Mark,
I am sure you have seen this before, but if not, it is a good read. This is a link to the Barker's write up on Mite History.
http://www.vpi.com/publications/the_...of_snake_mites

As stated in the reading, mite eggs usually hatch in 1 to 4 days. That is the reason PAM is so effective. It kills mites for up to 30 days. Therefore, you should be able to make it through one full life cycle before it wears off. However, just in case you didn't get everything killed, the can tells you to reapply 30 days after the original treatment.

Just some extra info,