NOVEMBER
2001

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

11-9-01

Traveling on Gossamer Without Wings

Spiders are wingless. But the lack of wings doesn't keep these arthropods from traveling. Sometimes spiders walk from place to place. Sometimes they hitch a ride. That explains how a cockroach-eating spider native to South America sometimes shows up in the United States. It travels compliments of imported grapes!

Spiders sometimes fly. Not under their own power, of course, but by a process known as ballooning. Ballooning spiders hitch a ride on their silk as the breeze carries it. Spider silk floating on wind currents is known as gossamer. It has attracted attention for centuries. The word "gossamer" is an old English term, apparently based on a period of warm weather in November, known as goose summer. That was the time of year when geese were eaten. Late fall is also the time when ballooning spiders are most likely to be seen floating on the breeze.

Airborne spiders are young spiders sometimes called spiderlings. Like all spiders, spiderlings produce strands of silk. These young spiders do not build webs. The newly produced strands of silk wave in the fall breeze like flags on a flagpole. At some point, the young spider lets go. Like a wind surfer being towed by a speedboat, the young spider then becomes airborne. The process allows the spiderlings to be carried to new locations. Sometimes the landing sites might not be hospitable to spiders. For instance, ballooning spiders have been found far out at sea. Probably not a good destination for terrestrial organisms!

Nonetheless, some of the ballooning spiders land in good spots, at least to spiders, and are able to develop into adults during the next season. Walt Whitman summarizes the process used by the ballooning spiders in these lines of poetry:
"A noiseless, patient spider, I mark'd where on a little promontory it stood isolated,
Mark'd how to explore the vacant vast surrounding,
It launch'd forth filament, filament, filament out of itself:
Ever unreeling them, ever tirelessly speeding them.
And you O my soul where you stand,
Surrounded, detached, in measureless oceans of space.
Ceaselessly, musing, venturing, throwing, seeking the spheres to connect them.
Till the bridge you will need be form'd, till the ductile anchor hold;
Till the gossamer thread you fling catch somewhere, O my soul."

In her sonnet LXIII appropriately named "The Gossamer," Charlotte Smith, nearly 200 years ago, wrote in the first four lines:
"O'er faded heath-flowers spun, or thorny furze,
The filmy Gossamer is lightly spread;
Waving in every sighing air that stirs,
As Fairy fingers had entwined the thread."

While spider ballooning occurs every year, in some years it is quite noticeable. It always occurs on warm, still days late in the fall. To see strands of spider silk floating over an open meadow is an interesting sight. Such was the case in late October when many people in the state of Indiana saw large amounts of gossamer floating about. The natural question was "What is going on?"

A good answer to that question is provided by Anna Botsford Comstock in her book, "A Handbook of Nature Study." She states: "Thus we see that the spiders have the same way of distributing their species over the globe as have the thistles and dandelions."

 

Writer: Tom Turpin
Editor: Olivia Maddox