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While the cicadas of 2038 slumber, scientists are reviewing what they learned from 2021’s Brood X

Mike Raupp is an emeritus professor of entomology from the University of Maryland. Like many researchers, he was excited to study the 2021 appearance of the Brood X periodical cicadas. (Paula Shrewsbury)
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Did last year’s periodical cicadas get all up in your face? Did they make you feel harassed? Don’t worry. Mike Raupp harassed them right back.

“I started this particular project back in 2004, so this is 17 years of harassment for the poor cicadas,” Raupp said.

Kids, don’t try this at home. Raupp is a professional cicada-botherer, a professor emeritus of entomology at the University of Maryland.

Like many bug experts, he was very busy last summer when billions of cicadas emerged from the ground in the D.C. area. Now it’s time for Raupp to study his findings, some of which he shared last week during a webinar sponsored by the Entomological Society of America.

Raupp has long been interested in the defenses insects deploy to keep themselves alive. In this regard, periodical cicadas have been dissed for decades. One 19th-century researcher wrote, “I've never seen animals more entirely stupid than the 17-year locusts. They make no effort to escape.”

Said Raupp in an interview, “The most common term is that they’re ‘predator foolhardy,’ a term I particularly like.”

Certainly many animals — birds, squirrels, dogs — chow down on cicadas. But do the bugs have absolutely no self-preservation instincts? To find out, Raupp went to a Christmas shop and purchased an artificial bird, the type you can put on a Christmas tree. It resembles a goldfinch.

“I tied it to a stick about two meters long,” he said. “This was my faux bird that I used to torment cicadas.”

He later used a simpler method. Rather than bird-on-stick, Raupp used hand-on-arm. He just went up to periodical cicadas and tried to catch them with his hand.

In most cases — 60 percent of the time — he could. But 40 percent of the cicadas did try to escape: Twenty-eight-percent flew away and 12 percent dropped from the plant they were on.

“The interesting thing to me was that these responses were temperature-dependent,” Raupp said.

When the temperature was in the lower 50s, cicadas made easy pickings. As it warmed up, they were more likely to make an escape. This isn’t surprising, given that insects are poikilotherms, i.e., coldblooded.

So, too, are the annual cicadas that come out each summer, but those critters use two protective methods. They have markings that allow them to blend in with foliage — “and they can fly like F-14s,” Raupp said. “They can fly three times as fast as periodical cicadas. These have a very different strategy. It’s just darn hard to even get close to a nonperiodical cicada.”

The main tactic used by periodical cicadas is predator satiation: You can’t eat us all. But, as Raupp proved, at least some brave souls do try to get away.

Among other scientists presenting at the webinar was Brian Lovett, a postdoctoral researcher in the Kasson Laboratory at the Division of Plant and Soil Sciences at West Virginia University. His topic: Massospora cicadina.

That’s the fungus that afflicted many unlucky members of Brood X. It caused the insects’ abdomens to fall off, replaced by a yellow fungal plug. It didn’t kill the afflicted bugs outright, though.

The freakiest thing in Lovett’s presentation was his description of how some males react to this tragic turn of events: They pretend to be female.

Male cicadas use an organ in their hollow abdomens to produce that characteristic sci-fi sound, which signals to females that they’re eager to mate. Females respond by snapping their wings. “That’s a signal to the male that ‘I’m interested,’ ” Lovett told me.

But once a male’s abdomen has fallen off, he can’t sing.

“Once the fungus has replaced the abdomen, there’s no way for it to continue to act like a male,” Lovett said. “The calling organ has been dismembered.”

So some infected males act like females, snapping their wings. This attracts uninfected males. They try to mate, which only serves to get the fungus on their abdomen, infecting them.

Massospora cicadina also infects females, but researchers haven’t seen them manipulated in the same way as the males. And they don’t know how males are made to change their behavior. There could be a chemical trigger. Researchers in the Kasson Lab have detected an amphetamine in the fungus that may be messing with the cicadas.

“There’s definitely an air of the macabre in these fungi,” Lovett said. “I think people recognize that. No one asks why they’re called ‘zombie cicadas.’ ”

Right now, Brood X’s Class of 2038 is slumbering below the frozen Earth, snuggled up near tree roots. In 17 years — well, 16 ½ — they’ll emerge and entomologists will go into overdrive trying to solve their mysteries.

Read more from John Kelly.

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