The genus Argiope are known to decorate their webs with various patterns. The purpose of these web decorations, referred to as stabilimenta, is still a subject of debate. They are believed to serve either as lures to attract prey insects or as a means of providing protection to the spider by enhancing the web's visibility to deter potential predators. In this study, we observed spider orientation with respect to the direction of the sun in a controlled laboratory environment. To assess the orientation preference of the spider, the frame was repositioned daily by reversing its direction. Over a period of 21 days, the orientation of the spider was meticulously recorded, distinguishing between the illuminated side (open side) and the shaded side (closed side). field emission scanning electron microscopy (FESEM) visualization were used to investigate the microstructural characterization of stabilimenta in both juvenile and adult spiders. Our results represent that the decorative structure of stabilimentum shows diverse microstructural features according to the maturation level of the spider. In addition, it has been confirmed that spiders tend to prefer the open side direction when stabilimentum is present.

Many animals are capable of detecting sensory information emitted by predators. When predation risk is high, orb-web building spiders should change its foraging strategy of the web construction. We examined web building behaviors of an orb-web spider, Argiope bruennichi providing sensory information of its predator, a yellow hornet, Vespa simillima. We observed web characteristics after providing sensory information of the yellow hornet (experimental group; N=29) and compared to the control group (no information provided; N=34). We hypothesized that the spiders in the experimental group would decrease investments in its web construction and stabilimentum decoration to avoid being located by the predator. The results rejected our hypothesis. Web and stabilimentum constructions decreased in the course of the experiment in both control group and experimental group. But the differences between control group and experimental group were not significant. The individuals did not reduce its stabilimentum length and did not decrease its web area in spite of sensory information of the predator.