Today I would like for us to turn our attention to the web -- not the internet, but the spider web in the summer garden, that big web with the zig-zag in the middle.
The black and yellow garden spider is often noticed because of its large size and its habit of building webs in gardens and grassy areas near houses. It is most typically found in tall grasslands. The small head and the thorax is tipped with silver hairs, and the slightly oval abdomen is patterned yellow (sometimes orange) and black. A black mid-stripe with four white spots in the center marks the top of the abdomen. The legs are black with yellow-orange stripes. The upper portion of the legs is more solidly colored orange-yellow. Females are much larger than males and can reach lengths from three-quarters to an inch, and bigger, as compared to a quarter to three-eighths of an inch for males. This spider can be found sitting head-down at its web's hub where the zig-zag silk band, the stabilimentum, extends vertically from the center. A variety of insects may fall prey to this spider, especially grasshoppers and katydids. Certain species of smaller spiders use yellow garden spider webs as their own and feed on the tiny insects caught in the web.
During mating, the males approach females with caution in order to avoid being eaten. The male garden spiders will usually mate with several females and then often die from starvation and exhaustion, since they spend little effort feeding while searching for females. The female spends a number of days inside her retreat. She then begins to spin an egg sac or cocoon, which protects the eggs. She stays close to the cocoon for a number of days before dying. The young spiders emerge from the cocoon in spring; they gather into dense groups until after their first moult, after which they disperse by ballooning, a form of dispersal in which the spiderlings are carried on the wind by a thread of silk.
Although spiders this big can be an intimidating site, the garden spider is harmless and actually beneficial to the garden. When this species is threatened, it rapidly shakes itself and the web up and down and may drop to the ground on a silk thread. The garden spider is not aggressive, and they are not poisonous to humans. Because they are not aggressive spiders, it is rare that one would actually bite a human. In some circumstances, if they feel threatened or if they are pressed up against human skin, in that rare occasion they might bite a human. Even though garden spiders are not poisonous, it is still important to seek medical attention just in case the species of the spider is not identifiable.
This summer, when you see this brightly colored spider in your garden, if at all possible, let it abide peacefully with you.
Happy gardening!
Peter Sutter is a life long gardening enthusiast and a participant in the MU Extension's Callaway County Master Gardener program. Gardening questions can be sent to [email protected].