Garden Spiders as Predators

Characteristics

• Female garden spiders grow to about 1-1/2 inch long, while males reach 3/8 inch in length. Both have a small front-body section with silver hairs and an egg-shaped back section with black-and-yellow stripes. Their legs have three claws at the end, an aid in web weaving.

Habitat

• Gardens and fields are garden spiders' prime habitat. They attach their webs to shrubs, tall plants and flower stems, and build along the eaves of houses. They prefer open, sunny places with little or no wind. If their webs are disturbed, they leave for more hospitable sites. In cold climates, garden spiders live about a year. In mild climates, the female lives for several years, although the male dies after mating.

Web

• Garden spiders are orb web makers. The female spins a web in the shape of a circle that spirals out from the center and can reach 2 feet across. The male spins a smaller web, a thick zigzag pattern of silk, at the outer part of the female's web. When an insect flies into an orb web, the force of its hitting the web is translated throughout the lines of silk so it does not bounce out and the spider is alerted to its presence. The female hangs head down in the center of the web, awaiting prey.

Prey

• Garden spider egg sacs hold more than 1,000 eggs. The baby spiders hatch in the fall but stay in the sac through the winter and emerge in the spring to eat. Both adults and young spiders are voracious predators of flies, moths, beetles, wasps, mosquitoes, gnats, aphids, grasshoppers and bees -- whatever flies into their webs. Spiders themselves are the prey of birds, shrews and lizards.