Scientists Have No Idea What Made These Weird Weblike Structures In The Rainforest

By Joelle Renstrom | Updated

This article is more than 2 years old

mystery structureI just spent an hour surfing the “what’s this bug” sub-Reddit. Great Maker, there are tons of crazy and terrifying bugs out there, and far more spiders than I care to count. And far too many people using the adjective “gorgeous” to describe them. But the scads of human databases that frequent the sub-Reddit are stumped, along with every scientist and entomologist asked to weigh in on a discovery made by a Georgia Tech graduate student.

mystery thing

The mystery thing, for lack of a better word, was found on June 7 in the Amazonian rainforest of southeastern Peru. Troy Alexander was at the Tambopata Research Center when he first saw this small structure, which measures at roughly two centimeters across, on the underside of a tarp. He saw three more on tree trunks in the rainforest. They might be spiders’ white picket fences. They might be the byproduct of fungi showing off. They might be the architectural feats of beetles who wanted to create an imposing tower. Or maybe it was a Beatle. Who knows?

I love when nature bewilders the scientists. Alexander posted his photos on Reddit, a Tambopata biologist posted on Twitter, and magazines such as Wired made the rounds, showing the photos and asking scientists for answers.

A Smithsonian Tropical Research Institute entomologist said he didn’t know what the structure was, much less what made it. The American Museum of Natural History’s curator emeritus of spiders said…hang on. There’s a curator emeritus of spiders?! That has to be the absolute worst job in the history of humankind. I would rather be president or work in waste disposal. But I bet that guy’s awesome at handling all the creepy crawlies in his house. Maybe I ought to put him on speed dial. Anyway…even the curator emeritus of spiders has “no idea what animal might be responsible.”

mystery thing

The National Museum of Natural History’s associate director for science was clueless too, having “never seen such a structure before.” Another spider expert — apparently they’re officially called arachnologists (that they’re bonkers is implied, I guess) — said that perhaps the structure was made by a lacewing, but that she wouldn’t bet on it. Lacewings have big, veiny wings similar to those of dragonflies (my favorite insect, if anyone cares, since they’re both beautiful and benign, and have never set up shop in my car). Lacewings, which can be green or brown, eat aphids and mites and are found all over the world.

Bucculatricidae
Bucculatricidae fence

Other scientists guessed that the responsible insect might be a moth from the Bucculatricidae family. Apparently, some moths do build something like a fence to protect their eggs, but they generally don’t look like the ones Anderson found. Wired magazine’s bug blogger thinks that whatever made the structure is probably a relative of a Vietnamese caterpillar that weaves net-like cocoons. But I think she put it best when she said, “We have no freakin’ clue. And that’s my expert opinion.” So say they all.

Vietnamese caterpillar
Vietnamese caterpillar

On his Facebook page, Anderson said that his favorite theory so far is that the structure is the work of spiders, and that the pole houses their eggs. After they hatch, the baby spiders climb the tower and ride a parachute of silk off to scare the bejesus out of people. Okay, so I added that last part.

The story ends without answers — for now. Maybe an insect will step forward to take the credit, or maybe some poor soul will go on a stakeout to the Peruvian Amazon, hoping to catch the architect at work. Or maybe the structures are currently summoning aliens who will take our minds off this pressing question when they arrive.

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