There are small (2mm) round, black, disc-like objects which seem to be attached to the leaves of my knockout roses by a very fine

Question

single filament. What are they and how do I get rid of them? They have just appeared in the last week and are not on any other plants that I have seen. I live in Charleston, SC.

Answer 1

It could be scale on your roses. Other sap suckers are aphids, mites, and thrips. Use an insecticidal soap to zap them. Scale are more difficult when they are in the hard shell phase, as the armor protects them. Here's how to control scale:
https://www.gardeningknowhow.com/plant-problems/pests/insects/control-plant-scale.htm