> Does anyone know of tests under inexpensive material such as
> polythene, or trials against larvae, eggs and pupae?
 
I visited a Californian queen breeder about 15 years ago who had
obtained a beat up old transport/shipping container.  As I remember,
he planned to fill it with his baby nuc equipment which was
vulnerable to moth damage.  He was then going to cobble together some
sort of smouldering-device to produce CO2 and monoxide, figuring
either/both should do the trick, and duct it into the container.  He
figured that he might not get so high a concentration, but could
readily afford to increase time.  I have no idea of the outcome(s)!