a picture of Cicadas

a picture of Cicadas

Every 13 or 17 years, residents in several regions of the eastern United States will see an unusual occurrence. Cicadas emerge from the earth in large numbers depending on where you live. But don’t be concerned. They do not harm humans or animals. They’re only here to have fun. 

Cicadas are Noisy!

It’s one of the noisiest bug gatherings you’ll ever witness — or hear. When a big group of adult insects congregates, the combined noise generated by males can reach 90 dB. That is comparable to the cost of a gas-powered lawnmower. 

In 2013, Michael Raupp told Science News for Students, “Where the cicadas emerge, it will be magnificent.” He is a professor of entomology at the University of Maryland, College Park. Cicada densities in specific remote locations can reach 1 trillion insects per square mile. That’s the equivalent of roughly 4 million cicadas emerging from a patch of earth the size of your bedroom floor (but not all at once, of course). 

These insects are found in almost 3,000 different species. Periodical cicadas are the most well-known species in North America. These 5-centimeter- (2-inch-) long insects emerge from the earth every 13 or 17 years on average. There are 15 distinct cicada broods, each of which emerges in a different part of the nation and is distinguished by a Roman numeral. The 2021 group, a 17-year variation, is known as “Brood X.” 

Periodical cicadas spend nearly all of their lives underground. They suck nutrient-rich fluids from the roots of various plants and bushes there. These subterranean youngsters are referred to as nymphs. This immature stage is similar to adulthood. 

Nymphs measure the passage of time by recognizing chemical changes in their food while hooked onto roots. The nymphs build escape tunnels to the surface in the final spring of their life. The insects will then retreat to root level until the soil temperature reaches around 64° Fahrenheit (18° Celsius). The nymphs will then resurface, climb out, and immediately scale the nearest tall object. Each molts one last time before becoming adult cicadas. 

Further Research

“You see the insects making a wild sprint towards the trees to live and mate,” Raupp added. “They will be eaten by birds and squirrels. It’s a fact of life. The end. It’s a love story. It’s a fantastic show of Mother Nature’s wonder – at its finest, in my opinion.” 

Adult cicadas have a lifespan of two to four weeks. They mate for a limited period, after which the females lay eggs in the delicate young branches of trees. After a few weeks, the eggs hatch. The children fall to the ground. Each little nymph immediately starts digging down to find plant roots to feed on. 

You’d think that having a considerable number of parasites sucking nutrients from the roots of trees and shrubs for a lengthy period would be bad for the plants. And Raupp said, “It’s a miracle we don’t see more damage.” However, research so far has not demonstrated that cicadas’ subterranean activities do considerable harm to their hosts. 

Overall, cicadas are likely to benefit rather than harm the ecosystem. Raupp observed that their burrowing churns up the earth, loosening the dirt. This not only allows oxygen to reach plant roots but also allows water to percolate deeply.