March
2007
Soaring spiders0
Links to free teaching resources for the story on ballooning spiders
Teaching resources (UK US) designed specifically for this story at www.realscience.org.uk
“Meet a jumping spider named after the character Portia in Shakespeare’s The Merchant of Venice, for her habit of deceiving her enemies. Another jumping spider demonstrates an affinity for watching TV, much to the surprise of arachnologists studying her behavior. Scientist Dave Clark suspects he could be seeing the first stage of an evolving spider species.”
When Gondwana broke up, spiders were isolated on separate continents, where they evolved independently… Spider species are often good travellers. Many of these spiders get around by behaviour called ballooning. “Young spiders, and even small adults of some species, put out silk threads which are caught by the wind, carrying them up and away.”
“Researchers have developed a new model that explains how spiders fly into new territory on single strands of silk – sometimes covering distances of hundreds of miles over open ocean.” Earlier news story on how the Rothamsted scientists developed their ballooning model.
“As you see in this episode, arachnophobia can be treated using virtual reality therapy.” SpiderWorld with virtual spiders.
Lovely series of lessons on spiders for K-3, which pulls together science, math and language. English and Spanish.
Some tiny insects and spiders drift through the sky in the same way that plankton drifts in an ocean. These tiny bugs floating through the air are called “aeroplankton” or “aerial plankton.”
How in the world did spiders get to Hawaii? They floated on air currents! One of the most popular spiders in the world, the Happy Face Spider
“Would you like to adopt a Hawaiian Happyface Spider? These tiny spiders were discovered in 1973 in the rainforests of Hawaii.”
Nice collection of ballooning and Charlotte’s Web activities. “Baby spiders have no wings, but can fly as high as the highest-flying insects and birds! In fact, ballooning spiders often hit airplane windshields. How can a spider, with no wings, possibly get this high in the air? You’ll find out by reading this week’s report and helpful links that follow.”
Links to more
Acorn Naturalists, resources for the trail and classroom.
The story:
Soaring spiders
Spiders ride the wind on silken threads. It is called ballooning. They do it to carry themselves out of danger or into new territory. And in the right conditions they can sometimes fly through the air for hundreds of miles.
But nobody knew until now why ballooning reaches a peak in spring and autumn, and is much less common in windy and sunny weather. Sunshine after all produces more updrafts, which are helpful for take-off.
Now a team at Rothamsted Research has developed a model of ballooning. This shows that light breezes and moderately warm weather are the best spider ballooning conditions. This is typical weather for spring and autumn.
These results could lead to a non-chemical alternative to pesticides for managing crops.
The team of biologists and mathematicians used the model to investigate travelling distances under a range of conditions of wind and sun. They were aiming to find the best weather for flight.
Hot days do indeed produce more updrafts. But the wind is not usually strong enough to carry the spiders very far, the scientists found.
On the other hand, if the wind becomes too strong the updraughts are disrupted, the model shows. This makes flight impossible.
Spiders hunt and eat pests like mites and aphids. So predicting spider ballooning peaks is important for crop management.
In the growing season, around 1800 spiders a day land in each hectare of arable farmland after ballooning, explains Dr Andy Reynolds of Rothamsted Research. “If the farmers can predict the influx of spiders, they can reduce the amount of pesticides accordingly.”
The research team is planning field experiments to test the model. This could provide valuable information on other organisms that use the wind for transport. These include mites and viruses.
This research is a good example of interdisciplinary collaboration, said Professor Julia Goodfellow. She is chief executive of the Biotechnology and Biological Sciences Research Council. “Biologists and mathematicians together have produced new knowledge which can help lead to environment-friendly pest control.”
Rothamsted Research is in Hertfordshire, England. It is a sponsored institute of the Biotechnology and Biological Sciences Research Council (BBSRC).
