Cicadas are insects recognized for the distinctive sounds produced by males, especially during warmer months. These creatures spend most of their lives hidden from view, emerging periodically to complete their life cycle. Understanding their specific dietary habits provides insight into their biology and their interaction with the environment.
Cicada Food Sources
Cicadas, both as nymphs and adults, primarily sustain themselves by feeding on xylem sap. Xylem sap is a watery solution transporting hormones, essential mineral elements, and other nutrients from a plant’s root system up to its leaves. Nymphs spend years underground, ranging from two to seventeen depending on the species, extracting these fluids from plant roots.
Adult cicadas continue this specialized diet, consuming sap from young twigs and small branches above ground. Their feeding is minimal, primarily for reproduction, not extensive nutrition. Cicadas do not consume solid plant parts like leaves or fruit. Many species show preferences for common deciduous trees such as oaks, maples, and hickories.
How Cicadas Feed
Cicadas possess specialized piercing-sucking mouthparts. These mouthparts form a rostrum or beak. Within this beak are needle-like components called stylets.
These stylets form a food canal and salivary duct, supported by mandibles for piercing. The entire stylet assembly is enclosed by a flexible sheath, the labium. When feeding, a cicada pushes its stylets through the bark of a plant or into roots to access the xylem vessels. They then suck the watery sap directly from these vessels, a process that can last for several hours.
Effects on Plants
While cicadas feed on plant sap, their feeding activities do not inflict significant long-term damage on mature, healthy trees. The more noticeable impact on trees comes from the female cicadas’ egg-laying behavior. Females use a saw-like appendage to create small slits in young branches where they deposit their eggs.
This egg-laying can weaken the affected branch tips, causing them to wilt, turn brown, and sometimes break off, a phenomenon commonly called “flagging.” While flagging can appear dramatic, especially during mass emergences, mature trees recover well from this natural pruning. Young or newly planted trees, however, are more susceptible to damage from extensive egg-laying due to their limited branch structure and can experience more severe impacts. Nymph feeding underground causes little noticeable harm to the plant.