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Drone comb loaded with mites

26K views 77 replies 23 participants last post by  BeekeepingIsGood 
#1 ·
I checked my back yard top bar hive which was started with a feral swarm. It seems to be doing well, though it has stopped expanding after filling about two thirds of its four foot length. I have harvested about a bar of honey over each of the last two months, and added a bar to the brood nest 4 times. Yesterday I pulled a heavy bar of capped honey--the bottom third was drone comb. I was a little surprised to find 2-4 mites on each of the drone larvae.

I haven't done an alcohol wash. Does the count in drone brood correlate with a dangerous level of varroa indicating need for treatment? How effective is drone comb culling in controlling mites?
 
#2 ·
I think it is high. Worker cells will be lower rate of infestation than the drone cells, but in my climate with cool spring I think that load of mites would really slow down buildup. Here is a pic of some drone comb I culled in August. Did not find any visible mites. The culling was mostly to check the effectiveness of the OA vaporization I did in April.
 

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#5 ·
If 25% of drone larvae have a mite in them, at that level it is likely that 6% of worker brood will have mites in them.

But you have to sample around 100 drone cells because the mites can "cluster" in one small area of comb and give a wrong reading in a small sample.

The 25% drone brood infestation is considered a critical level for the hive, the level at which many textbooks recommend the hive is treated. For you though, it is a simple matter to remove the drone brood thereby removing a good portion of the mites. As above, the comb can be discarded, or frozen then returned to the hive.

Just to complicate things :eek:, there is a body of thought in the treatment free community, that mite levels should be left to run their course in the hope that maybe the hive will throw off the mites. However if this is your only hive & you want to play safe you would treat it or at the very least remove drone brood and continue to monitor.
 
#7 ·
I have frozen complete deep frames of drone and returned it to the hive. It was a bad experience since the bees seem to dump most of the carcasses within a few feet of the entrance. That amounts to 4 or 5 pounds of stinking mess that attracts flies, ants, hornets etc. Even covering it with ashes the smell lingered for a long while.

You can uncap and blow the larvae out with air hose or a water hose sharp spray nozzle but that is a bit of a mess too, including your glasses. I tried a few foundationless frames and they get drawn out quickly and you can just cut the whole slab out leaving a fringe on the top bar and throw it back in immediately. My chickens enjoy cleaning the comb for me!
 
#8 ·
My fish pond took care of the drone larvae--no chickens. Are bees the gateway drug for chickens or vise versa?

The section I removed was the only drone comb I saw and there had to be at least 300 mites in that section of about 150 cells with an estimated 90% infestation rate. Guess that means treatment, but I'll try my first alcohol wash tomorrow to confirm.

Thanks for the responses.
 
#9 ·
>I was a little surprised to find 2-4 mites on each of the drone larvae.

That is high.

>I haven't done an alcohol wash.

A sugar shake won't kill the poor bees...

>Does the count in drone brood correlate with a dangerous level of varroa indicating need for treatment?

It is a high level of mites.

> How effective is drone comb culling in controlling mites?

You would remove the mites that prefer drones... which would select for mites that prefer workers...
 
#12 ·
Jfb58, if you do go the treatment route, might I recommend Apivar (not Api-Life-Var, a different product). This is because there are many pitfalls treating hives especially in a TBH. Some treatments such as thymol based ones or organic acid ones are virtually impossible to do effectively in a TBH.
Apivar is pretty fullproof, you just hang the strips between the combs, 2 or 3 strips would do for an average TBH, and you leave them there 8 to 10 weeks. Over that time they leach a chemical that kills the mites. Doesn't get the ones in brood cells so an 8 week time period is to catch 2 drone brood cycles just incase some mites didn't get caught first time around.
The active ingredient is called Amitraz, it is an artificial chemical, however it has a very short 1/2 life, ie, once it is out of the strip and among the bees it is chemically unstable and breaks down in a few days so does not remain in the hive for years like some other chemicals do.
With your high mite count, the hive may already be in more trouble than you realise, with possibly all the worker brood affected as well, and sometimes it can be too late to save such a hive even if all mites are removed because they cannot get a cycle of healthy brood through. So if you do decide to treat, do it soon as.
 
#13 ·
>Then the remaining mites....those that prefer worker brood.....would have a much lower reproductive success rate and the mite loads would grow much more slowly.
I like it.

But Apis cerana has the opposite arrangement and survive Varroa quite well. The Varroa only prefer the drones and the workers are not damaged. I think you already have the problem that they don't perfer the drones enough and that's why your workers are damaged. Less mites does not necessarily mean less damage as the cerana have shown us.
 
#14 ·
I did a count, had 7 mites on 203 nurse bees, 3.5%. These are locally adapted survivors from a swarm trap collected 6 months ago: not too bad to work with, but they were plenty p-o'ed when I brushed off a brood comb. This isn't my only hive, and no monetary risk, seems like a good opportunity to watch and see what happens. Mr. Bush, I look forward to meeting you in Arizona next month, hope you are still coming!
 
#17 ·
http://hal.archives-ouvertes.fr/docs/00/89/07/44/PDF/hal-00890744.pdf

That does seem to be the common view, but in this study they said they COULD reproduce contrary to what had been thought. Of 720 worker cells, 3 cells were infested with Varroa. of 132 drone cells 18 were infested. That is a ratio on workers of 0.0041666666666667 and a ration on drones of 0.1363636363636364 or a 32 times preference for drones... I would say they prefer drones and it looks like that is the reason they can tolerate them.
 
#20 ·
this study they said they COULD reproduce contrary to what had been thought. Of 720 worker cells, 3 cells were infested with Varroa.
Three worker cells containing a foundress mite hardly indicates that they can successfully reproduce in them.
You implied in an earlier post that culling drone cells would put selection pressure on those who reproduced in worker cells. The purpose of my initial response was to point out the silliness of such a 'hypothesis'. Getting bogged down in an equally ridiculous debate is a waste of both my time and yours.
 
#21 ·
>The mites prefer drones, and a new natural method of control is to introduce foundation sized for drones, and then remove and destroy it, therby lowering the colony mite population. Try it on purpose, you seem to have the perfect hive to experiment with. Good luck!

This is a top bar hive, so I don't know how to induce drone formation. Might try a piece of plastic "drone foundation" wedged onto a top bar.

>Let's know either way in due course jfb58, I'd be interested to see if they can throw off an infection that bad.

Me too!! The people on this forum who have reported success in snatching the brass ring of treatment free bees often seem to have done so with hot climate, swarm prone colonies. I have been happy so far in the productivity without feeding or chemicals, and they don't seem too mean to me. The mite load was a sobering, wish I would have checked for mites before:eek:
 
#22 ·
>Three worker cells containing a foundress mite hardly indicates that they can successfully reproduce in them.

Not really my point, but it was a conclusion of the study. My point is they prefer the drones by a very wide margin in cerana and that is why they don't have problems with Varroa.

>You implied in an earlier post that culling drone cells would put selection pressure on those who reproduced in worker cells.

How can it not?

>The purpose of my initial response was to point out the silliness of such a 'hypothesis'.

How much of an effect it is over what period of time, remains to be seen, but I think it's obvious that it would select for mites that perfer workers if you keep removing mites that prefer drones.

If I had the time to do all those uncapped mite counts I would be curious what the proportions are in large cell compared to small cell. A stronger preference for drones is likely part of why small cell works.
 
#23 ·
Can you see commercial beekeepers going around their hives fortnightly and culling all the drone comb? Can you even see many hobbyists doing it? Since better than 99% of hives are commercial, and of the remaining less than 1% hobby hives just a tiny proportion would have serious methodical drone culling, I cannot believe drone culling is done to anything like sufficient extent to have an effect on Mite evolution. Not even a thousand years from now.
There is no harm at all in this hobbyist doing it on one TBH, culling drones is not evil, and his actions will not bring about the destruction of world beekeeping.
Just the time waste and difficulty of this procedure will ensure it will never be used to an extent big enough to outweigh other evolutionary pressures.

re the Amitraz in honey issue, no you cannot (according to the label) have honey supers on when using it. It's academic now because he says he will not treat the hive, but if he were to, it does not have honey supers on it. If there was surplus honey he could remove it prior to treatment, but store it incase the bees need it back during the treatment period.
The Apivar label says not to treat with supers on, that will save their butt should there ever be any legal challenge claiming someone was poisoned due to it's use. In practise, it was many years before Amitraz was ever detected in commercially harvested honey, due to it's short 1/2 life, this despite in reality hives do get treated with Amitraz with honey on, in it's legal, and illegal formulas. ( Formulae, for the spelling cops. :) ) I personally, would have no difficulty consuming honey harvested from a hive with Apivar in it, honey does not readily absorb Amitraz, but if any does get in, it will not last long. Would I supply such honey to someone else? No. Not that I think it would do any harm, but more just a breach of faith type thing, if I am ethical, eventually people will perceive me that way.
 
#25 ·
Can you see commercial beekeepers going around their hives fortnightly and culling all the drone comb? Can you even see many hobbyists doing it? Since better than 99% of hives are commercial, and of the remaining less than 1% hobby hives just a tiny proportion would have serious methodical drone culling, I cannot believe drone culling is done to anything like sufficient extent to have an effect on Mite evolution. Not even a thousand years from now.
There is no harm at all in this hobbyist doing it on one TBH, culling drones is not evil, and his actions will not bring about the destruction of world beekeeping.
Just the time waste and difficulty of this procedure will ensure it will never be used to an extent big enough to outweigh other evolutionary pressures.
In case you didn't notice, this is the Top Bar Hive Forum:rolleyes: I also drain boils every day, not sure what your point is.
 
#24 ·
The mere suggestion that an individual beekeeper....or even a group of beekeepers could significantly alter the varroa mite/honey bee interaction, simply by culling drone brood is preposterous. The fact that anyone would attempt to defend this basic absurdity......astounds me.
 
#27 ·
Jfb58 to answer your question re drone foundation, you don't need to use it. The bees naturally need a percentage of drone comb. If you cut out the drone comb and put those bars back in the hive, once the bees perceive they have less drone comb that they want in the hive they will build more.

The exception is for very weak hives, which will build only worker cells if they think their very survival is at risk and they cannot waste resources on drone raising.
 
#31 ·
>I cannot believe drone culling is done to anything like sufficient extent to have an effect on Mite evolution. Not even a thousand years from now.

It's not evolution, it's selective breeding.

500 years ago the only horses that would trot were pretty much war horses. All the rest had been bred to not trot. Trotting was not considered a good trait. As roads improved and carts were common, trotting was more useful. In one mans life time the population of horses in the world were selectively bred from almost all not trotting to almost all trotting. That is not evolution. It's selective breeding. Evolution is an entirely different matter.
 
#32 · (Edited)
Drone culling is done on (maybe) 0.01% of hives, probably less. Was the transformation of horses achieved by selective pressure on only 0.01% of horses?

No?

Then perhaps you will have to agree with my point. A little drone culling on an infinitesimally small number of hives bees will not affect evolution or outweigh other evolutionary or selective pressures.

I'll even bet that while horses were being selected for trotting during the time frame you say, human nature being what it is, there would have been a few hold outs not happy with the modern trotting trend, and selecting against trotting. Probably more than 0.01% of horse owners. Yet you claim horses were transformed into trotting horses. The 0.01% was not enough to change the tide, so if horse breeding illustrates mite breeding as you imply, you have shown that a person with a TBH need not concern himself with the selective issues around culling some drone comb from his hive.
 
#34 ·
Was the transformation of horses achieved by selective pressure on only 0.01% of horses?
OT...you see how easy it is to get drawn away from the real question?
Any rational person following this knows that one beekeeper....or even a number of beekeepers..... doing drone cell culling isn't going to change the nature of varroa. And all of the attempts to make A cerana and horse analogies isn't going to erase the foolishness of the earlier post.
 
#33 ·
>Drone culling is done on (maybe) 0.01% of hives, probably less. Was the transformation of horses achieved by selective pressure on only 0.01% of them?

If a hobbyist or commercial person is doing drone removal religiously I'd say they are putting selective pressure on 100% of them or at least near that. And mites have much shorter lives and can be bred to a particular trait in a much shorter time. Having that in my yard is not what I want. Will it affect you in NZ? Probably not unless you are doing the same. We all need to be breeding for mites that live with the bees if we want to change things. Not the other way around.
 
#36 ·
If a hobbyist or commercial person is doing drone removal religiously.
Operative word IF. Almost nobody is. And as per you horse breeding illustration, that tiny number did not change the tide.

However I do understand where you are coming from but we also need to look beyond theory, and primarily look at what is actually happening. The guy with the top bar can cut his piece of drone brood, or not, I don't really care.
 
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