Brown Recluse Spider Spreading Into New Territory Throughout U.S., Scientific Study Says

By Ryan Villarreal | March 16 2012 12:33 PM

The brown recluse spider humbly holds the distinction of being North America's deadliest spider, unlike the runner-up, the black widow, which has long held the spotlight with its sleek black exoskeleton and gaudy red hourglass marking. The recluse, however, may soon become a household name.

PLoS ONE

A recent scientific study says climate change is moving brown recluse populations into new US states.

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Online science journal PLoS ONE published a study in March, 2011 titled, Tracking a Medically Important Spider: Climate Change, Ecological Niche Modeling, and the Brown Recluse (Loxosceles reclusa), which examines the impact of climate change on the brown recluse's territorial distribution and how that affects human populations.

We delineate range boundaries and demonstrate that under future climate change scenarios, the spider's distribution may expand northward, invading previously unaffected regions of the USA, reads the article. These results illustrate a potential negative consequence of climate change on humans and will aid medical professionals in proper bite identification/treatment, potentially reducing bite misdiagnoses.

One of the major problems, the articles identifies is the failure to diagnose a brown recluse bite due to a misunderstanding of the spider's geographical distribution. Bites that go untreated or are treated improperly can have grave consequences for the victims. The recluse's hemotoxic venom essentially eats away at soft tissue near the bite area, but the damage can be contained with proper medical treatment.

The authors of the article aim to spread knowledge of the brown recluse's distribution, so that medical professionals are better prepared to diagnose its bite.

Brown recluse populations are mostly concentrated in the Southeast and parts of the Midwest, but can be found from Florida to California. The study predicts that by 2020, in parts of northern states like Nebraska, Minnesota, Wisconsin, Michigan, South Dakota, Ohio, and Pennsylvania will see a significant increase in the spider's distribution. By 2050, they could be creeping into New York, Massachusetts and other parts of New England.

This may be welcome news for people living in the brown recluse's current habitat as the its numbers are expected to dwindle with rising temperatures in those areas.

PLoS ONE is an open-access, peer reviewed online journal, published by the Public Library of Science, a non-profit publisher aimed at promoting communication and discussion around scholarly research.