The Joro Spider (Nephila clavata) is a species of arachnid that is a member of the golden orb-web spider group. It is found in Japan (except HokkaidÅ), Korea, Taiwan and China.
The web of the female can reach up to 39 inches in width. The yellow threads appear rich gold in sunlight. The web has three layers: the central orb, plus two irregular layers in front of and behind the orb. The adult female is about 1 inch. The male is much smaller and is no bigger than 0.4 inches. The female has stripes of yellow and dark blue, with red near the rear of the abdomen.
In autumn, the male may be seen in the female’s web for copulating. After mating the female spins an egg sac on a tree and lays 400 to 1500 eggs in one sac. The life cycle ends by early winter.
Researchers at Shinshu University, Japan have succeeded in creating a silk thread that is stronger, softer and more durable than conventional silk by genetically modifying silkworms with Nephila drag line genes. A Japanese manufacturer is already experimenting with the thread, and spider socks, stockings and even fishing lines are expected to appear on the market within a few years.