What Nanci said, or go ahead and treat the corn too. If you handled the corn after handling the carpet, you may have picked up hitchhikers and unknowingly transmitted them to the corn.
What product are you ordering from LLLReptile? I like Provent-A-Mite. Every new animal that comes into my house is kept in an enclosure with aspen bedding that has been sprayed with PAM. I also quarantine for 90 days. I had a mite problem many years ago, and I hate those little buggers!
Kathy