You have probably heard all the hype around the great cicada invasion due to occur in Illinois in 2024. Is this a reason to pack up and head out of state? I don’t think so and here is why. Two periodic cicada broods native to Illinois, broods XIII & XIX, are due to emerge this summer. Brood XIII emerges every 17 years and brood XIX emerges every 13 years. If you do the math, these two broods only emerge together every 221 years. The last time this occurred was in 1803 and it will not occur again until 2245. Their chronological cycles may overlap this year but their geographical ranges overlap only in a narrow band in north central Illinois (near Springfield). In most areas, like Glenview, there should not be any more sightings than when only one brood appears. However, brood XIII, which emerges every 17 years in Northern Illinois will produce millions of cicadas over four states (IA, IL, WI, IN, & MI).
Cicadas are large insects ranging from 1-2 inches long. They are most commonly known for the high pitch song which the males sing to attract mates. Males make this sound by flexing muscles in their abdomen that pulls on a drum like organ called a tymbal. Females respond by flicking their wings.
Annual cicadas live underground for 2-5 years feeding on plant roots, but enough emerge every year to make them appear annually. Periodic cicadas live underground for many more years, depending on the brood and then emerge in large numbers every 13 or 17 years, making them some of the longest living insects in the world.
Periodic cicadas emerge when the soil temperature, 8 inches below the surface, reaches 64oF, usually from mid-May to late June. Cicadas are cold blooded meaning they are most active when air temperatures are between 65-83oF, with 72oF, being ideal for flying, singing, and mating.
Cicadas provide a bountiful harvest of food for many creatures that eat them, like, birds, squirrels, opossums, moles, snakes, raccoons, dogs, and even people. Search the web and you will find hundreds of recipes for cicada BBQ, kabobs, gumbo, stew, or deep fried.
-article written by GHA Board Member Jeff Hoyer
When: Sa, May 4, 10 am- 4 pm
Where: The Grove National Historic Landmark, Archives Building
Celebrate the arrival of the Brood XIII Periodical Cicada! Explore the phenomenal lifecycle of the 17-year Cicada with a full day of educational fun for the entire family!
Science programs • Family Activities • Crafts • Exhibits & Artwork • Nature Walks • Giveaways
When: Sa-Su, May 5-September 29, 10 am- 4 pm
Where: The Grove National Historic Landmark, Archives Building
The self-guided Cicada Exhibit is available to all visitors throughout the summer and early fall.
When: F, June 7, 7:30-9 pm
Where: The Grove National Historic Landmark, Archives Building
Fee (R/NR): $22/$24, register →
Join The Grove for an night of exploration, libation and natural wonder at Hops & Hike: Broods and Brew. Discover the fascinating world of Brood XIII periodical cicadas – a spectacle that occurs only once every 17 years. Enjoy craft beer tasting and camaraderie around the campfire as we are serenaded by the mating call of nature’s Romeo! Then it’s time to hit the trails on a guided evening hike. For ages 21+.
When: F, June 7, 6-7 pm
Where: The Grove National Historic Landmark, Program Barn
Fee (R/NR): Free, but registration is required and seating is limited, register →
Cicadas are here! Discover what all the buzz is about from Dr. Cicada himself! University of Connecticut-Hartford entomologist John Cooley, Ph.D. will be visiting The Grove and presenting an engaging, educational, hands-on cicada adaptive program for all. Brood XIII’s exact emergence dates are unclear so stay in the know!
annual cicadas are green and black with transparent wings and green veins on the wings
the periodic cicadas (Magicicada) which are dark brown to red on the body with red eyes and orange veins on the wings
Cicadas are sometimes called locust, but that is not correct. Locust are grasshoppers that periodically reproduce in large numbers and can cause extensive crop damage. While cicadas do drink some plant sap from roots and stems, they rarely cause significant damage. Young or sick trees may lose a few small branches when the female lays her eggs in grooves cut in the bark, but this probably helps the tree by eliminating weak branches. After hatching, cicada larvae fall to the ground where they burrow in and live peacefully for many years drinking sap from tree roots. Healthy trees have plenty of sap to share so it does not harm the tree. In fact, their burrows make it easier for the roots to grow by allowing more water and oxygen to enter the soil. Cicadas are also not lawn grubs which can kill portions of turf grass. Lawn grubs are larva forms of Scarab beetles, such as Japanese beetles and European Chafers. If you are worried about a young or weak tree, cover it with a net prior to the emergence, hose or pick off the cicadas by hand, or simply wrap some tape around the trunk, sticky side out, to trap the insects climbing up the tree.
Why do so many cicadas emerge at once? The answer is a term in ecology called predator satiation. This means by emerging in the millions, predators cannot eat all of them, ensuring some cicadas survive to reproduce and prevent extinction.
Why do broods emerge every 13 or 17 years? The answer lies in the fact that 13 and 17 are prime numbers (divisible only by 1 and themselves). This prevents predator populations which may peak in nonprime years from syncing up with cicadas and overwhelming them.
Do cicadas pee? Yes, all insects that drink sap secrete waste. If the number of cicadas in a tree is high enough, you may feel a slight mist under the tree called honey dew. Honey dew is mostly sugar and easily washes off, but it might be wise to park your car somewhere else during peak season.
Do cicadas bite? No, but their feet have raspy claws which might feel like a gentle bite.
Do cicadas stink? No, not until they are dead and decomposing. If you find a large number dead on the ground, rake them up and toss them in the yard waste.
