I think he would consider aphids as snack if he sits in front of tv
Now in winter I haven't got any insects in my basement and I even have to feed him. He gets small upto medium sized grasshoppers. But this was my first try with a mantis in the neps rooms and it works really great. This won't be my last mantis. Unfortunately they aren't getting very old. Maximum is about a year.
But if you get eggs of mantis the larves should be really a good protection. The larves are hunting from the first moment on and are always hungry. So aphids might be on there menu also. If they've cought all enemies they'll start to eat each other.