WSU scientist: Dreaded spider doesn’t live here

Contrary to what many people believe, the brown recluse, or Loxosceles reclusa, doesn’t live in the northwest part of the country, said Washington State University entomology professor Richard Zack. Instead, it dwells in the South and lower Midwest. And its bite, though toxic to humans, seldom causes the serious flesh-rotting symptoms we often hear about, he said.

“People often tell me they saw or they got bitten by a brown recluse; but if it happened out here, it’s probably another species of spider they’re talking about,” said Zack, who oversees WSU’s M.T. James Entomological Collection.

Simply put, the brown, eight-legged critter with a violin shape on its body “isn’t as sinister and all-present as so much of the public believes,” he said.

It’s not unusual for people to drop off or mail jars to the collection offices containing alleged brown recluses captured in or near their homes, explained Zack: “To date, not one has turned out to be a brown recluse.”

Rather, he identifies them as one of the many brown-colored arachnids that live in this region: the hobo, wolf and giant house spiders.

 

Despite numerous studies showing that brown recluses inhabit an area that excludes most of the western and eastern United States, widespread reports of recluse sightings and bites seem on par with rumors of Bigfoot prowling the woods or the late Mister Rogers serving as a Marine sniper in the Vietnam War.

 

Just last month, the death of heavy metal guitarist Jeff Hanneman in Los Angeles was blamed on a flesh-eating disease caused by a brown recluse that bit him in a hot tub. A few days later, the cause of death was attributed to chronic liver failure. In 2003, pop star Michael Jackson blamed a missed court appearance on a brown recluse that bit him while he was asleep inside his sprawling Southern California ranch: “Michael Jackson’s Spider Bite – Shocking Proof,” blared Globe magazine.

 

Sensational headlines, misdiagnosed skin ailments and a steadfast belief that the brown recluse lives where it doesn’t and inflicts pain in ways it rarely does “are out of proportion to its habitat range and capabilities,” said Zack.

 

Regardless of species, spiders use fangs to inject chemical toxins into their prey. Most of those toxins won’t affect humans. And even if they do, spiders – including brown recluses – want to eat insects, not people, said Zack: “They really just want to be left alone.”

 

Perhaps no one knows this better, Zack said, than entomologist Rick Vetter of the University of California, Riverside. Besides rearing recluses from babyhood, Vetter has spent the past 20 years trying to clear the defamed spider’s name. He has published numerous articles about recluses in entomological and medical journals, including the New England Journal of Medicine.

 

And, boy, he’s ticked off.

 

Map provided by entomologist Rick Vetter, University of California, Riverside.

“I’m bloody tired of everybody claiming that unexplained marks on their bodies are the result of brown recluse bites and who believe with religious zeal that brown recluses live everywhere from Panama to the North Pole,” said Vetter by phone from Riverside. “They’re not here!”

 

Despite years of amassed evidence, recluses have achieved an urban legend status due to “media-driven hyperbole and an anxiety-filled public,” he said.

 

In his research, Vetter asked people across the country to send him spiders they thought were recluses. Forty samples mailed from Washington state included hobos, wolf, funnel web and giant house spiders. One person even sent a daddy longlegs, he said.

 

“Many conditions can cause necrotic wounds that have been misdiagnosed as brown recluse bites,” wrote Vetter in a Western Journal of Medicine article, referring to the open skin ulcers that brown recluse bites rarely cause. Herpes simplex and zoster, oak dermatitis, fungal infections and Lyme disease can cause similar lesions, he wrote.

 

And what of that black, jagged scab across superstar Michael Jackson’s right shin that he and his doctor in 2003 claimed was caused by a brown recluse bite at his Neverland Valley Ranch?

“The fact that Michael Jackson says he has a spider bite is a bunch of crap,” Vetter told the New York Post.

Rest assured, if you suffer from arachnophobia, your worst nightmare does not lurk in the Northwest, said Zack. But black widows and hobos – whose venom occasionally makes people sick – do.

“If someone gets bit, it’s usually defensive in nature. Typically, the spider gets cornered by someone cleaning a shed, gardening or moving a stack of firewood and it strikes back,” said Zack, who’s been bitten twice by the WSU collection’s palm-sized tarantulas, yet never by a black widow or hobo.

 

The venom of those two species is not as threatening to humans as that of a recluse, he said. A black widow typically injects a neurotoxin that can make people feel sick as if they had the flu, according to the Washington State Department of Health website on venomous spiders. The venom of a hobo can produce a slow-healing wound around the area of the bite, the website says.

 

But again Zack stressed that the incidence of spider bites that actually inflict harm is quite low.

In this country, at least.

 

In South America, the banana spider, also called the Brazilian wandering spider, bears the distinction of the world’s most venomous spider, according to the Guinness Book of World Records. In Australia, a hassled Sydney funnel-web spider will stand on its hind legs while bearing its toxin-filled fangs just prior to plunging them into its antagonist.

 

Both species make our nation’s brown recluses, black widows and hobos seem a little less nerve-rattling, don’t they?

“As venomous spiders go, we’re fairly lucky,” said Zack. “I’ve seen and handled far worse.”

 

 

 

 

Contacts:
Richard Zack, WSU entomologist, 509-335-3394, zack@wsu.edu
Linda Weiford, WSU News, 509-335-7209, linda.weiford@wsu.edu