Take a Peek at Nature's Website:
Spiders Spin Steely Silken Splendor.

On foggy mornings, Charlotte's web was truly a thing of beauty. This morning each thin strand was decorated with dozens of tiny beads of water. The web glistened in the light and made a pattern of loveliness and mystery, like a delicate veil.

Perhaps the highest achievement of spiders is the orb-web. Orb-weaving spiders (Family: Araneidae) are remarkable artists fabricating intricate webs from the finest silks. Late autumn and early spring is when most display their best work.

Orb-weavers (and cob-web weavers) can produce up to six different types of silk from a different set of silk glands located in the spider's abdomen. Each variety of spider silk is somewhat different in protein composition and is used for distinct parts of the web or for different purposes. These special silks are drawn out of the appropriate silk gland as the weaver needs it. Spider silk has great tensile strength and elasticity; easily supporting the combined weight of spider and struggling prey, weighing thousands of times more than the web itself.

The large geometric webs found at this season of the year in urban and suburban yards are creations of the introduced orb-weaver, Araneus diadematus. This species gained fame as the first spiders to leave our planet when Arabella and Anita demonstrated their weaving skills in the absence of a gravitational field aboard Skylab. Another common introduced species, the large brown Giant House Spider, Tegenaria gigantea, lives mainly in buildings. Mature males of this species, which have leg spans of 2-4 inches, are roaming through bathrooms and bedrooms in the early autumn seeking mates and inadvertently terrifying sleepy-eyed humans.

Despite my fear of spiders, I think the small Jumping Spiders (Family: Salticidae) patrolling the library stacks are quite cute and interesting. According to Rod Crawford, Curator of Arachnids at the Burke Museum, they are unusual spiders because they are very visual and perceive the world in much the same way that humans do. They rely upon keen eyesight to find and stalk prey during daylight hours. Like many spiders, Jumping Spiders don't weave webs at all, although they do construct silken nighttime retreats and egg sacs. Jumping Spiders also use silk as a safety line by attaching it to the substrate prior to pouncing upon their prey.

Spiders are highly beneficial to humans because they prey upon insects and small animals. Unlike most predacious insects such as Ladybirds, spiders are active year-round. Additionally, spiders are generalist predators. They don't require prey populations to reach peak numbers before controlling them, contrary to many predacious insects that often are picky eaters. Crawford says, "Spiders are THE dominant terrestrial predators; one year's worth of spider prey outweighs all land vertebrates on the planet. Without spiders, the world would be a vastly different place."