there are tiny black bumps on my roses...?

It's called "scale". Get some spray, lemons are for flavoring water. Go to a garden center and take a leaf in a SEALED plastic bag and ask for a good treatment. Not Walmart either a garden place with plant professionals not shoe salesmen or tool salespeople. Cayenne is not for bugs they don't have the equipment to taste the heat, that is for groundhogs and muskrats and rabbits. You know while your at the garden center pick up a book about growing stuff instead of listening to people on these forums. There are even You Tube videos and Gardening forums you can go to. I am amazed at the interesting but useless ideas I read on this forum.

What bugs really hate is the scent of lemon. Put some lemon dish soap in your spray. I use Dawn since they do donate a dollar for each bottle we buy to help clean animals that gets trapped in oil when there is a spill. That's what they were using during the BP oil spill at the Gulf. I give my Knock Out roses a bit of Epsom Salt 2-3 times a year and they love it as it helps other plants too if you give them a dash. Spread by having some in the palm of your hand and toss it from one side to the other quickly so its not all in one place. Thankss

can you put a net over the roses