No this is not correct. Ophionyssus natricis is a snake mite, it can reproduce only on snakes. http://vpi.com/publications/the_life...of_snake_mites
I would be very cautious of P-A-M it is a potent poison and should be treated as a poison. In many places (growing list) it is banned for one reason or another. It works but is capable of harming snakes and other pets (and children) as well. make sure for follow all the precautions for it.
The other thing to remember is Permethrin breaks down to a phenol (the oil in cedar wood is also a phenol) that should be cleaned away roughly one month after use. It is not easily water soluble so alcohol is best.