I have cut all the buds and put them in a plastic bag and disposed of them. I sprayed the entire bush, then once a week thereafter sprayed buds with Ortho rose and flower insect killer. I also did this last year. I grew some new roses this year and they also have thrips.
How Do I Get Rid of Thrips on My Roses?
I recommend using some Bayer Tree and Shrub granules. The systemic action will get into the system juices of the roses and truly get at the thrips. Thrips are tough bugs to get rid of as they can hide from sprays so easily and thus go unphased by them. The Bayer granules mentioned seem to keep on working for the entire season for me. Here is a link to an article for you as well: https://www.gardeningknowhow.com/ornamental/flowers/roses/rose-thrips.htm