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any spider experts out there?

hello, Ive got a question for anybody with a good knowledge of spiders. For a while now, ive had angry, large and fast spiders living in my michigan house. about two years ago, my father was bitten by one on his foot. it turned his whole foot coke can red and left dark purple and almost black veins up past his knee. he contracted cellulitus from it and was hospitalized. the doctor said if he would have come in the next day they would have had to amputate it or possibly worse, it could have been fatal...from a bug bite! well, tonight, (two years later), i finally caught one. i found its a yellow sac spider. now, everywhere i looked, web sites said they were only about 1/4 inch big, but the one i have in my jar is about an inch and a half. thats not the worst part, the ones that were around when my father were bitten were around tarantula size. I have no proof of this, but i am concerned. I wanted to know if this could be something else or do they actually get this big? i havnt seen one that big since he was bitten, (thank god), but the ones that are here now are bigger than those of last year. whats the best way to rid my house of them? please if anybody could help me with this, I would deeply appreciate it. i doubt im going to come back on this site, so just email me at with any information you have. thanks.

Since you collected it,
I think you should take it to your local extension office.

I agree.
I'll add the following: The only large, native spiders you are likely to encounter there in Michigan are fishing spiders in the genus Dolomedes, specifically Dolomedes tenebrosus. They are almost invariably found on vertical surfaces. We have many images of this species in our guide pages. They do not have a bite that would cause the symptoms described, UNLESS a person is allergic to spider venoms, has a compromised immune system, OR, and this is most likely, the bite becomes infected. There is some evidence to suggest that some spiders may carry bacteria and other microbes on their fangs that cause complications in bite victims far worse than simple envenomation. Research is still pending to sort this out.

Lastly, there is always the possibility of a large, tropical spider being introduced on produce (bananas for example, but also houseplants) from Central or South America. I know personally of one such case. Some of these spiders (especially Phoneutria sp. "wandering spiders") are very toxic, and deaths from their bites are well known.

Please consult .edu and .gov websites for the most accurate information on venomous arachnids. There are very few species that cause problems, and universities and federal agencies can be relied upon to give appropriate information.

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