Beekeeping Experiment Participants wanted

If anyone is interested in participating, Walt Wright and I have put together an experiment we would like to have people try.

Checkerboarding vs. Opening the Brood Nest combined with Checkerboarding vs. Neither


Will bees given empty frames in the brood nest shift to "establishment" mode and make white wax well before the normal time and build up more because of more brood nest expansion and tend to not swarm. Will hives produce more/less/as much as when "Checkerboarded".

Background and Terms:


It would be better if you read Walt's articles, but I'll give a synopsis of the idea of checkerboarding here. Remember this is an oversimplification.

For a bee colony:

  • Survival is the primary motivation
    • Survival of the existing colony takes priority.
    • Bees will not do a reproductive swarm if they perceive it to jeopardize survival of the existing colony.
  • Survival of the species runs a close second.
    • Generation of a reproductive swarm is the secondary objective of every over-wintered colony.
    • The over-wintered colony expands the brood volume during the build-up by consumption of honey.
    • When the colony has expanded the brood nest to the amount of reserve that they consider appropriate, they are now able to move into the swarm preparation phase.
    • The first activity of swarm preparation is to reduce the brood volume by providing additional stores. As brood emerges, selected cells are filled with nectar or pollen.
    • Alternating empty drawn combs above the brood nest "fools" the bees into thinking they don't have enough stores yet for swarming and causes them to expand the brood nest, giving both a bigger field force and avoiding reproductive swarming.

To put some of this another way, the colony goes through different goals at different times.

A new swarm starts out with the goal of getting established. They draw a lot of comb and try to expand the brood nest as much as possible to get established and then they go into winter preparation, which is trying to store sufficient stores for the winter. If they accomplish all of this and get over crowded they might cast a swarm to relieve the population problem.

The next year the hive will start out with the goal of reaching a safe position to cast a reproductive swarm. That means the population has to build up enough to afford to lose that many bees and the stores have to be high enough for them to lose that many foragers. Then they go into swarm preparation mode and start backfilling the brood nest. At some point, which Walt calls the Reproductive swarm cut-off, they decide they will or won't swarm.

The goal of Checkboarding is to keep them in the build-up phase until after Reproductive swarm cut-off by making them think they don't have enough stores and giving the brood nest room to expand.

If you look at your bees and your blooms and your climate, this Reproductive cut-off is usually the peak of the apple blossoms or a week after the apples START to bloom. The time to do Checkboarding is 9 weeks before that. That's about when the Elm blooms or four weeks before the Maples bloom or five weeks before the Redbud blooms or eight weeks before the apples start blooming or ten weeks before the black locust starts blooming. Hopefully you have some idea when one of those blooms in your location. NOTE: in theory these are all ways of pinpointing the same stage of vegetative development, they are just different reference points to figure it out for your location, I'm just listing all the different blooms in case you know when one of them is to calculate from.

At that time (9 weeks before Reproductive cut-off/the peak of the apple blossoms) you checkerboard. You put alternating frames of capped honey and empty drawn comb above the brood nest.

Opening the Brood Nest

The underlying beekeeping principles are similar to Checkerboarding except by putting empty frames (not frames with foundation, but frames with either starter strips or comb guides or nothing) in the brood nest, to shift the colony to establishment mode and drawing wax much earlier and prevent backfilling of the brood nest. This causes the brood nest to expand and it controls swarming. To make room for the empty frames you should move frames on the outside of the brood box up to the next box or down or out altogether (depending on if your equipment is all the same size frames) and move the brood combs to the sides and put the empty frames between two frames of brood. To prevent chilling brood, make sure that you have enough bees to quickly fill the gap you've left with festooning bees before you insert the frame. This will ensure there are enough bees to manage the empty space. If there are not enough bees for this, then postpone for another week or two. For the sake of the experiment, it would be good to check the brood nest every couple of weeks and add more frames if the brood nest starts to recede (because of backfilling) or if there are enough bees to handle the extra space. If you want maximum yields this should probably stop about two weeks before the main flow (about four weeks after apple bloom starts and about the time Black Locust starts to bloom). If the box is brood from one side to the other, three frames of brood can be moved up into the next box to expand the brood nest up and fill in those gaps with alternating empty frames. If you get frames of drone brood (which you most often will for the first couple of frames) move them to the outside edge of the brood nest when you find them and put more empty frames in their place. Anytime you don't see enough bees to fill the gaps in the brood nest, wait until they have built up more. Some of this timing may vary by race as well as climate, so try to go with the bees.

Walt and I discussed this at length and concluded we think the best time to try this right after the elm bloom or right at the Maple bloom or 2 weeks before the Redbud bloom or two weeks or four weeks before the apple bloom or 6 weeks before the black Locust bloom. NOTE: in theory these are all the same point of seasonal development, I'm just listing all the different blooms in case you know when one of them is to calculate from. I do notice that going by Walt's chart (in the manuscript) I'm usually about a month behind him. But that seems to be a little more than that in some places. For instance, the Locust bloom here was mid May last year and six weeks before that would be the first of April. Yet at the first of April I'm past the elm and maple blooms. Here, the blooms at the first of April are wild plums and other early fruit trees. You might just look for early fruit trees blooming in your area to key on for opening up the brood nest. Before that there probably isn't any flow coming in to make wax from.

The other up side to Opening the Brood Nest is the production of natural cell sized comb. If you are trying to regress you'll get this a side benefit.

Beekeeping Experiment:

The idea is to do these side by side and see how the results compare. If you only wish to do one or the other feel free to give your results, but a side-by-side comparison would be more useful. Walt is quite certain of the results of the Checkerboarding compared to the typical brood box reversal system, but if you'd like to compare it to that, both for this experiment and for your own enlightenment, that would also be useful information.

These should be third year or more colonies. First and second year colonies have slightly different timing and goals.


If you open the hives every week and use thumbtacks or push pins to mark the top of the brood nest (three pins would work nicely, one in the center and one a couple of frames in from each side). You can log the brood nest expansion by that date by how many inches up it has moved. Also monitor overhead nectar storage. If the brood nest starts contracting before the peak of the apple blossoms then, for Opening the Brood Nest colonies it's time to add more empty frames. Make sure you have alternating frames over the brood nest of honey and nectar or empty drawn comb. You can do these alternating frames all the way to the top. Once you are two weeks before the main flow (one week after apple's stop blooming) I would stop trying to get them to expand the brood nest. Once the main flow hits you shouldn't need to monitor the brood nest anymore, but rather make sure there are plenty of supers on to prevent overcrowding.

So, to recap:
  1. Keep notes on when you do what manipulations by date.
  2. Keep notes on the size of the brood nest and the amount of expansion or contraction of it by date.
  3. Keep notes on when you see white wax.
  4. Keep notes on when you see different plants blooming in your area.

One way to keep track of some of the blooms, like Maple and Elm is to go to and see what they say is the prevalent pollen at the time.

If anyone has additional ideas please add them, but here's an idea for a template for a log entry:

Location ________________
Hive name/id ________________
Date _______________
Manipulations performed _________________
Estimate of brood nest size (diameter)______________________
Brood nest expansion/contraction (difference in height from last time to this time based on thumbtacks) __________________
Backfilling of brood nest (Y/N) _____________
Estimate of cluster size (diameter)___________________
White wax (Y/N) _____________
Swarm cells (Y/N) _______________
Currently blooming plants _____________________
Size of cells in newly drawn comb (if there are any) ______________________________ (measure across ten cells with a metric ruler and move the decimal to the left one place)
General observations __________________________________________

Reason for the Experiment:

Basically Walt believes (he would correct me and say he knows) that there is plenty of nectar well before the "main nectar flow" and the bees just have a lull there as they make up their mind to either swarm or go into storage mode. He says that second year colonies are still in establishment mode and what he sees in second year colonies is different than established colonies. First of all they are drawing white wax earlier and they don't have the lull. In other words there is a three or four week longer "nectar flow" for them because they don't have the lull. The issue we want to discover is whether putting empty comb in will set off making white wax early and put them into establishment mode and be able to "cash in" on that three week or so lull.

Here is Walt's response to the above "Reason" statement:

MB et. al.,

MB apparently invited my two cents worth. Up front, it should be made clear that I report what I see. If a conclusion is obvious, it might be stated as fact. If not, the conclusion may be offered as a plausible explanation, with the key words "I suspect" or "may be that." I try to make it plain when I'm guessing. Answers to the questions about the difference in colony operations between 1st, 2nd, and subsequent years of a colony are not obvious. It is easy to see the difference in objectives of first and third year colonies. But the difference between second and third year colonies has no obvious rationale in what we know about survival requirements. The two main observed differences are: A. The second year colonies do not have the storage lull of 3rd and subs. B. Second year colonies supersede promptly at repro cut off. SS is sometimes delayed into the main flow for 3rd and subs.

There may be other differences that have not come to my attention. Changes in colony internal operations are very subtle for the casual peeker-in.

Approaching establishment, the natural swarm will SS. They lift the parent colony with the old queen. The final step to lasting establishment is a new queen. A package will sometimes invoke this safety measure also, to the dismay of the beek. The age of the queen does not appear to me to be relevant to the differences in operation with colony age. All over-wintered colonies strive for reproduction in the spring season.

I have reported the two observed features above in different ways, but I don't think I have said, point blank, that the differences were an extension of first year establishment. That would be guessing, without enough evidence to support the conclusion. It's just different for unknown reasons.

Our European bees have survived hard times. They have had some semblance of their current survival format for eons. Somewhere, buried in their genes, is the period where the second year difference in operations was an advantage to survival. We may never learn why.

Having clearly noted my ignorance on the subject, would you care to speculate for another minute? If not, press on to something more interesting. "Survival of the fittest" is a recognized technique to improve genetics in any species.

Most offspring swarms perish in nominal seasons. (More survive in bountiful seasons) In the wild, the parent colony has already demonstrated its skill at establishment by virtue of its existence. During the parent colony lifetime, any offspring swarm that survives is selecting for the right stuff - genetics of species survival. The offspring swarm that survives establishment will, in turn, have its chance to further the selection process through its lifetime. The lifetime of a colony is relatively short in years. Sooner or later, they will misfire on queen replacement and fail. This paragraph is elementary, but is intended to get beginners thinking about survival traits.

Let's speculate: Today, automatic supersedure of the old queen is automatic, but we don't know that characteristic has always been part of the establishment format. "What if" failure of the old queen was an element of the format that needed adjustment? The natural selection process could have drifted toward supersedure of queens, if the colony didn't meet second season reproductive swarm requirements. That's a plausible guess for the automatic supersedure associated with CB/NM. But I'm more inclined to "suspect" the increased brood volume achieved by checker boarding (CB) puts the queen in a strain to keep up. The colony, sensing the queen has trouble with the increased demand, elects to SS at, or shortly after, repro cut off. Pure speculation - and not for general distribution.

The tendency of the second year colony to store overhead during the lull "may be" an adaptation to occupying larger cavities. The typical repro swarm can only do so much in their first year of establishment. They do well to build enough comb to store wintering provisions. However, filling the cavity with functional comb is complete establishment. If in the second year there is still empty space in the cavity, they want to fill that space with functional comb.

A conflicting observation is that both second year and subs, develop wax making capability at the same time - a strong three weeks after repro cut off. It would seem reasonable, if the second year were devoted to completing establishment, the colony would develop wax-making capability earlier, just another enigma of survival strategy.

I consider myself a student of colony survival traits. Learning these traits by observation is a slow process. Not only is there great variation from colony to colony, but seasonal influences in forage availability generate additional scatter in the data.

I don't take sides in the evolution versus creation aspects of those survival characteristics. Both evolution and creation by a super entity are equally incomprehensible to my small brain. But there are latent survival traits in the honeybee survival formal that we have never seen and couldn't guess at the reasons if we did see them.

So much for the" I don't know" answer.



Michael Bush

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Copyright 2006 by Michael Bush

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