Cicadas are known for their loud summer songs and sudden appearances, but have you ever wondered what they eat? Unlike many insects that chew leaves or fruits, cicadas have a very simple and specialized diet.
They feed mostly on plant sap using a straw-like mouthpart. In this article, we’ll explore what cicadas eat during their long lives underground as nymphs and their short time above ground as adults.
Understanding Cicada Feeding Habits
Cicadas have a very different way of eating compared to most insects. They don’t bite, chew, or eat solid food. Instead, they drink a watery substance called xylem sap, which flows inside plants. Cicadas use a special mouthpart, like a straw, to suck this fluid directly from roots, stems, or branches.
Their feeding habits also change with age. Cicada nymphs live underground for years and feed on the sap from plant roots. Once they become adults and come above ground, they may continue feeding, but they don’t eat much. Adult cicadas live only a few weeks, just long enough to mate and lay eggs. So while food is important for survival, they don’t need large amounts.
What Do Cicada Nymphs Eat?
Cicada nymphs live underground for several years, feeding on fluids from plant roots. Their diet is simple but continuous, allowing them to slowly grow and prepare for their emergence.
Tree Root Sap
Cicada nymphs attach their straw-like mouthparts to tree roots buried underground. Trees like oak and maple have strong, deep roots that provide a steady flow of xylem sap.
This sap is mostly water with tiny amounts of nutrients. Even though it’s not rich, it’s vital for cicada growth and survival during their long underground stage.
Shrub and Bush Roots
Nymphs often feed on the roots of common shrubs and bushes such as azalea or boxwood, especially when large trees aren’t nearby.
Different regions have different types of shrubs, so cicadas adapt to whatever is available, making use of local root systems to meet their needs.
Grass and Herbaceous Plant Roots
In grassy areas like lawns, cicadas may tap into the roots of grass and herbaceous plants such as dandelions or wildflowers.
These roots are easier for younger or smaller nymphs to access, but over time, heavy feeding may affect lawn health or garden growth.
What Do Adult Cicadas Eat?
When cicadas emerge as adults, they shift from root feeding to feeding above ground. Although their need for food is minimal at this stage, they still sip sap to stay hydrated during their brief time alive.
Xylem Fluid from Tree Branches
Adult cicadas use their needle-like mouthparts to pierce into soft tree branches and drink xylem sap.
Since adult cicadas only live for a few weeks, they don’t need much nutrition—just enough to keep them active for mating and egg-laying.
Preferred Trees for Adult Cicadas
Cicadas commonly feed on trees such as oak, maple, pine, apple, and cherry. These trees have abundant, moist branches and are widely available in many regions.
Their soft bark and active sap flow make them ideal for adult cicadas to tap into without much effort.
How Cicadas Feed
Cicadas feed using a long, thin mouthpart called a proboscis, which works like a straw. Unlike insects that chew or bite, cicadas use this tool to pierce into plant tissue and draw out fluid.
Once the proboscis reaches the plant’s xylem, it starts pulling up the sap. Xylem sap is mostly water with a small amount of nutrients, but cicadas consume a lot of it over time. Nymphs use this method underground to drink from roots, while adults tap into tree branches or stems above ground. It’s a simple but effective way for cicadas to stay hydrated and survive.
Do Cicadas Harm Plants by Feeding?
In most cases, cicadas do not seriously harm trees or plants just by feeding. Their method of sipping xylem sap is gentle and usually doesn’t affect healthy trees or shrubs.
However, problems can occur when there are large numbers of cicadas. Too many feeding in one area can stress young or weak plants. Adult cicadas can also damage small branches when laying eggs, which may cause twigs to split or die back — a condition called “flagging.” This is more of a concern for young trees or ornamental plants than for large, mature trees.
What Cicadas Do NOT Eat
Many people worry that cicadas will eat leaves, fruits, flowers, or garden vegetables — but that’s a myth. Cicadas do not chew or eat solid plant parts at all. They don’t have the mouthparts for it.
Cicadas rely only on xylem sap, which they drink through their proboscis. This means your fruits, flowers, and vegetables are safe, even during a cicada emergence. They don’t eat garden plants, they don’t bite people or animals, and they don’t destroy crops like some other pests.
Their diet is extremely limited — just plant sap — and their role in the ecosystem is more about aerating the soil, nourishing predators, and pruning weak branches than causing widespread plant damage.
Summary:
Cicadas feed only on plant sap, using a straw-like mouthpart to drink xylem fluid. Nymphs feed on root sap underground, while adults sip from tree branches. They don’t eat leaves, fruits, or garden plants. Though large numbers can cause minor damage, their feeding is generally harmless and part of a natural cycle.
