Signature Spider

Argiope luzona Walckenaer, 1842. The spider shown in my photos is a female and it has constructed a Discoid Stabilimentum (web decoration). That is not unusual, but there is something about this spider that does not fit with the current scientific view. The latest scientific opinion on the web decorations of A. luzona is that there is a direct relationship between the length of the spider’s body and the type of web decoration it constructs. The general rule is that young (smaller) spiders construct Discoid Stabilimenta and older (bigger) spiders construct Cruciate stabilimenta. Once the spider is big enough to start building Cruciate decorations, the whole thing becomes extremely complicated, but what we are looking at here is a young female with a Discoid Stabilimentum. The problem is the size of the spider. The norm is that a female A. luzona < 6 mm (measured snout-to-rump) builds a Discoid decoration and a female > 6 mm builds a Cruciate decoration. The spider in my picture was a little over 7 mm. So, it should be sitting on a Cruciate decoration. This female is approx. 20% over the size for this kind pf decoration. I know it doesn’t sound much, but it is anomalous.