Charles,
 
Thanks for "weighing in" on the soap discussion of how it kills bees.  The fact
that soap is a surfactant and the bees would suffocate by water penetrating
their breathing apparatus makes very good sense.  It's a whole lot better than
suggesting that they "dehydrate".  Garth suggested that the things I described
would happen "secondarily" to make sure the job is complete, but you may be
right that the surfactant effect is the main mode of action when spraying bees
or hornets with soapy water.  In the case of the beekeeper who washed his
frames with soapy water and let them dry, leaving a soap residue that
subsequently killed his bees (although more slowly), do you think the
surfactant effect was still the cause of death, or rather that in this case it
might have been caused by the toxicity of the soap.  Safer soaps have been
developed with the express purpose of killing insects.  If the surfactant were
all that was needed, then why bother using insecticidal soaps?  Just some
things I've been thinking about.
 
Layne Westover
College Station, Texas