Spiders weave alarm system through web zigzags for prey detection

A recent study by Italian researchers has uncovered the functional role of stabilimenta—the distinctive zigzag silk patterns woven into the webs of the spider Argiope bruennichi. Conducted over three years in Sardinia, the research combined field observations and computer simulations to demonstrate that these zigzags act as an alarm system for prey detection. While previous theories suggested stabilimenta might stabilize the web, protect spiders from UV rays, or attract/repel prey, this study reveals that the zigzag structures enhance the transmission of vibrations caused by struggling prey, alerting spiders even when they are distant from the prey’s location. The researchers found that while vibrations from prey striking the web perpendicularly were unaffected by the stabilimenta, the zigzag patterns effectively transmitted thrashing-induced vibrations across a wider area of the web. This mechanical function improves the spider’s ability to detect prey, serving as a critical enhancement to their hunting strategy. The findings not only solve a long-standing arachnological mystery but also have potential