Web of intrigue: U of I researchers find a new, Idaho-centric species of spider

It might be itsy bitsy, but it’s no small find.

University of Idaho researchers have unearthed an undiscovered species of spider in the Gem State. The newfound spider — dubbed Hexura vandal, in tribute to the U of I — appears to be confined to moist, coniferous forest in north-central Idaho.

Chris Hamilton, associate professor in the Department of Entomology, Plant Pathology and Nematology, and doctoral student Arnau Calatayud-Mascarell pose together with a container holding a Hexura vandal spider, a new species their research team discovered in north-central Idaho that appears to be endemic to the state. (University of Idaho photo)

The U of I research team wasn’t looking for a new species. Researchers were canvassing mountainous forests near Kooskia in 2024, surveying for spiders in the genus Microhexura, which are common in Idaho.

Postdoctoral researcher Ethan J. Briggs then noticed something unusual — a dark, nickel-sized spider that seemed to belong to the genus Hexura, which had not been seen in Idaho previously. Arnau Calatayud-Mascarell, a doctoral student studying entomology, studied the new find and drew the same conclusion.

“We didn’t care about Microhexura at all after that,” Calatayud said. “We found something way, way cooler.”

A female specimen of Hexura vandal (University of Idaho photo)

Calatayud’s adviser, Chris Hamilton, an associate professor in the College of Agricultural and Life Sciences, was skeptical at first. But after examining a specimen, he agreed that the spider is a distinct species of Hexura.

The research team’s paper on the new find was published this week.

Since the initial discovery, researchers have returned to the area several times — and have found that Hexura vandal is abundant in moist forest but nonexistent in nearby, drier habitat.

“I feel incredibly confident that this is only going to be found in Idaho, and it’s going to be restricted by mountains, increasing elevation and the drying out of habitats, and in some places the physical barriers of rivers, as well,” said Hamilton, who hopes Hexura vandal will be designated Idaho’s state spider. “This species is an indicator of a unique, remnant habitat that’s found in Idaho and needs to be looked at more closely and monitored.”

Kevin Richert

Kevin Richert

Senior reporter and blogger Kevin Richert specializes in education politics and education policy. He has more than 40 years of experience in Idaho journalism, and extensive experience covering state politics and the Legislature. He is a frequent guest on "Idaho Reports" on Idaho Public Television. He can be reached at krichert@idahoednews.org

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