This is Duplex, my black-top desert hairy scorpion, Hadrurus spadix, under a blacklight. In normal light she looks like this:
You should NEVER leave a blacklight on a scorpion long-term. The intense UV rays will eventually kill the nocturnal animal. Some pet stores market scorpion habitats with blacklights because they look cool, but they don't tell you the facts.
This photo is also featured on an eHow tutorial for finding scorpions
And on a list of strange things that have made it onto planes: