Jon,
I enjoyed your thoughtful post.
You said that high gut osmolarity causes diarrhea, but this isn't true. Watery diarrhea is caused by pathology of the cells lining the intestines: They fail to transport water and electrolytes properly. This is one of the major causes of death in diseases like cholera and Ebola....uncontrolled osmotic and electrolyte balance due to intestinal lining failures. Not diet per se....we eat all kinds of stuff that can wildly affect osmotic pressures and our guts handle it all just fine, adding or subtracting water and electrolytes....as long as the cells lining the passages are healthy.
Bees exhibit diarrhea too....we see the symptoms of Nosema and spring dysentery all over the hives around their entrances. We know that Nosema damages ventricular (gut lining) cells. However I do not know how these pathologies affect the bees' hemolymph tonicity....that would be interesting to know! As you point out they have a diet that is hypertonic. But they also drink water. Perhaps they can suffer from cellular dehydration if their intestinal/ventricular wall cells are unable to manage transport functions properly. That's what I would expect anyway.
Christina
***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html