swarming stimuli

[Rosie]

I was just reading a thread about the stages of worker development, ie 3days, 6 days and 12 days and the fact that the proportion of eggs to open brood to sealed brood gives an indication of colony development.

It reminded me of my own swarming theory which I have not had chance to air yet, apart from to friends in my local association. I would like to bounce this off some of the readers here as I am sure a discussion will be helpful and perhaps interesting to others - even if nobody agrees with my theory!

Here goes:

It is standard thinking that if a colony has a greater proportion of, say,open brood than half the closed brood then the queen's laying rate has, during the period between 3 days and 9 days ago, been greater than it was in the previous 12 days. If there is also plenty of eggs then it shows that the colony is expanding. Now, according to my theory, one of the factors that controls expansion rate is the capacity of young workers to feed brood. If all other things are equal (weather, nectar availability etc) a colony that expands quickly suggests that its workers can produce brood food more quickly than one that expands slowly. This would explain my observation that a pure and non-prolific queen will often produce a much bigger colony and expand more quickly if the workers she produces display hybrid vigour.

Now Eddie Woods observed a droning sound that he put down to nurse bees that had nowhere to deposit their royal jelly while a queen was being slimmed down in preparation to swarm. However, my guess is that the sound is from nurse bees that are too plentiful in numbers and don't have enough open brood to feed. It does not normally happen early in the season because the queen is laying at the rate commensurate with the workers' ability to nurse. To maintain this happy state the queen needs to keep increasing her laying rate so that the colony is forever expanding.

Soon after this expansion stalls the nurses start to become redundant, start moaning about it (Eddie's drone) and swarm preparations are started. It makes perfect sense because the nurses are redundant and are a burden to the colony and probably get on everyone's wick to boot. Hence it costs nothing to bundle these trouble makers off in a swarm and get back to expansion mode again.

If my theory is right then the way to capitalise on it is to constantly rob hives of sealed brood. It limits the number of nurses available at any time and increases the number of open larvae.

In 2012 we had a terrible season. It start well but it quickly deteriorated and queens stopped laying after accelerating up to speed very quickly. It meant that the colonies had only half built up in size before they stalled. We all thought we were safe from swarming because the colonies were all so weak. We were wrong. They swarmed suddenly and caught everyone in these parts unprepared. This can be explained by my theory as the queer season resulted in plenty of young nurse bees but little or no brood to keep them occupied.

This season I have been testing my theory and am now more convinced than ever of its value. Conventional swarm prevention methods such as ensuring there is always expansion space in the hive all help to put off the day when the nurses outnumber their charges and so work until the queen reaches her maximum laying rate or the weather intervenes.

That's my theory. I hope I managed to explain it clearly although it's quite simple really.

[Black Comb]

A few thoughts.

Have you read Wisdom of the Hive by Tom Seeeley. He has some interesting observations and theories re. swarming behaviour and also noise.

In 2012 there was a warm patch in March so queens started to lay like mad, it then went cold but by then the colonies were expanding and many kept on going. when a sudden very warm snap came they took the chance to swarm as they were all full of bees. All of my colonies swarmed the same week.

Some books advise giving 50% foundation frames in first and or second super to keep the nurse bees happy in the earlier part of the season.

[Rosie]

Here they swarmed in 2012 when the weather was still poor and the colonies were still weak. It went against conventional theory and started me thinking about why it should have happened. I, too, use a lot of foundation and even more starter strips but that's to keep the nest free for eggs rather than force bees to put stores in there. It all helps but as I said in my post my theory, if true, explains why it helps.

I should have read Sealey although I must admit I haven't so thanks for pointing it out BC.

[Rosie]

I just looked up wisdom of the hive on Amazon. It's £86 so no wonder I hadn't read it.

[Beefever]

Was it Gurstung who formed the brood food theory? I while since I read about this but he thought a surplus of brood food in a colony would cause them to swarm.

[The Drone Ranger]

I just looked up wisdom of the hive on Amazon. It's £86 so no wonder I hadn't read it.

Hi Rosie
I think what we see in our own experience is more important than books

Quick question on your swarm theory
Why don't the bees divert to another task ?
I did some poking about, and one overlapping task for bees of that age is attending to the queen
Could that be a factor if too many decide to get involved in that job ?

[Jon]

If you keep taking brood away and replacing it with frames of drawn comb, as you do in a queenright cellraiser system it is extremely rare for a colony to get into swarming mode.
To me that suggests that giving the queen lots of cells to lay in probably helps, combined with moving loads of bees and brood above the queen excluder thus reducing congestion.
If you have bees with swarmy genetics it is all academic as they will try to swarm well before the brood box is full.
I know people with bees like this and I suspect it has come about through generations of making increase from swarms and from the first queen cells to appear, ie, artificially selected swarmy stock.

[Rosie]

Thanks BF. I did a bit of searching and found the following written by Wally Shaw:

"Snelgrove based his method on the Gerstung theory of swarming, which claims that swarming is the result of a colony having
an excess of nurse bees producing brood food compared with the number of larvae that need to be fed. Snelgrove knew the
theory had its detractors and retained an open-mind but still regarded it as a useful way to think about swarming. Preemptive
splitting effectively removes a lot of nurse bees from the presence of the queen and brood. The Gerstung theory was
finally disproved as a result of work by Butler and Simpson at Rothampstead in the 1950`s but, theory or no theory.,
Snelgrove`s methods still works."

My money is on Gerstung rather than Butler and Simpson. They might have been working with strains from a different environment.

DR. I suspect that at a certain age bees are more suited to feeding brood or producing royal jelly than any other task and when their instincts are frustrated they start using their excess royal jelly to fill queen cells. furthermore, when a colony has a surfeit of these bees it's an ideal time to swarm because they will not miss the bees that leave the nest.

[The Drone Ranger]

Hi Rosie
I use Snelgrove boards every year and have all his books
Stops swarming right through the oil seed rape period

When the brood all goes above the board they must hatch with the potential to become brood feeders
Perhaps that's why they are so happy to raise grafted queen cells

[Rosie]

I hope this is acceptable etiquette but I just found another reference on the BBKA forum.

"The brood food theory of Gerstung with regard to swarming was once accepted as correct and led to various swarm management techniques yet we now know that it really doesn't stand up to rigorous scientific scrutiny and now has only a historical significance."

It might explain why the technique does not appear in any of the BBKA courses that I have seen or the current crop of books available.