Sunday, August 21, 2011

Spider Sunday: The Cross Spider

’Tis late summer, now, in most parts of North America, anyway, and orb weaver spiders are becoming more conspicuous as they mature into large adult specimens and spin bigger webs (soon to be revealed by falling autumn foliage). Among the most abundant of these spinners is the “Cross Spider,” Araneus diadematus.

The Cross Spider is a European immigrant, just like most of us human residents of the U.S. and Canada, so the species feels most at home in northern climes. It is recorded from Newfoundland and Nova Scotia to British Columbia and south to northern California, Michigan, Ohio, Pennsylvania, New York and Rhode Island. It is plenty accustomed to people, too, so it is a regular occupant of gardens and yards in urban areas.

Araneus diadematus gets its popular English name not from an angry disposition, but because it usually sports silvery-white dots that form the pattern of a traditional Christian cross on its abdomen. This is a relatively consistent marking, but as with most orb weavers, there can be exceptions. The spiders usually hang head-down in the very center (hub) of their webs, but sometimes an individual spider may be more reclusive, and connect herself to the web via a bundle of “signal threads” that run from the hub to her hiding place in a rolled-up leaf or other nearby retreat.

The reaction of homeowners to the presence of this and other species of orb weavers runs the gamut from curiosity to consternation. No species of orb weaver is known to be dangerously venomous to people or pets, so there is no reason to fear them. The spiders themselves will literally shake at the close approach of a person or other large animal, vibrating their web and no doubt startling the inquisitive visitor. Should that tactic fail, most orb weavers drop abruptly from their web, anchoring a dragline to the hub so they can climb back up once danger passes.

This species happens to include some real celebrities. No, seriously. “Anita” and “Arabella” were two female Cross Spiders sent into space on Skylab 3 in 1973 to study the effects of zero gravity on web construction. Prior to that, several specimens were used as guinea pigs in the study of how psychoactive drugs affect spiders’ ability to spin webs. Those experiments were first conducted by a German scientist beginning in 1948, then repeated by NASA scientists in 1984. For an absolutely hilarious send-up of that research, you must see ”The Wood Spider” video on YouTube. I take no responsibility for laughter-induced fatalities.

An adult female Cross Spider has an average body length of about 13 millimeters, though gravid females certainly appear larger. Like the story of Charlotte’s Web, each spider’s life from egg to adult spans only a year. Enjoy their handiwork and pest-controlling services while you can.

26 comments:

  1. Love it! We have them in Maine and this time of year their webs are snarling me up all over the place.

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    1. I live in Texas, we found this spider on our patio, he was doing fine
      this morning we went out to check on him, & sad to say he was on
      the patio dying, what on earth could have happened to him?
      Thank You
      R. Puckett

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    2. Ray, this particular species is not found in Texas. You probably observed a species in the genus Neoscona instead.....Spiders have a finite lifespan. Males die shortly after mating, females shortly after completing an egg sac. The first hard frost usually kills most orbweavers in autumn. Wasps, other predators, parasites, even fungi, also take their toll. Hard to know what happened to your particular spider.

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    3. Bug Eris, I live in Texas also - Austin to be specific - and I currently have had this exact spider on our patio for about a month now. We have actually been throwing small moths into its web and watching it do its handy work on them. I could sen you a pic of it so you can confirm, as we have a lot of pics of him sitting still and even videos of him when he has attack the prey. He tucks into a ball just like some of the pics I have seen and he sleeps under a leaf on the plant that his web attaches to. He sits in the dead center of his web, head down when waiting for prey or eating one he has caught and brought to the center. Let me know if you want me to send you the pics to confirm, but I know its this spider, without a doubt.

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    4. My daughters first grade class is keeping one of these for a class pet. So I am trying to do research but so far I see nothing on 'how to take care of one", lol. Do to her larger size I am calling it a her, so she has a little twig and my daughter caught some little aunts for her. How do they get water? any recommendations?

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    5. The spider needs a large terrarium and a framework of sticks to string her web. She will not eat ants. The ants could even kill her. Misting her web with distilled water each day will allow her to drink. Be aware her days are numbered. She is likely to die of natural causes shortly.

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    6. Monica: Again, this species does not occur in Texas. Perhaps it is a Cat-faced Spider instead.

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  2. I just found one hanging on my sceen porch door. It has cast a rather large circular web and appears to have already had lunch...I've never seen one in Minneapolis MN before. I am quite a lover of spiders so I am always on the lookout
    judibrandt@aol.com

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    1. I live in Mound and I saw a big one with web across our deck in front of the door. If I hadn't noticed it I would've walked right into it. How the heck do they get from one side of the deck to the other. And this sprung up just over night. My wife was scared of it so I sucked it into the vacuum cleaner. THUG! Now I feel bad that I didn't catch her and toss her into the woods. I found out they were harmless.

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    2. Live from Studio 5: Don't worry too much, now you know better next time. :-) To begin a web like the one this species spins, the spider simply issues silk strands from her abdomen and lets the wind take them. When they catch on something, she anchors the other end and that becomes the first line in the framework of a new web. This process could easily take her from one side of your deck to the other.

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  3. I've been watching one of these outside my porch for awhile, I'm glad you had info on them (and I loved the video!) because it was giving me the huge creepy jeepies as it had the tendency to startle and come down from it's web any time I was watering my garden. I'm glad to know it's not dangerous. ^_^

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  4. Thanks for this post. Just captured one of these with my two little kids and we had fun learning about our new little pet. My wife however is less than interested ;-)

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    1. Hahaha! Happy to help, thank you for sharing :-)

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  5. I have had one of these as a room mate for almost two years now. IT lives in the corner of my kitchen window . It is very beautiful, and I wanted to find out what it was named. My nephew has always's called it the Jesus spider, now we know it's real name. I am amazed it has lived so long, and another reason I wanted to look it up. Thanks for the info !

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    1. Thank *you* for sharing that story! You must have had a mild winter or something because normally they *don't* live that long.

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  6. Good morning from "The Emerald City" ! It is a gorgeous day here in Seattle and "Spidy " is waiting in her web for Lunch.
    I forgot to mention that she is INSIDE my kitchen in the corner of the window above the sink. I will let you know when she moves on to the great hereafter ! ha ! I really look forward to seeing her every time I go in there....

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  7. I have a large female that has been living on my porch all summer here in NE Ohio. It's been a very mild fall and as of November 18th, she's still hanging in there! Her coloring is very faded, but she's still got enough energy to spin a web for me to walk into! I will miss her when she finally passes on, she's a strong one. :)

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  8. I'm in Edinburgh, Scotland and have had the pleasure of a Cross Orb spider on the inside of my kitchen window all summer. Missed her web daily (it's fun to see her drink and clean herself) and ha sight and tossed flies in her web.
    It's been extremely educational and interesting to have her this summer, will be more than a tad upset when she passes.
    Thank you for the page!

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    1. Thank *you* for sharing your experience, and for taking such good care of your spider friend. :-)

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  9. Hello, I'm currently enrolled in an Intro to Animal Behavior class and I was thinking about writing a scientific paper on Cross Orb-Weavers and I was completing some observation on web sighting and spider sightings while trying to predict their future actions. I'm in Eugene, Oregon and the fall season has officially started. I was able to start my observations before the rain started to fall on a daily basis. There are a set of 66 arborvitae trees, I had many questions and after doing some research a lot of my questions were answered and now I am having a hard time coming up with a good hypothesis relating to these cross orb-weavers and their physical environments. The webbing itself, the webbing behaviors and the females are highly interesting to me. Is there any way you could help me come up with a few good ideas for hypothesis testing?

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    1. I'm sorry, but I am not a scientist. I am a writer specializing in the interpretation of scientific information on the subject of insects and arachnids. You might try contacting Dr. Greta Binford at Lewis & Clark College in Portland. You can tell her I sent you, if you like. She is a professor there, and this is right up her alley. Good luck.

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  10. I have had a cross spider outside my 2nd floor urban window since mid-Sept. and have gotten quite attached to her, but we are starting to get frost. After a chilly night and a couple chilly days, she disappeared for a bit, and then appeared two days ago with what looked like neurological damage, legs tangled, barely moving, and seeming to hang by one leg. I was sure she was a goner, but this morning she seemed normal again, so perhaps she's got a few more days!

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  11. I can't handle them. I just can't. I wish one of you lived in my neighborhood, I'd give all 5 we currently have in various places in my backyard to you. I'm confused though. Mine create a brand new web every evening and pack it all in just before sunrise. Every single day. I didn't read that in your description. They look like this picture but I have no problems admitting I have never EVER gotten close enough to get a super good look at them. I just know they are this shape and some have had a cross shape on them. My guy told me one had a pattern that looked like a skull, haha.

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    1. The behavior you describe fits perfectly with another kind of orbweaver, Eriophora ravilla, which erects its web *only* at night. That species is found only in the southern U.S., though, and you do not give your location.

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  12. Hello, I ran into the web of one of these spiders, I live in Califoria US and I see these a lot but this one is a lot bigger. I want to house it and keep it as a pet but is it worth the money to spend on an enclosure if it's lifespan is short ?

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    1. Only you can answer that question. If this is for a classroom setting or other public exhibit, the answer might be "yes."

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