Cicadas emerge in Southern Indiana


The cicadas are coming.

Any day now, hoards of cicadas will begin their ascent from the ground and cover many areas of Dubois County for the following weeks. The creepy-yet-harmless insects are part of Brood X, which emerges every 17 years and covers 15 states, including most of Indiana.

They’ve already started to appear in Perry County, said Megan Abraham, director of the DNR Division of Entomology and Plant Pathology, so the rest of Southern Indiana should be close to follow.

One way to tell they’re about to emerge is if there are little mud tubes underneath large trees, which the insects will use to travel above ground once the soil warms up to about 64 degrees.

“As soon as the soil gets warm enough, they will eventually emerge out and start climbing up those trees to molt,” Abraham said.

Although the insects can look pretty grotesque and find mates by making a buzzing noise of up to 100 decibels — the same as a jackhammer or power lawn mower — they can’t bite, sting or pose any real threat to humans.

“These guys aren't dangerous. They're horrible fliers, so they might bump into everybody, but there's nothing to be alarmed about,” Abraham said. “They’re also not extremely smart, so sometimes they’re going to be attracted to noises you might make, like motors or a lawn mower.”

Additionally, with the emergence of Brood X will eventually come cicada killer wasps, which will also not harm humans unless provoked. However, because they live in the ground, it’s important to be careful of stepping on any nests.

Every 17 years, the female cicadas lay eggs by making slits in the soft, new growth of trees and leaving the eggs in there. This means that although larger trees will not be harmed, saplings can be saved from damage by covering them in a fine netting for about six weeks.

“Anything that's a few years old is probably going to be just fine,” Abraham said. “It'll look ragged by the end of the summer, but it will come back next year.”

Abraham said the cicadas likely emerge in masses every 17 years so that there is a higher chance of carrying on their genes.

“If there's so many of them that all the predators can't get to them to eat them all, then there's a much higher chance of success of being able to pass on their genes and start the next 17 year cycle,” she said.

Cicadas are eaten by rodents, birds and small mammals, which means that they can actually help other populations. For example, the turkey population typically grows in years after cicada emergence, Abraham said.

Those interested in recording cicada emergence in their area can download an app called “Cicada Safari” on a mobile device. The closest sightings on the app so far are near Bloomington and Louisville.

Because the insects laid eggs in trees 17 years ago, newer houses or neighborhoods with younger trees likely won’t be as affected as those living in wooded areas or those with older trees.

“If you're in an area that's brand new, like maybe within the last 10 years your neighborhood came out from a cornfield, then you're not going to see as many cicadas,” Abraham said. “But if you're somewhere that had trees 17 years ago, it's going to get loud for you guys.”

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