From: DISEASE REMOVAL BY ALTERED FLIGHT BEHAVIOR OF FORAGER HONEY BEES (APIS
MELLIFERA) INFESTED WITH NOSEMA APIS
J. Kralj, S. Fuchs, J. Tautz
National institute of Biology, Slovenia

As quoted by Peter Borst:

"This behavior can be interpreted as *suicidal pathogen removal*, serving 
as a disease defense mechanism which reduces the colony's load of parasites 
or pathogens."


Peter,
   I’m having a hard time making the connection between the impaired 
ability of individuals to make it back to the hive because of the adverse 
effects of parasites and the impulse of individuals to commit suicide for 
the benefit of the colony because of said parasites.  The former seems a 
much more obvious explanation for why individuals would not make it back 
than the latter. 
   Beyond that, I don’t see how one could distinguish between death by 
suicide and death as a result physical impairment.  Is there something in 
the studies that you site that shows more directly how the conclusions are 
made:  first of all that bees are deliberately leaving to die rather than 
just leaving and dieing:  and secondly that this would really be of 
survival benefit to the colony? Presumably it would have to be shown that 
the removal of parasites from the colony owing to this behavior would 
outweigh the adverse effect of losing otherwise viable individuals.  In the 
summer and early fall at least, it seems to me that you would have a 
tendency toward decreased adults in the colony at the same time you would 
have an increase in the emergence of mites from brood, setting up a cycle 
of doom for the colony unless more parasites were being carried away than 
were emerging.  If that is true it is difficult to see how this suicide 
behavior mechanism would be a survival benefit to the colony even if it 
could be clearly demonstrated that such behavior was actually occuring.

I appreciate your posting these kinds of things.  They get me to thinking.

Steve Noble

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