Aphids on rose bush
Almost every year my roses get infested by aphids. Some are green, others pink. I have been able to narrow it down to genus Macrosiphon and strongly suspect that they are the introduced aphid, Macrosiphon rosae. I would like confirmation. Here are some images. I could supply higher resolution photos or specimens if necessary. http://bugguide.net/node/view/354050 http://bugguide.net/node/view/355930
Montgomery County Pennsylvania
Aphid species that attack roses seem to vary by area of the country. Clemson Cooperative Extension says "Various species of aphids feed on roses, but the predominant species is the rose aphid (Macrosiphum rosae)." If you want a positive identification, you can take a sample to your Penn State Extension and have it sent to entomology. Meanwhile, I will also try to refer your question to an entomologist on eXtension.