Thrips show up heavy during the spring and fall. Once the blooms are getting ready to show color in the buds, I spray the tops of the bush's every 36 hrs. with Ortho's Complete Insecticide. I have a little over 100 rose's and it takes about 1 1/2 gals. of spray, using a 2 gal. pump sprayer, every time. To me, it is well worth it. Thrips will destroy a bloom in a big hurry.

I use Orthene and I spray only the buds. You should also remove any spent or damaged buds and blooms and put them in a sealed plastic bag and throw them out. It helps to keep the population down.

Thanks to both of you for your response. I will start spraying the buds.