JUDY WOODRUFF: Everyone would agree this past year has been tragic in so many ways.
It's also been strange.
But something is about to happen to make it even stranger.
The bugs are coming, billions of bugs.
The periodic cicada invasion is just days away in many states.
And we are so pleased that one of our own, John Yang, has gone and learned what you need
to know to cope with the coming brood.
MICHAEL RAUPP, University of Maryland: Let's see if we can find somebody under here maybe.
JOHN YANG: Entomologist Mike Raupp, A.K.A The Bug Guy, and I are hunting cicada in his
neighbor's backyard in Columbia, Maryland.
MICHAEL RAUPP: Oh, boy, there we go.
Look at that.
Oh, yes.
JOHN YANG: Specifically, Raupp, his neighbor Tim Hughes and I -- by the way, all of us
are fully vaccinated -- along with Hughes' 3-year-old granddaughter, Emily, were looking
for Brood X cicadas.
What do you think?
MICHAEL RAUPP: Pretty good?
JOHN YANG: Good?
GIRL: Yes.
MICHAEL RAUPP: He's pretty cute, isn't he?
(LAUGHTER)
JOHN YANG: We dug up the cicadas and then put them back.
But, soon, we won't have to look very hard for them.
They will climb out from holes in the ground after 17 years below the surface.
And there will be a lot of them.
MICHAEL RAUPP: Twelve, 13, 14 holes, that's probably going to translate in an acre to
several hundred thousand cicadas per acre.
JOHN YANG: Wow.
Just in this backyard.
MICHAEL RAUPP: It is going to be crazy.
There are literally going to be billions, if not trillions of periodical cicadas emerging
in 15 states from Georgia to New York City, and then West to the Mississippi River, Ohio,
Indiana, and Illinois.
JOHN YANG: Northern American periodical cicadas emerge together in groups called broods in
distinct geographic areas after spending 13 or 17 years underground.
Brood X is one of the biggest and will come out when the soil reaches 64 degrees.
MICHAEL RAUPP: These guys have been underground for 17 years, sucking on the sap of tree roots.
They're going to make a jailbreak just at nightfall.
Their skin is going to split open on the back.
They're going to pop out of there.
Then they're going to move to the safety of the treetops.
Then, within a span of about maybe a week or 10 days, it's going to be a big boy band,
because only the males sing.
JOHN YANG: And they are loud, up to 100 decibels.
That's as noisy as a lawn mower.
MICHAEL RAUPP: John, it's going to be all about romance at that time.
Remember, these are teenagers.
They're 17 years old.
They have been underground.
It's been dismal.
Once they're up in the treetops, he's going to do his very best to convince that special
someone that she should be the mother of his nymphs.
If she likes it, she's going to flick her wings.
They're going to hook up.
They're going to mate.
It's just going to be wonderful.
JOHN YANG: The females lay their eggs in small tree branches and then the grownups die.
After the eggs hatch, the nymphs fall to the ground, burrow into the soil, and start the
cycle all over again.
MICHAEL RAUPP: These are the very parents of the class of 2021.
JOHN YANG: Raupp saved some cicadas from the last emergence in 2004.
MICHAEL RAUPP: We have two different species in the box right now.
These are called the septendecims, where these little guys right here, those are my favorites.
Those are called the cassinis.
JOHN YANG: Chris Hughes remembers feeling overwhelmed 17 years ago.
TIM HUGHES, Maryland: It's just dramatic, how many there were.
Literally, the entire yard was moving.
In fact, it was moving so much that we got up, and you know how you feel when you get
off a boat, you're a little woozy?
That's exactly how we felt.
JOHN YANG: Instead of sea legs, you had cicada legs.
TIM HUGHES: Cicada legs, yes.
CHRIS SIMON, University of Connecticut: These are from Long Island.
JOHN YANG: Evolutionary biologist Chris Simon says there's a reason for their abundance.
CHRIS SIMON: When they come up, everything eats them.
They have this sort of safety in numbers strategy.
Eventually, predators get tired of eating them, and enough are left that they can survive
and reproduce.
And so they will all come out at exactly the same time.
JOHN YANG: Cicadas have even become cultural icons.
Simon showed us souvenirs like this jade cicada.
CHRIS SIMON: They have traditionally been put in the mouths of dead people in Asia to
carry their spirits into the next world.
This is a bumper sticker from Nashville.
This one says "Sing.
Mate.
Die."
Cicadas are also really well-loved in Japan.
This can transform into a robot.
It's called Cicadacon.
JOHN YANG: But periodical cicadas may be transforming in real life.
Simon is studying whether climate change is spurring them to mature faster.
CHRIS SIMON: We have seen many more cicadas coming out four years early, and not only
coming out four years early, but coming out four years early in larger numbers.
And they mate and lay eggs.
And the eggs hatch.
In previous years, we have seen them come out four years early, but there weren't as
many.
They don't establish a self-reproducing population.
So, we used to think it was an evolutionary dead end.
JOHN YANG: But not anymore.
In 2017, Simon tracked Brood X cicadas that emerged four years early and estimates there
were millions of them.
CHRIS SIMON: With climate change, there's warming.
And the warming provides longer growing seasons for the trees and for the cicadas.
And so, as the feeding season gets longer, the cicadas can grow faster.
JOHN YANG: The Brood X emergence will give Simon a chance to collect new data.
But for those who may fear the appearance of billions of bugs?
MICHAEL RAUPP: They're not going to bite.
They're not going to sting.
They're not going to grab dogs and small children like the monkeys in "The Wizard of Oz" and
fly away with them.
These are harmless creatures.
JOHN YANG: Raupp cannot wait for the cicada-palooza.
MICHAEL RAUPP: This is like having a National Geographic special right in your own backyard.
It's going to have birth.
It's going to have death.
It's going to have romance in the treetops.
It's going to have cicadas battling predators.
It's going to be better than an episode of "Game of Thrones."
JOHN YANG: So, sit back and enjoy the show.
For the "PBS NewsHour," I'm John Yang.
JUDY WOODRUFF: But who's to say enough of them couldn't pick someone up and take them
away?
We will see.
I know they're harmless, but they're grossing us all out.