# Survey of Mite Infestation in Drone and Worker Brood in a Treatment Free Colony



## Solomon Parker (Dec 21, 2002)

So I was out working the bees today and I was removing some deep frames from a medium hive. The bees had built comb hanging from the bottom of the frames. It was the only way I had to get a deep nuc into a medium hive last year.

I took the best of the brood comb and tied it into a foundationless frame:
​ 
However, a lot of the comb was drone and so out of curiousity I started pulling out the drone brood and counting and separating them by which ones had mites and which didn't. Then out of more curiosity, I did the same with the last little bit of worker brood there was on a similar piece of comb. 



Here are the results: Of the drone brood, I uncapped 56 drones, finding 15/56 (27%) infested with at least one varroa, and two with two mites for a total of 17 mites. Of the worker brood, I uncapped 73 and found 5 infested with a mite (7%) only one having successfully reproduced, showing multiple mites in the cell, in the typical ages of a mite lifecycle in a honeybee cell (1.4%). I did not find any reproducing mites in the drone cells, but as you can see in the picture above, the drones were all recently capped whereas many of the workers were near emergence.

What does this demonstrate?

First, I have mites. No surprise there, I have been saying that for years.

Second, I have plenty of mites. No tiny insignificant population here. This is not a hive that has demonstrated hygienic traits, yet survives nonetheless. 

Third, the mites obviously prefer the drone brood, infesting at a rate of one in four while worker brood was only infested at a rate of one in fourteen.

Fourth, some hives are capable of handling a substantial mite load without crashing or even showing detrimental effects. This hive is about the fourth strongest in this yard of nine. I used it as my cell builder this year.

Five, if these numbers hold out, mites are not terribly successful at reproducing in worker brood in this hive, only about 1 in 71 worker cells result in mite reproduction.

And for some background data, I measured the cell size of this piece of nearly perfect free form comb and found the cell size to be a consistent 5.2mm. The rest of the comb in the hive is 4.9mm wax or 4.95mm plastic.


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## curios1 (Jul 2, 2012)

interesting !


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## Solomon Parker (Dec 21, 2002)

Bump


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## Robbin (May 26, 2013)

Very Interesting bump!


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## Huntingstoneboy (Feb 10, 2013)

Very Interesting!


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## Robin G Bedard (Mar 2, 2013)

I as well have done the sort of take apart frame and count the mite deal. My results where very near yours and that got me to use drone frames in all my hives. After breeding is over, those same drone frames will head to the freezer when 75% of those cells are capped, and another drone frame will take it's place. In 2 weeks the rotation will take place again. At the end of the summer take a peek at the last frame of drones. Be patience because it will take some tries to find some mites. The best part of the whole deal for me is that those mites are destroyed before they are born and never see my girls


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## beemandan (Dec 5, 2005)

Having made this objective measurement, by next spring you can make an educated assumption. If the colony collapses this winter…you can be pretty sure mites were a factor. If it comes out of winter going gang busters…you can say….this colony is able to handle significant mite loads without noticeable effects.
For the life of me….I cannot understand why anyone is so resistant to collecting this kind of objective data.


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## Solomon Parker (Dec 21, 2002)

I requeened the hive, so there's not much point in keeping track of it yet.


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## Oldtimer (Jul 4, 2010)

Why the requeen? Too many mites so try a different queen?


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## Slow Modem (Oct 6, 2011)

Those are some great pictures. New folks should really look at them. They definately show what mites look like on larvae.


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## sqkcrk (Dec 10, 2005)

Good job Solomon.


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## scallawa (Jul 6, 2013)

Solomon thanks for taking the time to do the test. This was helpful data. I would be curious to see more treatment free beeks doing this test. My last test showed a 6% infection rate and I keep hearing they are going to die if you don't treat.


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## Solomon Parker (Dec 21, 2002)

I often hear the same thing.


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## Oldtimer (Jul 4, 2010)

Why the requeen?


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## mike bispham (May 23, 2009)

beemandan said:


> Having made this objective measurement, by next spring you can make an educated assumption. If the colony collapses this winter…you can be pretty sure mites were a factor. If it comes out of winter going gang busters…you can say….this colony is able to handle significant mite loads without noticeable effects.


Dan,

You'd know what you need to know next spring anyway!



beemandan said:


> For the life of me….I cannot understand why anyone is so resistant to collecting this kind of objective data.


In my case because it would take a lot of time (34 colonies at present) which is better spent doing other things ... because... the result wouldn't cause me to do anything differently.

Without examining them all I wouldn't know which have a higher mite load.

If I did that I'd know some were coping well with a high mite load, and some might be holding down numbers better - but I wouldn't know which is the better thing.

I wouldn't know if this was a freak for this hive - some heavily loaded bees with a high-fecudity strain might have flown in and caused a freak event.

If I took the time to examine all and make comparisoms I wouldn't know which might have been afflicted by such temporary circumstances.

Nothing I could learn would offer any sense of direction.

Letting them alone to build winter stores and winter bees, and letting them use those to build nicely next year and produce a crop... will tell me something. It'll tell me which are the better bees in the current environment - which includes varroa. That will tell me which to graft from. 

There is another drawback: removing a significant part of the drone population from this hive will have the effect of helping it. That will give you false results next year when evaluating the colony. You'll be spoiling your chance getting a true reading of its mite-managing ability.

Mike (UK)


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