Monday, 29 December 2008
ABC Wednesday St Andrew's Cross Spider for X
This very well known spider is also known under the name 'garden spider'. I took this photo in Australia, while we were climbing to some rocks to see rock paintings.This one is called : Argiope ocyaloides.
There are 25 known species in this genus but the most beautiful and spotted one is the Argiope Keyserlingi ( formerly aethera) or 'St Andrew's cross spider'
The spiders of this family are easily identified by the zig zag silk construction (stabilimentum), usually a cross, they make in their web.
It is believed that the spider uses it to camouflage itself in the cross and to warn birds not to fly through the web.
But there are also other hypotheses.
Perhaps the most important function of stabilimenta is to attract insects. The silk of the stabilimentum reflects UV light and pollinating insects are lured to these threads.
If the spider is attacked it starts shaking vigorously in her web. The whole web becomes white because of the stabilimentum. This frightens off attackers.
The web is usually constructed a few decimeters above the ground in tall grass and among shrubs.
The spider on this photo however had made its web on a rock, but you can see the zigzag construction of the web around him. For more information and pictures of these spiders go Here
Thanks to Denise Nesbitt, who has hosted this ABC game for the third round to the letter X for ABC Wednesday. For more ABC posts click on ABC picture in my side bar.Join us in this wonderful meme!