Quick Methods to Identify Emerging 13-Year Periodical Cicadas

Periodical cicadas are among the most fascinating and unique insects in the world, captivating entomologists and nature enthusiasts alike. Unlike their annual cousins, periodical cicadas have synchronized, long life cycles , spending most of their lives underground as nymphs before emerging en masse after 13 or 17 years. This article focuses on quick methods to identify the emerging 13-year periodical cicadas, a rare and intriguing natural phenomenon.

Understanding the 13-Year Periodical Cicadas

Before diving into identification techniques, it’s essential to understand what makes 13-year periodical cicadas special.

Life Cycle Overview

• Nymph Stage: The majority of their 13-year life is spent as nymphs underground, feeding on root sap.
• Emergence: After 13 years, large broods emerge simultaneously to molt into adults.
• Adult Stage: Adults live only about 4-6 weeks, during which they mate, lay eggs, and then die.
• Species: Some of the most studied 13-year species belong to the genus Magicicada, including Magicicada tredecim, Magicicada tredecassini, and Magicicada tredecula.

Geographic Distribution

13-year cicadas tend to be found predominantly in the eastern United States. Different broods emerge in different regions based on their synchronized cycles.

Why Quick Identification Matters

Accurately identifying emerging 13-year periodical cicadas can help in:
– Studying population dynamics and ecological impacts.
– Educating the public about expected cicada emergences.
– Preparing for agricultural or landscaping considerations due to egg-laying damage.
– Contributing citizen science data to track broods.

Emergences are massive events, often involving millions of insects per acre, making quick identification practical for researchers and enthusiasts alike.

Visual Identification: What To Look For

Size and Shape

• Body Length: Adults range from about 1 to 1.5 inches (25-38 mm) in length , larger than many common cicadas.
• Robust Body: They have stout bodies with a somewhat bulbous abdomen.

Coloration

• Pronotum (Thorax Shield): Typically black with orange-red markings.
• Wings: Clear with orange veins; wings are longer than the body.
• Eyes: Bright red or orange-red eyes are a hallmark of periodical cicadas.

The bright red eyes distinguish them from many other cicada species, which often have brown or black eyes.

Distinctive Markings by Species

• Magicicada tredecim: Has an orange or yellowish underside with three stripes on the abdomen.
• Magicicada tredecassini: Largely black-colored underside.
• Magicicada tredecula: Slightly smaller and darker overall.

Auditory Identification: Recognizing Their Song

One of the fastest ways to confirm 13-year periodical cicadas’ presence is by their distinctive mating calls.

Male Calling Song

Males produce loud, rhythmic buzzing and clicking sounds intended to attract females. The calling song characteristics include:

• A rapid “weeeee-wah” or “pharaoh” sound repeated continuously.
• Loud volume that can be heard across several hundred feet.
• Often synchronized choruses when many males call together, creating a drone-like effect.

Periodical cicada songs differ slightly from annual cicadas in pitch and rhythm but require some experience to differentiate. Using smartphone apps designed for insect sound identification can speed this process.

Behavioral Signs During Emergence

Identifying emerging cicadas isn’t just about seeing or hearing adults, behavioral signs before and during emergence can assist:

Soil Disturbances

• Large numbers of exit holes (about dime-size) appear in the soil where nymphs break through.
• These holes typically cluster near tree bases and shrubs.

Molting Evidence

• Empty exoskeletons (exuviae) cling to tree trunks, branches, or man-made structures.
• Freshly molted adults appear pale and soft before darkening within hours.

Tree Activity

Females lay eggs by cutting slits into young twigs, which may cause visible damage such as wilting or flagging branches. Spotting these signs on certain tree species (oak, hickory, maple) can indicate active periodical cicada presence.

Quick Field Identification Tools & Techniques

To accelerate identification during emergence events, researchers and enthusiasts can use several tools:

Magnifying Lens or Hand Lens

A simple magnifier helps inspect key features like wing vein color or eye color up close without needing a microscope.

Smartphone Apps & Online Resources

Several apps identify insects by photo or song recording:
– Seek by iNaturalist
– Cicada Safari , specifically designed for periodical cicadas
These apps help verify sightings quickly and contribute data to communal databases.

Sound Recorders with Spectrogram Analysis

Using a digital audio recorder paired with software that displays frequency spectrograms allows precise comparison between cicada songs and reference libraries.

Timing & Location Tips for Quick Detection

Knowing when and where to look enhances quick identification success:

Emergence Timing Window

• Typically late spring through early summer (May to June).
• Soil temperature around 64degF (18degC) at ~8 inches depth triggers emergence.

Habitat Preferences

Look near:
– Mature deciduous forests
– Suburban areas with abundant native trees
Avoid areas dominated by conifers or extensive turf lawns where emergence is less likely.

Differentiating 13-Year vs 17-Year Broods Quickly

Since both types of periodical cicadas exist, rapid methods to distinguish emergences include:

Consulting local brood maps maintained by entomological societies will indicate expected broods for your location and year.

Conclusion

Identifying emerging 13-year periodical cicadas quickly is feasible using a combination of visual cues, auditory signals, behavioral signs, timing knowledge, and modern digital aids. Recognizing their distinctive red eyes, orange wing veins, synchronized mass emergence behaviors, and characteristic songs can make this unique natural event accessible even to amateur observers.

By applying these quick methods during emergence years, you can enjoy one of nature’s most spectacular phenomena while contributing valuable observations that support ongoing scientific understanding of these remarkable insects. Keep an eye out every 13 years, you might just catch a glimpse of this extraordinary underground-to-sky transformation!

References

1. Williams KS & Simon C. “The Ecology Evolutionary Biology of Periodical Cicadas.” Annu Rev Entomol.
2. Karban R. “Cicadas.” Encyclopedia of Insects.
3. Magicicada.org , Brood Maps & Identification Guides
4. iNaturalist & Cicada Safari app user guides