Study says that cockroaches make use of fast and slow twitch muscle fibers at the same time adding a ‘force boost’ to their mandibles making it possible to chew on tough materials.
The study has been published today in PLOS ONE.
Lead author of the study, Tom Weihmann from the University of Cambridge’s Department of Zoology explains, “Since insects have an important role to play in many ecosystems, understanding the amount of force that these insects can exert through their mandibles is a significant step to better understanding behavioral and ecological processes and enabling bioinspired engineering.”
Findings reveal that these slow twitch muscle fibers are only triggered by cockroaches when they have to chew onto some tough object like wood. Such materials need repetitive, hard biting to create a bite force that is 50 times more powerful than their own body weight.
He further added that insects constitute an integral part of faunal biomass in many terrestrial ecosystems. They are, hence, a crucial food source but also important as decomposers of plants and animals. In this way they are crucial for material cycles and the ecological balance.”
Weihmann informed that theirs is the first study ever to calculate the bite forces of ordinary insects. His team found that the American cockroach, Periplaneta americana, is able to generate a bite force that is five times stronger than the force a human can generate with their jaws.
There have been studies done earlier on the biting force of larger animals, specifically vertebrates, having jaws full of teeth that they use to grind food, catch prey, or fend off other animals.
Cockroaches, however, are among insects having different biting mouthparts. They are equipped with a pair of strong, horizontally aligned bladelike jaws, or mandibles. Mandibles play a crucial part in the life of insects and are used up only to tear apart food, and also for digging, transferring food, defending, and feeding its offspring.
An mandibles are attached to the head capsule of the cockroach of thin multi-layered cuticle that form an intricately designed portion of their exoskeleton. The head capsule has the driving muscles for all parts of the mouth along with some of the other important organs of the central nervous and digestive systems.
This means that there is limited space for the muscles required to operate their scissor-like mandibles; so many insects have muscles with oblique fibers reducing the amount of widening that takes place when the muscles contract.
When examining the bite force is in question, cockroaches have the ideal system. According to Weihmann, they are “extraordinarily ordinary insects with regard to their mouthparts and biting abilities.”