I spent $800. on a quart of this for use on my tropical hibiscus because the owner of the nursery where I bought many of them said that he uses an Avid type for spider mites once a week 2 times, and then Pylon on the 3rd week. So, I did exactly as he did in my greenhouses with the Avid type 2 times and then used Pylon on the 3rd week. However, even though I had carefully took off extra leaves off of plants for better coverage and carefully sprayed each leaf on the upper and under sides, the spider mites were back within 6 days. I cannot perpetually be spraying for mites every week of my life. I am thinking that the plants from his nursery have become resistant to this product.