One Deep Brood Box, or Two? Mathematical Rambling Thoughts

Beekeeping - Basics
1

I have been wondering about this for a long time, and I wanted to do a thought experiment. This will be very flawed and approximate, and I welcome any input or ideas.

Basic Facts
Langstroth Deep Frame – 3,500 cells per side
Queen laying – 1,000 to 3,000 eggs per day
Time for workers to hatch – 19-22 days

Assumptions
Queen lays 2000 eggs per day (She is young and vigorous, right? :slightly_smiling: )
Queen only lays workers (not true)
Using 8-Frame Langstroth Deeps for brood box
Average worker emerge time (from egg) 21 days
Brood frame is about 50% worker brood maximum (I don’t have any evidence, this is just observation), and probably 30-40% maximum across the whole brood box. The rest is honey, pollen, other brood (queens or drones) and empty cells.

How long to fill a single brood box?
So with these starting points, how long would it take a queen to fill an 8-Frame Flow hive deep brood box?

Let’s assume a maximum of 40% of cells is worker brood, which is 40% of 3,500 x 2 sides per frame x 8 frames per box = 22,400 worker cells. Probably an overestimate, but let’s move on…

At a rate of 2000 eggs per day, the queen could fill that box without being honeybound in just over 10 days. Now, that is assuming all comb is drawn, honey flow is maximal, well-established colony, no disease etc.

So in order to give enough space for the queen to maximize laying throughout the nectar flow season, with my very rough assumptions, we will need 2 Deep boxes for all workers to reach maturity.

Now if you have a colder climate, or a nectar dearth, or a slow queen, one box may be enough. I just did this calculation out of curiosity. When we looked into beekeeping my area, I was very surprised that SoCal beekeepers run on 2 deeps or triple mediums (same volume), but now I can get an idea of why that may not be unreasonable.

Please let me know what you think of my amateur musings. :blush:

5 Likes
2

and then if you want to let them store pollen and honey for themselves you go to 3 deep boxes.

1 Like
3

Agreed, but I haven’t had to do that yet. Seems to be enough honey and pollen around the tops and edges of the deeps for them. Hopefully my bees will get stronger as I learn how to deal with California oddities. To my mind, you are an exceptional beekeeper - way above average. I am just average. :wink:

Dawn

1 Like
4

That 3rd box is for us cold climate beekeepers. It allows for a huge winter cluster along with allot of pollen and honey storage. By having all that pollen the queens seem to start laying much earlier than in my small hives. With the small hives they have to wait for fresh pollen to start coming in before they get going. The result is a big foraging force once the first blooms open and lots more honey :slight_smile:

3 Likes
5

Pollen in early spring has to be a good thing. Glad you are so aware of what your bees like to have in their homes. :smile:

1 Like
6

From the bees’ point of view…

Sometimes I feel
Like my only friend
Is the city I live in
The city of angels
Lonely as I am
Together we cry

The Angels could be us as beekeepers. The City can be our friend when they decide to take the side of our bees. We cry together when our colonies suffer, but we try to learn, and improve, doing it better next time.

Thank you so much for your inspiration @Anon

Dawn

2 Likes
7

The bees need pollen to feed the brood so if it is in short supply (1 or 2 box colony) they have to wait until it starts coming in from the Spring blooms. With the big hive, the majority of the frames in the bottom box are pollen from the previous season so brood rearing commences much earlier. It seems the hives are an entire brood cycle ahead of the smaller hives and of course that means more foragers for the early spring honey :slight_smile:

1 Like
8

I’m finding in my climate that one deep super is more than enough for brood rearing. Recently I’ve inspected the brood of really strong hives to find only half the frames were used for raising brood. I reckon that a second or third box dedicated to brood could be overdoing it, considering the extra boxes & frames that needs to be allocated for this purpose.

I have found in most cases where I used 2 supers for brood, the bees worked on the top super & the middle part of the bottom super, leaving the outside frames in the bottom super mostly empty & unprotected from SHB infestation.

It’s important to make sure that every frame you have in the brood is used to it’s maximum potential. Some people have multiple supers for brood, however using frames that are not up to scratch & should have been freshened up with fresh foundation years ago. Therefore needing multiple supers to house all those dodgy frames in order to be just as effective as one super with all good frames. This is how I see it. cheers

1 Like
9

Hi Dawn, I love your amateur musings. I do a little bit of that myself. Sometimes when I’m doing preemptive swarm controls, I’ll find 6 or 7 deep frames at least 66.6% of sealed or younger brood. I round it off at 4,000 bees per frame in 21 days. Say, you work on 6 frames, that = 24k bees in 21 days. 48k in 6 weeks. That IS a phenomenal population increase in such a short time.

I’m constantly reminding people of the advantages of adding just one frame of sealed brood to a weak colony. Especially if you can estimate that frame to be 2/3’s sealed brood. Adding only 4k bees to a weak colony can make a big difference.

3 Likes
10

I like the thoughts and recommend two brood boxes, however I would suggest the queen laying rate would be more accurate at closer to 1000 per day for your calculations

11

I totally understand that, but experienced beekeepers like @Michael_Bush have quoted numbers of up to 3,000 per day, so I just took a “median” number. :wink:

Dawn

12

They say a queen can lay up to 3000 eggs per day, but that is dependent on how many cells are prepared for for her to lay in. How many eggs a queen lays is also dependent on how much food she is fed. It’s all relative to the size of the colony & how much food is coming in & what time of the season it is.

1 Like
13

Exactly, which is why I made an approximate assumption to cover the average maximum likely to be seen by average beekeepers. :slightly_smiling:

Thanks Jeff

1 Like
14

Queens are NOT laying 3,000 a day all the time, but here is what Dzierzon said:

“As the queen is capable of adapting the sex of the eggs to the cells, so she is also able to adapt the number of eggs to the requirements of the stock, and to circumstances in general. When a colony is weak and the weather cool and unfavourable she only lays a few hundred eggs daily; but in populous colonies, and when pasture is plentiful, she deposits thousands. Under favourable circumstances a fertile queen lays as many as 3000 eggs a-day; of which any one may convince himself by simply putting a swarm into a hive with empty combs, or inserting empty combs in the brood-nest of a stock, and counting the eggs in the cells some days after.”–Jan Dzierzon, Rational Bee-Keeping, 1882 English edition, Pg 18

“We occasionally read in books on bees, or works on natural history, that the queen in her lifetime lays about 60,000 eggs. Such a statement is simply ridiculous; 600,000 to 1,000,000 would be somewhat nearer the truth; for most queens, in spacious hives and in a favourable season, lay 60,000 eggs in a month. The queen, as a rule, commences laying eggs in February, and continues until September, though not always at the same rate. An especially fertile queen in the four years, which on an average she lives, may thus lay over 1,000,000 eggs. The Author once had a queen fully five years old, which was still remarkably vigorous, and might have lived for another year or two if she had not been destroyed. It is, therefore, quite credible that the age of the queen occasionally extends to seven years, as we are assured by some bee-keepers who have made this observation; yet when we are told that in exceptional cases queens have continued alive for eleven to twelve years, the assertion probably rests on a delusion, or such a case is as rare as that of a man attaining the age of one hundred years or more. There is certainly a great difference among queens as regards fertility; the best mothers are those that lay a great number of eggs and deposit them in the cells regularly, neither laying two eggs in one cell nor missing a cell. With such a queen in the hive the brood is nicely arranged, and much of it hatches simultaneously, thus making it easy for the queen to repeat the operation of depositing eggs when the cells have been emptied. When such is the case the stock will be thriving, its well-being depending chiefly on the queen, who, as it were, is the soul of the hive.”–Jan Dzierzon, Rational Bee-Keeping, 1882 English edition, Pg 18

as far as how many days he said this:
“When the young worker-bee has left the cell — which, reckoning from the egg, will be the case at the end of nineteen days, under favourable circumstances, but generally at the end of twenty to twenty-one days…”–Jan Dzierzon, Rational Bee-Keeping, 1882 English edition, Pg 20

So 19 was the normal number on natural comb. Huber says the same.

As far as how many cells on a frame:
http://bushfarms.com/beesfaqs.htm#cellsonaframe
Deep frame of 5.4mm foundation 7000
Deep frame of 4.9mm foundation 8400
Medium frame of 5.4mm foundation 4620
Medium frame of 4.9mm foundation 5544

1 Like
15

Wow, thanks Michael, you put a lot of time and effort into that!

:blush:

Dawn

16

I got my calculator out. Say a queen lives 5 years & lays an average of 1000 eggs per day for those 5 years, that equals over 1.8 million.

18

I’ve only ever run single 9 frame brood boxes so don’t have experience with doubles or more. However from my experience the queen will lay in 7ish plus sometimes a little on the outside frames during peak season. And the frames will be about 90-95% worker brood. We run queen excluders and the bees move almost all the honey upstairs to make room for the queen to lay so we get a better honey harvest, plus it’s so much easier managing hives when you only have to worry about the 1 box.

As far as pollen stores go, we don’t collect pollen yet so there’s usually lots but I’ve read that when trapping pollen you can get enough in 1 season to feed pollen patties to 50 spring colonies. Could always trap and give them pollen as they need in spring buildup?
Just my thoughts.

3 Likes
19

Part of the issue with how many brood boxes is climate. People in the deep South of the US usually run only one brood box and don’t seem to have any issues with that. People in the North usually run two deep ten frame boxes for brood and that seems to be about right. In the middle (say Tennessee or so) they tend to run one deep and a shallow for brood and that seems to work out about right. This leads me to the conclusion that bees in a warmer climate don’t build up as explosively as bees in a colder climate. It’s as if the bees sense that winter is coming so they work harder and the queen lays more eggs because they are in a race with winter. So one deep brood box has proven inadequate in cold climates.

1 Like