You’ve probably heard of Brood X and it may seem like the stuff of nightmares. Fear not, it’s just the arrival of a large group of cicadas and they’ll be gone in 6-8 weeks.
Brood X has been waiting 17 years to reemerge, since its last presence in 2004. Cicadas groups are labeled by broods, with the state of Indiana being geographically dominated by Brood X.
Thanks to habitat alteration, some broods haven’t had numbers as high as before, with some dying off entirely. Cicadas are classified as cousins to leafhoppers, despite their visual similarity to grasshoppers. That’s why they’re often confused with locusts, even though they’re not, due to their lack of chewing mouthparts.
With more than 190 varieties in North America and 350 worldwide, annual and periodical cicadas, which Brood X is considered, vary in appearance as well as size. Periodical cicadas have red eyes with orange tinted wings, while annual cicadas are larger with a greenish tint on their wings. Both emerge at different times of the year.
According to Amy Thompson, agriculture and natural resources educator of the Monroe County Purdue Extension, there is folklore associated with cicadas.
Back in the day, it was said that if people saw a W or a P on a cicada’s wing when it emerged, it signified whether there would be a time of war or peace.
Thompson gave a virtual class recently on Brood X, with 100 registrants. It’s been a hot topic in the garden world, Thompson said, and one that has people on edge wondering about how much damage their plants will face.
Cicadas start out as eggs that hatch, take a few days to harden, then go underground and feed on trees and tree roots until they mature into their adult form, and find a mate.
Male cicadas use a special organ called a tymbal to produce their rasping songs in order to attract a mate, one of the characteristics people most recognize about cicadas.
Once each cicada has found a mate, male cicadas can fertilize up to 800 eggs, which the female adult cicada then lays in clusters of 25 in woody plant material. Then, the cycle resets.
According to Thompson, their song in large groups can reach up to 100 decibels, the equivalent of the sound of a running lawn mower.
Gardeners are concerned about the damage they’ll cause this summer, but Thompson says not to worry.
“Smaller younger trees are most at risk for extreme damage. Consider delaying pruning to mid-July or delay planting of new trees and shrubs,” Thompson said.
Trees such as maples, serviceberries, dogwood, redwood, and many fruit trees are the most vulnerable to cicadas, but the damage will only be to this year’s growth, so established plants should survive.
Other options include putting up mesh screening that’s half-inch or smaller so the large insects are unable to penetrate it, but put the mesh up now before it’s too late, Thompson said.
The good news is cicadas will not harm people, even though they can be found in numbers as large as a million and a half per single acre.
“They don’t bite, don’t sting, can’t harm you in any way. They need several days to harden. We do expect high numbers; in northern Indiana with flatter ground, the population will be more sparse and more localized,” Thompson said.
If you’re also interested in new cuisine, cicadas are considered a food source and can be used in a variety of meals.
“Lots of recipes are out there,” Thompson said, but warned not to eat them if you have shellfish allergy, as it’s not uncommon to react to cicadas too if you already have that allergy.
Common cicada enemies include cicada killer wasps, spiders, blue herons, moles and even house pets.
Furthermore, people are invited to track the cicadas as they emerge through the Citizen Science iNaturalist App. The app allows people to track sightings of cicadas all over the state.
More information, including photos of cicadas, is available at extension.entm.purdue.edu/publications/E-47/E-47.pdf.