I have switched from potatoes to carrots and the mealies love them. They have a lower moisture content than potatoes which is good because I had a grain mite scare a while back. Good luck!
I'm using carrots right now, and I just want to give them a little variety. I've read about your mite infestation, sorry to hear about that =(. I'll take the potatoes out after one day of it being there, like I'm doing with the carrots. Thank you!