In spring of 2024, two different broods of cicadas, ones that live on a 13-year cycle and the other that lives on a 17-year cycle, will emerge at the same time from underground in a rare event that last occurred in 1803.
This year’s dual emergence is a once-in-a-lifetime event for residents of the U.S. and in North Carolina. While any given 13-year brood and 17-year brood can occasionally emerge at the same time, each specific pair will see their cycles aligned only once every 221 years. As for this year’s cicada groups, known as Brood XIII and Brood XIX, they happened to make their homes adjacent to one another, with a narrow overlap in central Illinois.
These types of cicadas are periodical insects that spend most of their lives underground feeding on tree roots. After 13 years or 17 years, depending on their brood, the cicadas make their way to the surface to reach their maturity level and engage in a month-long, noisy search for a potential mate. The cicadas typically surface in the spring once soil reaches a temperature of around 64 degrees Fahrenheit.
Brood XIII cicadas appear in the Midwest region of the U.S., mostly centered in Illinois but also stretching into Wisconsin, Ohio and Iowa. Brood XIX cicadas have been spotted over a much larger geographic area that includes Missouri, Illinois, Louisiana, North Carolina, Virginia and Maryland.
When these insects emerge, they do so in large numbers. For those who enjoy going outside to play sports or other activities around this time will find swarms of these flying cicadas when spending time outdoors.
The insects are known to emit a high-pitched buzzing noise that can reach up to 100 decibels, which can be seen as the equivalent to the sound of a motorcycle or a jackhammer.
While the insects themselves are harmless to humans, billions of them emerge in a short time-frame from underground generating noise for several weeks before the cicadas reach the end of their life cycles. Once such happens, residents will see masses of dead insects on the ground.
After 2024, Brood XIII and Brood XIX cicadas won’t emerge from underground again for another 221 years.
