Sporadic in occurrence, potato aphid infestations are rarely severe enough to kill plants. Aphids pierce veins, stems, growing tips and blossoms with their needlelike mouthparts. As a result, blossoms are shed and yield is reduced. New growth becomes stunted and curled. Heavily infested plants turn brown and die from the top down.
Aphids tend to spread rapidly from field to field transmitting a number of viral diseases.
These include various mosaics, leaf roll, spindle tuber and unmottled curly dwarf. In South Carolina, female potato aphids feed and reproduce year round. No eggs or males are produced. Without mating, wingless females give birth to about 50 live nymphs. During warm weather, each of these nymphs matures in two or three weeks.