I've always thought spider mites to be an insect that is very easy to eradicate. I use a 1 percent spray of horticultural oil, being sure to spray both sides of the leaves, and the wood. Very, very rarely do I have to apply a second application. Insecs, never become resistantance to horticultural oils. -Recently I noticed red spider mites on greenhouse strawvberries, and eradicated them with just plain water. Millet

Here this Bayer product is commercialized as "Masai", its active ingredient is tebufenpyrad.
Mites are also developing resistance to it very rapidly, I am alternating it with Neemoil to avoid this.