Communities brace for the deafening buzz of the 2024 cicada invasion
HUNTLEY — Back in 2021, My Huntley News reported on the 17-year cicada Brood X that made its noisy debut in western Illinois, which fortunately didn’t impact Kane and McHenry counties.
This year, however, northern Illinois can expect to see the emergence of Brood XIII, the brood with the reputation for being the largest emergence for periodical cicadas in the state. Additionally, Brood XIII and XIX will be emerging throughout much of Illinois at the same time.
According to Ken Johnson, a horticulture educator with the University of Illinois Extension program, the emergence of two periodical cicada broods will be the first time this has happened since 1803, and will not happen again until 2245.
While the two broods will be emerging at the same time, Johnson states that only a few places in central Illinois, mostly around Springfield, may see the broods overlapping. This means that residents can rest assured that they will only have to deal with one of the two broods of cicadas emerging this year.
Huntley will be exposed to the periodical cicadas from Brood XIII, also known as the Northern Illinois Brood. Johnson said that Brood XIII contains all three species of 17-year periodical cicadas: Magicicada septendecim, M. cassini, and M. septendecula. The cicadas from this brood will also be emerging in Indiana, Iowa, Wisconsin, and possibly Michigan.
Those residing in the southern half of Illinois will see the emergence of Brood XIX, or the Great Southern Brood. This group will feature four species of the 13-year periodical cicadas and will be the largest of the 13-year broods.
“Periodical cicadas are among the longest-lived insects on the planet, living for 13 or 17 years. They spend the vast majority of that time living underground, feeding on tree roots,” stated Johnson. “Once the soil warms enough in the spring (64°F at eight inches deep), they will begin to emerge, depending on where you are located, sometime in May or early June.”
After about a month of completing their mating cycle, adult cicadas will begin to die. Individuals may take notice of large piles of cicadas accumulating under trees, which will seem unpleasant, however, the decaying cicada bodies will serve as great fertilizer for plants.
In six to ten weeks, the eggs laid by the female cicadas will begin to hatch. The tiny cicada nymphs will proceed to drop to the ground and feed on mostly grass roots. In due time, the nymphs will dig down into the soil, eight to 12 inches deep, and re-start the periodical cicada life cycle until it’s time for them to emerge in the next 13 or 17 years.
The emerging broods of cicadas do not pose a threat to people or animals and should just be left alone if they are encountered. Experts note that insecticides are not recommended to manage periodical cicadas in home landscapes.
Large, healthy trees can survive egg-laying with no long-term impacts. In addition, insecticides are not as effective in protecting smaller trees and shrubs from cicadas as setting up netting. Applying pesticides to control cicadas may harm other organisms, including animals that eat cicadas.
As an added takeaway, periodical cicadas are different than the annual or dog-day cicadas that appear every summer. Annual cicadas only take two years to complete their development and have overlapping generations that are not synchronized to emerge at certain times, unlike their periodical cicada counterparts.
Annual cicadas also look different. They are about one and a half to two and a half inches long and have a green and brown pattern to green and black pattern with a mostly white underside, according to Johnson.
Periodical cicadas are smaller and have shiny, jet-black bodies with orange wing veins and red eyes.
