Chapel Hill, North Carolina – Trillions of periodical cicadas from two broods are emerging from their underground habitats in over a dozen states this year, creating a cacophony and drawing attention to their unusual lifecycle.
This year, both the 13-year Brood XIX located mainly in the Southeast and the 17-year Brood XIII in the Midwest are appearing in a combined 17 states, including Illinois and Iowa. The simultaneous emergence of these two broods is a rare occurrence that last happened in 1803.
The emergence of cicadas is triggered by warm rains when the soil 8 inches underground reaches 64 degrees. Due to the warm temperatures, cicadas have already been spotted above ground in states across the Southeast and Midwest.
Once male and female periodical cicadas have mated and the females have laid their eggs, the insects will die after spending only a few weeks above ground – usually about three to six weeks after they first emerge. This means that many of this year’s periodical cicadas are expected to die off in June.
Cicadas have a complex lifecycle, starting with mating and egg-laying in tree branches and shrubs. The eggs hatch after six to 10 weeks, and the cicada nymphs burrow into the ground, where they remain dormant for two to 17 years. They eventually emerge as adults, starting the lifecycle over again.
The last time the two cicada broods emerged together was in 1803, during Thomas Jefferson’s presidency. This year’s emergence is a rare event, drawing fascination from scientists and the public alike. The noisy and short-lived presence of these creatures is a reminder of nature’s intricate and mysterious cycles.