London, Nov 1 : A new study has found that during night time spiders lure unsuspecting prey using coloured abdomen stripes, which are otherwise hidden in the daylight.

The study, conducted by Min Tso, Jen-Pan Huang and Chen-Pan Liao of Taiwan's Tunghai University, focused mainly on brightly coloured orchid spiders, which have green bodies, silver stripes on their backs and yellow or bright green stripes on their abdomens.

The team monitored orchid spider's hunting behaviour with video cameras for 24 hours a day.

The observation found that the number of active night hunters was ‘two to three times higher than (those orchid spiders that hunted) during the day.’

The researchers also experimented with various colour manipulation tests that involved painting over the silver, yellow or green parts of the orchid spider.

Obscuring the yellow stripes considerably reduced moth catches, which provided evidence that the colours probably functioned as night lures.

A clue to detecting night-prowling spiders is coloration. Dark grey or brown spiders usually are nocturnal, since during the day their drab colours serve to reduce their visibility.

However, many spiders have different patterns and colours on their abdomen.

For example- Neoscona and Araneus from East Asia, possess either yellow stripes or yellow spots in their abdomen.

"During the day, these spiders usually perch on twigs or barks near their webs with their brown-colored (back side) facing upwards and the yellow abdominal markings obscured," the Discovery News quoted the researchers, as saying.

"However, at night while the spiders are sitting on their orb webs hunting, they fully expose the yellow markings," they added.

The findings give answer as to why arachnids like the giant wood spider and the orchid spider have been observed eating large amounts of carefully wrapped prey on their webs just before sunrise.

The team believes that the spider's silver back stripes might even function ‘as a thermal regulator by reflecting sunlight during the hot hours of the day.’

The discovery also suggests that entomologists might have underestimated the activities of some spiders when darkness falls.

The study will be published in the journal Animal Behaviour. (ANI)