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Entomology (Study of Bugs)/A lot of red spiders found in basement


Red spiders on trap
Red spiders on trap  

Red spider
Red spider  
Hello! Sorry, I sent the last email without the here they are. I live in Illinois, and I had a sticky trap down in the basement and I just found a bunch of these red spiders on it. One of them looks like it was pregnant too. I am wondering if you can tell me what type of spider this is? My 7 year old daughter suffered some serious complications from a spider bite a couple of months ago, and now she has gotten additional bites on her arms, legs and face that have swelled up. I originally thought that they were mosquito bites and she was having an allergic reaction to them, but now I am concerned that these are also spider bites. Any help you can provide in figuring out what type of spider this is would be greatly appreciated


Ah, ok, this is much better.  I can tell you that the spiders are "Woodlouse Hunters," Dysdera crocata , and are *not* dangerously venomous to the average, healthy human.  Here's my blog post about them:

The first image also shows a ground beetle, genus Scarites , and a House Centipede, Scutigera coleoptrata , likewise not dangerous.  Apparently there are plenty of prey insects and woodlice in your basement!

My previous comments on "spider bites" still apply.


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Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

Awards and Honors
One of the top 50 experts in all categories for, 2009.

Past/Present Clients
Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

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