Body Temp

Andrew R · Post by **Andrew R** » Sun Dec 17, 2006 4:08 pm

Hi, what is the lowest temp a butterfly survive during winter hibernation?

Thanks Andy

eccles · Post by **eccles** » Thu Dec 21, 2006 12:39 am

Commas hibernate as adults out in the open so I would imagine they can handle being subjected to lower than the freezing point of water. How they do it is a mystery to me.

Andrew R · Post by **Andrew R** » Thu Dec 21, 2006 1:30 am

Thanks.

It makes food for thought that something so delicate can survive some real cold snaps.
Today it was -4 in Durham City.
So cold I brought the dogs in the house for a warm up.
Mind I still let the wife goto work!

Post by **Pete Eeles** » Thu Dec 21, 2006 7:33 am

There is some, rather technical, rationale here:

http://entomology.unl.edu/ent801/cold.html

But the summary is that the insect seems to increase its production of "anti-freeze" agents (such as glycerol, which has a much lower freezing point than water). A temperature of -20 degC is mentioned

Cheers,

- Pete

Andrew R · Post by **Andrew R** » Thu Dec 21, 2006 10:31 am

Thanks Pete

eccles · Post by **eccles** » Thu Dec 21, 2006 2:53 pm

Interesting article. Glycerol apparently not only acts as an anti-freeze in the commonest sense, i.e. lowering the freezing point of water-based cells, it also enables further supercooling down to the quoted -20C without ice formation. Moreover, it will protect cellular structure from damage when frozen to even lower temperatures, and is an essential ingredient in long-term human and animal sperm storage. This explains how Arctic midges and mosquitos can survive. UK winters are comparitively balmy by comparison.

I heard once that camberwell beauty butterflies cannot survive UK winters because they aren't cold enough to trigger the deep hibernation that they require.