E-Mail to Emily


Search EmilyCompost

Emily's Mailbox

Plant Index



Gardening with Kids

Selected Links

The Signature Spider

Signature SpiderWe used to call it the Signature Spider because of the zigzag pattern that it places in the middle of its nest. According to "Florida's Fabulous Spiders" it is the Yellow Garden Orb Weaver (Argiope aurantia), a spider that is common throughout much of the US.

The orbweaver usually builds its nest in fields or in open woodlands, but backyards seem to provide satisfactory environments, also.

The "National Audubon Society's Field Guide to North American Insects and Spiders" calls the spider the Golden Garden Spider and the Black and Yellow Spider. Nevertheless, by whatever name it goes by, the orbweavers all weave a nest with a signature.

The white vertical zigzag above and below the center of the nest is a stabilimentum. Other orbweavers may use a slightly different pattern. "Florida's Fabulous Spiders" says that there are four theories of why these spiders integrate it into their nests.

First, as the name implies, it adds stability and strength to the nest.

A second theory is that it helps the spider attract a meal. Some flying insects are attracted to ultraviolet light reflected from flowers. The stabilimentum attracts insects by mimicking this.

The spider may also use the stabilimentum as camouflage for itself while it is lying in wait on the web.

A fourth theory, and a more popular one, is that the white zigzag is there to warn large insects and birds so they might avoid the nest. The spider does not want to keep rebuilding the nest and the birds do not need a sticky silk scarf while they are flying. (Some birding vendors have capitalized on this theory by making a "warning web" to stick on your window to let birds avoid headache producing collisions.)

Whatever the reason, next time you are walking through your garden on a sunny morning - watch out for the signature.