How to Identify 17-Year Periodical Cicadas in Your Area

Every 17 years, a remarkable natural phenomenon occurs in certain parts of North America: the emergence of the 17-year periodical cicadas. These insects captivate both scientists and nature enthusiasts with their synchronized mass appearances, loud mating calls, and unique life cycle. Identifying these cicadas in your area can be both exciting and educational. This guide will help you understand how to spot 17-year periodical cicadas, what to look for, and where and when you might find them.

What Are 17-Year Periodical Cicadas?

Periodical cicadas belong to the genus Magicicada, with the 17-year species being one of the most famous due to their lengthy underground development cycle. Unlike annual cicadas, which emerge every year, these cicadas spend nearly two decades underground as nymphs feeding on root sap before emerging simultaneously in huge numbers.

Their synchronized emergence is believed to overwhelm predators, increasing their chances of reproduction. Once above ground, they live for about 4-6 weeks, during which they mate, lay eggs, and then die.

Where Are 17-Year Periodical Cicadas Found?

The 17-year periodical cicadas are native primarily to the eastern United States. They are divided into different “broods,” which are specific populations that emerge in different geographic areas and different years. For example:

• Brood X: One of the largest and best-known broods, emerging across parts of the mid-Atlantic and Midwest.
• Brood V: Located in parts of Ohio, Pennsylvania, and West Virginia.
• Brood XIX: Found mainly in southern Illinois and nearby states.

Knowing which brood is expected to emerge in your area helps narrow down when to look for these cicadas.

When Do 17-Year Cicadas Emerge?

As their name suggests, these cicadas emerge every 17 years. However, different broods emerge in different years. It’s important to check local resources or entomology departments at nearby universities for the expected emergence year in your region.

Typically, emergence happens between late April and early June when soil temperatures reach about 64°F (18°C) around 8 inches below the surface. The timing can vary slightly depending on geography and weather conditions.

How to Identify 17-Year Periodical Cicadas

Physical Characteristics

Periodical cicadas have distinctive features that set them apart from other insects:

• Size: Adults are about 1 to 1.5 inches long (2.5 to 4 cm).
• Body Color: Their bodies are mostly black with bright orange or red markings on their thorax.
• Wings: Their wings are translucent with orange veins.
• Eyes: One of their most notable features is their large red eyes.
• Legs: Their legs are strong with spines used for digging and climbing.

Difference From Annual Cicadas

Annual cicadas tend to be green or brown without red eyes or bright orange markings. Their emergence is not synchronized, so only a few appear every year.

Sounds: The Signature Song

Male periodical cicadas produce a loud, high-pitched buzzing sound to attract females. This chorus can reach over 100 decibels and is often described as a continuous drone or rattling buzz. Listening carefully during warm spring days can help confirm their presence even before you see them.

Signs of Emergence

• Holes in the Soil: After spending years underground, nymphs dig exit tunnels reaching the surface soil.
• Exoskeletons: Look for tan-colored exuviae (shed skins) clinging to tree trunks, branches, or plants.
• Trees with Egg Nicks: Females lay eggs by cutting slits into small branches; this causes noticeable damage often called “flagging,” where tips of branches wilt and die.

Habitats Favoring 17-Year Cicadas

The nymphs live underground feeding on tree roots — hardwood trees such as oak, maple, hickory, and elm are favorite hosts. Emergence sites typically coincide with mature deciduous forests but may also include suburban areas rich in tree cover.

Steps to Spot Periodical Cicadas in Your Area

1. Research Local Brood Activity

Check with local universities’ entomology departments or extension services for information on which brood emerges near you and in what year. Websites like the USDA Forest Service or cicada enthusiast groups provide maps and schedules.

2. Monitor Soil Temperatures

Emergence starts when soil reaches about 64°F (18°C) at roughly eight inches deep. Garden thermometers can help you track this if you want to predict when cicadas will start appearing.

3. Walk Through Wooded Areas During Peak Season

Late April through June is prime time. Visit wooded parks or forest edges during warm afternoons when males are most active singing.

4. Listen for Their Calls

Approach areas with loud buzzing sounds; this often signals large groups of males calling mates.

5. Look for Exuviae on Tree Trunks

Even if adults aren’t immediately visible, shed skins stuck on rough bark provide clear evidence of recent emergence.

6. Observe Trees for Flagging Branches

Small dead branch tips caused by egg-laying females help confirm that periodical cicadas are present.

Tips for Photographing or Observing Cicadas Safely

• Avoid handling adult cicadas excessively; while harmless to humans, they are delicate.
• Use binoculars or zoom lenses to observe from a distance.
• Stay hydrated during hot days; emergences occur during warm weather.
• If collecting specimens for study or education, check local regulations first as some areas may have restrictions.

Why Identifying Periodical Cicadas Matters

Understanding periodical cicada patterns helps scientists monitor ecosystem health and insect population dynamics. For gardeners and farmers, recognizing when these insects appear can aid in managing any potential damage caused by egg-laying activities on young trees.

Additionally, witnessing a brood emergence is an extraordinary opportunity to connect with nature’s rhythms — a chance many people only experience once or twice in a lifetime!

Common Misconceptions About Periodical Cicadas

• They Do Not Sting or Bite: Despite their intimidating buzzing noise and size, periodical cicadas pose no threat to humans.
• They Don’t Cause Long-Term Harm: While egg-laying may cause minor damage (“flagging”), healthy mature trees usually recover without issue.
• They Are Not Locusts: The term “locust” is sometimes mistakenly used but true locusts belong to a different insect group entirely.

Conclusion

Identifying 17-year periodical cicadas involves understanding their unique physical traits, knowing when and where they emerge, recognizing their sounds and signs of activity around trees. By following the steps outlined above — researching local brood data, listening for their calls during peak season, looking for exoskeletons and egg-laying damage — you can successfully spot these fascinating insects during their rare appearance.

Whether you’re a casual nature lover or an avid entomologist, tracking periodical cicada emergences offers a rare glimpse into one of nature’s most extraordinary life cycles — an event well worth experiencing firsthand!