drone brood removal

[drobbins]

Howdy,

I've been reading about using the drone brood removal approach to varroa control
looking at these pictures

http://www.masterbeekeeper.org/calen...rone_brood.htm

it looks like they're gonna waste a lot of worker brood also.
couldn't you just uncap the drone brood instead of putting it in the freezer and killing the whole frame??

Dave

[oldgreyone]

If I understand it right, a major part of the success is because of the number of mites killed by freezing also. To just uncap the brood would probably just reduce the number of mites produced in those frames.

[ekrouse]

Drobbins,

Your linked photos are not right. Drone comb should be almost solid drone cells. The picture on the left of that webpage shows mostly capped workers... IT IS DEFINATELY NOT DRONE COMB. For drone comb I use Pierco's one piece drone frames. The bees draw the entire thing out as drone comb. The mistake I made last year is giving the bees an extra week to draw out the foundation. As a result when I checked after 1 month most of the drones had emerged and where running all around! See Dyce Lab's (Cornell Univ) website for the correct timing.

[Dick Allen]

couldn't you just uncap the drone brood instead of putting it in the freezer and killing the whole frame??

sure you can. if you have a small number of hives and the time to do it, all you need to do is use a cappings scratcher. dig out the drones and put the frames back into the hives. the bees will clean them up in no time and queenie will put some more drones in there for your next batch of mites to be dug out.

[Dick Allen]

A handy reference book about different methods for controlling varroa is ‘CONTROL OF VARROA A Guide for New Zealand Beekeepers’ It’s available in PDF:
http://www.biosecurity.govt.nz/pests...es/control.htm

And, speaking of drone trapping for control of varroa, one of the procedures described in the book is the hive splitting varroa control method in the BIOTECHNICAL CONTROL section.

“According to the field trials carried out by the Dutch researchers, on average this method is 83.4 to 93.4% effective in removing mites from all three colonies (depending on the amount of drone brood available for trapping). The researchers have managed 70 colonies using this method for 5 years in Holland without using any additional, chemical control.”

In the ‘Point of View’ section you can also link to a site explaining the method or go directly to it here:
http://www.xs4all.nl/~jtemp/dronemethod.html

It's fairly simple, although when first read, it seems more complicated than it really is.

[drobbins]

Dick,

Thanks for the links
clarify 1 point for me
is it nescessary to remove the pupea, doesn't uncapping it destroy it?
I can understand removing some for inspection but removing all would be labor intensive

Thanks
Dave

[Dave W]

You need to KILL the "drone brood" so your hive does NOT become ALL drones.

You are removing "drone brood" to reduce the quantity of Varroa.

Freezing a "drone frame" (frame of MOSTLY drone brood) does BOTH.

[HarryVanderpool]

I have always had an objection to this procedure, and that is the amount of wasted energy and resourses invested by the bees.
It seems really inefficient.
It takes A LOT of feed coming in, and labor that could be spent on workers and honey production if another varroa control method is employed.
Am I off on this?

[drobbins]

Dave W

I understand that if you have an entire frame of drone foundation you may as well freeze it and kill everything. Actually you need to so you don't end up with WAY to many drones. I was thinking more along the lines of during a regular inspection, of regular frames, uncapping any groups of drone cells that were easy to get all at once as a means of killing the pupae and also the mites. As Harry mentions, having the bee's raise an entire frame of drones so I can kill em seems expensive for the bee's. Obviously you couldn't do this if you had a lot of hives but I don't. Currently 1 hive and probably 4 or 5 next year. I can do such labor intensive things without much trouble

Dave

[ekrouse]

The thing to keep in mind is that queens want to lay about 10% drones. By providing her a place to do it (drone trap) you avoid having some of the worker foundation reworked into drone comb.

[ekrouse]

Here are Prof. Nicholas Calderone's recent comments on drone traps.
Dyce Laboratory
Cornell University

Female Varroa mites (Fig. 2) invading drone cells produce about twice as many offspring as those invading worker cells. Not surprisingly, mites are found 8 - 15 times as often on drone brood as on worker brood. You can exploit this difference as part of an IPM program for control of V. destructor. By removing drone brood from your colonies, you remove a disproportionately large number of mites without affecting the size of the worker population. The drone brood removal method has been found to reduce mite levels up to 10-fold and to maintain strong populations during the summer and early fall. This is the time when many colonies succumb to mites, a phenomenon known as ‘fall collapse’. Try this method and you will prevent fall collapse and be treating healthy bees in the fall.
You will need four drone combs per colony to use this method. Drone foundation can be purchased from several supply houses. The foundation is wired into frames and drawn out by colonies. One piece plastic drone combs are also available. Use two deep hive bodies for brood chambers, and separate them from the honey supers with a queen excluder. Cull worker combs in the brood nest with more than 1-2 square inches of drone cells (Fig. 3). Remember! The goal is to get the colony to consolidate all of its drone production in the removable drone combs.

Place two drone combs in the upper brood chamber, one or two combs in from each side. Visit your colony every 26-28 days, remove the drone combs (Fig. 4), and replace them with the drone combs that you removed on the previous replacement date. Place the combs of capped drone brood in a freezer, and keep them there until you are ready for your next exchange. Allow drone combs to come to ambient temperature before placing them back in a colony. Be sure to visit your bees at least every 28 days to exchange combs because you don't want too many drones actually emerging in your hive. If a drone comb becomes filled with honey, you will need to substitute an empty drone comb and extract the honey before reusing it. In the north, you can exchange combs up to six times a season using a 26-28 day interval between exchanges. The more often you exchange combs, the more you will suppress the mite population. At Dyce Lab we exchange drone combs from apple blossom until we remove the fall crop just before the end of the goldenrod flow. The drone brood removal method has no known deleterious effects on colonies, and honey production may be marginally increased.

[Note! Yes, it only takes 24 days to rear a drone, but it takes the bees a couple of days to clean out the combs, and it takes the queen a couple of days to fill them up. So, the 26-28 day interval works. However, if you are ambitious and want to exchange combs more frequently, go right ahead.].

[Michael Bush]

>It seems really inefficient.

That has been why I haven't done it. I was considering it as a backup plan for while I was regressing but found it unecessary.

[MichaelW]

Does introducing drone comb foundation increase the percentage of drones in the colony, or is the percentage fairly fixed and the drone foundation simply concentrates the drones on two frames? I'm assuming it dosen't increase drone numbers otherwise the whole thing would be counterproductive (more drones, more mites). I'm not looking to use drone comb, just curious.

[Michael Bush]

According to research I saw presented in 2003 the proportion of drones to workers at a given time of year is constant regardless of how much drone comb is in the hive. The bees regulate it based on their need for this proportion.

But the idea of removing it is to get rid of the mites. Of course, the bees will just make more drones somewhere else if you do, or waste their energy trying if you keep stopping them.

[Dick Allen]

I won't disagree that removing removing drones likely takes some energy and resources from the hive. But, having mites in the hive does too.

[ekrouse]

FREE NEWSLETTER From Cornell Labs

For anyone interested, you can directly access Nick Calderone's comments through Dyce lab's newsletter at

http://www.masterbeekeeper.org/

Click on "Northeast Beekeeper Newsletter" for the issue about Drone traps. Also on the bottom right corner of the page you can click on "Sign Up for CUBees" and you will automatically receive the newsletter by email all for free.

-Eric