How Spiders Outside Its Own Trap

The secret spider is in the form in which they move.

The mystery of how these animals escape their own traps has intrigued scientists for decades. One hypothesis was that the legs were covered with a sticky substance.

Scientists in Costa Rica now found the answer using computer techniques to capture in detail the movements of araneidos, a family of spiders with about 3,000 species, including the most common in gardens, and is characterized by the construction of cobwebs in the form of circular spiral.

Researchers led by Daniel Briceño and William Eberhard, Smithsonian Tropical Research Institute and the School of Biology, University of Costa Rica, published the results of their work in the journal Natural sciences.

“The araneidos are very common in many parts of the world and its ability to build without getting caught adherent fabric has caught the attention of scientists for over a century,”

Spiders barely touch the fabric with the hairs of their legs.

minimal contact

In the early twentieth century, some observers noted that the spiders legs daubed with oil produced in the mouth, but the observation was never confirmed by the absence of adequate digital techniques.

More recent studies indicated that spiders walk on a delicate, barely touching the cloth with the hair on their legs.

However, during construction of the fabric legs have a much greater contact with the thread, yet the spider is not trapped.

To solve the mystery, Eberhard and colleagues combined a video camera and a microscope to record the movements of the spider in every minor detail.

They identified three factors that combine to prevent spiders trapped: leg hairs that reduce the contact surface, a chemical that coats the legs by reducing the membership, and how delicate the animals move.

“The spiders move their feet very carefully so that they can easily come off the strings,”
drip

The microscope showed that when a spider touches a sticky thread, tiny drops of adhesive is transferred to the hairs of the legs.

But when the animal withdraws the paw of the fabric, the drops slide down the hair covered with a special coating and fall.

Scientists compare this “drip” with the way water flows easily from the leaves of some tropical plants.

The researchers who developed the first hypotheses to solve the mystery of the spiders were Henri Fabre and R. W. G. Kingston, which Eberhard refers to as his “heroes.”

“Fortunately we were able to confirm some of the theories formulated long rudimentary experiments based on these two naturalists pioneers.”