Maintaining a drone population

[Jon]

There is also the question of drone quality versus quantity. Full combs of drone brood are not desirable if you want to produce QUALITY drones.

Hi Duncan. I am not sure I agree with that. A strong colony can easily keep a couple of drone combs laid up over the summer. I reckon my strongest colonies have 3000-4000 drones peak season.

I have combs like this:

drones on frame.jpg

[Duncan]

As I said, there are drones and there are DRONES. When doing AI, I can see the difference in semen quantity. A large number of drones have a very small amount of semen or are firing blanks!
Another interesting observation is that the drones that are on the small side often produce the most semen! These are from the same hive as the larger ones that are often duds. Just some things that I have noticed over the years.

[Little_John]

As I said, there are drones and there are DRONES. When doing AI, I can see the difference in semen quantity. A large number of drones have a very small amount of semen or are firing blanks!
Another interesting observation is that the drones that are on the small side often produce the most semen! These are from the same hive as the larger ones that are often duds. Just some things that I have noticed over the years.

Is there a definite correlation between the amount of semen a drone produces, and the amount of viable sperm within it ?
LJ

[Jon]

Hi Duncan. I realise that some drones are infertile but I don't see how you can link that to the quantity of drones a hive is making. There are 101 reasons why a drone might be infertile. Age and disease would be two obvious variables which spring to mind.

[Duncan]

If you are unable to appreciate the difference between a colony raising 1000 and 5000 drones, then I do not see any point in continuing the discussion.
As mentioned above, give a colony 100 queens cells to feed, they might complete all of them but queen quality would be very low, they would produce good quality queens if > 20 were offered.

[Jon]

Duncan, a colony feeds worker larvae at the same time it feeds drone larvae so the total number of mouths to feed would be more important than just considering the amount of drone brood. The key factors will also include number of nurse bees in the colony relative to colony size, nectar flow to the colony, pollen intake and variety of pollen amongst others.
I insert drone combs into the brood chamber so that the colony will raise a relatively large number or drones relative to the total population of the colony.

[mbc]

Everything points to quality being more important than quantity with drones, barring the swallow bait effect.

[Little_John]

Is there a definite correlation between the amount of semen a drone produces, and the amount of viable sperm within it ?
LJ

With no answer forthcoming, I decided to have a 'google' around ... Seems that this is yet another poorly researched area: it's suggested that there are many variables involved (age, size and weight, genetic lines, season, climatic condtions and so on ...), so perhaps that is why

But - not only does it appear that there's no definite correlation between semen volume and sperm concentration, but the 'experts' do not even agree (in terms of the number of sperm observed) on what constitutes a 'healthy' drone, nor what constitutes a 'healthy' mating.

Oh well, back to the muddy waters ...

LJ

[busybeephilip]

As I said, there are drones and there are DRONES. When doing AI, I can see the difference in semen quantity. A large number of drones have a very small amount of semen or are firing blanks!
Another interesting observation is that the drones that are on the small side often produce the most semen! These are from the same hive as the larger ones that are often duds. Just some things that I have noticed over the years.

I agree with what Duncan is saying having observed the same although I have always avoided undersize drones so cant comment on that. Rearing drones is hard on a colony which has been set aside for that purpose. I am talking about at least a minimum of a full super of drone comb with brood in all stages. The colony needs continuous gentle feeding and often to be supplemented with pollen substitute. Its not a case of simply adding a frame of drone comb to obtain II drones. For II, a large number of drones of the correct age are needed, the age window appears to be rather narrow, too young you get nothing and similarly to old is no use due to popping. You can tell immediately when the drone inverts (some don't) from the color of the horns whether its worthwhile trying to harvest. As Duncan comments, the amount of semen does vary quite a lot. Semen quality is a different matter which I have never tried to investigate fully although dead and live can be stained with fluorescent dyes and counted under a UV microscope - only a useful tool if one intends to store semen for lengthy periods

[Jon]

A couple of years ago I spent an afternoon everting drones with Tim B and a lot were firing blanks, or were too old. I think if you want drones of the correct age for II you need to get the timing right with regard to when the comb goes in and when the drones are harvested. The ones that we were popping were just randomly harvested at the entrance of a colony by placing an excluder over the front once they were out flying on a sunny afternoon. You would need to be more organised than that. Proper nutrition is critical for queen cell production or any aspect of beekeeping for that matter. With a flow on and abundant pollen you get more cells started and better fed queens. I had about 15 virgins emerge in the past 10 days and some of them look like nice specimens so let's hope there is time and the weather for them to mate with the remaining drones. A colony I opened at the weekend had a big slab of sealed drone brood but those ones will be no good for at least 3 weeks.