Interestingly, that video suggests that some beekeepers actually prefer the aggressive, "africanized", bees as they can be more productive than less aggressive bees in the right situation. But they're a public health hazard, so most beekeepers choose to euthanize more aggressive hives to deliberately breed calmer, safer, bees.
This video also suggests that the high level of aggression wasn't optimal in at least some areas, so it's being evolved out and the bees are becoming less aggressive: https://www.youtube.com/watch?v=psBomn2cPNw
IIUC workers (or at least worker larvae) can become queens under the right conditions, so it's more likely for the undesirable genes to be removed if the entire hive is euthanized.
Also, in the case of that video, IIRC having the still aggressive workers in the locations available to that beekeeper wouldn't be desirable, even if later generations were calmer.
> it's more likely for the undesirable genes to be removed if the entire hive is euthanized.
Yes, removing the genes is needed, but that can be done by killing the old queen, waiting a day then putting in a caged queen of known good genes. There is no need to kill the hive that I am aware of.
Requeening to correct temperament is part of beekeeping and killing the hive seems extreme. It is also wasteful of the equipment and comb because depending on the method used it won’t be able to be salvaged.
Killing hives is generally done by pouring petrol in the top then sealing the hive up, and is seen as one of the more humane methods. However I’ve only known this being done for American Foul Brood, not for temperament.
The improved temperament sometimes happens almost instantly, but is generally over a about a month as the workers die off. The total lifespan of a worker is only about 6 weeks in midsummer.
I keep bees, but in New Zealand an aggressive colony is a lesser beast than an africanised monster. I hope I’m missing something (eg what is africanised bees reject new queens, but I can’t find anything suggesting this is the case).
It's not about the queens, it's about the drones (male bees).
The workers only start laying eggs if the hive goes without a queen for several weeks, and either way the eggs they lay are unfertilized and therefore cannot be raised into new queens. So requeening it is certain to work in that regard.
However, unless you euthanize whole hive, the aggressive drones will continue to live for a while and can mate with queens in neighbouring hives and spread the aggressive genes that way. So there is an advantage to euthanizing the whole hive instead of requeening it.
Requeening is ideally done with a queen that is from known good stock, not by emergency requeening.
I’ve just done it at home. It’s cheaper to raise your own, but you will get traits that are undesirable, aggression being one.
The drones in a hive are not all raised there, they move about hives, so killing the hive won’t get them all.
Hives that have got a laying worker are also very hard to requeen and it usually isn’t possible. One way is to shake all the bees out some distance away then hope the laying worker doesn’t make it back to the hive (she can’t fly). However those hives are hard to fix, as they usually reject the new queen.
There is a lot of differences in beekeeping region to region and country to country, so whatever I have seen and done may be very different to other places.
Interestingly, that video suggests that some beekeepers actually prefer the aggressive, "africanized", bees as they can be more productive than less aggressive bees in the right situation. But they're a public health hazard, so most beekeepers choose to euthanize more aggressive hives to deliberately breed calmer, safer, bees.
This video also suggests that the high level of aggression wasn't optimal in at least some areas, so it's being evolved out and the bees are becoming less aggressive: https://www.youtube.com/watch?v=psBomn2cPNw