Saturday, December 12, 2015

Hyptiotes cavatus, an interesting spider indeed

Today was unseasonably balmy indeed, the thermometer striking 70 F here in central Ohio. I spent the afternoon with David and Laura Hughes in the beautiful and biodiversity-filled Clear Creek Valley searching for interesting things. Of which we found plenty, and Dave and I came away with many "keeper" photos.

This tiny spider was at the top of the heap of fascinating subjects. Laura, with her eagle eyes, somehow spotted the small web which the animal had stretched between beech tree saplings. The spider is just right of the pointy beech bud, with its elegant triangular web flaring out through the rest of the image, and beyond. The spider is quite tiny; it measures only a few millimeters. In addition to its manner of capturing prey, which we will soon see, it is also a representative of the family Uloboridae, which are noteworthy for being nonvenomous.

The spider is holding several silken lines, which connect to critical parts of its web. She will remain motionless and keeping tension on those lines until prey strikes the web.

A closeup of our hardworking spider, who is also a brilliant engineer. As she completed construction of the core of the big triangular web, she attached a tension line securely to this beech bud. She then used that to pull herself backwards and into the bud, in the process ratcheting the entire web tighter and tighter until it is finally taut as a firm trampoline. When a victim - small fly or some such beast - blunders into the web, she will instantly release her tension lines. You can see the excess slack in these now taut lines piled up over her abdomen like a little opaque bubble.

When the lines are released, the web collapses over the victim, sort of like having a parachute dropped over one's head. Hopelessly snared, the hapless prey does not have long to wait until the spider rushes out and even more thoroughly enshrouds it in a dense cloak of silk.

For a fabulous video of the whole process, courtesy of Sir David Attenborough, CLICK HERE.

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