Thanks for the quick feedback!
A quick google on waxworms indicates that they wouldn't be any harm to orchids - although our decimated honeybee population would probably want me to keep them from escaping

And the fruit flies are pretty benign. But my case may not be tight enough in all spots to keep them inside - and I've already caused enough marital grief by spending all my time working with plants. A few bugs in the house and I think she'd kick me out with my plants.
Are there any readily obtainable (or culturable) predators that would serve as frog bait, stay in the case, AND eat scale?