By Susan Milius
Crab spiders can scuttle, but apparently they can’t hide.
Long touted as an example of cryptic coloring, the female Misumena vatiaspider switches her body color over the course of days depending on the flower where she lurks. Contrary to the textbook scenario, though, a white spider on a white flower doesn’t catch more prey than a white spider moved to a yellow flower, researchers report online November 3 in Proceedings of the Royal Society B.
Nor does a yellow spider on a yellow flower get a color-coordination bonus, says study coauthor Rolf Brechbühl of the University of Fribourg in Switzerland. He and his colleagues reached this conclusion after videotaping some 2,000 occasions when an insect buzzed over to a flower that held a spider. Sitting on a bloom ready to pounce on pollinators, the spider supposedly shifts to match her background by switching between white and yellow. To human eyes, she looks as if she’s becoming harder for her prey to see.