No, this is not a story extolling the virtues of the
Internet’s Wide World Web. (Although I have often praised its prodigious
offerings of information for my countless researches.) Instead, this posting is
about the wonders of the webs that spiders weave. Sitting in the tub the other
night, dusk coming quickly on, my eye was attracted by an active blob bouncing
around in the nearby trumpet vine. The black blob was barely visible against
its dusky background. Being the only thing moving over there, however, it drew
my attention.
It took a few minutes for me to realize that the bobbing blob of
inkiness was a spider and that it was weaving a web, before bedding down for
the night. (Don’t spiders sleep when it’s dark?) I’ve watched spiders construct
their amazing webs before, so I could imagine what was happening in the
gloom—as it carried on in the deep shadows of the vine, even though I could not
see its web at all.
A spider’s web is formed from spider silk—a proteinaceous
material made of long chains of very large amino acid molecules. Pound for
pound, it’s stronger and more elastic than steel. (That’s why Spider Man can
accomplish so many amazing feats with his web.) The spider emits its web
filaments from spinnerets on the hind end of its body. (Well, OK, pulling them
right out of its ass.) A significant amount of energy is required on the
spider’s part to create its silk strands, so it may later eat some of its old
web, to recoup that energy, when it comes time to build a new one. Some spiders
reel out up to eight different kinds of threads—according to the job each
thread is intended to do.
To start its web, a spider feeds out a very fine and
sticky thread, which the slightest breeze will swing to and fro, until it
contacts and sticks to something solid. Next, the arachnid will delicately
rappel down the fine thread, strengthening, tightening, and thickening it as it
moves along; turning it into a solid anchor line that will support the
remainder of the web.
After securing a few more anchor lines, the little
engineer will then begin adding several radial lines that will further support
the spiral web. Most of the spiral threads are very sticky, to trap its meals,
as bugs become intercepted by the web. The spider will space several sticky
spiral threads with a non-sticky one, upon which to later adroitly run out, to grab its prey.
More web stuff next time…
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