A good number of orbweavers decorate their webs with stabilimenta: constructs of pale silk laid out in a zig-zag stitch and arranged in various styles, from an X-shaped formation or a series of concentric rosettes with a scribbled heart. The latter is most often seen in the hubs of young Argiope, which mature into wandering males or webmistresses who mark their traps with broken crosses, or in the case of a mangrove endemic, a single, disjunct, line.
Unlike the sticky spiral that encircles the hub, the stabilimentum consists of aciniform silk, a tough protein used to envelope victims, wrap eggcases, and some say, convey messages to mankind. Some suspect, and have gathered proof, that, being diurnal hunters, St. Andrew's cross spiders use the strands as warning signals to birds and other creatures that might blunder into a painstakingly woven web. Other arachnologists have noted the reflective qualities of stablimenta, particularly to ultraviolet radiation, and see a link with the tendency of many insects to zoom towards patches of imagined sunlight. It could well be that both attributes contribute in varying degress to the success of the spiders, whose orbs can be found in fair numbers amid low vegetation in local scrubland, forest fringes and mangal.
A few individuals, however, neglect to bedeck their homes on a regular basis and yet survive to occupy their own corner of the fitness landscape. The same threads that lure bees and flies also attract predatory wasps and arachnophagous salticids, so it has been suggested that the owners of undecorated webs eat rather more poorly but last longer than their counterparts who dance with danger. Evidence from the ground is inconclusive, though, and the true picture is likely to be a complex and dynamic interplay of traits acquired by successive generations of predator and prey as they search for new chinks in each other's armoury of adaptive strengths.