Insect debris fashion goes back to the Cretaceous

Some insects make dirt look like — well, dirt. And they’ve been doing it for a while.

Donning a bit of debris to blend in with the environment is common practice for a subset of insects and other creepy-crawlies trying to hide from predators. (Crabs, spiders and snails do it, too.) To investigate when this behavior originated, Bo Wang of the Chinese Academy of Sciences and colleagues examined insects preserved in amber from Burma, France and Lebanon that date back 100 million years to the Cretaceous period.

Out of 300,000 insect specimens examined, 39 of them sported what appear to be dirt and vegetation disguises. Anatomical analysis suggests that these insects are early relatives of lacewings, assassin bugs and owlflies. The ancient critters decorated themselves with soil, sand, bits of wood and even tiny ferns, the team reports June 24 in Science Advances.

Until now, only one preserved, dirt-decorated insect from the Mesozoic era had been discovered. But the new finds suggest that this behavior was already widespread in some insect families back then.