Question
Dear Lynnette,   I have small, round, white balls on my rosebushes and evergreens in South Jersey.  Can you tell me what they are and how to treat them?   Thank you for your help.

Answer
The cotton balls are an insect called scale, that protects itself from predictors by secreting a with a white waxy material. Here is some more information for you. I would agree with what they say to get rid of them. If you can't get any horticultural oil, then use canola oil with a teaspoon of liquid soap (preferable something mild for babies clothes) and spray the rose bushes with that.
http://www.honolulurosesociety.org/pests.html
If you have a lot of patience, then you can also get rid of them permanently by dipping a Q Tip into rubbing alcohol and dabbing it on to the bug. Scales can cause a problem for a rose because they suck on the sap which will make the rose bush weak. If you have a lot of roses then spraying them with lime sulphur  (a dormant oil and sulphur spray use the instruction for roses) will do the job for you. Also if scale is a big problem in your area, the a lime spray in the spring is a must.