Researcher: Brown Spiders Not Deadly After All

Diane Barger's family had been living in their Kansas home for more than five years when her 13-year-old daughter noticed that there was something distinctive about the spiders she had seen so often in the 150-year-old house.

Many of the spiders had the violin pattern on their backs that is characteristic of the dreaded brown recluse spider, widely believed to be so poisonous that a single bite can cause death. Barger quickly collected a few of the spiders and headed down to the University of Kansas, where her son had just enrolled as an entomology major.

Indeed, the daughter had been right. The spiders were brown recluses. That finding sent Barger and her husband and two children off on a mission that should lead to a re-evaluation of the threat of brown recluses, and a new image for one of the most feared members of the world of arachnids.

Spider Hunt

Here's the bottom line. The brown recluse is undeserving of its horrid reputation, and thousands of reports each year of serious injuries from brown recluse bites are clearly wrong. The brown recluse can cause a nasty wound, but there is not a single confirmed death in the United States from a brown recluse spider, according to Richard S. Vetter, the leading expert in the field who found in Barger the collaborator he had been looking for.

Vetter is a researcher in the department of entomology at the University of California, Riverside, and brown recluses have become his passion. Not just the spiders, but how they are perceived. Vetter believes that thousands of doctors each year routinely misdiagnose potentially deadly skin lesions as brown recluse bites, so the victims receive the wrong treatment.

He bases that on the fact that many reports come from areas where there simply are no significant numbers of brown recluses, like California. And Barger helped him demonstrate something else. It takes a lot of brown recluses to pose a significant threat.

Vetter asked Barger to capture as many spiders as she could and send them to him, dead or alive. So for six months Barger and her husband and children crawled around the attic and basement of their old limestone house, catching as many spiders as they could.

"It was our quality time," Barger later told Vetter.

They published their findings in the November issue of the Journal of Medical Entomology, and the numbers are nothing less than astounding.

Not a Bite

The family collected 2,055 brown recluse spiders during that six-month period, including some they found crawling on them as they slept, or stuffed clothes into the washing machine, or picked up the newspaper. The spiders were found in every room of the house, including "high human use areas such as bedrooms, kitchen, and bathroom," according to the study.

Yet here's the most astonishing part. During the six years that the family has lived in the house no one has received a single bite. Not even one.

Even Vetter was surprised by the numbers.

"You would think that's an incredible infestation, and people are going to die," he says. Nobody got bitten, he says, because it isn't in a spide's interest to go looking for trouble. A spider typically bites out of self defense, and the brown recluse is no exception.

"They don't bite, unless you roll over on one while sleeping," he says.

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