An adult cicada ovipositing into an apple twig.
An adult cicada ovipositing into an apple twig.

When the soil temperature in regions of the eastern part of the U.S. reaches 64 degrees F., the 17-year cicadas will emerge by the billions from the earth. This year’s brood of the 17-year magicicadas, and different broods emerge on different years, is one of the biggest. The noise made by them could be deafening.

What is called ordinary cicadas emerge from the ground every year around the world, including the U.S., but these 17-year magicicadas are different. Those who have seen them up close notice their red-eyes. These magicicadas are seen only in the eastern half of the United States, which still goes almost to Colorado, and nowhere else in the world. The estimate of total magicicades in the ground ranges from 30 billion to 1 trillion.

Experts actually hedge their bets on how many years the offspring of each brood stays in the soil—from 13 to 17 years.  

"There will be some places where it's wall-to-wall cicadas," the Associated Press quoted University of Maryland entomologist Mike Raupp as saying.

Entomologists say these cicadas won't hurt people or animals. The worst thing they seem to do at high populations is damage a few saplings or young shrubs. The wingless nymph form of the insects have been a few feet underground sucking on tree roots and waiting for some trigger to know it is the exact time to emerge after years and years of maturing. They come out and molt into winged adults able to fly.

After a few weeks in and on trees and shrubs, the magicicadas will die and their offspring will go underground, not to return until 2030. But while these cicadas are around, they are going to be really, really noisy. The males are making their extreme sound to attract females to have sex and complete the reproduction cycle so that billions of their offspring can go back into the ground for 17 years.

In good weather and growing conditions, the cicada population that will emerge can be smaller or larger than the previous 17-year brood because a female cicada can lay around 600 eggs, which can hatch and drop to the soil to burrow into the ground. The majority of cicadas staying close to home can account for some areas having tons of the noise makers and other areas not having many or none. Additionally, the vegetation makes a difference, too.

It could really be a noisy May for some areas of the country.