“Slingshot Spider” Flings Sticky Web at Prey, Spider-Man Style

In a move worthy of Spider-Man, a potential new species of spider uses its web as a slingshot to ensnare prey.

Like most spiders, this talented arachnid weaves a standard orb web out of silk. But it’s no regular web: The center is attached to nearby plants by a long thin line, and the tiny spider sits in the center of the web and pulls it back toward the vegetation.

The slingshot spider prepares to launch its web toward prey. Photograph by Larry Cremer, Perunature.com

As potential prey approaches, the spider suddenly lets go and the web snaps forward like a slingshot—with the spider still attached. If the spider aims right, its insect dinner is trapped in the sticky web. Then, all the spider has to do to prepare its meal is slowly walk over. (Also see “Tarantulas Shoot Silk From Feet, Spider-Man Style.”)

“It seems to me that these spiders are specializing in capturing freshly emerged flying insects, likely flies or small mayflies, as they emerge from the water to disperse,” said Lary Reeves, who identified the spider while doing unrelated research at the Los Amigos Biological Station in Peru.

Along Came a Spider

Reeves first found the spider by accident while searching the jungles of Peru for the spectacled caiman (Caiman crocodilus).

Watch a video of the spider in action.

Besides the caimans, he was also keeping his eyes peeled for harmful bullet ants (Paraponera clavata), so named for their nasty sting. His eagle eyes paid off: One day he noticed an absurdly small spider about 0.4 inch (less than a centimeter) long sitting in the center of a cone-shaped web. He called his colleagues Geoff Gallice and Lindsay Whelan over to take a look. (Watch a video of the world’s largest spider.)

That’s when Reeves saw the spider in action, as it slingshotted the web toward a nearby mosquito.

Reeves knew enough about spiders to be on the lookout for some bizarre behavior, but this seemed pretty unique.

He thought he had identified a species of spider that was new to science, and traveled back to Los Amigos and the nearby Tambopata Research Center in December with entomologist Phil Torres to take a closer look. They also brought photographer Jeff Cremer to document the spider’s behavior.

Near Tambopata, the scientists discovered similar slingshot spiders, although these were slightly bigger—around 0.3 inch (a centimeter) long. With Cremer’s camera lenses, they were able to capture the spider’s behavior on film.

Mystery Arachnid

Both Reeves and Torres were convinced this was a new species of spider until a literature search revealed an obscure family of spiders that had first been documented over 80 years ago.

Native to the jungles of Central and South America, the family of Theridiosomatidae spiders were known primarily by professional arachnologists, due in part to their small size.

slingshot spider picture
A close-up of a slingshot spider. Photograph by Jeff Cremer, Perunature.com

Comparing the photos of the spiders near Los Amigos and Tambopata revealed that at least one of these spiders had been described before. (Also see “Mystery Picket Fence in Amazon Explained.”)

The species Reeves first discovered by Los Amigos looks almost identical to a species known as Naatlo splendida, although specimens will have to be collected to make a firm identification.

Speed and Stickiness = Success

As for why a spider would slingshot itself through the air, the scientists believe it’s just the lengths that a predator will travel for a good meal.

“Other spider webs may be more limited in how they entangle their prey—they are reliant on how sticky their web is, combined with the flight of the prey impacting the web,” Torres said. (See National Geographic’s spider videos.)

“This method of flinging the web appears to make it much more likely that the prey will get tangled,” Torres said.

“Imagine the difference between bumping into a sticky trap and having a sticky trap flung at you.”

If this spider is new to science, what would you call it, readers?

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Wildlife

Carrie is a freelance science writer living in Virginia. When she's not writing about cool critters, she's spending time outside, drinking coffee, or knitting. You can visit her website at http://www.carriearnold.com