Cicada Broods Emerge Together for a Rare and Fascinating Event
The cicada population is always making noise come springtime, with their loud, shrill mating and gathering calls irritating communities nationwide.
But in the spring of 2024, the cicada population is causing a different kind of noise, this time in the media, as a double brood of cicadas will emerge together for the first time in over two centuries, a truly rare and fascinating event.
According to mapping by the University of Connecticut Cicada Project, the double cicada emergence will primarily impact parts of Illinois, Iowa, Kentucky, Missouri, Arkansas, Tennessee, Mississippi, Alabama, Georgia, South Carolina, North Carolina, and Virginia.
This year’s double brood of cicadas is known as Brood XIII, which has a 17-year life cycle, and Brood XIX, which has a 13-year life cycle. These two broods, when they emerge together, could unleash billions of insects per square mile, a staggering number that underscores the magnitude of this natural event.
With so many cicadas making noise all at once in some areas, sound levels could reach upward of 90 to 120 decibels, equivalent to a gas lawnmower or motorcycle. Thankfully, they only produce their loud, shrill sound during the day.
The two emerging broods, Brood XIII and Brood XIX, are referred to as periodical cicadas. Though there are more than 3,390 species of cicadas globally, only seven are known to be periodical in North America.
Periodical cicadas are a genus of seven species named for their highly synchronized life cycles. This is surprising given they spend the majority of their lives underground, where they primarily feed on the juices and sap of surrounding tree roots.
Numerous scientific studies have been conducted over the years, but the mystery remains: how do periodical cicadas stay so perfectly synchronized for emergence?
Some experts speculate that periodical cicadas can monitor the changing of the seasons based on the xylem (a transport tissue in vascular plants) they feed on, but the exact mechanism is still unknown, inviting further scientific exploration.
While a great deal of factual and fictitious information is circulating online, the certified arborists here at SavATree are here to clarify what will undoubtedly be a noisy spring in some areas of the country.
- The cicadas will begin to emerge from the ground once soil temperatures reach 64°F and will be active for about four weeks before the adults die off.
- While cicada populations are very noisy, they do not bite or sting and are entirely harmless to humans and animals.
- Females lay their eggs in small slits they cut into small branches (usually the width of a pencil eraser). While cicadas often cause minor damage to trees, if multiple females lay their eggs in one branch, the branch can break or die off as the cellular structure is disrupted. Younger trees are typically susceptible to damage, while mature trees incur only aesthetic damage.
- Treatments are ineffective against these insects. As adults, they do not feed on trees and shrubs but only use them to lay their eggs. Therefore, it’s ideal to simply let nature take its course, as cicada populations disappear within a month.
- The male cicadas are the ones making all the noise. The first two weeks after emergence, periodical cicadas “sing” as part of their mating ritual, which lasts from one to six days. In fact, male cicadas produce some of the loudest sounds of any insect in the world.
The next time these two broods will again emerge together will be in the year 2245, which makes one wonder what the environment on planet Earth will be like as they rise from the soil. Regardless, we’re sure it will be loud.
For more information or questions about cicada populations on your property, give your local SavATree branch a call today!
