What Do Lanternflies Eat?
Lanternflies, specifically the spotted lanternfly (Lycorma delicatula), are sap-feeding insects that primarily feed on the sap of various trees and plants. Their main food source is the phloem—the vascular tissue responsible for transporting nutrients in the plant. The spotted lanternfly has piercing-sucking mouthparts, which it uses to extract the sap from the plants.
Some of the plants they commonly target include:
Tree of Heaven (Ailanthus altissima) – This is the primary host plant for lanternflies, and they often thrive on it.
Fruit trees – They can also feed on apple, peach, grapevines, and other orchard crops.
Maple trees – Lanternflies are often seen feeding on the sap of maples.
Birch and pine trees – They may also feed on various other deciduous and evergreen species.
Other plants – The lanternfly has a broad host range, including various shrubs, vines, and ornamental plants.
Their feeding behavior can weaken the host plants, potentially causing damage such as leaf discoloration, wilting, and even the death of branches or entire plants. Additionally, the lanternfly excretes a sugary substance known as honeydew, which can promote the growth of black sooty mold, further harming the plants. The pest is considered a major agricultural threat in certain regions, particularly in the U.S. where it has become invasive.
How Do Lanternflies Eat?
Lanternflies (specifically the spotted lanternfly, Lycorma delicatula) feed by piercing plant tissues with their specialized mouthparts and sucking out the sap. They don’t chew or bite like many other insects — instead, they use a long, straw-like structure called a proboscis (or stylet) to extract nutrients directly from a plant’s vascular system:
Piercing the plant surface: The lanternfly inserts its sharp proboscis through the outer bark or surface of a plant, often targeting the phloem, the part of the plant that carries sugary sap.
Extracting sap: Once the stylet reaches the phloem, the lanternfly begins to draw out nutrient-rich sap. This sap is high in sugar but low in other essential nutrients, so the insect must feed continuously to get enough sustenance.
Excreting “honeydew”: Because they consume large quantities of sap, lanternflies excrete the excess sugar and water as a sticky liquid called honeydew. This residue can coat leaves, branches, decks, and outdoor furniture, often leading to sooty mold growth, which damages plants further and creates unsightly black surfaces.
Preferred host plants: Lanternflies feed on a wide range of plants (over 70 species), but they strongly prefer Tree of Heaven (Ailanthus altissima), as well as grapevines, maples, willows, fruit trees, and hardwoods.
Their feeding causes serious stress to plants, weakening them, making them more vulnerable to disease, and in agricultural settings (like vineyards), resulting in significant crop loss.