News Animals

To climb trees, cicadas look to the shadows

A shadow-sensing skill known as skototaxis helps cicadas find trees to molt on

A cicada nymph with white paint around the top of its head clings to a stick on a bed of grass

Researchers temporarily coated cicadas’ eyes and light-sensing organs with white paint, blocking the contrast between light and dark that the insects use to find trees.

Martha Weiss

By Elie Dolgin

When periodical cicadas surface after years underground, they don’t grope blindly for trees. They head for the shadows, researchers report March 20 in the American Naturalist.