Signature Spider Stabilimentum

Description:

The purpose of this spotting is to draw attention to the spider silk used by Argiope luzona in the construction of stabilimenta (web decorations). In recent months, I have become increasingly fascinated by stabilimenta and have been reading everything I can find to try and learn a little about them. My interest in this subject has arisen from the fact that I cannot avoid seeing them on a daily basis. These Argiope spiders, especially A. luzona, are everywhere. They are in our garden and backyard. They are on hedges and other vegetation along the roadside. The spiders are beautiful. Their orb webs are very fine and don't catch the eye unless the sunlight just catches them at an angle which makes them glint, but these bright white stabilimenta almost jump out at you as you pass by. So, I thought that if I have to live "cheek-by-jowl" with web decorations, then I might as well learn something about them. I am enjoying finding out a little about spider silk, but as is often the case in science, there are more questions than answers. The question I am struggling with right now is shown in my two photos. The second picture shows the "usual" stabilimentum with a clearly defined "zig-zag" form, but the first photo shows a (less often seen) "fuzzy" or "wooly" decoration. I have not come across any reference to the fuzzy kind of silk and very little information on the zig-zag kind. I have gone off at a tangent, once or twice, looking at things like cribellate and ecribellate silk, but that was entirely the wrong direction. Then, I found a scientific paper which explained that the stabilimentum was made of the same silk as that which is used in wrapping prey which is quite different from the silk used in the construction of the web. So, little by little, I am making progress, but I have not seen any attempt to explain the difference between the "zig-zag" and the "fuzzy". I would like to find out more about this. If anyone can point me in the right direction, I would be very grateful.

Habitat:

Both of the spider webs in my photos were spotted in the rice mill front yard. One is on foliage at the left side of the entrance to the front yard and the other is on the right side of the entrance. Vehicles pass in and out every day, but the spiders do not seem to be disturbed in any way by this traffic.