Despite their relatively short lifespans, aphids can be quite prolific. In fact, aphids can reproduce faster than any other insect. Migrants returning to the primary host are winged males and winged parthenogenic females which produce egg-laying sexual females. Later on, winged parthenogenic females return to the secondary host. Some aphids feed on foliage, while others feed on the twigs, limbs, branches, fruits, flowers, or roots of plants.
Some species inject toxic salivary secretions into plants as they feed.
If left unchecked, aphids can stunt plant growth, deform and discolor leaves and fruit, or cause galls to form on leaves, stems, and roots. Some species also produce large amounts of white waxy filaments that cover their bodies and litter infested plant parts. This energy-rich anal secretion falls on leaves and other objects below the infestation. As a result, sunlight is unable to reach the leaf surface, which restricts photosynthesis which produces the plant sugars. Honeydew-covered surfaces, including car exteriors, decks, and sidewalks, become sticky and blackened with sooty mold.