Global Warming: Man or Myth?

Scientists can also wear their citizen hats

It’s the Spiders, Stupid!

with 7 comments

Recently I have been publicly presenting a talk regarding the impacts of climate change on nature and humans titled: Climate Change is Not Being Nice to Mother Nature.  In this talk I describe the impact of climate change on oceans, Arctic mammals, birds, fish, frogs, trees, lakes and ponds, and humans.  Human impacts include, among others, sea level rise, stronger hurricanes, extreme heat, increased risks to health, higher costs for recreational activities, and serious geopolitical implications including war.

However, the slides that get the most reaction are those about the northward expansion of the Brown Recluse spider.

Many brown spiders are often mistaken as the Brown Recluse.  The tell-tale signature of this spider is the violin-shaped marker on its thorax. 

Brown Recluse Spider

Brown Recluse Spider

Brown Recluse spiders are notorious for their necrotic bites.

Necrotic Spider Bite

Necrotic Spider Bite (, 2010)

In a recent study by Saupe, et al. (2011) titled: Tracking a Medically Important Spider: Climate Change, Ecological Niche Modeling, and the Brown Recluse (Loxosceles reclusa), the authors model the future habitats of the Brown Recluse in a warmer world.  By 2080, perhaps only 5% of the spider’s current range — which extends from Kansas across to Kentucky and from Texas across to Georgia — would remain suitable for the Brown Recluse spider.  Climate change could make portions of Wisconsin, Michigan, Indiana, Ohio, Pennsylvania, New York, Nebraska and South Dakota habitable to the spiders in the future.

Current Range of Brown Recluse Spider

Current Range of Brown Recluse Spider (Ibid)


Future Range of Brown Recluse

Future Range of Brown Recluse (Ibid)

H/T to Peter Sinclair for pointing me to this study.

Written by Scott Mandia

May 9, 2011 at 8:28 am

Posted in Uncategorized

7 Responses

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  1. That second picture requires a warning. Good thing I hadn’t just eaten.

    Byron Smith

    May 9, 2011 at 8:56 am

  2. Great post. Why not add some advice on (1) how to avoid these spiders and (2) what to do if bitten.

    Hunt Janin

    May 9, 2011 at 8:57 am

  3. Loads of information are just a mouse click away:


    “Brown Recluse spiders are the Navy seals, the Green Berets…and 
the Top Guns of the spider world.” 

    Kansas State University –
    Brown Recluse Research Project
    ~ ~ ~

    How to Avoid Bites
    ~ ~ ~

    How to Prevent Brown Recluse Spider Home Infestation
    ~ ~ ~


    May 9, 2011 at 9:16 am

  4. Yikes. I am a bit of an arachnophobe, so I hope they never reach Canada!


    May 9, 2011 at 11:07 am

  5. You are right but in second place maybe ticks. As noted at climate signals and as a New Englander who works in the field, can attest ticks like winters with no extreme cold.


    May 22, 2011 at 7:16 pm

  6. My father-in-law suffered a bite on his inner thigh. He lost muscle and a very nasty and deep scar. The recluse range will expand but they already show up outside their natural range. Central heating and moving vans have seen to that.

    Jay Alt

    July 5, 2011 at 11:29 am

  7. They are also in California, Bakersfield to be exact. These things are rutheless for sure.. My aunt and I were both bit in the same night. It really sucked.


    August 4, 2011 at 3:58 pm

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