Eastern Nebraska residents should brace themselves for a rare invasion in late May and early June.
Cicadas that have been underground for 17 years will emerge -- and they'll come out with a racket.
"The sound, I won't say it's deafening, but it's incredibly loud," said Leon Higley, an entomologist and professor of applied ecology at the University of Nebraska-Lincoln's School of Natural Resources who witnessed an emergence in 1981 at Platte River State Park near Louisville. "You couldn't have a normal conversation, they're so loud."
The insects are part of Brood IV, commonly referred to as the Kansan brood, which is one of 12 across the country. The last time they emerged was in 1998.
In Nebraska, the cicadas will come out in parts of Cass, Douglas, Johnson, Otoe, Pawnee, Saunders, Sarpy and Cuming counties. They'll also emerge in Texas, Oklahoma, Missouri and Iowa.
Some species emerge every year, but others follow biological life cycles of three, seven, 13 and 17 years -- all prime numbers.
"The theory is that the reason they have life cycles that correspond with prime numbers is that predators have difficulty in getting in synch with their life cycles," said Higley. "They are avoiding something, and they can do it by this long life cycle."
People typically don't see cicadas emerge from the ground. Rather, they find the hard, empty exoskeletons attached to the sides of buildings, trees, etc.
The insects mate and die in about three weeks, but first, the females inject their eggs into tree branches. When they hatch, the insects find their way to the tree roots, where they feed, molt and complete their development.
Jim Kalisch, an extension associate at UNL, said the egg-laying process can damage tender twigs and new growth on larger trees.
Cicadas feed on plant juices and do not bite or sting people.
And they're not locusts, Higley said. Locusts are large, swarming grasshoppers that early settlers may have confused with 17-year cicadas.
Seventeen-year cicadas typically emerge in forested areas, so Platte River State Park and other state park areas along the Platte River are ideal spots to see -- and hear -- the emergence.
Kalisch said it's hard to predict the exact timing, but the insects should start to emerge when temperatures get warmer and trees have more foliage.
He saw the 1998 emergence and called it a once-in-a-lifetime event and a must for family outings.
"I was just astounded by it because it was so loud," Kalisch said, adding that it was interesting to watch the cicadas flit from tree to tree.
"It's almost like a choreography. When one starts the others will start to do it," he said.
Said Higley: "I once likened it to going to the Serengeti. This is one of the rare phenomena of nature but you don't have to go to another country to see it. It happens right here."