Climate change could have dangerous spider crawling northward

This brown recluse spider is among the many that have come to KU graduate student Erin Saupe. The geology and Biodiversity Institute student researched how climate change will affect the habitat of brown recluse spiders.

As temperatures creep northward over the next couple decades, so will the poisonous brown recluse spider.

That is the prediction of one Kansas University graduate student.

Erin Saupe, a geology and Biodiversity Institute student, has spent the past year and half studying how climate change will impact the habitat of brown recluse spiders.

The spiders are of particular concern because their bites can kill tissue (known as necrosis) leaving behind deep sores, scarring and in severe instances a loss of a limb.

A common find in old Lawrence homes, these spiders like to hide in dark places like basements and boxes and frequently crawl into clothes that have been left lying on the floor or between bed sheets.

Ever since Erin Saupe, a KU graduate research assistant, asked colleagues to bring her brown recluse spiders from their homes, she's had a steady supply of them. They are common to the area. Saupe had a couple of the spiders on her desk in glass jars.

“It is a very dangerous species if you are bitten,” Saupe said.

As of now, brown recluse spiders are primarily found from Iowa south to Texas, Mississippi and Louisiana, and in Kansas east to Kentucky.

It’s rare to find brown recluse spiders outside of that region, Saupe said. Yet some doctors misdiagnose spider bites in areas where they aren’t known to live. When they do, Saupe said they could be overlooking other important illnesses, such as cancer, fungal infections or lymphoma.

Establishing the distribution of brown recluse spiders and how that could change as the climate warms is important, Saupe said.

“It can be helpful in terms of the medical community to say ‘OK, I see that this looks like a brown recluse bite, but based on where I am and based on the history of this patient, it probably is not. Maybe we should look for other reasons,'” Saupe said.

Erin Saupe, a KU graduate research assistant, photographed this brown recluse spider in her lab (don't worry it's frozen). For a size comparison, these spiders would sit within the circumference of a quarter coin, with the ends of the legs reaching a little beyond the quarter.

Brown recluse spiders thrive in areas that are hot and wet. The climate in the West is too dry, Florida is too hot, and the Great Lakes region too cold.

But that could change.

Using computerized models, Saupe looked at different climate change scenarios for the years 2020, 2050 and 2080. Under those models, brown recluse spiders will migrate northeast into parts of South Dakota, Michigan, Minnesota, Wisconsin, Michigan, Ohio and Pennsylvania.

Along with being a tool in helping those in the medical field diagnose spider bites, Saupe said the research is part of a body of work looking at the effects of climate change.

“This could be a wake-up call because this species is so in the public eye and people care about this,” Saupe said.

Saupe’s research was published in Friday’s edition of the journal PLoS ONE.