Feeding by Aphids can stunt plant growth, deform leaves and fruit, or cause galls on leaves, stems and even roots. Many Aphids also excrete a sticky, sugar-containing substance known as honeydew. This material will drop onto the leaves, twigs, and fruit of a plant. A black, sooty mold soon begins to grow on this sugar-rich substrate. This mold not only mars the appearance of the plant, but when abundant, will also reduce the food-making process of a plant known as photosynthesis.
Honey dew is attractive to ants, flies, hornets, and yellowjackets.
It can also mar cars, chairs, tables or other objects that are beneath Aphid-infested plants. In some cases, proper pruning, fertilizing, and watering play an important role in preventing or suppressing an Aphid infestation. Beneficial insects play an important role in Aphid control. Ladybird beetles, lacewings, some flower flies and tiny parasitic wasps will use Aphids as a source of nourishment for their development. Remember certain insecticide applications will destroy these beneficial insects as well as the targeted pest species.