Billions of cicadas to rise up in US for mating after 17 years of slumber

As the second-largest periodical brood after Brood XIX, this group spends years feeding on tree roots beneath the surface, waiting for the soil temperature to hit approximately 64 degrees Fahrenheit (18 degrees Celsius).

Once above ground, their synchronized appearance will mark one of nature’s most dramatic and noisy mass events.

A survival strategy

While there are more than 3,500 cicada species, periodical cicadas, which emerge in massive numbers every 13 or 17 years, are found almost exclusively in the eastern U.S., with only two unrelated species known to exist outside the region, in northeastern India and Fiji.

However, Brood XIV, which was first documented in 1634 and notable for its size and historical significance, is considered the original brood from which all other 17-year cicadas diverged.

“Everybody’s fascinated by them, because you see nothing for 13 or 17 years, and then all of a sudden, your house and car are covered in these insects,” Chris Simon, PhD, an ecology and evolutionary biology professor at the University of Connecticut, said.

Once Brood XIV emerges, the cicadas surface in near-perfect unison, a survival strategy that overwhelms predators such as birds, raccoons, and snakes. Their sheer numbers help ensure that, despite heavy predation, enough individuals survive to reproduce and sustain the brood.

The cicadas’ mating process is marked by intense noise, as males emit high-pitched buzzing calls to attract females, reaching very loud volumes over 100 decibels, comparable to a jackhammer or motorcycle.

After mating, females deposit their eggs in tree branches. Within weeks, the adult cicadas die off, their decomposing bodies enriching the soil. The newly hatched nymphs then drop to the ground and burrow beneath the surface, beginning another 17-year cycle underground.

Balance or disruption?

While Brood XIV’s emergence brings ecological benefits such as increased food sources for wildlife and nutrient cycling, it also disrupts the balance. For instance, bird populations that feed on cicadas often increase during emergence years.

However, this shift in predation can leave other pests, such as caterpillars, unchecked, resulting in greater damage to oak trees and surrounding vegetation.

In addition, climate data indicates that rising soil temperatures driven by climate change could disrupt the timing of future cicada emergences, with periodical cicadas potentially surfacing earlier than expected, a phenomenon known as ‘straggling.’

Some scientists also warn that if parts of a brood emerge out of sync, it could weaken their predator saturation strategy and reduce survival rates. However, current observations indicate that Brood XIV is on track.

The emergence is expected to be most intense across parts of Georgia, South Carolina, Tennessee, Kentucky, Ohio, Indiana, Illinois, Missouri, and extending through Pennsylvania into New England. The next appearance of Brood XIV is expected in 2041.