Natures wonders: yellow spots lure spider prey (Introduction)

by David Turell , Monday, March 02, 2020, 23:37 (1725 days ago) @ David Turell

They are on the spider belly as it sits astride its web:

https://www.sciencenews.org/article/bright-yellow-spots-help-some-orb-weaver-spiders-lu...

"Orb weaver spiders get their name because they spin and sit on circular webs (SN: 8/8/17). But these spiders and their bright colors are a paradox. Why would a predator that relies on stealth for its next meal look so conspicuous? Scientists have hypothesized that bright colors on orb weaver spiders might serve to warn predators, to blend into vegetation or to attract prey.

"In the new study, researchers examined if yellow colorations on a species of golden orb weaver spider (Nephila pilipes) attract their flying insect prey. Found across Asia, this spider sits on its web day and night with its underside — mottled and striped yellow on black — facing open space. The team found more than 250 wild N. pilipes females in the wild. They removed each female and either left its web vacant or replaced it with a cardboard spider. These cardboard models had paper strips of yellow, blue or black color glued onto them.

"After almost 1,800 hours of video recording the faux arachnids, the team found that during the daytime, the yellow-striped model that resembled a real N. pilipes attracted more than twice as many insects, including bees and flies, as any other fake spider or empty web. What’s more, the yellow color worked just as well at night attracting moths, the scientists report.

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"Scientists don’t yet know why insects are attracted to yellow on orb weaver spiders. Perhaps the prey mistake a spider for a yellow-flecked flower, a hypothesis supported by the fact that most prey attracted were pollinators."

Comment: This is a marvelous example that demands a designer. I can't imagine a hungry spider deciding to put a spot on its belly.