Cicadas 101: What Are Cicadas?

by Alex Schnee | August 13, 2025 | Blog

If you’ve ever experienced a summer filled with an unmistakable buzzing chorus that seems to come from everywhere at once, you’ve encountered cicadas. These fascinating insects emerge periodically in massive numbers, creating one of nature’s most remarkable spectacles. While their loud singing and sudden appearance in large quantities can be startling, understanding what cicadas are, their lifecycle, and their ecological role can help you appreciate these unique insects rather than viewing them as pests.

What are cicadas?

Cicadas are large insects belonging to the order Hemiptera, related to leafhoppers and aphids rather than locusts or grasshoppers as commonly mistaken. There are over 3,000 cicada species worldwide, with about 190 species in North America alone. They’re categorized into two main groups: annual cicadas (appearing every year in smaller numbers) and periodical cicadas (emerging every 13 or 17 years in massive broods). 

What makes cicadas particularly noteworthy is their unique lifecycle, with most of their existence spent underground before emerging for a brief adult phase focused solely on reproduction. During this emergence, their populations can reach astonishing numbers—sometimes exceeding a million per acre. Cicadas are primarily known for the males’ loud acoustic displays, produced by special organs called tymbals, which create their distinctive buzzing or singing sound to attract females.

What do cicadas look like?

Adult cicadas have a distinctive appearance that makes them relatively easy to identify. They typically measure between 1 to 2 inches in length with robust, stocky bodies. Their most notable features include two pairs of large, transparent wings with prominent veins that fold roof-like over their bodies when at rest. These wings span wider than their bodies, giving them a substantial appearance. 

Cicadas have wide-set, bulbous, reddish-orange or black compound eyes on either side of their head, with three small simple eyes (ocelli) arranged in a triangle on their forehead. Their short antennae protrude between the compound eyes. Body coloration varies by species, ranging from black to green, brown, or even vibrant patterns, often with darker markings. Their powerful front legs allow them to cling tightly to tree branches and trunks, where they typically congregate during their brief adult stage.

Lifecycle of a cicada

The cicada lifecycle represents one of the most unusual development patterns in the insect world, particularly for periodical species. It begins when a female uses her ovipositor to slice into small tree branches and deposit up to 600 eggs. After 6-10 weeks, tiny nymphs hatch and drop to the ground, immediately burrowing into the soil. These nymphs then spend the next 2-5 years (annual cicadas) or 13-17 years (periodical cicadas) underground, feeding on tree root fluids. 

During this time, they gradually grow through five developmental stages or instars. When soil temperatures reach about 64°F at the appropriate time in their cycle, the mature nymphs tunnel upward, emerging often in enormous synchronized numbers. They climb vertical surfaces, shed their nymphal skins, and transform into adults. This adult stage lasts only 2-6 weeks, focused entirely on mating and egg-laying before the cycle begins again.

Are cicadas locusts?

Cicadas are frequently misidentified as locusts, but they are entirely different insects belonging to separate orders. Locusts are a type of grasshopper (order Orthoptera) that can transform from solitary individuals into swarming populations under certain environmental conditions. They’re herbivores with powerful hind legs for jumping and chewing mouthparts that can devastate crops and vegetation. 

Cicadas, conversely, belong to the order Hemiptera (true bugs) and have piercing-sucking mouthparts for extracting plant fluids. While both can appear in large numbers, locust swarms actively travel long distances consuming vegetation, whereas cicada emergences remain relatively localized around their underground development sites. The confusion likely stems from biblical references to locusts and early American colonists who mistakenly applied the term “locust” to periodical cicadas during mass emergences. Unlike locusts, cicadas pose minimal threat to mature plants and crops.

What are the differences between cicadas and crickets?

Cicadas and crickets differ significantly in appearance, behavior, and lifecycle. Physically, cicadas are larger (1-2 inches) with broad bodies, transparent wings, and prominent eyes, while crickets are smaller (½-1 inch) with a more cylindrical body and long antennae that often exceed their body length. Their sound production varies dramatically—male cicadas create their distinctive buzz using specialized organs called tymbals on their abdomen, producing among the loudest insect sounds on Earth, primarily during daylight hours.

Crickets, however, produce their familiar chirping by rubbing their wings together (stridulation), typically at night. Lifecycles also differ substantially: cicadas spend years developing underground before a brief adult stage, while crickets have shorter lifecycles (typically under a year) spent entirely above ground. Habitat preferences contrast too—cicadas prefer trees where adults feed and reproduce, whereas crickets inhabit ground-level spaces like tall grass, leaf litter, and occasionally enter homes.

What are the differences between cicadas and grasshoppers?

Cicadas and grasshoppers represent distinctly different insect groups with notable contrasts in appearance, behavior, and ecology. Taxonomically, cicadas belong to the order Hemiptera (true bugs) while grasshoppers are in the order Orthoptera along with crickets and katydids. Physically, cicadas have stout bodies with large, clear wings held roof-like over their body and prominent eyes, whereas grasshoppers feature elongated bodies with powerful hind legs specialized for jumping and smaller, less transparent wings. 

Their feeding habits differ significantly—cicadas have piercing-sucking mouthparts to extract plant fluids from woody plants, while grasshoppers possess chewing mouthparts that can consume entire leaves and plant tissues. Sound production varies too: cicadas generate loud buzzing through specialized abdominal organs called tymbals, while grasshoppers create sound by rubbing their hind legs against their wings or body.

Perhaps most dramatically, their lifecycles contrast sharply—cicadas spend years developing underground with brief adult stages, while grasshoppers complete their entire lifecycle above ground within a single year.

What kind of damage do cicadas cause?

Despite their imposing appearance and massive numbers during emergences, cicadas cause surprisingly limited damage compared to many other insects. The primary concern involves their egg-laying behavior, where females use their ovipositors to create slits in small tree branches (typically ¼ to ½ inch in diameter) to deposit eggs. This process can cause a phenomenon called “flagging”—where branch tips turn brown and sometimes break off, particularly on young or newly planted trees. 

More significant damage can occur to nursery stock and young orchards less than four years old. Cicada feeding activity, where they extract plant fluids through piercing-sucking mouthparts, rarely causes notable harm to established trees. Ground disturbance from emerging nymphs creating exit holes is superficial and temporary. 

Unlike many agricultural pests, cicadas don’t consume leaves, destroy crops, or spread plant diseases. Their ecological role as food for various wildlife and their soil aeration benefits often outweigh the minor, primarily cosmetic damage they cause.

Are cicadas dangerous?

Cicadas pose virtually no danger to humans or pets despite their intimidating size and extraordinary numbers during emergences. These insects don’t bite or sting—their mouthparts are designed for piercing plant tissues to extract sap, not for defense or attacking animals. They don’t carry or transmit any diseases affecting humans or domestic animals. If handled, cicadas might attempt to pierce skin with their proboscis in a case of mistaken identity, but this rarely breaks skin and isn’t an aggressive action. 

The primary concerns regarding cicadas involve noise disturbance during mass emergences (their calls can reach 100 decibels, similar to a motorcycle engine) and very rare allergic reactions in sensitive individuals. For pets, particularly dogs who might consume large quantities of cicadas out of curiosity, mild digestive upset can occur, but serious complications are exceptionally uncommon. 

Rather than being dangerous, cicadas actually provide ecological benefits through soil aeration, natural tree pruning, and serving as a food source for many wildlife species.

How to know if you have a cicada emergence

Identifying an upcoming or active cicada emergence involves recognizing several distinctive signs, particularly if you’re in an area due for a periodical cicada brood. The most obvious pre-emergence indicator is the appearance of numerous small, perfectly round holes in the soil—about ½ inch in diameter—typically in late spring when soil temperatures reach approximately 64°F. These exit holes often cluster near tree bases where nymphs have been developing underground.

Once emergence begins, you’ll find discarded brown exoskeletons (shells) attached to tree trunks, fence posts, and other vertical surfaces where nymphs have crawled up to transform into adults. These empty casings remain intact and can persist for weeks after the cicadas themselves have moved higher into the tree canopy.

The most unmistakable sign is auditory—the distinctive, intensifying chorus of male cicadas that can reach exceptional volume levels, particularly during midday when temperatures are highest. This synchronized singing creates a pulsating drone that’s difficult to miss and often described as otherworldly when experienced at full intensity.

Visual confirmation comes from spotting the adult cicadas themselves, typically clustered on trees and shrubs during the day. For periodical cicadas, the sheer numbers are overwhelming—sometimes exceeding a million per acre in peak areas—making their presence obvious through both sightings and the crunch underfoot of those that have completed their lifecycle.

How to prevent a cicada emergence

Unlike many pest situations, preventing a cicada emergence is largely impossible since these insects emerge based on biological timing rather than in response to specific conditions you can modify. For annual cicadas that appear in smaller numbers each summer, their presence is a natural part of the ecosystem. 

For periodical cicadas, their 13 or 17-year underground development cycle will proceed regardless of surface conditions, culminating in synchronized emergences that can be predicted years in advance based on historical records.

However, you can take protective measures for vulnerable young trees if you’re expecting a significant emergence. Covering small trees with fine netting (apertures smaller than ½ inch) secured around the trunk can prevent female cicadas from accessing branches for egg-laying. 

This protection is particularly important for trees less than four years old or valuable ornamental specimens with small branches. Delayed planting of new trees until after an expected emergence period is also advisable in areas where periodical cicada activity is anticipated.

For existing landscape trees, a professional pest control service can provide targeted treatments for highly valued specimens if necessary. However, most arborists and entomologists recommend allowing the natural cycle to proceed, as established trees typically recover quickly from any minor damage. Professional advice from a pest control expert can help you determine which trees might benefit from protection and which will naturally withstand the temporary presence of these fascinating insects without lasting harm.

When to call a pro

If you’re experiencing the unmistakable chorus of cicadas around your property or noticing significant numbers of emergence holes in your soil, contact our partners associated with Pest Control Experts today for a free quote and get your customized protection plan! While cicadas are primarily a temporary nuisance rather than a destructive pest, our trusted experts can help safeguard vulnerable young trees from egg-laying damage and recommend appropriate protective measures for your valuable landscape specimens.