Hygienic behaviour - natural selection

[boca]

Exactly 50 years ago Rothenbuhler discovered that colonies that show this behavior are resistant to AFB. This is clearly advantageous to the colony (and to the beekeeper). However only 10 - 12 % of the colonies have this trait. In the competition it seems most often the lower or not hygienic trait is stronger.
What could be the disadvantage of this behavior?

 

[mintmoth]

Speaking from the point of view of a total newbie, it seems to me that opening cells containing dead or diseased larvae/pupae and dragging the offending body/bodies across comb through bees and out of the hive, plus cleaning out the cells, runs the risk of spreading a disease throughout the hive. Better to leave it sealed, abandon the infected comb, and if necessary abandon the whole nest.

Perhaps in the pre-historic past, bees that abandoned dead brood survived better than bees that removed it, which would maybe account for the 90% - 10% split?

 

[REDWOOD]

All bees are hygienic

 

[pargyle]

Speaking from the point of view of a total newbie, it seems to me that opening cells containing dead or diseased larvae/pupae and dragging the offending body/bodies across comb through bees and out of the hive, plus cleaning out the cells, runs the risk of spreading a disease throughout the hive. Better to leave it sealed, abandon the infected comb, and if necessary abandon the whole nest.

But the bees don't understand this ... they will move heaven and earth to get rid of something that offends them inside the hive .. dead bee bodies, dead larvae, mummified brood as a result of disease indeed ANYTHING that they consider alien and which should not be there will be dragged out of the hive.

When you have watched them for a year or two you will be amazed at the tenacity of the cleaners and undertakers in the colony. As Redwood says - they are one of the most hygienic forms of life - they could certainly show man a thing or two judging by the pavements and grass verges of some places I visit !

 

[boca]

I also think as mintmoth. There must be something that favors those that do not touch the dead larvae. Did you came across some report that selected highly hygienic lines were more sensitive to some disease? EFB perhaps?

 

[mintmoth]

All bees are hygienic

From what I've read, though, to paraphrase Orwell, it seems some bees are more hygienic than others.
But as I have indicated, I am a complete tyro, here to learn, and really know nothing about bees. (Learning lots here though)

I also think as mintmoth. There must be something that favors those that do not touch the dead larvae. Did you came across some report that selected highly hygienic lines were more sensitive to some disease? EFB perhaps?

No, it was a passing idea, that's all.

Another thought that came to me was that as the bees find the corrupt cells by smell, evidently it's going to be the bees with the best sense of smell that are considered the most hygienic, since the more sensitive the olfactory response, the quicker they will discover and clean the corrupt cells.

So over the centuries that man has kept and bred bees, has selective breeding to produce better honey gatherers, or better temperament etc resulted in the sense of smell being diminished in some strains, as it has not been selected for (in the same way that some breeds of dog are better "sniffers" than others because they've been bred to it)?

 

[pargyle]

No, it was a passing idea, that's all.

Another thought that came to me was that as the bees find the corrupt cells by smell, evidently it's going to be the bees with the best sense of smell that are considered the most hygienic, since the more sensitive the olfactory response, the quicker they will discover and clean the corrupt cells.

Not necessarily .. bear in mind that worker bees follow a pattern and it is the youngest bees that tend to be the cleaners and undertakers and the oldest ones are the foragers with a variety of jobs in between. Also take into account that a bee has the ability to sense odours (and separate them) in tiny concentrations - parts per billion - so a strong smell in the hive is going to be very easily noticed - like a brick wall I would think !

I suspect that the bees have more than just sense of smell to rely on for their in-hive operations - they can probably sense movement as well (or a lack of it) in sealed cells and will uncap and eject dead larvae. Who knows what other super-senses bees have built in and developed over 50 odd million years - I wonder where homo sapiens will be in another 49.7 million years in terms of OUR development ? At present, I think HS is REGRESSING not advancing in terms of our sense-abilties or should that be SENSIBILITY ?

 

[mintmoth]

But some bees clean well, and some not so well.

I found this interesting reading http://onlinelibrary.wiley.com/doi/10.1002/neu.10219/abstract

 

[mbc]

All bees are hygienic

Nail on head.
For us to observe "hygenic" behaviour too many of the subfamilies in the colony are focused on this facet to do well in open competition with colonies with more diverse subfamilies, after all, AFB is uncommon.

 

[Dishmop]

But the bees don't understand this ... they will move heaven and earth to get rid of something that offends them inside the hive .. dead bee bodies, dead larvae, mummified brood as a result of disease indeed ANYTHING that they consider alien and which should not be there will be dragged out of the hive.

When you have watched them for a year or two you will be amazed at the tenacity of the cleaners and undertakers in the colony. As Redwood says - they are one of the most hygienic forms of life - they could certainly show man a thing or two judging by the pavements and grass verges of some places I visit !

I have seen them drag bits of a leaf out that got trapped between boxes on an inspection...Elastic bands.....bits of wood shaving...newspaper after uniting.

 

[REDWOOD]

Bees will enter a hive white full of HB pollen and leave immaculately groomed, so what happens in between is either sell grooming or other bees doing it for them, I have never seen a white bee leaving a hive unless it's a dead bee.

 

[The Drone Ranger]

Depending on the brood disease there will be a time when the larva is at its most infectious so if it is removed before that point its an advantage but the same behavior facing another threat might make matters worse in which case leaving a sealed cell might be better ?

 

[Scutellator]

Exactly 50 years ago Rothenbuhler discovered that colonies that show this behavior are resistant to AFB. This is clearly advantageous to the colony (and to the beekeeper). However only 10 - 12 % of the colonies have this trait. In the competition it seems most often the lower or not hygienic trait is stronger.
What could be the disadvantage of this behavior?

Here you will find the answer

https://www.youtube.com/watch?v=txZtQrMTeag

 

[bontbee]

Thanks for this link - I found some of the references useful, as well as the general substance. Cheers.