Bean aphid

Bean aphid is a dark olive green to black aphid. It is most easily confused with the cowpea aphid. Bean aphid has a dull, matte appearance while cowpea aphid is shiny. The cauda of the bean aphid has more hairs than that of the cowpea aphid and thus appears bushy. Except for the presence of wings, the winged form of the bean aphid is similar in appearance to the wingless one.
Damage. Injury from bean aphid occurs from virus transmission and from direct feeding on sugarbeet leaves. Bean aphids transmit Beet yellows virus, Beet western yellows virus, and Beet mosaic virus. Although bean aphids do not vector viruses as efficiently as green peach aphid, generally bean aphid occurs at higher densities, which tends to negate the differences in virus transmission efficiency.
Infestations of bean aphid generally begin on young leaves in the center of the crown. As the number of individuals increases, older leaves are colonized. The aphid is found mainly on the underside of leaves and only rarely on upper surfaces. Infested leaves curl under and inward and become severely distorted. The leaf margin and eventually the entire leaf become necrotic. Heavy populations may kill foliage, even in large mature plants. Bean aphid produces large amounts of honeydew, and infested leaves are usually covered with sooty mold. If the aphids are killed, either by insecticides or natural enemies, leaves resprout from the crown and new foliage begins growing