After 17 years underground, billions of cicadas …

When the spring I have arrived at northern hemisphere, the Eastern United States will be the scene of a extraordinary natural phenomenon: trillion cicadas -also known as cicadas- will emerge from underground after awakening from a 17-year hibernation, and they will fill the air with a deafening buzz of up to 100 decibels.

This phenomenon called Brood X o Large Eastern Brood, which will perform as in 2004 and 1987, can be seen in the States of Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, New York, Ohio, Pennsylvania, from Tennessee, Virginia, West Virginia and Washington DC.

After 17 years of cultivating underground and feeding on tree roots, cicadas will take advantage of warm weather and the surface, climb trees and lose their immature exoskeletons.

“Communities and farms with a large number of cicadas emerging at any given time can have a substantial noise problem,” explained Eric Day of the Entomology Department at Virginia Tech. However, he clarified that “any disturbance is tempered by the rarity and surprise of this event.”

Why does this phenomenon occur every 17 years?

These massive appearances of cicadas occur periodically every 13 to 17 years, depending on the species. It turns out that these long cycles are part of the evolutionary strategy of the cicada dating from the Pleistocene era. Back then, summers could be unpredictably cold in the eastern United States – this condition created a problem for cicadas because if the temperature stays below 10 degrees for too long, it is too cold for them to s. ‘mate and survive.

Then, cicadas have developed cycles of different lengths to improve their chances of survival. A baby cannot survive a cold summer on earth, but surviving a cold summer underground is not a problem. The less cicadas emerge from the ground, the less likely they are to be wiped out by an unusually cold summer.

The exact reason for the number 17 is unknown, but scientists have theories. One idea suggests that the unusual life cycle with prime numbers prevents generations of cicadas from coping with the life cycles of the wasps that feed on them. Another theory says that the prime number cycle reduces the likelihood of 17-year-old cicadas to mate and hybridize with cicadas of different species or generations.

Such hybridization would reduce the size of these generations, bad news for a species that needs large numbers to survive.

What risks does this phenomenon entail?

Despite the generation of a loud noise which can be annoying, cicadas do not present any danger to humans. While their large size can be scary, they don’t sting and are largely harmless, even to cats and dogs.

However, these insects pose a threat to orchards, ornamental tree nurseries and vineyards from the region, not because they are eaten, but because they are used to lay eggs.

The implantation of the egg damages branches and leaves and can even retard growth or directly on small trees and young plants.

After a few months of flying, mating, and filling the forest with their deafening songs, adult cicadas die off at the end of summer.