Female Signature Spider, Argiope anasuja resting at the centre of her web
I photographed this fairly common but striking species of Orb spider, Argiope anasuja in the Adyar Theosophical Society Gardens. The mature female (which is larger than the male) rests at the centre of the orb with her head facing downwards.
Like other species belonging to this genus, it builds a web with 1 to 4 stabilimenta. These are zig-zag markings on the web made by the spider using spider silk. It is conjectured that these stabilimenta are present to make the web visible to larger creatures. As construction of an elaborate web is quite expensive in energy terms, it is probably worthwhile for the spider to expend some additional energy to construct stabilimenta to ward off larger creatures which may inadvertently destroy the orb spider’s handiwork (or should one say, her fancy footwork!). The orb has an opening at the centre and when disturbed, the spider goes through this opening and exits on the other side of the web.
Like almost all other spiders, Argiope spiders are harmless to humans. Like most other garden spiders, they eat insects and are capable of consuming prey up to twice their size.
Nature Rambles Book 