Aphids are green, brown, red or black soft-bodied insects that suck plant juices causing stunting and deformation of leaves and blooms. They are found on the underside of leaves, usually on the newer, more succulent growth. They deposit sticky honeydew on the leaves, which can lead to sooty mold. They reproduce quickly and may also spread plant viruses.
Rinse off the aphids if possible and spray with insecticidal soap or End-All.