Big trouble: mites

[Rorey]

I don't know if everything is ruined. My son checked my plants today and noticed mites. He also said he thinks they're very close to ready to harvest. So is there any point in harvesting, or is everything ruined because of the mites?

I've got some stuff to use on vegetables that said it can be used up to three days before harvest. I might also have some neem oil. I just don't know if I should use anything this late. Soapy water?

I should add that years ago this son grew marijuana very well (before it was legal), but his grows were always in a controlled environment. He never had to deal with issues of growing outside.

Help!!!