Cicadas are an extraordinary group of insects renowned for their unique life cycles and the cacophonous sounds produced by the males. Among the 3,000 species found worldwide, a select few exhibit a remarkable synchronized emergence pattern, surfacing from the earth only once every 12 to 17 years. These long-lived insects manage to thrive underground for most of their lives by tapping into the sap of tree roots for sustenance. One particular group, known as Brood X, is set to reappear across the mid-Atlantic region after a 17-year hiatus since their last emergence in 2004, making them one of the most notable cicada broods due to their extensive life cycle.
The Life Cycle of Cicadas
Cicadas have one of the most fascinating life cycles in the insect world. After the eggs hatch, the nymphs drop to the ground and burrow into the soil, where they will spend the majority of their lives. During this time, they undergo several stages of development while feeding on the fluids of plant roots. This subterranean phase can last for an astonishing 12 to 17 years, depending on the species. As the end of this period approaches, the nymphs prepare to emerge en masse when the soil temperature reaches about 64 degrees Fahrenheit, typically in late spring or early summer. Once above ground, they shed their exoskeletons, mature into adults, mate, lay eggs, and then die shortly thereafter, completing their lengthy life cycle.
Brood X: The Great Eastern Brood
Brood X, also known as the Great Eastern Brood, is one of the most densely populated groups of periodical cicadas. This brood is particularly well-known due to its vast geographical spread, affecting areas across the mid-Atlantic, including states such as Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Washington D.C. The sheer number of cicadas emerging simultaneously creates a natural spectacle, with the air filled with their distinctive mating calls that can reach up to 100 decibels.
Survival Strategies Underground
The survival of cicadas through their extended underground phase is a testament to their evolutionary adaptability. By feeding on xylem sap from tree roots, they gain the necessary nutrients to support their development over many years. This diet is low in nitrogen and other essential nutrients, which likely contributes to their prolonged developmental period. The nymphs also construct tunnels and chambers near the roots, which serve as their habitat until it’s time to surface.
Impact on the Environment and Human Life
The emergence of periodical cicadas like Brood X has both ecological and societal impacts. Ecologically, the massive influx of cicadas provides a food bonanza for predators, while the death of the adult cicadas after mating results in a significant nutrient input to the forest floor. This can benefit the growth of plants in subsequent years. For humans, the event can be both a nuisance and a wonder. The noise can be overwhelming, and the large numbers of cicadas may cause damage to young trees due to females laying eggs in small branches. However, the phenomenon also offers opportunities for scientific study and community engagement with nature.
Preparation for the Emergence
As Brood X prepares to emerge, communities and scientists alike gear up for their arrival. Homeowners are advised to protect young trees with netting and to delay pruning until after the cicadas have died off. Meanwhile, researchers plan to seize the opportunity to study various aspects of cicada biology, behavior, and their impact on the ecosystem. Citizen scientists are also encouraged to participate in tracking the emergence through various projects and apps dedicated to mapping cicada activity.
While no conclusion is needed for this factual article, it is clear that cicadas, particularly those belonging to Brood X, play a significant role in our understanding of insect lifecycles, environmental science, and the interconnectivity of ecological systems. The 2021 emergence of these remarkable insects will be yet another chapter in the long history of cicadas and their interaction with the world around them.
