Nature Bulletin No. 165   October 18, 1980
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

****:SPIDER WEBS

This is Spider Time. Now they appear to be most numerous and busy 
at millions of spiderlings that climb to high perches and spin long 
filaments of silk by which they are wafted aloft on currents of warm 
air and may be carried hundreds or thousands of miles. Probably that 
is why there are spiders on lonely Islands, deserts and almost every 
part of the world except mountain tops and arctic regions. When we 
walk through a woodland these days, cobwebs, strung from tree to tree, 
cling to our faces. In the mornings, on lawns and sparkling with dew 
drops, we see dozens of filmy handkerchiefs spun by grass spiders. In 
gardens and fields we see the marvelous webs of orb-weavers.

There are at least 2000 species of spiders In this country but only a few 
families of them build elaborate webs. In each family the females 
construct a distinctive type of web and there are four general types: orb 
webs, funnel webs, sheet webs, and the irregular festoons built by 
house spiders. All of them are built for a purpose: as traps to catch 
insects.

One of the truly wonderful performances by any animal is the intricate 
web constructed with geometric precision by the big black-and-yellow 
garden spider -- one of the orb-weavers -- and If necessary she can 
complete it In one hour.

Although the garden spider has eight eyes, she builds a web almost 
entirely by touch. Underneath her abdomen are six spinnerets that can 
be extended or compressed and used like the fingers of a human hand. 
Each spinneret has "faucets" and "spools" connected by tiny tubes to 
several types of glands. Each type manufactures. In liquid form, a 
different kind of silk. Filaments of the several kinds are used singly or 
in combinations for specific purposes In certain locations. Most 
strands are composed of more than one filament. They solidify and 
become stronger than steel when drawn out and exposed to the air.

The sheetllke webs that sometimes appear overnight on lawns and 
meadows, especially in autumn, are built by the funnel-web or grass 
spider. Each sheet extends outward from a funnel-like opening 
beneath which the spider lurks in waiting for grasshoppers and other 
insects that may alight upon It. She constantly enlarges the web and. If 
undisturbed, it may become a square yard In area. In autumn, after 
laying eggs In one or more sacs that are hidden In secluded places, she 
dies. The spiderlings emerge in spring and their delicate webs may be 
seen in May.

The common house spider is detested by housewives because it 
sometimes spins a web near the ceiling in a corner of some room or 
closet. Generally, however, they frequent dark less-used places such as 
attics, cellars, barns, sheds, or under porches; and are useful as 
destroyers of flies, mosquitoes and moths. A typical web, usually built 
at night, has a central sheet of densely woven silk which serves as a 
hiding place and is anchored by numerous guy lines that are long and 
strong. This spider is one of the large family known as the comb-
footed spiders.  On each of the hind pair of legs they have a row of 
curved bristles used to fling strands of silk over any insect that 
blunders into the web and render it helpless. They have been known to 
capture, kill, and suck the body liquids from a baby mouse.

In autumn, most of the gossamers In fields and drifting through the air 
were spun by the tiny Balloon Spiders. Sometimes, borne away by 
those streamers, they are found far above the clouds or far out at sea.

Threads of gossamer, threads of life, fairy bridges by a spider's wife.