In Aphidinae, migrants returning to the primary host are winged males and winged parthenogenic females which produce egg-laying sexual females. Some species have lost their host-alternating behavior and only have a complete life cycle on a herbaceous plant. In these species, males produced may be winged, wingless or both. Both parthenogenesis and host alternation have enabled aphids to exploit their food plants, particularly short-lived herbaceous plants such as most agricultural crops. Some aphids feed on foliage while others feed on twigs, limbs, branches, fruits, flowers or roots of plants.
Some species inject toxic salivary secretions into plants during feeding.
As aphid populations develop, infestation sites become littered with cast skins. Many aphid species secrete a sticky substance called 'honeydew' which is similar to sugar water. 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, restricting photosynthesis that produces the plant sugars. Honeydew also attracts ants, flies and other insects.