UV Rays for Sterlization

UV kills everything that is exposed to it. If there were no ozone layer, there would be no life on Earth.

Well, sort of... Much like Keith Richards, insects have been shown to adapt rather quickly. Studies were performed in the 60's that showed many insect could withstand ionizing radiation levels that would kill you or me.

Additionally, many insects can see well into the ultraviolet. Special photography has shown that there is a world of patterns and directors on the surface of flowers that are invisible to us, but show the insect exactly where to go for the nectar. So guess why your bug zapper has an ultraviolet light in the middle of it. It sure ain't the UV that kills that pesky mosquiteo.

As far as the fungus thing is concerned, I'm not sure. The problem is that wood eating fungi usually reside deep in the tree, where not much UV can reach. X-rays might be a better fungus killer, provided you didn't fry the tree. However, as a gardener friend of mine has told me on several occasions: 'If you can see the fungus, it's already too late for the tree.'

Vermin-

Did you know that UV is responsible for the ozone layer? The wavelength of 248 nm splits the O-O bond in molecular oxygen (O2), generating atomic oxygen, which then reacts with more of the molecular oxygen present, generating ozone (O3). Without the ultraviolet light from the sun, and molecular oxygen there would be no ozone layer.