Maintaining a drone population

[Jon]

What is that window MBC? They are fertile about 2 weeks from emergence but how long does fertility last after that point?

Lindsey - I have some colonies which definitely overwinter a small number or drones.

[prakel]

Could it be that the current years drones get chucked out over the winter and the ones we see in a drone laying colony in the early spring have been laid after the brood break? That’s my $64,000 question.

I think Dr Jurica based his system around the idea that by the Spring there would be a lot of younger drones even if the older ones were still present. Which is one reason why he needed to fill the brood-nest with drone comb in order to get the consistently good results which he reported.

[mbc]

In the natural course of events, I'm not sure anyones recorded it, but certainly those who practice II find it difficult to harvest useful semen from drones over a month old.

[Jon]

In the natural course of events, I'm not sure anyones recorded it, but certainly those who practice II find it difficult to harvest useful semen from drones over a month old.

so likely just a couple of weeks from maturity?

[mbc]

so likely just a couple of weeks from maturity?

Well, you know what they say Jon, bees know best, I would think they do it a little better than a manual drone everter
but I think it is a shrinking and hardening of the testes that makes the older drones useless for II so one would imagine the same effect would also come into play during natural copulation(or failure to do so) but perhaps not quite so soon after emergence.
In Queen Bee: Biology, Rearing and Breeding by David Woodward, it actually says they only use drones between 12 and 20 days old.

[Jon]

Yes, I imagine they have peak fertility a couple of weeks from emergence and that it tails off. Some of the papers I have read that look at the DNA in a queen's spermatheca show that a single drone can contribute maybe 30% of the semen and others only a few percent. I guess one explanation for that could be the viability of an individual drone's sperm but there could be several other explanations for the non random contribution from each drone.

[Adam]

When I was studying for the BBKA queen rearing module, I recall 90 days as a maximum for drones as a viable 'bonk by date.' with a 1 month ideal time. I would be surprised if over-wintered drones were much good unless they were to go into a 'winter-drone' state in the way we have winter bees. (Fat bodies build up perhaps?) There is currently a little drone comb in a few of my colonies - just the odd corner of old drone comb here and there - so for me there would still be a chance of drones going into October if they're not chucked out first. The worry for me is whether the drone brood is indicative of a failing queen. In nature, I would guess that there are probably enough colonies in any one area that have queens that fail during winter to act as drone producers for spring supercedure queens - then it's up to the weather.

For supercedure, I've had a couple that worked well this year. One in the summer as the brood nest was shrinking when it should have been increasing and a perfect supercedure where I saw mother and daughter on the comb this weekend. A big fat daughter with the brood nest increased from what it was a few weeks ago. In both cases Mum had not produced drones but was slowing down markedly.

[Adam]

mbc - is David Woodwards book to be recommended? I have Eigil Holms book and don't like it - the translation is rubbish and it's difficult to understand.

[mbc]

mbc - is David Woodwards book to be recommended? I have Eigil Holms book and don't like it - the translation is rubbish and it's difficult to understand.

The Woodward book is a bit of a "how to" manual, with an emphasis on the Cloak board method, and no flowery narrative, but its very clear, I particularly liked the genetics bit, so clearly and simply explained that even I made some sense of it.
I would highly recommend it, but I'm sure to many of you it would seem a bit of a "bricklayers" queenrearing book.

[Jon]

I looked in a few colonies today and a couple of queens had started laying again in drone comb. 10 September today. Do these bees who know best really think they will have a use for fertile drones around mid October? I have about 15 queen cells due to emerge on Sunday, grafted into a queenless colony last Tuesday in a moment of madness so maybe I might get a few of those mated. Sunday in the 14th so in theory they could fly and mate from about 20th September.

I had several colonies superseding and their new queens all started to lay in the past week. last Thursday it reached 22c so any queen who failed to fly and mate on that day needs its 'bees know best' head examined.

Came across the latter stages of a mating swarm today as well, a little cluster with a queen on top of a water bottle which was acting as a weight on top of a Payne Poly nuc.
They were acting a bit aggressive with their queen, starting to ball and sting at times. I have seen them kill the queen at this stage. Not sure why they would do that as it is colony suicide, well in reality apidea suicide in this case. There was only one Apidea on the site with a virgin. I checked it and she was not at home. I'll have a look in a couple of days to see if she made it back in one piece. I have a couple of gammy leg queens in apideas at the moment.