In the deserts of southwestern North America lives a tiny beetle barely two centimeters long that seems to defy the laws of physics: the diabolical ironclad beetle (Phloeodes diabolicus). Unlike the vast majority of insects, which are instantly crushed by a human footstep, this animal can emerge unharmed after being run over directly by a car tire.
In 2020, a team of engineers and biologists from the University of California, Irvine analyzed its exoskeleton using computed tomography and mechanical compression testing. They discovered that it can withstand a colossal force of up to 149 newtons, which equals about 39,000 times its body weight. To put this in human perspective, it would be equivalent to a 70-kilogram person enduring the weight of about 25 commercial airplanes on their chest without fatal injury.
The secret to this supernatural resistance lies in the biological architecture of its shell:
- Fused elytra: It has sacrificed the ability to fly to seal its forewings into a rigid, airtight shield that protects it from desiccation and predators.
- Jigsaw-like sutures: The dorsal seam is not a straight line, but a series of interlocking pieces that distribute the mechanical load across the entire structure.
- Controlled delamination: The microscopic layers of chitin and protein do not shatter under pressure; instead, they gradually slide and separate, dissipating the impact energy.
This biomechanical marvel is so impenetrable that entomologists often bend steel pins when trying to mount preserved specimens, and its design is already inspiring new ultra-resistant joints in aeronautical turbines.
Source: Nature (Rivera et al., 2020: 'Toughening mechanisms of the diabolical ironclad beetle')
