did you see the UCD paper I posted last week about mites? In California they are becoming resistant to pyrethrum and permectrin.
Time to break out the Seven dust!
You have it backwards. They are resistant to Sevin dust.
"Also, pyrethrins and synthetic pyrethroids are a good choice for use in a chemical rotation program because they
are chemically unrelated to the organophosphate and carbamate pesticides traditionally
used for mite and louse control. If you rotate the type of pesticide that you use, you
can slow the pest’s development of pesticide resistance. Northern fowl mite is known to
be resistant to both carbaryl and malathion in some parts of California. "
I looked it up because I'm having difficulty getting rid of the mites here. I'm using permectrin 10 spray.
Works great for flies!