Periodical Cicadas To Emerge Soon In Downstate Illinois

The cicadas are coming ---- but not just the cicadas that can be heard every summer.

These are periodical cicadas that emerge from the ground for mating in 13 and 17 year cycles. This particular brood of 13-year cicada is known as the Great Southern Brood, or Brood XIX. And they will soon be seen and heard in the billions in a region that stretches from the southeast out to Missouri and Arkansas --- and includes central and southern Illinois.

University of Illinois entomologist James Appleby said you will know when the Great Southern Brood is here, by their mating song.

"Their song is referred to as the long, drawn-out word, 'Pharoah,'" Appleby said. "So they'll go, 'Phar-aoh, phar-aoh, phar-oah' - that's the song. And it's extremely loud when all these males emerge."

While the males make all the noise, the female cicadas do all the damage ... to the branches of trees where they lay their eggs. Appleby said mature trees usually survive the onslaught, but the cicadas can pose a risk to younger, smaller trees. With the huge numbers of cicadas expected, he says homeowners may want to take precautions.

"If you have a young tree that you just purchased this year, perhaps last year, to protect it, I think it would be a good idea to get some nylon meshing or some type of netting and just net the tree ... the branches, because that's where the females will deposit their eggs," said Appleby, who makes bi-monthly appearances on WILL's "Illinois Gardener".

Cicadas from the Great Southern Brood have already emerged from underground in many southern states. Locally, Appleby said he has already seen the chimney-like exit holes that cicadas make in preparation for their lives above-ground. They will die off in about five weeks, at which time their eggs will hatch, sending a brood of nymphs underground, to emerge in 2024.