25 March, 2009

Golden Orb and Friends

This Golden Orb Spider, Nephila pilipes, is not actually on my face but they are very friendly spiders.As she moults to maturity she will become a really big spider. She will share her web with many other spiders like this beautiful but tiny Dew Drop Spider which you can see is aptly named.
Here she is on the web and below on the back of my hand.
Many other species of small spiders can be found in her web. They eat the things that are too small for her to worry about. Sometimes they suck the juices from her prey right under her lip.
The male is small but the same body shape as the female. His pedipalps or feeding feet are however shorter with clubs and hooks on the end. She does not get to eat him as he mates when she moults for the last time and is still soft.
As a young spider the Golden Orb is silver on the dorsal surface which is seen from below the web ..
.. and green, brown and black when looking from above, wonderful camouflage. At this stage she builds a horizontal web. Later as she morphs towards the adult form she will start building vertical webs.
She also develops the colourful golden knees at this time and the web takes on its golden hue. This golden colour is more pronounced in spiders living under dry conditions with less food. My impression is that the golden webs are stronger but I guess that they are more expensive in terms of energy to produce. Being more easily seen they can be avoided by birds.
This is a closely related species, Nephila edulis with her male in attendance. I think I would have to be very hungry to eat her.

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