Friday, April 23, 2010

Long Legged Sac Spider (Cheiracanthium sp.)

click for large

A Long Legged Sac Spider (Cheiracanthium sp.) I found in my basement. A lot less menacing than it looks, probably only 3/4 of an inch including legs. These are very very common spiders in the house, no doubt you have a few around too. This is a male, you can tell by the large black furry palps. You can see a photo of a female here. The male seems to have much longer legs and a wider carapace.

Several reports classify these spiders as possibly harmful, but real study shows their bites are not poisonous or necrotic to humans.

Raynox DCR-150 mounted on my Panasonic Lumix FZ8. I used a simple styrafoam bowl as a flash diffuser for the lighting. Worked out very well if you ask me.


  1. Hi there, I stumbled upon your interesting and shudder-inducing blog while googling to find out what type of spider I just found in my bed (ICK). It was a crab spider, I discovered.

    I was wondering if you could help me out with a spider identification. I don't have a picture, unfortunately, but I'll describe it. In 2003 I was a summer nanny for a family in the Minnetonka area. It was August and I was headed to their basement when on the steps I saw the biggest spider I have ever seen in Minnesota. It was 3-3.5" in diameter including the legs. It was fat and hairy looking. It was brown and light brown. It looked like a wolf spider, I think, but HUGE--do they get that big?? I called my dad because I was so scared. He suggested hitting it with a rolled up newspaper (don't hate me... I was terrified and the girls I nannied for were hiding under chairs). I rolled up a fat wad of newspapers and tried to stomp it with the blunt end. It started skittering back and forth to avoid it and HISSING audibly. I did eventually kill it. I spent the rest of the day shaking and itching from fright!

    SO, what was it?

  2. The largest spider in Minnesota is the Fishing Spider, (Dolomedes sp.) It fits your description perfectly.

  3. How do you tell this "long legged sac spider" from a "cellar spider"--they look about the same to me. I have some I thought were the "cellar spiders" and that I found in a U of M text book labeled as "Squinty eyed" spiders. These are those that make webs in the corners of your living room, hang upside down in them, and spin frantically if anything touches their web. I had a bunch of these in a house that I bought in the Duluth area, and initially I thought they were cute. I observed their habits for weeks, and noted they appear to make multiple small webs in many corners; then instead of sitting in one web, hoping that something get snared, they make a daily trek about the place, "checking their traps." I watched them move, quite quickly across from web to web, and eventually they would end up in their "home" corner--usually with no game. I called them "dancing spiders" until I learned that they are attempting to snare you into their web. These spiders do bite, and I have been bitten multiple times by them. Also, they are quite aggresive. They wait on the ceiling above you, until you are quiet for some time and they think you are sleeping. They then drop onto you and make one or more bites that develop into a raised, sore and itchy red spot about 2 inches in diameter, that takes up to two weeks to resolve. I have observed this dropping onto a warm body behavior twice and suspect that due to their inability to see clearly, they respond to heat sensations. Their bite is not lethal, but they are not "cute" either! If you have comments, you can reach me at

  4. Was one of those kind of spiders in my daughters bedroom and I ended up killing it.