Researchers in the United Kingdom have discovered how cockroaches are able exert a force 50 times stronger than their own body weight in order to chew on the toughest materials.
In a study featured in the journal PLOS ONE, Tom Weihmann and his colleagues at Cambridge's zoology department found how these insects manipulate the twitch muscle fiber in their mandibles to be able to make hard and repetitive bites on highly durable materials such as wood.
Since insects play a vital part in numerous ecosystems, the researchers believe it is important to understand how much force they are able to use through their mandibles as the first step in studying their ecological and behavioral processes. This in turn can help fellow scientists develop inspired engineering.
"Insects provide a major part of the faunal biomass in many terrestrial ecosystems," Weihmann said. "Therefore they are an important food source but also crucial as decomposers of plants and animals."
Bite Force of Cockroaches
In their analysis of insect bite forces, the researchers discovered that the American cockroach (Periplaneta Americana) is capable of generating a bite force up to 50 times stronger than its own body weight. Weihmann said this force is five times more powerful compared to the force humans can produce with their jaws.
Earlier studies have examined the biting action of larger creatures, particularly vertebrates, which use their teeth-filled jaws to catch prey, grind food and even fend off potential predators.
Insects such as cockroaches, however, make use of a different set of mouthparts that they use to bite. Their mouths consist of a pair of powerful, bladelike jaws known as mandibles, which they also use to dig holes, feed their offspring and defend themselves against attackers.
The mandibles of an insect can be found attached to its head capsule, which is comprised of multiple layers of thin cuticles and is part of the creatures' complex exoskeleton.
Aside from enclosing the vital muscles the insect's mouth parts, the head capsule also contains many other organs crucial to the creature's digestive and nervous systems. This leaves only a small space to allow its muscles to effectively operate its bladelike mandibles.
The Cambridge researchers studied the biting force of cockroach specimens using the various opening angles of their mandibles. The team discovered that the insects are capable of exerting varying degrees of force ranging from weak, short biting actions to longer and more powerful bites.
Weihmann said the shorter, weaker bites were produced by the cockroaches' fast muscle fibers, while the longer, more powerful bites were generated using an additional set of muscle fibers that take a longer time to achieve their full force.
The slower and stronger muscle fibers provide the insects' mandibles with a force of up to 0.5 Newtons while they try to sustain a chewing or grasping action.
Weihmann and his colleagues believe getting a better understanding of the insect's complexly-structured head capsule can help fellow researchers develop engineering applications inspired by nature.
Other Insects with Powerful Jaws
While the mandibles of cockroaches give them a particular advantage over other insects, they are not the only species of bugs to show a set of very powerful jaws.
Leafcutter Ants
Despite its diminutive size, the leafcutter ant has proven itself to be one of the strongest creatures on Earth. This tiny insect can easily lift an object approximately 50 times heavier than its own body weight (around 500 milligrams) using its mandibles.
This incredible show of strength is equivalent to a grown man carrying a full-size truck using his teeth.
Titan Beetle
A titan both in size and in strength, this species of beetle has a formidable set of mandibles capable of snapping tree branches in half and even cutting through flesh. While titan beetles are not known to attack other creatures unless provoked, these gigantic bugs should be handled with care as they can still cause serious injuries to people.
Photos:
Steve Snodgrass | Flickr
Ross Elliott | Flickr
Bernard Dupont | Flickr
