Pleasant Dreams

You can enlarge any image in this blog by clicking on it.  Click again for a full screen image.

I was poking around our yard the other morning when I came upon a spider web.  The web’s shape told me immediately that it belonged to an orbweaver spider.  Orbweavers are the family of spiders that spin geometrically symmetrical webs.  Their webs are marvels of engineering both in terms of their design and in terms of their function.  This one’s web was shaped like a wheel with radial spokes that served as structural supports and lateral strands made of sticky silk designed to entrap small insects.

There are many species of orbweavers.  This one might be an “arabesque orbweaver” (Neoscona arabesca) based on its appearance, but I wouldn’t be prepared to swear to it.  This species is a common, widespread species, however, and it’s the common ones that one is most likely to encounter, simply because there are so many more of them.

The little spider (about 1/4 inch in diameter) had retreated to an upper corner of its web and hung there, motionless.  I took a close look and noticed that it had tucked its first three pairs of legs tightly around its thorax.  It appeared to have rolled up into a tiny ball and it seemed to be hanging onto a structural strand of silk by its hind legs.  Here’s a dorsal view of the spider:

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The spider was oblivious to me.  It continued to hang there, motionless, as I took a series of flash photographs, not reacting at all to the camera’s flash.

I moved around to the other side of the web and took some more photos in order to obtain a ventral view:

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In the ventral view you can see that the spider is indeed hanging from its back legs but that it has wrapped its forelegs around a couple more strands of silk.

What was this spider doing?  My conclusion is that it was asleep.  Many species of orbweavers are primarily nocturnal hunters.  During the day they retreat from the centers of their webs and become dormant until the following evening.  Some orbweavers even dismantle their webs each morning, leaving only a couple of structural strands of silk, and rebuild them each evening.

This spider, although asleep, was not insensate to its environment.  By wrapping its forelegs around its web’s structural support the spider remained attuned to any vibrations.  Any potential prey or potential predator touching the web would trigger vibrations that the spider would sense immediately.

Images made with a Canon 5DS-R, 180mm f3.5L Macro Lens assisted by Canon 600EX-RT Speedlite, M setting, ISO 160, first image shot at f14 @ 1/160, the second at f13 @ 1/160.

One response to “Pleasant Dreams”

  1. tkiiatmindspringcom says :

    Great photographs Steve! Thanks for this view of the Orbweaver.

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