Brood Ten Cicadas Making Another Unscheduled Local Appearance

May 29, 2018

Periodical cicadas are coming out of the ground again this spring, but a Mount Saint Joesph University cicada expert isn't expecting a big show. Gene Kritsky says these particular insects are stragglers from Brood Ten, which is expected to return in 2021.

"All the cicadas emerging this year are in areas where they emerged last year during that four-year early acceleration," he says. "What we're seeing, most likely, is either one year late from last year, or three years early for 2021. One of the two is happening." 

Kritsky says enough cicadas emerged last year to qualify as their own sustaining brood. He doesn't expect this year's appearance to be as big.

Kritsky says off-year emergences are not uncommon and are a defensive strategy. "If we had periodic cicadas coming out every year or even every other year, then we would expect some specialized predator to evolve to come out at the same time. But since its either one or 17 years there's no intermediate steps for these predators to evolve to match these cicadas," Kritsky says.

He says many of these cicadas appear to be falling victim to predators and most people might not even notice the emergence.

He's hoping for reports from the public so scientists can get a better idea of how widespread it is.