> corona virus can survive 3 days on plastic
> and less than one day on copper and cardboard.
> Does that say anything about the lifespan of bee
> viruses? We already discussed here the waiting
> time to use material after an infection with DWV,
> CBPV and others.
I was considering corona virus a few weeks ago, looking at the literature.
Here are some rule-of-thumb rough guesstimates for sunlight exposure, and
the UV that makes it through the atmosphere to us.
https://dx.doi.org/10.1128%2FJVI.79.22.14244-14252.2005
There was also this news article, giving some estimates of sunlight exposure
required for the Covid-19 virus, but not mentioning any other viruses
https://www.washingtonpost.com/news/powerpost/paloma/the-health-202/2020/04/
27/the-health-202-sunlight-does-kill-the-coronavirus-but-not-in-the-way-trum
p-suggested/5ea5993e88e0fa3dea9c2b24/
https://tinyurl.com/y7krj5yh
But my money is on heat, rather than sunlight for beekeeper use.
Heat also breaks viruses apart, and many beekeepers have rigged up "warm
rooms", or "stack warmers" for supers of honey, so it may be far easier to
for beekeepers to use heat the gear to kill off the common bee viruses.
When the sun is shining, supers and brood boxes tend to be "in use", so I'd
guess that the heat approach would be more practical in making gear more
"virus-free". We know that we don't want to heat combs to a point that they
melt, so the question becomes "how long at 130 F (54 C)" to break down
viruses? This has got to be a function of the particle sizes of the
viruses.
My understanding is that viruses are held together by lipids (fat), so
drying out that fat seems to be the goal of the heating to inactivate the
viruses.
Many viruses have "envelopes" - proteins, and more lipids, so this coating
would imply a need for more heat or more sunlight to break down the
envelope.
Heat alone seems to work for inactivating corona virus, for example, 135 F
for 15 mins seems to kill corona reliably enough to convince Ford to offer a
new software feature to heat police vehicles up for this purpose.
https://www.nytimes.com/2020/05/30/business/coronavirus-police-cars-heat.htm
l
https://tinyurl.com/y7q6tow4
How to extrapolate to bee viruses? Dunno - maybe particle size is a place
to start.
Cornoa virus is about 120nm, most bee viruses are only about 30 nm, so
assuming rough spheres for our model, there is a lot less volume and thus,
mass, to need to heat up in a bee virus particle.
Radiation would also work, but that can only be used so many times before
the woodenware starts to degrade (at least when using the gamma-ray beams
used to irradiate fruit and veggies). (I had hopes that the "e-beam" gear
that the post office bought to sterilize any anthrax in the mail might
become available to beekeepers on the secondary market, but the e-beams,
while working well with envelopes, could not even penetrate cardboard boxes
very well, so forget woodenware.)
We already know that AFB spores can easily outlive the beekeeper to infect
another day, and can survive temps that would kill the beekeeper.
The viruses can't be as tough as AFB.
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