Singapore - Ultraviolet rays have been found to be essential for a spider courting females, a published report said Friday.

National University of Singapore (NUS) Associate Professor Li Daiqin said that the rays, invisible to the human eye, are very much visible to the eight-legged arachnids in courtship rituals.

He has proven that a particular type of light, ultraviolet B (UVB), is used in communicating, The Straits Times said.

Female jumping spiders spent twice the amount of time ogling males with UVB-reflecting markings on their body, compared to those where the light wave had been filtered out.

The scientific community had long assumed that animals could not detect UVB light due to its small wave range and because such rays can harm the eyes, Li told the newspaper.

The discovery was made after three years of collaboration among researchers from China and Singapore to determine why male spiders of the Phintella vittata species had UVB-reflecting markings on their bodies.

Li, who is known as the Spider Man of NUS, is looking at how the spiders protect their eyes from the damaging effects of UVB rays.

Such work could lead to the development of better sunscreens or treatments for eye damage, the report said. (dpa)