Some years ago one of our NZ bee scientists was working to find a good
'knock down' type chemical for killing bees in a hive, one that was (1) able
to kill quickly and effectively (2) leave no residues in the honey/wax (3)
would make for minimal clean up (hopefully with the bees dropping to the
floor upon death (4) allow for full reuse of wax, frames, boxes and (5) safe
for operator...

Only chemical I remember specifically him talking about at the time was
resmetherin, described now as a mosquito adulticide.

Any comments on what might be possible?  Other chemicals?