Aphids are herbivores, and they eat juice and sugars from the leaves, stems and roots of plants. Aphids consume virtually every part of the plant, including stalks and flowers. They eat large quantities of sugar, which is excreted in large volumes to produce a slimy substance called honeydew.
Aphids prefer to eat young, succulent plants and seedlings, which generally contain the highest amounts of sugar and nutrients. The leaves, stems and stalks of these plants are high in protein and fiber as well, which enhances aphids’ diets. Aphids feed upon plants and vegetation of all varieties, but prefer sweet and fragrant fruit-bearing plants and shrubs over grasses and weeds.