Small Ivory coloured Spider - Cheiracanthium

Bye Bye MR. Spidey. Caught hi

Bye Bye MR. Spidey. Caught him in a glass and as much as I hated putting him out in the 5C weather, I don't fancy a bite either!

… Teri Murphy, 28 October, 2005 - 1:01pm

Thanks for the input

Now all I have to do is find her! And to think she was practically on my lens when I took the picture.

… Teri Murphy, 28 October, 2005 - 10:32am

Sac Spider...

I believe this to a be a sac spider in the Corrinidae or Liocranidae family. The eye pattern is a good match for either genus (based on what I can see from the image...) I used the key from AMNH: Blackrock forest to confirm my suspicions, and to get it to a potenital family (or two). :)

This spider is most likely nothing to worry about, but there are some sac spiders that resemble this that can bite (Cheiracanthium mildei or Cheiracanthium inclusum), so I would just be careful. It is a hunting spider, and does not spin a web (for catching food). It does spin a sac web for resting and for egg deposition, often in a darker, out-of-way type of place.

Here is the guide page for C. mildei, just for informational purposes.

Very nice and very clear images!

… Christopher Hunt, 25 October, 2005 - 3:37pm

Chris, what do you think

about Robin's

? And notice that this image ended up in Miturgidae, which is not how we interpreted your comment.

… john and jane balaban, 26 October, 2005 - 4:39pm

Cheiracanthium

Believe or not, Miturgidae::Cheiracanthium is the correct place. I planned to correct it once I got a chance... I researched it more, and there are mild variations in the eye pattern which would slightly modify the family key I used (they generalized the eye arrangement). I ran through the key with the new info, and it is a Cheiracanthium sp. spider. (DOH!)

I am very sorry about that Teri! I would be careful with this spider, it can bite if it gets trapped (in clothing, etc.). I would remove it from your house. You can remove it via the "glass and card" trick.

… Christopher Hunt, 26 October, 2005 - 5:22pm

The other images...

Robin's specimen is most likely a sac spider as with the other two sets of images referenced on her image page, but which family I can't easily tell.

The only way to tell is a "really" close examination of the eyes. (If the eye arrangement is correct, you then measure "Anterior Median Eye (AME) diameter" distances from the bottom row to the edge of the carapace. If it is less that one eye diameter, it is one family (Clubionidae; some genera reclassified to Miturgidae), if it is greater, check if the AMEs are bigger (Corinnidae) or smaller (Liocranidae) than the Ant. Lateral Eyes (ALE). To get to a genus then requires looking at the setae on the legs and sometimes also the chelicerae.

… Christopher Hunt, 26 October, 2005 - 5:18pm