Signature Spider

Description:

Araneidae; Argiope luzona (Walckenaer, 1841). The purpose of this spotting is to show that Argiope spiders display extraordinary sexual dimorphism. The size and style of web construction also differs between the sexes. I took only two photos, one of the female and one of the male. When I was preparing my spotting, I felt that the female was much more beautifully detailed than the male, So, I cropped the female photo and added the enlarged result to my spotting. By placing it first, I hoped that it might attract some attention and encourage viewers to read about this amazing spider. So, the second picture shows a female on her web, displaying her "cruciate" stabilimentum. The female is a large spider (body length can be as much as 24mm, but this one is young and measured about 20mm). The last picture shows a male which is truly minuscule with a body length of 6mm, sitting on his "discoid" stabilimentum. Obviously, I was unable to show the male and female photos side by side in truly proportionate sizes, the male had to be greatly enlarged otherwise it would be almost impossible to see him. There is a huge amount of information presented in the scientific paper published in https://www.researchgate.net/publication... - and the section dealing with stabilimenta is especially interesting. It explains the many variations in the stabilimenta. They differ, not just according to the sex, but also the maturity of the spider. It is also pointed out that the more mature spiders build their webs higher from the ground and many other factors affect the web. It is one of the best papers I have ever read. It was written jointly by four Philippine academics, three from Mindanao State University and one from The University of the Philippines, Los Banos.

Habitat:

I spotted these two Argiope luzona spiders yesterday in the front yard of the rice mill. Both webs were build on the trunk of a huge Mango Tree which is referred to as a Century Mango by the local people, obviously because it is known to be more than 100 years old. The web of the female is about 5 feet from the ground on the west side of the trunk. The web of the male is off to the right about two feet, but much lower on the trunk, only about 18 inches from the ground.

Notes:

The following website deals with a different species, Argiope Aurantia, but in general terms, pretty much everything mentioned could equally be applied to Argiope luzona. So it is worth reading. - https://edis.ifas.ufl.edu/publication/IN... The following are my previous Spottings of Argiope spiders - https://www.projectnoah.org/spottings/86... https://www.projectnoah.org/spottings/51... https://www.projectnoah.org/spottings/10... https://www.projectnoah.org/spottings/94...