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More advanced beekeeping discussion forum.
 #1817  by AdamD
 31 Jan 2019, 19:52
One of the other posts got me thinking about the number of bees in a hive and the laying rate of a queen.
According to the Thornes catalogue, 10 BS deep frames has 45,000 cells and if we assume that a good frame, on average has, say, 80% of the cells with brood in we would have 3600 per frame. My colonies tend to stick at around 14 - 16 good frames of brood in summer in a double brood set up, so lets say out of 15 frames, the equivalent of two are being prepared for egg-laying at any one time so 13 frames at 3600 eggs/larvae each, which is 46,800 eggs laid in 21 days which is 1950 eggs per day, 81 per hour. This gives the circa 2000 eggs/day usual figure for a good queen. Does this seem about right? And if we assume that bees live for 3 weeks in the hive and 3 weeks as foragers, that would give us 93,600 bees. Too many?
 #1820  by Chrisbarlow
 01 Feb 2019, 08:31
I believe that 2000 eggs per day is too many, I always believed egg laying rate is about 1500 (the one big caveat on this though would be bee race). I would also suspect that 2 frames being "cleaned up" might not be enough but this ties in with 80% of the frames being used, youve put 3600 cells per frame , I always thought that brood frames had over 5000cells and having checked I think they have 5400 cells per frame. At 3600 being 80% that suggests youve got a figure of 4500 cells. I might have that wrong. Its still early.

Across all frames I suspect % used to be much lower. Core frames in my opinion would be close to 90% but these would be very few and the ones on the edge might be down to as as low as 10% or lower (however you know your bees best). I would suggest a percentage useage across all frames might be as low as 30-40%

So I would throw in a figure of 15 frames of brood at 35% useage. I wont include any frames that are being cleaned as I have included this in the 35%useage. So each frame is 5400 and 35% is 1890, so x21 is 39690 new bees over 21 days, giving a suggested colony population over 6weeks of 79380, thats still a lot of bees.

Also 46800 eggs over 21 days is 2228 not 1950.
If you do work out at an egg paying rate of 1500 per day, thats gives a population of 6 weeks of 63000bees
and an egg laying rates of of 2000eggs per day over 6 weeks is 84000 bees.

a piece of research here from 2015 comments about the 1500egg paying rate and also has a population graph
https://articles.extension.org/pages/73133/honey-bee-queens:-evaluating-the-most-important-colony-member
Its definately something to ponder.
 #1824  by Jim Norfolk
 01 Feb 2019, 12:36
I have just counted the useable cells on a drawn Hoffman frame and it amounts to 40 rows of 56 cells which comes to 2240 per side, or 44,800 in a 10 frame WBC. They make a line of cells at the top right up to the wood, but the cells do not go right up to the sides or bottom bar. So I agreee with Adam's figure of 45,000 as a good round number. However I doubt there will be many frames laid up to this level. There are the empty cells for Jurgen Tautz's heater bees to sit in as well as the odd removed egg or larva. Then there are holes or beeways between frames and even a bit of drone comb. A max figure of 80 - 90% occupancy seems reasonable. Many outer frames will have pollen and honey so as Chris suggests the average useage could be as low as 30 to 40%.

However queens do not lay at a steady rate. Looking at Varroa mite drop shows that it goes in cycles. Since mites drop mainly from emerging brood then brood must also go in cycles. The average laying rate will be much less than 2000 per day.

How do we guestimate the number of bees in a hive anyway? Are the book figures correct? So much in beekeeping is being revised in the light of research and observations.
 #1829  by NigelP
 01 Feb 2019, 17:27
Jim Norfolk wrote:
01 Feb 2019, 12:36
I have just counted the useable cells on a drawn Hoffman frame and it amounts to 40 rows of 56 cells which comes to 2240 per side, or 44,800 in a 10 frame WBC.
That has got to be on a par with watching grass grow....
;)
 #1840  by Jim Norfolk
 02 Feb 2019, 09:34
[/quote]
That has got to be on a par with watching grass grow....
;)
[/quote]
Grass isn't growing at present, having to make do with watching paint dry today:cry:
 #1841  by AdamD
 02 Feb 2019, 13:09
Apart from my maths error, (thanks for the correction) a good queen should lay around 80% (maybe more) of the central frames and, I agree, less as you move outwards although my best guess is that 30 - 40% of brood per laid frame is too low.* Some of the central frames may not have pollen in them as the pollen could be in the first super above the queen excluder; just above where the queen is allowed to lay. A colony constrained by the box they are in, can have solidly packed brood on 10 of the 12 frames in a box - which is why I use double brood with many of my colonies. The biggest colony of mine last year had 20 frames of brood - and decent frames at that. Another colony did well (for honey) and only had 8 frames of brood - it might be that those bees lived just a day or two longer to give a good performance.

*Maybe more careful measurement is required next summer.