Canon PowerShot SX100IS
(From the Archives)
Banded Garden Spider (Argiope trifasciata)
The banded garden spider (Argiope trifasciata)is the most common “garden spider” found in the western US. They produce large, conspicuous webs amongst shrubbery and other large vegetation in late summer. The webs of the garden spiders are very concentric and resemble those of the most famous garden spider of all- Charlotte’s Web.
The banded garden spider spends the winter either as eggs in a large silken sack or, primarily, as tiny “spiderlings” hidden in protected areas of the garden. These very young spiders get around primarily by “ballooning”, carried by breezes that catch silken threads the spiders produce. Upon settling on an appropriate site, they begin to produce their characteristic webs between sticks, grass, or other upright vegetation.
Flying insects that become caught in the webbing are quickly paralyzed by the bite of the spider and are wrapped in a sheet of webbing. After feeding, the spiders usually cut the dead insects out of the web and allow them to drop to the ground. While tending the web, the female typically remains in the center both day and night, repairing it when it gets torn.
The spiders grow throughout the summer, reaching full-size in late August and September. The males, which are much smaller than the females and do not produce webs, roam around the vegetation and mate the females in late summer. The female then lays one or more egg sacks, that appear somewhat like a small kettle drum with a tough papery cover and may contain 1000 eggs apiece. The spiders die after frost and there is only one generation produced each year.
Information shared from http://coopext.colostate.edu/4DMG/Pests/banded.htm