BugBytes: Click beetle has a move worthy of the Olympics

Thorax

Marian Lyman Kirst

Click beetles are unique among beetles in their ability to flex at the union that joins the insects’ prothorax and mesothorax. Other beetles are stiff by comparison, their thoracic unions allowing for only minor movement.

And … the Olympics is over. Whew.

I have to admit, I’ve never been a huge fan of the Games. Of all the events, though, the gymnastics portion has always held a certain fascination for me. It’s largely wistful. I used to do gymnastics, you see.

And, wow, was I terrible.

Case in point: my best apparatus was the practice pit.

For real gymnasts the practice pit is just a foam-block-filled cement pool, into which one artfully lands after vaulting out a double back-handspring, twisted Yurchenko with lime, or some nonsense. For me, it was where I dominated my 9-year-old classmates in foam pit hide-and-seek, a game in which kids squirreled to the pit’s cushioned depths to hide from a designated seeker tasked with tagging them “out.”

PrintI freaking ruled that game. I could squirm my way to the pit’s bottom so quickly and stay there so long that—on more than one occasion—I would emerge, flecked with foam and smugly triumphant, to find the game long-since ended, its players packing to leave.

“We all got tired of trying to find you, stupid,” a classmate explained.

Sadly, the sport’s other (actual) apparatuses proved either too terrifying or too tall—and I too weak and filled with Pringles and Pop-Tarts—to successfully tackle.

Indeed, my gymnastics career came to an abrupt and undignified end when, after watching me struggle (yet again) to pull myself onto the lowest of the parallel bars, a fed-up classmate said, “Maybe you’re just too heavy for gymnastics?”

Breathless and red-faced, I considered this, decided she was right, pushed her, suggested maybe she was too heavy for gymnastics (and also, “like, super mean!”), and we both quit on the spot.

Since then, I’ve always had a fondness for the sport and, during this summer’s Games, for Simone Biles in particular.

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Biles’ furious, muscle-fueled floor routines are a joy to watch, not least because her signature move, “The Biles,” reminds me of the escape maneuver of one of my favorite coleopterans: the click beetle.

Click beetles belong to the coleopteran family Elateridae and are also sometimes called skipjacks, snapping beetles or jackknife beetles.

Their colorful monikers are inspired by the beetle’s ability to flip through the air when provoked. The physics of this action, like those powering “The Biles,” is intense and somewhat counterintuitive.

To “perfect 10” the hell out of her signature move, Biles has to double-flip in a “layout” position, half-twist her outstretched body, and then stick a blind landing.

Click beetles achieve their gymnastic getaway by arching their backs and then quickly bending forward (at the “waist”), which snaps a stiff spine on the beetle’s “chest” (or pro-sternum) into a corresponding groove on its upper belly (or mesosternum). The force of this insertion vaults the beetle, with a loud “click,” into the air and, ideally, out of harm’s way—the beak of a hungry bird or the filthy mitts of a grabby entomologist, for example.

Elley

Elley Swan

“Out on a limb” by BugBytes Illustrator Elley Swan: a beautiful interpretation of Marian’s first encounter with an eyed elater in Montana.

The audible “click” associated with the beetle’s tumbling talents may also have—if you’ll allow me to stick with sports metaphors here—a Venus Williams grunt-type effect: A loud, sudden sound that effectively startles the enemy into a miscalculation.

The beetles also use the click trick to right themselves should they wind up on their backs. Thus, gently turning a suspected click beetle onto its dorsum is a fun way to determine if your ID is correct.

If you’re lucky, the overturned beetle will immediately click-and-flip itself back onto its feet. If the bug gods have spurned you, however, the beetle may decide to conserve its energy and play dead (a process known as “thanatosis” in animal behavior), instead. In this case, the click beetle will pull its legs into its body and tightly tuck its head and antennae beneath its chest.

Click beetles can maintain this morbid pretense for a frustratingly long time, as many a bug nerd, who’s ever tried to impress her friends with click beetle gymnastics, well knows:

“I swear, it’s gonna click any second, just wait. Any time now…”

“Are you sure it’s not just dead?”

“I’m sure.”

“Because it looks dead, you know.”

“I know! It’s faking, damn it!” (Come on, Mr. beetle. Help a lady out!)

“This is taking forever. You suck, Marian.”

Sigh. “I know…”

Anyway, adult click beetles are fairly easy to recognize: their bodies are long, narrow and vaguely flattened. Many have serrated antennae and a thoracic shield that ends in sharp, slightly flared corners. They are most often found under or on bark and on vegetation, where they feed on pollen, nectar, fruit and fungi.

The larvae are called “wireworms” and can be found in soil, decaying vegetation and rotting wood. Some are economically important pests that can seriously damage crops by feeding on plant roots and seeds. Most wireworms, though, are beneficial predators of wood-boring beetles.

Click beetles range markedly in size, from just a few millimeters long to over two inches in length. And while the majority of Montana’s click beetles are blackish-brown, some are brightly colored, metallic, or dramatically “eyed.”

Elater

Marian Lyman Kirst

This handsome specimen was found last July near Norm’s Island, just south of Billings. The eyed elater’s distinctive white mottling resembles fur or fuzz but actually consists of clusters of tiny scales, and is often particularly pronounced around the beetle’s eyespots.

Indeed, my all-time favorite click beetles are the eyed elaters (genus Alaus), a group of nearly 2-inch-long, black and white-mottled insects that boast large, matte-black, dorsal eyespots, just behind the head.

It is thought that these “false eyes” like those found on the wings of some butterflies and moths, help protect the beetles by frightening or confusing potential predators, at least for a second, allowing the beetle a window of time in which to escape.

I found an eyed elater for the first time in Montana last July near Norm’s Island. The beetle was perched atop a twig of buffaloberry. It was caked with mud, suggesting it had only recently emerged from the subterranean chamber in which it had pupated as a larva.

The bug gods smiled upon me that day, my friends, as eyed elaters are not terribly common. So if you find one this fall, count yourself king or queen of the beetles, take a picture, and give the click trick a try (just leave “The Biles” to the professionals).

The Nitty Gritty

Common Names: click beetle, skipjack, snapping beetle, jackknife beetle

Order: Coleoptera

Family: Elateridae

Where to find: During the day, look for adults under bark and on vegetation during late spring through early fall. Some click beetles are strongly attracted to lights at night and I’ve often found them under my lighted patio after 10 p.m. during the summer. Eyed click beetles in our area are probably most likely to be found on and under bark or on vegetation near logs or felled trees. In the Beartooth foothills and surrounding meadows, I often find small click beetles clinging to grass blades.

When to find: Adults are most commonly found during the day from spring through late summer but some overwinter under bark and so can be found year-round.
Marian Lyman KirstM.L. Kirst is a Billings-based, bug-obsessed freelance writer and photographer with a background in environmental studies and science journalism, and she is currently working on a degree in entomology. Her work tends to focus on natural history and wildlife conservation. But her prime directive is to blend art, science and writing in a way that inspires others to celebrate the beauty, ingenuity, and diversity of insects, spiders and their kin.

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