Well - if you know of a simple 'green' method of keeping several hundred drawn brood combs wax-moth-free over winter ... I'm all ears.
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So - what's the green answer ?
LJ
There is no "green answer" for all applications, yet one specific answer could be deployed in your situation, LJ.
That answer lies, as always, in looking at the target;
http://agriculture.vic.gov.au/agriculture/pests-diseases-and-weeds/pest-insects-and-mites/wax-moth-a-pest-of-combs-and-honey-bee-products"Damage occurs mainly in the warm and hot months of the year when wax moths are most active. However, considerable damage can still occur during the cool part of late autumn and early spring as greater wax moth can produce a large amount of metabolic heat which can raise the immediate temperature around them by up to 25C above the normal environment temperature. Little if any damage is seen in the extremely cold winter period, because the larvae are relatively inactive.
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"The eggs hatch within 3 - 5 days when temperatures range from 29C to 35C. Hatching is delayed when temperatures are colder and at 18C hatching commences about 30 days after egg laying."
So... in your barn/shed a palletised stack of boxed frames could be wrapped in builders plastic, taped to a loose seal to ground, and fed by a simple cobbled together timed gas feed of dry nitrogen initiated/terminated via a "top of stack" mounted thermostat with a set point of 0.Celcius and a diffetential of 5.
The operation would then inject nitrogen say twice a day for four hours when the stack ambient reached 0.Celcius, becoming inactive at ambients below -5.Celcius.
https://en.m.wikipedia.org/wiki/Lighter_than_air"Nitrogen gas (density 1.251 g/L at STP, average atomic mass 28.00 g/mol) is about 3% lighter than air, insufficient for common use as a lifting gas."
Of lower usage cost then Argon and only marginally more cost inhibitive than CO2 - given quantities used - nitrogen should prove a safe cheaper alternative than options put so far. Though I am liking Robo's option as it suits us in the tropics whereas the nitrogen option may prove a higher cost over the electrical charge for ozone generation, for us.
http://www.rentfreegas.com.au/hvac-nitrogen-bottle-rent-free-cost-comparison/https://www.google.com.au/url?sa=t&rct=j&q=cost%20of%20dry%20nitrogen%20per%20cylinder&source=web&cd=6&ved=0ahUKEwjs_KuSutLVAhUDW7wKHaifAKkQFggoMAU&url=http%3A%2F%2Fwww.umass.edu%2Fprocurement%2Fcontracts%2FCA11-RH-4042%2520-%2520Pricing%2520Recap%2520for%2520Air%2520Gas.pdf&usg=AFQjCNGQDlYMPCqi3HTdMCi34xVIDifgLAhttp://www.peakscientific.com/genius/?gclid=EAIaIQobChMI8Ki5i8HS1QIVk4C9Ch26IQjMEAAYAyAAEgKZz_D_BwEhttp://www.bubble-o-meter.com/bom.php?curPos=BOMFlow control is achieved via a 24hour timer controlling a thermostat initiated solenoid which feeds a simple glass/poly bubbler from a regulated nitrogen cylinder. For fault protection all that electrical apparatus could be fed from a 20AmpHour gel cell battery charged through a self regulating 12Volt amorphous photovoltaic cell, roof mounted.
For myself none of any of these options for wax moth control are or ever have been required as it just not something I have ever had to worry about in either a commercial or domestic apiary operation.
Storing comb long term is not a feature of Aussie bee management, in my experience.
The above is simply what has been put together from some light reading and a little thought around how - in a past life - we handled farm-gate produce pest and disease control, using ethlyene and fumicides for hundreds of tonnes of produce daily.
If required I could supply electrical and gas plumbing schematics.
Cheers.
Bill