Last here in 2004, the Brood X cicadas are making a comeback. These unique, large insects, typically known for their buzzing sounds, are resurfacing after spending 17 years underground. Cicadas spend most of their lives underground with only certain broods, or specific geographical and distinct groups, emerging annually. However, this spring the Brood X cicadas will come out of the ground in massive numbers, counting toward the billions in total, creating a sight for all to learn about and prepare for.

What are Brood X cicadas?

Cicadas are grouped by scientists based on how many years it takes for them to emerge from the ground after developing into adults. Named for the order in which the cicadas were originally tracked, Brood X was the tenth group, using roman numerals. Also known as the Great Eastern Brood, Brood X is characterized by the large geographical space it covers and the large number of cicadas that will emerge across several states. In their lifetime, these cicadas develop underground as nymphs, or immature forms of the adult insects, before emerging. After emerging, they shed their skins, leaving hollow shells, and become adults. During their time as adults, female cicadas cut slits into tree bark and leave around 20 eggs each, according to Pest World. The adult cicadas then die after breeding. After six to ten weeks, the eggs hatch and the nymphs fall to the ground and burrow, living off of tree roots for the next 17 years. The cycle then repeats. 

Cicadas are commonly known for their loud, buzzing noises. These sounds are produced by the males using their tymbals which is a part of their sound-producing organs. Reaching around 100 decibels, these noises can be as loud as motorcycles when combined. Creating the classic cicada “chorus,” the males use this to attract mates, achieving their main purpose of life. 

Why every 17 years?

The reason why the Brood X cicadas emerge after every 17 years most likely has to do with evolutionary survival purposes. While this still remains a large mystery to scientists and is still being studied, some believe that the reason they have long underground periods dates back 1.8 million years ago to the Pleistocene Epoch, when the last Ice Age occured. During this time, winters were not only extremely cold but summers were sometimes shockingly cold as well. Cicadas are unable to survive in cold weather, so the extended period of time underground is to be believed as assisting with their survival.

The exact reason for the number 17 is widely up for debate. Some theories suggest that the number aligns with the life cycles of wasps that are predators to them while others suggest that the unique number helps prevent this exact species of cicadas from breeding with other species and generations. While the reason is still unknown, this adds to the uniqueness of Brood X cicadas and the scientific learning opportunities that come with the emergence this spring.

Where will the Brood X be?

The Brood X emergence will take place across fifteen states this year including Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia.

Scientists say that Brood X will first emerge in Georgia and the southern states in late March, but it will not take much longer for them to begin emerging elsewhere. “We are at the epicenter of an event that happens nowhere else on the planet except here in the Eastern United States,” said University of Maryland entomologist Mike Raupp.

A chance to learn

The Brood X cicada presence provides an opportunity for scientists to study and understand questions about evolution, biodiversity and many other important topics. Not only providing this chance for scientists, it is also a great time for the public to learn about their surroundings and try to understand unique insects like cicadas. Even addressing important hot topics, scientists have been noting the effect of climate change on periodical cicadas like Brood X. These cicadas are very sensitive to the climate and it is undecided whether specific species of periodical cicadas will adjust to new environments as climate change and humans impact them. 

Cicadas are not as scary as the public often accredits them to being. This event allows for many to realize this and gain an appreciation toward a part of our natural world. Having an opportunity to study them, scientists are relying on the public for help tracking and locating the emerging Brood X cicadas. Using a mobile application called Cicada Safari, people will be able to send pictures and information to scientists at Mount Saint Joseph University in Cincinnati, Ohio. 

Are they harmful?

Brood X cicadas are not harmful to humans and they do not bite or sting. However, they are dangerous to young trees. As female cicadas lay their eggs in twigs and tree bark, this can be damaging to younger and smaller trees, both cosmetically and developmentally. Despite this, cicadas actually offer some environmental benefits to our world. They serve as food for many other animals during their time here and when the nymphs are underground, the tunnels they create help aerate the soil, allowing easier access to nutrients and oxygen for tree roots. According to the Chicago Botanic Garden, cicadas can even be eaten by humans and are high in protein, though it is suggested to limit your ingestion of them to a few. 

How to prepare and what to expect

The presence of the Brood X cicadas will bring along some interesting occurrences throughout this spring and summer. Knowing they are coming before they emerge, they are some ways to prepare and things that you can expect.

Ways to Prepare:

• Educate yourself and children about the cicadas
• Wait until next year to plant tree saplings
• If you have young trees, place small mesh nets over them to prevent damage
• Avoid using chemical sprays and insecticides as they can harm beneficial insects and animals

What to Expect:

• Cicadas are not drawn indoors, but may rest on the outside of your house
• Animals, including dogs and cats, may eat large amounts of cicadas (which is ultimately harmless)
• Loud, buzzing noises of the cicada chorus
• Seeing and finding empty cicada shells on trees, houses, mailboxes, etc.