What Do Cicadas Eat?

Cicadas are specialists in drinking plant sap, a feeding strategy shared with many wildlife species. An adult cicada uses a sharp needle-like mouth part called a proboscis to punch through plant tissue and suck the watery fluids flowing inside. They target the sapwood layer of trees, where nutrients and water move upward. Once a cicada finds a good spot on a branch or trunk, it stays there for hours, slowly draining sap. Underground, nymphal cicadas feed on root sap in a similar way, using their proboscis to pierce tiny rootlets. Different cicada species prefer different trees. Some like oaks and hickories, while others choose ash, elm, or fruit trees. Cicadas don't chew leaves or stems. They're entirely dependent on the liquid sap that flows within the plant, making them specialist feeders unlike grasshoppers or beetles that munch solid plant material.

The 13-year and 17-year periodic cicadas have the most dramatic dietary shifts. For most of their lifecycle, they remain underground as nymphs, feeding steadily on root sap for over a decade. Then they emerge as adults for only a few weeks. During those adult weeks, they feed on sap from branches and twigs high in trees. Annual cicadas, which emerge every year, have shorter underground phases lasting just one or two years. Their nymphs follow the same sap-feeding strategy but spend less total time underground. Once above ground, both periodic and annual cicadas seek out woody plants in late spring and summer. As plants enter dormancy in fall, sap flow slows down, and adult cicadas disappear. By winter, all cicadas are either pupating underground or dead, with the next generation of nymphs still feeding quietly on root sap far below.

In the Texas region, cicadas feed on live oaks, pecan trees, and various shrubs adapted to heat and drought. Cicadas in Illinois and the Midwest focus on hickory, oak, and maple trees that dominate those forests. In Maryland and the Eastern Seaboard, they target ash, elm, and dogwood among other hardwoods. Southern cicadas encounter different tree species and feed on magnolia, sweetgum, and various pines. Western cicadas working through semi-arid regions adapt to smaller trees and shrubs, though species diversity is lower out there. Regardless of region, cicadas are not picky once they're underground. Root sap from any woody plant will sustain a nymph. The real differences come when adults emerge and climb to the canopy, where they switch to whatever trees are most abundant locally. This regional flexibility allows cicadas to thrive coast to coast.

Cicadas don't hunt in the way predators do. Instead, they're stationary feeders that locate plants by chemically sensing sap. A cicada lands on a branch or finds its way to tree roots, then uses its proboscis like a needle to probe the plant tissue. Once the sharp tip pierces the outer bark and reaches the sapwood, the cicada begins sucking. The process is slow and passive. A cicada can feed at the same spot for hours without moving. Periodical cicadas spend most of their underground life this way, attached to root sites. When they emerge, they repeat the behavior in the canopy. Unlike mobile feeders that search for multiple food sources, cicadas stay put and let the plant's internal pressure push sap toward their mouth. This strategy works because sap is abundant wherever there are trees. The downside is that cicadas can't move fast or respond to threats. They rely entirely on the plant's health and their ability to find new feeding spots if a tree declines.

Baby cicada nymphs are miniature versions of adults and eat exactly the same food: plant sap. When an egg hatches, the tiny nymph falls from the tree to the ground and burrows into the soil. It then seeks out tree roots and feeds on root sap for years. A 13-year cicada nymph will feed this way for 13 years, growing slowly through five distinct stages called instars. Each time it molts, it enlarges and develops more fully. Throughout all these years, the diet never changes. Root sap sustains them completely. The only real difference between juvenile and adult feeding is location. Nymphs work underground on roots. When they finally emerge and transform into adults, they move up into the canopy to feed on branch sap. This switch takes only a few weeks. The adult phase is short, often just four to six weeks, and during that time they focus on feeding and breeding rather than finding new food sources.

Cicadas will readily feed on trees in yards, parks, and gardens if those trees are available. They're not attracted to or repelled by human presence. An old oak in a suburban yard is just as appealing to a cicada as a forest tree. They feed on landscape trees like maples, elms, birches, fruit trees, and ornamental species. Heavy cicada feeding can cause minor twig damage, but cicadas rarely kill trees. The threat of cicada damage is overstated. Trying to poison or trap cicadas in yards is ineffective and unnecessary. The best approach is to leave them alone. If a tree has cicadas, it will continue to grow and thrive. The only situation worth managing is if you have newly planted young trees with tender bark. Wrapping stems loosely with netting can help, but this is rarely essential. Unlike some garden pests, cicadas are not attracted to feeders, fruit, or human food. They feed only on plant sap and cannot harm people, pets, or property.

Cicadas are often confused with locusts, which are actually grasshoppers, and with insects called cicada killers, which are wasps. True locusts are grasshoppers that chew leaves and vegetation, totally different from cicadas that drink sap. Locusts are also more mobile and form swarms that travel. Cicadas are stationary feeders that never form swarms. Another look-alike is the katydid, which resembles a grasshopper and also chews leaves. Cicadas have a rounder body and that distinctive needle mouth. Treehoppers and spittlebugs also feed on plant sap, just like cicadas, and they're far more closely related to cicadas than to locusts. However, treehoppers are much smaller and far less visible. Spittlebugs produce foam on plants that cicadas never do. Aphids also drink sap, but they're tiny and cluster on plants in masses, while cicadas are larger and usually solitary feeders. The key difference across all these insects: cicadas use that straw-like proboscis to pierce and drink, while grasshoppers chew solid plant tissue, and other sap-feeding insects vary widely in size and behavior.