There has been a bit of discussion lately about various methods of killing bees
efficiently, economically and cleanly.  Burning sulfur smoke has been used by
some, soapy water by some, vodka (alcohol) by some, gasoline (petrol) by
others, and I am sure there are other ways too.  One post stated the "theory"
that detergent (dish soap) washes the waxy coating from the bees and they die
from dehydration.  I would like to propose an alternative theory of how the
soapy water kills bees (and other flying insects) based on a discussion I just
had with a pesticide specialist/toxicologist at Texas A&M University.
 
From my own personal experience, I know that soapy water kills bees cheaply,
efficiently and quickly.  It knocks them down like they've been hit by a club.
That does not suggest "dehydration" to me, especially when the bees die while
they are still wet and covered with the soapy "water".  I propose that soapy
water is toxic to bees.  I may not get all the details exactly right, but I
will give it my best shot:
 
Soaps (especially detergents and particularly phosphate detergents) contain
toxic fatty acids.  The cell membrane contains a fluid matrix that contains
phospholipids, proteins, enzymes, ion gates, g-proteins and many charged
molecules that are necessary for the various functions they perform.  When
toxic fatty acids (soapy water) are applied to a bee, they quickly dissolve
into the phospholipid matrix and disrupt the cell functions completely.  They
quickly interfere with critical life functions.  The exoskeleton is full of
pore canals, and these are protected only by a thin layer of oil, which is
easily and quickly penetrated by soapy water.  Gasoline, solvents, acetone,
alcohol will all do something similar, but soap seems to kill them even better
and more quickly.  Potassium soaps work better.  This has been known since the
1700's.  It's also possible that the glial cells which surround the neural
membranes are attacked by the toxic fatty acids, so the bees' nervous system
is poisoned.  This all makes a lot more sense to me than "their waxy covering
gets washed off and they dehydrate."  That doesn't satisfy.  Soap is toxic to
insects.  It's poisonous to them (luckily less toxic to us).
 
Out of all the ones I've heard, I like the suggestion to use the food grade
alcolhol the best.  Seems the cleanest.  A local friend of mine got a new
package of bees this Spring and they didn't do well.  The hive kept weakening
and the bees kept dying off until finally the whole hive expired.  He asked me
and others what was killing his bees.  After asking him some very pointed
questions, he finally admitted to washing his frames with soapy water so they
would be clean for the bees since it was used equipment.  He just neglected to
rinse it off.  Soapy water is a cheap easy way to kill bees.  Most everybody
has some dish soap around somewhere.  If you don't think soapy water is toxic
try drinking some and see what it does to YOUR system.  I'll bet it does more
than just "wash off the wax."  Have a great day and fun beekeeping.
 
Layne Westover
College Station, Texas