Plant fluids are the foods that aphids consume. The insects in question (Aphidoidea superfamily) have piercing, sipping moouthparts for puncturing plant tissues in leaves, stalks and stems. They prey upon the nutrient-rich, up-flowing xylem and the sugar-rich, down-flowing phloem that keep plant interiors developing as life cycles and natural histories intend.
Aphids depend on the sap of plants for food, while some species feed on only a particular type of plants. Most aphids feed on different types of roses, while others feed on bamboo, willow, oak, walnut, maple, sugarcane, lettuce, alfalfa and more. Some types of aphids are also known to feed on grape vines.