Posted by LordV on 14-10-2006 12:14
#56
Cor Zonneveld wrote:
I wonder about the physics of the process. Flies are generally some rather dark colour, so they take up solar heat easily. The fluid drops are mostly translucent, so any light just passes through them and little heat will be absorbed.
I attach a photograph of a small Sepsidae with a bubble. It was fully clouded weather, and on top of this, the fly would have been in full shadow if there were any sunshine!
So to me physics and some observations are not consonant with the heating-up-your-food hypothesis.
I'm sorry I cannot come up with something more positive...
Think you are probably correct ie heat transfer is not significant factor. I think it much more likely that it is purely a concentrating process by evaportion of perhaps a chance to remix the stomach contents with a new batch of salivary gland enzymes.
Brian V.