at one time)?



FlowerPlanter said:


> Here's a step by step recipe;
> 
> Here's the link I was talking about: http://articles.extension.org/pages/30984/selecting-for-varroa-sensitive-hygiene
> 
> ...


That's a good article, but it seems much less direct than checking for infertility rate. A broad selection like that is not a bad thing though, as there probably many other traits that are beneficial!


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## grozzie2 (Jun 3, 2011)

SRatcliff said:


> We all know of the description of the test at the extension.org website,
> ....
> Any other advice or thoughts are welcome.


I didn't, but, google is my friend. I started reading one of those articles, and it's fascinating. I dont want to derail your thread into something different, but, this article describes the testing, and has some VERY interesting commentary along this line.

http://articles.extension.org/pages/65450/varroa-mite-reproductive-biology

In the section 'Factors Affecting Mite Reproduction', read part C very carefully. This is the paragraph that made me sit up and re-read pieces very carefully.



> Our own study suggests that cells that are too large also reduce mite reproduction (Zhou et al., 2001). In a study trying to determine the mechanisms of why varroa mites do not reproduce on worker brood of A. cerana, we accidentally discovered that in both A. cerana and A. mellifera queens laid worker eggs in drone cells in the fall. We took advantage of this, and compared the reproductive output of mites on two hosts: workers reared in worker-cells (WW) or workers reared in drone-cells (WD). In 2001, both the fertility and fecundity of the two groups were significantly different (Fig. 4). It is not clear why mites would reproduce less on identical hosts that were housed in larger cells. One possibility is that workers reared in drone cells are fed a different diet by nurses (One study showed workers reared in drone cells were heavier and had more ovaries, suggesting a different diet or more nutrition). A second possibility is that workers spin larger cocoons in drone cells, and mites detect the extra space, and this affects their reproduction.


The gist of it, workers reared in drone cells (much larger than worker cells) had mite populations that did not reproduce. 

This really does fly in the face of what we read about typically with regards to cell size and mite populations.


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## AstroBee (Jan 3, 2003)

SRatcliff said:


> Are there any other good descriptions on uncapping brood and counting the mites, or any videos?
> 
> Any other advice or thoughts are welcome.


This link might be helpful: http://www.elgon.es/diary/?p=716


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## SRatcliff (Mar 19, 2011)

AstroBee said:


> This link might be helpful: http://www.elgon.es/diary/?p=716


That's very helpful. Thank you.


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## Oldtimer (Jul 4, 2010)

SRatcliff said:


> Thanks OT! Do you think think the test could be accurately done throughout the season(rather than testing lots of colonies at one time)?


Yes of course. Just, if comparing one colony with another both should be done at the same time to rule out potential seasonal differences.


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## SRatcliff (Mar 19, 2011)

On a related note to AstroBee's link, here is a bit of conversation about it at VSHBreeders: http://vshbreeders.org/forum/showthread.php?tid=192

Adam Finkelstein and and Erik Osterlund(Elgon Blog) make some good posts. I know its almost a few years old and has been posted here before, but I'm surprised more people are doing these tests themselves? Or am I missing another bee breeding forum somewhere?


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