It says it kills their eggs, too, and I believe it. It's quite literally the only stuff I've ever used that I didn't have to immediately spray a 2nd coat after 2 days. Usually even with
Neem oil you have to go do a 2nd spray after a couple of days after the eggs hatched again, but with this stuff I've seen very very few eggs hatch after first spray. One spray and you'll almost completely wipe out the entire spider mite population (if done right, taking care to spray under leaves and spray down branches and such). A follow up spray a couple of days later and you won't see another spider mite again unless you completely missed something.
I had a buddy who was literally killing himself trying to get rid of spider mites on his grow op. He had 2 full grow rooms and a greenhouse FULL of spider mite infested plants. He was using everything under the sun, including
Eagle 20 (a very bad bad product to use on cannabis) and the spider mites were just becoming immune to everything he was spraying.
One day I brought some of this stuff over and told him to use it, he sprayed it once and it almost immediately turned his whole grow op around. He had both red and 2 spotted spider mites and it worked wonders on getting rid of all of them.