The Shell of the Diabolical Ironclad Beetle

The diabolical ironclad beetle (Phloeodes diabolicus) lives in western North America. According to researchers, this beetle can withstand a load of about 39,000 times its own body weight and can even survive if run over by a car. How can this beetle bear up under so much pressure?

The top and bottom sections of the beetle’s shell join at ridges along each side. One type of ridge firmly resists deformation when compressed, protecting vital organs. Another type is less stiff, allowing more easily for deformation. A third type of ridge allows the beetle’s shell surface to shift. The flexibility of this third type of ridge allows the insect to squeeze under tree bark or hide between tight rock crevices.

In addition, the seam along the center of the beetle’s shell has multiple protrusions, called blades, which interlock like pieces of a jigsaw puzzle, spreading out stress. The blades are composed of layers that are glued together by proteins. When compressed, the proteins develop tiny cracks that eventually heal and allow the blade to absorb the pressure without coming apart.

Researchers say that this beetle’s shell may inspire safer designs for structures that must resist pressure or impact, such as vehicles, bridges, and buildings.

What do you think? Did the shell of the diabolical ironclad beetle evolve? Or was it designed?