Sounds like a scale infestation. If the bumps are removable by scratching them off it's pretty much a given. If they'll take it back - return it. Aside from handpicking, the window of opportunity for treating scale is somewhat limited. Horticultural oil is effective in the "crawler" stage while systemics are on call when the shells are established.

Al

RE: help sick eugenia topiary- black spots on branches
Posted by jwarner191 10 (jwarner191@excite.com) on Sun, Aug 8, 04 at 8:23

I am an entomologist in Boca Raton, FL. Although I really work with ants, I have seen Eugenia with these insects all over Broward and Palm Beach counties, and ants feed on the honeydew produced by these scale insects. The Eugenia plants look like they were hit by a flame-thrower. As I said, the scales produce honeydew which they excrete and then sooty mold (black) grows on the honeydew. I asked my friend who works with scale insects about this. He says that this is the work of the Florida Wax Scale, Ceroplastes (he does not know which species). The family is Coccidae. I can email photos if anyone wants to see them. Maybe I will post them on my website.
Many people have asked me what they should do about this. I have seen Eugenia dying all over and, really, if you want to spend time fighting this, you will probably have to keep spraying the plants with a systemic insecticide like Merit continually, and even then, it might be an uphill battle all the way. Usually in a case like this with a well-established insect pest, the best thing to do is to plant resistant varieties, or some other ornamental plant. I don't know if there is a Eugenia variety that is resistant to this wax scale, maybe someone on this forum knows.

John Warner, PhD qualified entomologist
University of Florida
Fort Lauderdale Research and Education Center, Ant Lab
3205 College Avenue
Fort Lauderdale, FL 33314
USA