I have read that spinosad can be used systematically but the directions on the packaging of the concentrate that I use to control spider mites only has directions for using this product as a spray. My issue is that by the time I discover the pest on my plants, they have already taken over. I am seaking information from persons that have used this product in the soil and head to he suckers off at the pass.
I haven't used spinosad as a soil drench except on ants but I use it for just about everything else. Your question aroused my curiosity so I did a little online research and found out that spinosad does in fact act as an excellent means of controlling spider mites when used as a soil drench. The only problem with using it is the monetary costs. I cannot rid myself of spider mites but I can control them long enough to have a complete harvest. https://www.ncbi.nlm.nih.gov/pubmed/16180075
I switch back and forth between spraying spinosad and neem oil to control my spider mite issues. Well, at least it seems to be doing the job at the moment. There is no reason for switching back and forth, just my idea of giving them the double whammy... I have now started spraying whether I see the little so and so's or not. They seem to be very adept at hiding..
