Saturday, September 15, 2007

Spiders -- two types

OK, if you don't like spiders, I suggest you skip this one!

The brown spider to the right is a "Writing Spider," Argiope aurantia.

It used to be that these were about the only large spiders we saw on our property. We might see two or three around our place and other places. And then a few years ago, the "Golden Orb" spiders arrived and seemed to largely displace the writing spiders. This year, we had two writing spiders on our front porch -- those are the only ones I've seen.

Acording to the link above, the white "writing" in the web is called stabilimenta. This extra thick webbing helps prevent birds from flying through the web. But apparently also helps insects (a.k.a. "dinner") from flying into the web as well. Perhaps that is why we see fewer writing spiders than golden orbs, who do not use stabilimenta.

This lovely lady (left) is a Golden Orb spider, Nephila clavipes. I have recently discovered a bit more about these spiders. The "Orb" in the name describes the type of web they weave -- the big circular type. In fact the writing spiders also weave orb-type webs.

In this picture, you see the same spider and her mate. You can also see the golden strands in the web. The Wikipedia article, referenced above, suggests that these spiders weave a golden colored web, but Marc suggested that some of the strands (the sticky ones) have attracted bits of pollen. This makes more sense to me, as only certain strands of the web are "golden". Another interesting thing is that these spiders use multiple-strands to create the anchors of their webs. Sometimes the anchors are not attached to something fixed, but to a bit of broken branch or large leaf. It is a bit of a shock to be driving out of the driveway early in the morning and have a small floating branch suddenly smack your windshield!


Lee said...

Great pics, again, Stormy and Marc. I've got a huge spider in my bathroom at present. He stays out of my way and I stay out of his...we have a chat every time I shower! ;)

CarlaCarlaCarlaCarla said...

From what you've written, I get the impression that the Golden Orb spider spins a new extra-large web each evening. The webs of our nighttime spiders (not Goldens, but something big and creepy) oftentimes span a walkway. Compared to the too-close encounters I've had on summer nights or before the sun's up, your windshield story sounds dreamy!