Varroa treamtents with and without brood

[Michael Bush]

I wish I could get charts to format correctly, but I can't.

A lot of you use some treatment, (it doesn't really matter what for this discussion), and your mite drops don't change much afterwards and you assume you're not killing mites. So let's just look at some numbers

Independent of WHAT the treatment is, here is jsut a rough idea of what goes on. Theses are round numbers and probably underestimate the mites reproduction and underestimate how many get groomed off by the bees.

Assuming treating every week and a treatment with 100% effectiveness on phoretic mites. If you assume that half the Varroa are in the cells and you have a total mite population of 32,000, and if we assume half the phoretic mites will go back in the cells and in one week, half of the mites in the cells will have one offspring each and emerge then the numbers look like this:
Week 1 Phoretic 16,000, In cells 16,000 Killed by treatment 16,000, Reproduced 8,000, Emerged 16,000 (half of the 16,000 plus the 8,000 offspring), went back into cells 4,000
Week 2 Phoretic 12,000, In cells 12,000 Killed by treatment 12,000, Reproduced 6,000, Emerged 12,000 went back into cells 3,000
Week 3 Phoretic 9,000, In cells 9,000, killed by treatment 9000, Reproduced 4,500, Emerged 9,000, Went back into cells 2,250
Week 4 Phoretic 6750, In cells 6,750, killed by treatment 6,750, Reproduced 3,375, Emerged 6,750 went back into cells 1,688

Now lets Assume treating every week and 50% effectiveness on phoretic mites. If you assume that half the Varroa are in the cells and you have a total mite population of 32,000, and if we assume half the phoretic mites will go back in the cells and in one week half of the mites in the cells will have one offspring each and emerge then the numbers look like this:
Week 1 Phoretic 16,000, In cells 16,000 Killed by treatment 8,000, Reproduced 8,000, Emerged 16,000, went back into cells 4,000
Week 2 Phoretic 20,000, In cells 12,000 Killed by treatment 10,000, Reproduced 6,000, Emerged 12,000 went back into cells 5,000
Week 3 Phoretic 17,000, In cells 8,500, killed by treatment 9000, Reproduced 5,500, Emerged 11,000, Went back into cells 4,250
Week 4 Phoretic 15,250, In cells 9,750, killed by treatment 7,625, Reproduced 4,875, Emerged 9,750 went back into cells 3,813

Now lets Assume treating once every week with 50% effectiveness with no brood in the hive
Week 1 Phoretic 32,000, In cells 0 Killed by treatment 16,000, Reproduced 0, Emerged 0, went back into cells 0
Week 2 Phoretic 16,000, In cells 0 Killed by treatment 8,000, Reproduced 0, Emerged 0 went back into cells 0
Week 3 Phoretic 8,000, In cells 0, killed by treatment 4,000, Reproduced 0, Emerged 0, Went back into cells 0
Week 4 Phoretic 4,000, In cells 0, killed by treatment 2,000, Reproduced 0, Emerged 0 went back into cells 0

Then of course there's 100% with no brood:
Week 1 Phoretic 32,000, In cells 0 Killed by treatment 32,000, Reproduced 0, Emerged 0, went back into cells 0
Week 2 Phoretic 0, In cells 0 Killed by treatment 0, Reproduced 0, Emerged 0 went back into cells 0

[ January 24, 2006, 03:44 PM: Message edited by: Michael Bush ]

[George Fergusson]

Good Job Michael. Even if one doesn't agree with all your assumptions, the basic premise is clear.

[Jim Fischer]

Wyatt Mangum did some serious work on the
subject of varroa reinfestation via drift
within the apiary, and his numbers showed
that we can't ignore drift as a significant
issue in its own right.

But yeah, style and panache with push-in queen
cages is more important than your choice of
treatment.

[ February 07, 2006, 11:02 AM: Message edited by: Jim Fischer ]

[Michael Bush]

A real mathematical model should probably take into account a lot of things including drifting, robbing, hygenic behavior (chewing out), grooming, time of year etc. I was just hoping to get the general principle across.

>But yeah, style and panache with push-in queen
cages is more important than your choice of
treatment.

And if you time it right you can end up with a broodless period, knock down the Varroa AND get more honey.

[PA Pete]

OK - point made. My question now is what's a practical approach to treat during a broodless period? Cage the queen for three weeks, then treat for a week (or two)? I'd considered trying this but would like to hear if anyone has any experience with it. My thought was I'd consider trying this immediately following the nectar flow when I suspect mite populations will be high (along with colony population) and the colony would potentially benefit most.

Thoughts?

[Michael Bush]

>what's a practical approach to treat during a broodless period? Cage the queen for three weeks, then treat for a week (or two)?

That depends on the efficacy of the treatment you intend to use. If it's 50% effective it will take several weeks to really put a dent in the mites. If it's 100% (or close) then one treatment can be quite effective.

If varroa control is your goal, I'd be tempted to cage the queen three weeks before the flow and treat once, or wait until the flow is over and cage the queen for three weeks and treat however many times you need to for the treatment you're using. If that's once a week for three weeks or just once.

Just before or just after the flow would be good times to be broodless for a short time.

[Bob Russell]

To all
A method of requeening in New Zealand is ideal to achieve a complete brood break for what ever method you choose to treat with.Caged queens and 10 day cells will only give you a partial brood break.This method (2 day old cells) has been practiced for about 60 years in NZ using a unique way of producing the cells and transporting.Should the weather fail they are carried over to 10 day.No queenless period is required before introduction,the whole hive finishing one cell only.The following photos shows 2 day old cells ready for introduction and a emerged cell demonstrating the size of cell when finished by a whole hive.When the new queen starts laying the hive is completely broodless.

http://tinyurl.com/3k589

Ignore the carry cell pad in the photo.

[ January 25, 2006, 02:17 PM: Message edited by: Bob Russell ]

[George Fergusson]

I just finished reading Nick Calderone's article in the February 2006 Bee Culture about drone comb removal for varroa control.

What struck me most is that even THIS method is best used when a hive is broodless.

[Jim Fischer]

> If varroa control is your goal, I'd be tempted
> to cage the queen three weeks before the flow
> and treat once...

Depending upon what you use to "treat", this
could be a very bad idea. Even something non-toxic,
like sugar dusting, is going to result in "residues",
so the basic problem is that one needs some time
between treatment and reprovisioning of supers
on the hive.

[Bob Russell]

George and all
What the article is saying is very true,with a complete brood break you have the opportunity to kill or mop up all of the varroa in a matter of days and not weeks.The following is a cut and paste so as not to identify the Beesource member that emailed me this morning.

"I am a German beekeeper. On beesource I read an interessting post on requeening using 2 day old cells from a person named Bob Russel from New Zealand. Because I am believing that methode would be quite an improvement over my current methode (queen caging, 10 day old cell etc to get them broodless), I started an extensive but unsuccessful search over NZ beekeeping sites eager to find some helpful information. Then I accidently stumbled over your email address."

No information will be found on the New Zealand sites as it has never bee published,however there was a small article in "The APIARIST OF NEW ZEALAND" many years ago that alerted me to follow up the method that has been practiced for over 60 years by the family generations who at one stage were reported to be running 17000 hives in New Zealand.It was that article that prompted me to follow up their process before varroa arrived in New Zealand as an advanced requeening method,then when varroa did arrive in New Zealand to then also use the method to achieve a total broodless control with varroa treatment methods of ones own choice.I don't believe this method has been on any other sites,yet it is just so simple.

[George Fergusson]

>What the article is saying is very true,with a complete brood break you have the opportunity to kill or mop up all of the varroa in a matter of days and not weeks.

Exactly my point. Why spend all summer processing drone comb after drone comb when it could be done much faster with a lot less work- and less resources spent by the bees themselves.

According to a Dutch site that discusses a drone comb trapping method:

"It is possible, in a broodless hive, to capture an adequate number of mites (500 cells per kilo (2.2 lb..) of bees)."

Now, figuring out exactly what they're saying requires some thought, but it sounds like they're saying that 500 capped drone cells per kilo of bees in a broodless hive will trap "an adequate number" of varroa. We're left wondering what an adequate number of varroa are.. and how many drone cells are on a typical deep frame. Or medium frame for that matter.

George-

[db_land]

Jim, you posted
"Dwight Mangum did some serious work on the
subject of varroa reinfestation via drift
within the apiary, and his numbers showed
that we can't ignore drift as a significant
issue in its own right."
I can't find anything about this on the www; can you provide a pointer reference please? Thanx,

:cool:

[Bob Russell]

George
I have just measured drone foundation off a New Zealand mill.Cell size is 5.6 mm.Full depth frame giving 60x33x2=4026 cells per full frame.It would be an over kill using full depth.

[Michael Bush]

>Cell size is 5.6 mm.Full depth frame giving 60x33x2=4026 cells per full frame.It would be an over kill using full depth.

That sounds more like 7/11 foundation which we use to keep the queen from laying in the comb. Small cell bees might view it as drone comb. On the few occasions that I've seen a queen lay in them she layed drones. According to Finsky (from Finland) that is now the standard worker cell size for foundation in Siberia.

[George Fergusson]

>I have just measured drone foundation off a New Zealand mill.Cell size is 5.6 mm.Full depth frame giving 60x33x2=4026 cells per full frame.It would be an over kill using full depth.

Thanks Bob for doing the bean counting. I don't mind a little over kill.. and cycling a full frame of drone brood would be acceptable but cycling 8 full frames over the course of the summer.. now THAT is overkill!

I just checked the Dutch document again, I recall the frames they're using are smaller:

"One frame in Holland ( foundation 198 x 340 mm) counts 3000 drone cells."

My deeps are like 204mm x 430mm.

I think it's admirable that Bee Culture is advocating biological methods of varroa control, but the method described in the article involved a lot more work than necessary and was overall less effective than it could have been simply because the hives weren't broodless for the treatment.. which was my initial point: even drone comb trapping of mites is more effective in a broodless hive.

[George Fergusson]

>That sounds more like 7/11 foundation which we use to keep the queen from laying in the comb.

Hrm. Our posts crossed. So, how many "drone" cells are there on a standard langstroth deep frame? Barring that information, how big ARE typical drone cells? I don't have any drone foundation handy, or any combs to measure, at least not right now. It's irrelevant really, just a point of interest.

[Michael Bush]

I never counted before. But typical drone foundation is 6.6mm. The natural drone cells I see vary greatly in size from 5.9mm to 7.0mm. Some of those drones look like aliens from outer space.

Number of cells on a frame of worker brood
Cells on one deep frame of 5.4mm foundation 7000
Cells on one deep frame of 4.9mm foundation 8400

[Bob Russell]

George,Michael,all
I came across a frame of natually drawn drone comb in the honey house today measuring 6.7 mm.As George's deep is the same dimensions as ours in New Zealand, 6.7mm would give 64x30x2=3840 cells per frame approx.

[Dave W]

George Fergusson . . .

>Nick Calderone's article in the February 2006 Bee Culture about drone comb removal for varroa control.

>What struck me most is that even THIS method is best used when a hive is broodless . . .

If one is trapping V-mites in drone comb, how can the hive be "broodless"? Please explain your above comment.

thanx smile.gif

[George Fergusson]

>If one is trapping V-mites in drone comb, how can the hive be "broodless"? Please explain your above comment.

Sure smile.gif First you create a broodless condition in your hive by whatever means you choose- frame manipulation, caging the queen, requeening, splitting, etc.

Then you introduce a frame of drone comb from another hive containing eggs and uncapped drone larvae. This is basically the method used in the Dutch/NZ method of splitting for varroa control (another topic in the Diseases and Pests forum).

Of course, this necessitates you have at least 2 hives to work with. I suppose you could create a broodless condition in your one hive perhaps by caging the queen, then introduce an empty drone frame and confine the queen on it, but I haven't really thought much about this.

George-

[brent.roberts]

Would we need to use a full frame, both sides for a drone trap. Maybe after the first rotation, when the population started to go down, fill one side of the frame, assuming so kind of foundation or plastic , and let the queen lay on only one side, or maybe only part of each side. The filler could be wood or high density styrofoam.

Seems like it would save a lot of eggs and a lot of feeding if you did run it over the entire summer.

[George Fergusson]

>Would we need to use a full frame, both sides for a drone trap

Dunno for sure Brent since I'm speculating wildly about it. I have however read about other people's drone comb trapping experiments and experiences and therefore feel I can at least speculate wildly, with some accuracy smile.gif The topic of the thread is "the effectiveness of treatmens with and without brood" and it clearly appears to me that drone comb trapping of mites is every bit as much as treatment as any chemical treatment and is therefore also more effective in a broodless hive.

What initially struck me about the Bee Culture article was that they trapped out 95% or so of the mites in the hive using 8 frames of drone comb over the course of the summer. Knowing what I know about mite reproduction rates and the effect of treatments when there is brood in the hive (a scenario well put forward by Michael at the beginning of this thread) I think it's safe to say they didn't trap out all their mites with the first comb.

So what was the efficacy of their "treatment"? I'd say it wasn't very high on a per-comb basis. They didn't publish ongoing mite counts or infestation levels during the test, so we can't say for sure. That would have been a nice touch, to see how the mite population dropped over time.

I'm guessing there was a pretty constant removal of mites over the summer, perhaps 10% or a little more per set of drone combs removed. This is because mites were actively reproducing at the same time i.e., the hives were not broodless. I dunno, maybe it was more effective at first, less effective towards the end. Maybe they hardly trapped any mites at all with frames 7 and 8.

If you've got a broodless hive and all your mites have been phoretic for several weeks and they are just twiddling their thumbs waiting for some brood to arrive, and all of a sudden you put 3-4000 ready-to-eat young drone larvae and eggs in the hive... I think you're going to catch a LOT of mites. Perhaps almost all of them.

[Dave W]

The "drone brood removal method" described in Feb 06 BC (and many other places) says to remove/replace the drone frame more than once. Its hard to see that as a "broodless" hive.

>Maybe they hardly trapped any mites at all with frames 7 and 8.
How many DRONE eggs will a queen (any queen) lay in September?

My quess is the most "treatment" occurs w/ first 2 may 3 frames removed. Frame 2 or 3 probably having the most mites. These first frames reduce the mites to a level that their reproduction from then on is almost nill (low number to reproduce and very low qty of drone brood being produced.

[George Fergusson]

>The "drone brood removal method" .... says to remove/replace the drone frame more than once. Its hard to see that as a "broodless" hive.

They're not describing nor advocating a broodless hive for drone comb trapping. I am smile.gif

I can't help it if people want to practice drone comb trapping the WRONG way, or should I say, the LESS EFFICIENT way smile.gif

Are you confused over terminology or disputing the effectiveness of treatments in broodless vs broodfull (?) hives? It's pretty simple from my point of view. If the hive has brood in it, it's not broodless. If it doesn't have brood in it, then it's broodless. Nobody is saying a hive has to be broodless for drone comb trapping to be used. I'm just saying that employing drone comb trapping, like any other treatment, is more efficient in a broodless hive.

In other words, putting a frame of drone comb containing eggs and young larvae into a BROODLESS hive with the intention of taking it out a week later after it's capped does not make it a hive "with brood" IMHO. I don't have a problem here smile.gif

>My quess is the most "treatment" occurs w/ first 2 may 3 frames removed. Frame 2 or 3 probably having the most mites.

I don't know. I doubt it. I wish they'd published drop counts over the course of the summer, it would have helped understand what was going on. Think about the logistics of it:

Mites enter cells to breed 1-2 days before the cells are capped. That's a pretty narrow window, really. Given that mites are phoretic for from 3 to 13 days (and NEED to be in fact) before they are ready to breed, how many of them are going to enter cells during the 2 day period when your drone comb is "ripe"? Hard to say, but I'd guess about 1/5th of them (assuming 100% will enter cells over a 10 day period, 20% should enter cells in a 2 day period). Then, are they all going to enter the to-be-culled combs? No. Some will enter worker brood. Some will enter the drone cells found elsewhere in the hive. Meanwhile, while you're taking mites out, you've got more mites maturing and emerging all the time. 60% or better of the mites in the hive are in cells reproducing at any given time. Under these circumstances, does drone comb trapping sound all that efficient?

Now consider a truly broodless hive where all the mites are phoretic and have been for several weeks. You throw in a comb of drone eggs and young larvae. How many of them are going to dive into cells when the larvae are the proper age?

Most of them.

[Dave W]

>They're not describing nor advocating a broodless hive for drone comb trapping . . .

Thats what Im saying smile.gif


>confused over terminology or disputing the effectiveness?

Whos confused?


>You throw in a comb of drone eggs . . .

Young larvae, yes. Eggs dont matter.


>Now consider a truly broodless hive where all the mites are phoretic and have been for several weeks. You throw in a comb of drone eggs and young larvae. How many of them are going to dive into cells when the larvae are the proper age?

Sounds like all we need to do is just KEEP our hives BROODLESS smile.gif

[George Fergusson]

>Whos confused?

Nobody apparently. Certainly not me!

>Young larvae, yes. Eggs dont matter.

Feh...

>Sounds like all we need to do is just KEEP our hives BROODLESS

Oh Dave, now you're being silly smile.gif

[Michael Bush]

>Sounds like all we need to do is just KEEP our hives BROODLESS

Well, you won't have any Varroa. ;)

[George Fergusson]

>Well, you won't have any Varroa.

It's right up there with your idea for using dynamite as a permanent solution to varroa smile.gif

[Michael Bush]

>It's right up there with your idea for using dynamite as a permanent solution to varroa

It's the same basic principle but much easier on the equipment. smile.gif

[Jim Fischer]

"Wyatt Mangum did some serious work on the
subject of varroa reinfestation via drift
within the apiary, and his numbers showed
that we can't ignore drift as a significant
issue in its own right."> I can't find anything about this on the www;
> can you provide a pointer reference please?

Not everything is on the web just yet. smile.gif
Dwight spoke about this at a beekeeper meeting
(VA? MD? I dunno, somewhere in the East), but
I don't know if he has written anything yet.

E-mail him - he's a nice enough guy, and is sure
to send you something or other, perhaps a
pre-print or a copy of his presentation.
wmangum@mwc.edu

[db_land]

I emailed him. Thanx :cool: