>>What is the mechanism whereby CO2 causes this effect?

One possible explanation is offered in this study where bees were anaesthetized with CO2, nitrogen, and chloroform and pollen foraging virtually stopped in the CO2 and N2 treated bees. They wrote:


"The  close similarity  of the  results  of  the  CO2 and N2 treatments  indicates  that  the
effects  are  produced  by the  same  mechanism  in  both  cases. The  factor  common  to
both treatments  is that they deprive the  bee  of oxygen; the  effects may therefore be
ascribed  to  oxygen  lack.  They  are  not  produced  by CHCI3, which  acts  upon  the
nervous  system. Dr Wigglesworth,  in  conversation,  has  suggested  the  possibility
that oxygen lack prevents the oxidation  of acid metabolites produced by the activity
of the  bee, and that temporary  high accumulation  of these metabolites  gives rise in
some  way  to  permanent  effects."


Ribbands, C. R. "Changes in the behaviour of honey-bees following their recovery from anaesthesia." Journal of Experimental Biology 27.3 (1950): 302-310.

Bill Hesbach

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