A team of Italian researchers has recently discovered the purpose of stabilimenta, a special thread that spiders weave into their webs. They journeyed deep into the forests of Sardinia to study the structure, discovering that it functions as a secret alarm system.
Secret Spider Alarm System
Authors of the new study highlight that scientists have long been interested in the “ornamental structures” in spiral, wheel-shaped orb webs. The level of diversity and complexity in the webs has always left scientists wondering whether they serve some crucial functional purpose.
Between 2018 and 2020, a team of Italian researchers from distinguished European universities conducted an investigation to study the stabilimenta produced by three distinct populations of the spider Argiope bruennichi in the forests of Sardinia. This spider weaves distinct zigzag patterns, which research suggests could help them detect prey caught in other areas of its web.
The function of the stabilimentum, however, has been the subject of an ongoing debate. Yahoo News, for example, previously reported proposals that the structures stabilize the web, shield spiders from UV rays, collect water, or even visually attract or repel prey.
Explore Tomorrow's World From Your Inbox
Get the latest science, technology, and sustainability content delivered to your inbox.
I understand that by providing my email address, I agree to receive emails from Tomorrow's World Today. I understand that I may opt out of receiving such communications at any time.
Though the webs certainly function as protection from predators, researchers in this study examined the vibrations traveling through the silk. The study clarified the stabilimenta’s mechanical role by merging extensive field observations with computer simulations.
Using computer simulations, they digitally imaged six different stabilimentum types and modeled how the vibrations spread through various webs.
In a press release, study authors stated that the findings could inspire designs for bio-inspired materials with tunable elastic properties. They found that, when prey struck the web perpendicularly, the waves were unaffected by the stabilimenta. When prey was stuck and struggling in the web, however, the stabilimenta transmitted the alarm to a wider area of the web.
“This study reveals that the decorative stabilimentum in Argiope bruennichi webs is more than just ornament, for it subtly changes how certain vibrations travel through the web,” study authors explained in a press release.
The study is available on the journal PLOS One.