Cold torpor - how long until terminal ?

[Karol]

Don't know specifically for bees but lower temps mean lower metabolic demands which is why some people have survived being stuck in frozen lakes for a few hours. They generally had specialist help to recover.

However, there is a limit. For most organisms, if the water in their cells freezes, the crystals will burst their cell membranes and they will not recover. Some species have specialist adaptations to cope with/avoid this, bees are not, as far as I know, one of them.

I have a friend who put some bees in a jar in the freezer overnight for a course and the next day at the course they woke up part way through and started flying around in the jar. Haven't quite figured that one out.

I did some "lab" work on this albeit with queen wasps. What I found was that speed of exposure determined survival in that queen wasps need time to 'urinate', i.e. drain their abdominal cavities to avoid rupture when deep frozen. When I got the interval between freeze, thaw, feed, freeze etc (+20°C to -20°C) optimised I managed to freeze and thaw a queen wasp successfully a dozen times. Whether this is an attribute shared with honeybees I have no idea but I can't see why it shouldn't be a possibility.

 

[Antipodes]

Without noticeable negative effects to laying ability/longevity? Asking because there's been questions asked about cold (and heat) damage to queens in shipping for a long time.

I keep very poor records , but I recall that they are probably not so good...
On a somewhat different slant, whenever I've seen older queens balled, they don't seem to last long after the incident but young and vigorous laying queens that are balled are much tougher and can stay alive and go onto lay ok. I read somewhere though, that once balled and then later accepted (say on a second try), they usually get superseded not too far down the track. It might have been Jay Smith that wrote about it?

 

[rolande]

I keep very poor records , but I recall that they are probably not so good...
On a somewhat different slant, whenever I've seen older queens balled, they don't seem to last long after the incident but young and vigorous laying queens that are balled are much tougher and can stay alive and go onto lay ok. I read somewhere though, that once balled and then later accepted (say on a second try), they usually get superseded not too far down the track. It might have been Jay Smith that wrote about it?

Jay Smith certainly wrote a few things which sound similar, so yes you're probably right.

 

[Wilco]

I did some "lab" work on this albeit with queen wasps. What I found was that speed of exposure determined survival in that queen wasps need time to 'urinate', i.e. drain their abdominal cavities to avoid rupture when deep frozen. When I got the interval between freeze, thaw, feed, freeze etc (+20°C to -20°C) optimised I managed to freeze and thaw a queen wasp successfully a dozen times. Whether this is an attribute shared with honeybees I have no idea but I can't see why it shouldn't be a possibility.

Very cool.

 

[Newbeeneil]

Very cool.

The content or the temperatures?

 

[Sutty]

I did some "lab" work on this albeit with queen wasps. What I found was that speed of exposure determined survival in that queen wasps need time to 'urinate', i.e. drain their abdominal cavities to avoid rupture when deep frozen. When I got the interval between freeze, thaw, feed, freeze etc (+20°C to -20°C) optimised I managed to freeze and thaw a queen wasp successfully a dozen times. Whether this is an attribute shared with honeybees I have no idea but I can't see why it shouldn't be a possibility.

How long were you able to keep them frozen for and still revive successfully?

 

[Karol]

Very cool.

Needs the right kind of temperament I agree.

 

[Karol]

How long were you able to keep them frozen for and still revive successfully?

That wasn't the intent of the study primarily because queen wasps are known to survive Scandinavian and Siberian winters without any difficulty. The purpose of the study was to assess the impact of cold snaps on emergent queen wasp survival.

 

[Nige.Coll]

30 mins in a freezer normally does it but if it's a jar with a ball of bees some of them survive, where a single bee does not. If they can cluster then -15 isn't much to deal with for a short period if they have a full stomach.

 

[Prof]

30 mins in a freezer normally does it but if it's a jar with a ball of bees some of them survive, where a single bee does not. If they can cluster then -15 isn't much to deal with for a short period if they have a full stomach.

They generally don't recover after 2 hours in the freezer. Some can recover after 30 minutes though (depending on your freezer, etc) even if frozen enough to rattle individual bees in the jar, I have found.