Emerging Brood X cicadas have citizen scientists on the lookout

As hundreds of cicadas emerge from Kathryn Reilly's suburban front yard, she's letting the lawn grow.

"My husband and I are having a disagreement because he wants to cut the grass," she told CBC Radio's Day 6. 

"And I'm like, 'You can't. They're everywhere and they're in all stages and they've just started singing.'"

That singing is the mating call for the billions of cicadas that are surfacing from the ground across the eastern United States — a phenomenon that's expected to last four to six weeks.

The insects, which include three different species better known as Brood X, only make themselves known every 17 years. After emerging from the ground as nymphs, where they feed on sap from certain trees, the cicadas molt and mature before mating. 

Part of the reason they surface in such large numbers is to protect themselves from predators like birds, small mammals and other insects. The more cicadas that surface at once, the better chance many will survive and go on to mate.

English professor Reilly and her 10-year-old daughter, Madeline Gilbert, have become citizen cicada researchers after the brood flooded the Crofton, Ma., property her family moved into seven years ago.

Using an app known as Cicada Safari, Reilly and Gilbert have been snapping photos — somewhere between 800 and 900 so far, landing them in the app's list of top 10 contributors — that are then uploaded for scientists and researchers to examine. The aim is to map where, exactly, Brood X is appearing.

"This is a great way to be interested in the natural world and it's easy to get involved with. You don't have to buy anything. You don't have to prepare or travel for it," said Reilly.

"For us, it's right here and it's accessible."

Tracking the cicadas

Reilly and Gilbert are not alone in their quest to track when and where the periodic cicadas are appearing. 

Greg Holmes, a photographer from Hutchinson, Kan., has driven more than 17 hours from his home in order to map their emergence.

In his truck is a computer connected to a GPS receiver. As he drives around — often on smaller, back roads — he catalogues which species of cicada can be heard in the area, from the moment he begins to hear their song, to the moment it stops.

"All of that will be added to an aggregate map that, in the end, will give us a much more accurate picture of the borders of Brood X than we have previously," he said.

Each of the species has its own unique song. He describes the sound of Magicicada septendecim like the whoosh of a punctured aerosol can. Magicicada cassinii is shriller, while a group of Magicicada septendecula sounds like "Santa's sleigh bells," he said.

The billions of cicadas that will emerge from the ground over the coming weeks are undoubtedly loud. A chorus of the bugs can reach 90 to 100 decibels, or about as loud as a lawn mower.

But it's music to Holmes, who has had an interest in cicadas since childhood.

"I remember riding my green Otasco bicycle along the sidewalks of Joplin, Mo., and cicadas would be closing or moulting overhead on the low branches," he recalled.

"In the evening, their wings would hang down and they would catch the light of the streetlights, and other cicadas would be maturer and singing already. 

"It was simply part of the soundtrack of my youth."

'They are edible'

Reilly and her daughter have also been unbothered by the cicadas' stirring.

"I think enough have come out that they're starting to work to find a mate, the ones that emerged earliest. But it's louder at night." said Reilly.

"It's like, 'Let me sing you the song of my people — loudly.'"

She expects the cicadas' emergence has neared its peak, and that soon her lawn and gardens will be left with nothing more than the insects' molted shells.

But in the meantime, Gilbert offered a surprising admission when asked what she looks forward to as the uprising continues.

"I would like to taste the cicada — they are edible," she said, while Reilly noted that one recipe said they taste like shrimp.

But the mother adds that they won't be on the menu any time soon.

"I may just let the wildlife gorge and have the buffet … I don't know if I'm that adventurous to eat cicadas."

Written by Jason Vermes. Interviews produced by Annie Bender.

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